[Federal Register: August 28, 2008 (Volume 73, Number 168)]
[Notices]
[Page 50856-50869]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr28au08-116]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF VETERANS AFFAIRS
Determination of Presumption of Service Connection Concerning
Illnesses Discussed in National Academy of Sciences Report on Gulf War
and Health
AGENCY: Department of Veterans Affairs.
ACTION: Notice.
-----------------------------------------------------------------------
SUMMARY: As required by law, the Department of Veterans Affairs (VA)
hereby gives notice that the Secretary of Veterans Affairs, under the
authority granted by the Persian Gulf War Veterans Act of 1998, Public
Law 105-277, title XVI, 112 Stat. 2681-742 through 2681-749 (codified
in part at 38 U.S.C. 1118), has determined that there is no basis to
establish a presumption of service connection at this time for any of
the diseases, illnesses, or health effects discussed in the December
20, 2004, report of the National Academy of Science, titled ``Gulf War
and Health, Volume 3. Fuels, Combustion Products, and Propellants''
based on exposure to fuels, combustion products, or propellants during
service in the Persian Gulf during the Persian Gulf War. This
determination does not in any way preclude VA from granting service
connection for any disease, including those specifically discussed in
this notice, nor does it change any existing rights or procedures.
FOR FURTHER INFORMATION CONTACT: Rhonda F. Ford, Chief, Regulations
Staff (211D), Compensation and Pension Service, Veterans Benefits
Administration, Department of Veterans Affairs, 810 Vermont Avenue,
NW., Washington, DC 20420, (202) 461-9739.
SUPPLEMENTARY INFORMATION:
I. Statutory Requirements
The Persian Gulf War Veterans Act of 1998, Public Law 105-277,
title XVI, 112 Stat. 2681-742 through 2681-749 (codified at 38 U.S.C.
1118), and the Veterans Programs Enhancement Act of 1998, Public Law
105-368, 112 Stat. 3315, directed the Secretary to seek to enter into
an agreement with the National Academy of Sciences (NAS) to review and
evaluate the available scientific evidence regarding associations
between illnesses and exposure to toxic agents, environmental or
wartime hazards, or preventive medicines or vaccines to which service
members may have been exposed during service in the Persian Gulf during
the Gulf War. Congress directed NAS to identify agents, hazards,
medicines, and vaccines to which service members may have been exposed
during service in the Persian Gulf during the Gulf War.
Congress mandated that NAS determine, to the extent possible: (1)
Whether there is a statistical association between exposure to the
agent, hazard, medicine, or vaccine and the illness, taking into
account the strength of the scientific evidence and the appropriateness
of the scientific methodology used to detect the association; (2) the
increased risk of illness among individuals exposed to the agent,
hazard, medicine, or vaccine; and (3) whether a plausible biological
mechanism or other evidence of a causal relationship exists between
exposure to the agent, hazard, medicine, or vaccine and the illness.
Section 1118 provides that whenever the Secretary determines, based
on sound medical and scientific evidence, that a positive association
(i.e., the credible evidence for the association is equal to or
outweighs the credible evidence against the association) exists between
exposure of humans or animals to a biological, chemical, or other toxic
agent, environmental or wartime hazard, or preventive medicine or
vaccine known or presumed to be associated with service in the
Southwest Asia theater of operations during the Persian Gulf War and
the occurrence of a diagnosed or undiagnosed illness in humans or
animals, the Secretary will publish regulations establishing
presumptive service connection for that illness. If the Secretary
determines that a presumption of service connection is not warranted,
the Secretary is to publish a notice of that determination, including
an explanation of the scientific basis for that determination. The
Secretary's determination must be based on consideration of the NAS
reports and all other sound medical and scientific information and
analysis available to the Secretary.
Although section 1118 does not define ``credible evidence,'' it
does instruct the Secretary to take into consideration whether the
results (of any report, information, or analysis) are statistically
significant, are capable or replication, and withstand peer review. See
38 U.S.C. 1118(b)(2)B). Simply comparing the number of studies that
report a significantly increased relative risk to the number of studies
that report a relative risk that is not significantly increased is not
a valid method for
[[Page 50857]]
determining whether the weight of evidence overall supports a finding
that there is or is not a positive association between exposure to an
agent, hazard, or medicine or vaccine and the subsequent development of
the particular illness. Because of differences in statistical
significance, confidence levels, control for confounding factors, and
other pertinent characteristics, some studies are clearly more credible
than others, and the Secretary has given the more credible studies more
weight in evaluating the overall weight of the evidence concerning
specific illnesses.
II. Prior National Academy of Sciences Reports
NAS issued its initial report titled, Gulf War and Health, Volume
1: ``Depleted Uranium, Sarin, Pyridostigmine Bromide, Vaccines,'' on
January 1, 2000. In that report, NAS limited its analysis to the health
effects of depleted uranium, the chemical warfare agent sarin,
vaccinations against botulism toxin and anthrax, and pyridostigmine
bromide, which was used in the Gulf War as a pretreatment for possible
exposure to nerve agents. On July 6, 2001, VA published a notice in the
Federal Register announcing the Secretary's determination that the
available evidence did not warrant a presumption of service connection
for any disease discussed in that report. See 66 FR 35702 (2001).
NAS issued its second report titled, ``Gulf War and Health, Volume
2: Insecticides and Solvents,'' on February 18, 2003. In that report,
NAS focused on the health effects of insecticides and solvents that
were shipped to the Persian Gulf during the Persian Gulf War. The
pesticides considered by NAS were organophosphorous compounds
(malathion, diazinon, chlorpyrifos, dichlorvos, and azamethiphos),
carbamates (carbaryl, propoxur, and methomyl), pyrethrins and
pyrethyroids (permethrin and d-phenothrin), lindane, and N,N-diethyl-3-
methylbenzamide (DEET). NAS considered 53 solvents in eight groups:
Aromatic hydrocarbons (including benzene), halogenated hydrocarbons
(including tetrachloroethylene and dry-cleaning solvents), alcohols,
glycols, glycol esters, esters, ketones, and petroleum distillates. On
August 24, 2007, VA published a notice in the Federal Register
announcing the Secretary's determination that the available evidence
did not warrant a presumption of service connection for any disease
discussed in that report. 72 FR 48734 (2007).
III. Gulf War and Health, Volume 3. Fuels, Combustion Products, and
Propellants
NAS issued a third report, titled ``Gulf War and Health, Volume 3.
Fuels, Combustion Products, and Propellants,'' on December 20, 2004. In
that report, NAS focused on the health effects of hydrazines, red
fuming nitric acid, hydrogen sulfide, oil-fire byproducts, diesel-
heater fumes, and fuels (for example, jet fuel and gasoline).
In its report, NAS classified the evidence of an association
between exposure to a specific agent and a specific health outcome into
five categories:
Sufficient Evidence of a Causal Association: This category
means the evidence is sufficient to conclude that there is a causal
association between exposure to a specific agent and a specific health
outcome in humans. The evidence is supported by experimental data and
fulfills the guidelines for sufficient evidence of an association. The
evidence must be biologically plausible and satisfy several of the
guidelines used to assess causality, such as: Strength of association,
dose-response relationship, consistency of association, and a temporal
relationship.
NAS did not find any health outcomes that met the criteria for this
category.
Sufficient Evidence of an Association: This category means
the evidence is sufficient to conclude that a consistent association
has been observed between exposure to a specific agent and a specific
health outcome in human studies in which chance and bias, including
confounding, could be ruled out with reasonable confidence. For
example, several high-quality studies report consistent associations,
and the studies are sufficiently free of bias, including adequate
control for confounding.
NAS found sufficient evidence of an association between exposure to
combustion products and lung cancer.
Limited/Suggestive Evidence of an Association: This
category means the evidence is suggestive of an association between
exposure to a specific agent and a specific health outcome, but the
body of evidence is limited by the inability to rule out chance and
bias, including confounding, with confidence. For example, at least one
high-quality study reports an association that is sufficiently free of
bias, including adequate control for confounding. Other corroborating
studies provide support for the association, but they were not
sufficiently free of bias, including confounding. Alternatively,
several studies of lower quality show consistent associations, and the
results are probably not due to bias, including confounding.
NAS found limited/suggestive evidence of an association between
exposure to combustion products and cancers of the nasal cavity and
nasopharynx; cancers of the oral cavity and oropharynx; laryngeal
cancer; bladder cancer; low birthweight/intrauterine growth retardation
(with exposure during pregnancy); preterm birth (with exposure during
pregnancy); and incident asthma.
NAS found limited/suggestive evidence of an association between
exposure to hydrazines and lung cancer.
Inadequate/Insufficient Evidence: This category means the
evidence is of insufficient quantity, quality, or consistency to permit
a conclusion regarding the existence of an association between exposure
to a specific agent and a specific health outcome in humans.
NAS found inadequate/insufficient evidence of an association
between exposure to fuels and cancers of the oral cavity and
oropharynx; cancers of the nasal cavity and nasopharynx; esophageal
cancer; stomach cancer; colon cancer; rectal cancer; hepatic cancer;
pancreatic cancer; laryngeal cancer; lung cancer; melanoma; nonmelanoma
skin cancer; female breast cancer; male breast cancer; female genital
cancers (cervical, endometrial, uterine, and ovarian cancers);
prostatic cancer; testicular cancer; nervous system cancers; kidney
cancer; bladder cancer; Hodgkin's disease; non-Hodgkin's lymphoma;
multiple myeloma; myelodysplastic syndromes; adverse reproductive or
developmental outcomes (including infertility, spontaneous abortion,
childhood leukemia, central nervous system (CNS) tumors, neuroblastoma,
and Prader-Willi syndrome); peripheral neuropathy; neurobehavioral
effects; Multiple Chemical Sensitivity symptoms; nonmalignant
respiratory disease; chronic bronchitis; asthma; emphysema; dermatitis
(irritant and allergic); and sarcoidosis.
NAS found inadequate/insufficient evidence of an association
between exposure to combustion products and esophageal cancer; stomach
cancer; colon cancer; rectal cancer; hepatic cancer; pancreatic cancer;
melanoma; female breast cancer; male breast cancer; female genital
cancers (cervical, endometrial, uterine, and ovarian cancers);
prostatic cancer; testicular cancer; nervous system cancers; ocular
melanoma; kidney cancer; non-
[[Page 50858]]
Hodgkin's lymphoma; Hodgkin's disease; multiple myeloma, leukemia;
myelodysplastic syndromes; preterm births (based on exposure during a
specific time period during pregnancy, such as the first trimester);
low birth weight and intrauterine growth retardation (based on exposure
before gestation or during a specific period during pregnancy, such as
the first trimester); specific birth defects, including cardiac effects
(with maternal or paternal exposure before conception or maternal
exposure during early pregnancy); all childhood cancers identified,
including acute lymphocytic leukemia, leukemia, neuroblastoma, and
brain cancer; neurobehavioral effects; post-traumatic stress disorder;
nervous system subgroupings (or individual nervous system diseases);
Multiple Chemical Sensitivity symptoms; chronic bronchitis (less than 1
year of exposure); emphysema; chronic obstructive pulmonary disease;
ischemic heart disease or myocardial infarction (less than 2 years of
exposure); dermatitis (irritant and allergic); and sarcoidosis.
NAS found inadequate/insufficient evidence of an association
between exposure to hydrazines and hematopoietic and lymphopoietic
cancers; digestive tract cancers; pancreatic cancer; bladder cancer;
kidney cancer; emphysema; ischemic heart disease or myocardial
infarction; and hepatic disease.
NAS found inadequate/insufficient evidence of an association
between exposure to nitric acid and stomach cancer; melanoma;
lymphopoietic cancers; pancreatic cancer; laryngeal cancer; lung
cancer; bladder cancer; multiple myeloma; and cardiovascular diseases.
Limited/Suggestive Evidence of No Association: This
category means the evidence is consistent in not showing an association
between exposure to a specific agent and a specific health outcome
after exposure of any magnitude. A conclusion of no association is
inevitably limited to the conditions, magnitudes of exposure, and
length of observation in the available studies. The possibility of a
very small increase in risk after exposure studied cannot be excluded.
NAS did not find any health outcomes that met the criteria for this
category.
A. Combustion Products
1. Sufficient Evidence of an Association
NAS found sufficient evidence of an association between combustion
products and lung cancer. NAS found that there was evidence of
associations between exposure to ambient air pollution, engine
exhausts, and heating sources (coal) and lung cancer. Cohort and case-
control studies showed consistently that risks increased with
increasing ambient air pollution. There was evidence from both cohort
and case control studies that increasing exposure to engine exhausts
and its components such as polycyclic aromatic hydrocarbons (PAHs)
increased the risk of lung cancer.
Based on 82 epidemiological studies, NAS derived a positive finding
of ``sufficient evidence of an association'' between exposure to
combustion products and lung cancer. The epidemiological studies
included cohort studies on the health effects of ambient air pollution
on people dwelling in cities, workers exposed to motor vehicle exhaust,
and case-control studies of lung cancer patients. The case-control
studies were of lung cancer patients who were exposed in their
occupation, or in their homes or daily lives to indoor air pollution
from combustion products from wood, coal, kerosene or gas burning
stoves or heaters over years. Relevant occupational exposures included
working as a bus, taxi, or truck driver, or as a miner or railroad
worker.
NAS pointed out that lung cancer from all causes is the leading
cause of cancer death among both men and women, and that smoking may be
responsible for 80% of lung cancer cases. Nevertheless, NAS concluded
that ``there was evidence of associations between exposure to ambient
air pollution, engine exhausts, and heating sources (coal) and lung
cancer.'' Cohort and case-control studies showed consistently that
risks increased with increasing ambient air pollution. There was
evidence from both cohort and case-control studies that increasing
exposure to engine exhausts and to its components increased the risk of
lung cancer.
The Secretary has determined that, although there is sufficient
evidence of an association between combustion products and lung cancer,
VA does not consider this exposure to be ``associated with'' the 1991
Gulf War. Please see section IV for further detail.
2. Limited/Suggestive Evidence of an Association
NAS found limited/suggestive evidence of an association between
exposure to combustion products and cancers of the nasal cavity and
nasopharynx; cancers of the oral cavity and oropharynx; laryngeal
cancer; bladder cancer; low birthweight/intrauterine growth retardation
and exposure during pregnancy; preterm birth and exposure during
pregnancy; and incident asthma.
The results of the studies of the relationship between combustion
products and cancers of the nasal cavity and nasopharynx were
inconsistent, and indirect methods were used to assess exposure.
However, positive associations were reported between combustion
products (particularly wood smoke) and cancer of the nasopharynx.
NAS's positive finding of ``limited/suggestive evidence of an
association'' between exposure to combustion products and cancers of
the nasal cavity and nasopharynx was based on 4 epidemiological case-
control studies. These studies involved patients with nasal cavity and
nasopharynx cancer, who were exposed regularly to combustion products,
by virtue of their occupation or in their daily lives, over many years.
Relevant exposures included exposure to fumes from the burning of wood
and other materials, use of fuels, and occupational exposures such as
working as a motor vehicle driver. Although NAS found these studies
showed inconsistent results, they concluded that positive associations
were reported by studies conducted in China between combustion products
(particularly wood smoke) and cancer of the nasopharnyx.
NAS's positive finding of ``limited/suggestive evidence of an
association'' between exposure to combustion products and cancers of
the oral cavity and oropharynx was based on 9 epidemiological case-
control studies. These epidemiological studies were of oral cavity and
oropharynx cancer patients who were exposed to ambient air pollution in
the cities where they lived, or who were exposed over many years due to
their occupation or to indoor pollution in their homes due to
combustion products from wood, coal, kerosene or gas burning stoves or
heaters. Occupational exposures included working as a motor vehicle
driver or railroad employee. NAS concluded that results of several
studies suggested an association between cancers of the oral cavity and
oropharynx and exposure to combustion products.
NAS's positive finding of ``limited/suggestive evidence of an
association'' between exposure to combustion products and laryngeal
cancer was based on one epidemiological cohort study of workers exposed
to diesel exhaust, and 16 epidemiological case-control studies of
patients with laryngeal cancer. These studies involved people who were
exposed to combustion products due to their occupations as railway
workers, motor
[[Page 50859]]
vehicle drivers, or as city commuters exposed to ambient air pollution.
The studies also included people who used wood and other fuel burning
stoves regularly. Several studies reported positive findings, including
two studies regarding exposure to the emissions of fossil-fuel stoves
and one study regarding exposure to wood-stove emissions. Several
studies reported small increases in laryngeal-cancer risk for some
exposures; however, overall, the results were inconsistent. NAS
concluded that the epidemiologic literature overall provided limited/
suggestive evidence of an association between exposure to combustion
products and laryngeal cancer.
NAS found ``limited/suggestive evidence of an association'' between
exposure to combustion products and bladder cancer. Studies that
assessed the relationship between exposure to combustion products and
bladder cancer have not been consistently positive, and no studies
assessed measurements of exposure. One pooled analysis of occupational
exposures found questionably increased risks in exhaust-related
occupations, and the risk was increased with higher exposures to
polycyclic aromatic hydrocarbons (PAHs) and benzopyrene, which are
combustion products. A slightly increased risk was observed for diesel
exhaust. In a related study, similar findings were noted with some
exposures to exhausts and PAHs. A more detailed assessment of PAH
exposures based on expert review of work-history information found
apparently stable associations with average and cumulative PAH
exposures and total duration of PAH exposures. Taken together, the
results constituted limited or suggestive evidence of an association
between combustion products and bladder cancer, but the lack of
exposure measurements and the heterogeneity of results precludes
classifying the association as sufficient.
NAS's positive finding of ``limited/suggestive evidence of an
association'' between exposure to combustion products during pregnancy
and low birthweight or intrauterine growth retardation was based on 8
epidemiological studies of pregnant women. These women were exposed to
ambient air pollution ``smog'' in heavily polluted cities in the Czech
Republic where coal was burned, and in urban cities located in South
Korea, China, Canada, and the United States.
Two studies found evidence of a relationship between low
birthweight or intrauterine growth retardation and combustion-product
exposure. Their analyses controlled for several known risk factors,
including maternal smoking. Several other studies reviewed by NAS
provided supportive evidence of a relationship, but most were unable to
adjust for maternal smoking.
NAS's positive finding of ``limited/suggestive evidence of an
association'' between exposure to combustion products during pregnancy
and preterm birth was based on four epidemiological studies. The
studies that found evidence of a relationship between preterm birth and
combustion-product exposure were based primarily on maternal residence
during pregnancy. Most of these studies controlled for several known
risk factors for preterm birth (such as maternal age, race, education,
and access to prenatal care), but none of the studies could completely
control for maternal smoking, which is an important risk factor for
preterm birth.
NAS's positive finding of ``limited/suggestive evidence of an
association'' between exposure to combustion products and asthma was
based primarily on two studies, which evaluated an association between
asthma and exposure to combustion products in ambient air pollution.
NAS also relied on a study of veterans of the 1991 Gulf War that found
an association between oil-well fire smoke and asthma, and a study
associating ``biomass combustion'' and asthma among people over 60
years old living in India.
The epidemiological studies found that new cases of asthma were
associated with combustion-product exposure in air pollutants. A study
of Gulf War veterans using an objective exposure-measurement method,
found an association between oil-well fire smoke and asthma in Gulf War
veterans, but could not distinguish between new cases arising after the
war and exacerbation of pre-existing conditions. Although the other key
Gulf War study found no relationship between exposure and asthma, its
definition of asthma was inadequate. Other studies of biomass-fuel
combustion and outdoor air pollution supported a relationship between
combustion exposure and asthma.
The Secretary has determined that, although there is limited/
suggestive evidence of an association between exposure to combustion
products and cancers of the nasal cavity and nasopharynx; cancers of
the oral cavity and oropharynx; laryngeal cancer; bladder cancer; low
birthweight/intrauterine growth retardation (with exposure during
pregnancy); preterm birth (with exposure during pregnancy); and
incident asthma, VA does not consider this exposure to be ``associated
with'' the 1991 Gulf War. Please see section IV for further detail.
3. Inadequate/Insufficient Evidence
NAS found inadequate/insufficient evidence between exposure to
combustion products and esophageal cancer; stomach cancer; colon
cancer; rectal cancer; hepatic cancer; pancreatic cancer; melanoma;
female breast cancer; male breast cancer; female genital cancers
(cervical, endometrial, uterine, and ovarian cancers); prostatic
cancer; testicular cancer; nervous system cancers; ocular melanoma;
kidney cancer; non-Hodgkin's lymphoma; Hodgkin's disease; multiple
myeloma, leukemia; myelodysplastic syndromes; preterm births (based on
exposure during a specific time period during pregnancy, such as the
first trimester); low birth weight and intrauterine growth retardation
(based on exposure before gestation or during a specific period during
pregnancy, such as the first trimester); specific birth defects,
including cardiac effects (with maternal or paternal exposure before
conception or maternal exposure during early pregnancy); all childhood
cancers identified, including acute lymphocytic leukemia, leukemia,
neuroblastoma, and brain cancer; neurobehavioral effects; post-
traumatic stress disorder; nervous system subgroupings (or individual
nervous system diseases); Multiple Chemical Sensitivity symptoms;
chronic bronchitis (less than 1 year of exposure); emphysema; chronic
obstructive pulmonary disease; ischemic heart disease or myocardial
infarction (less than 2 years of exposure); dermatitis-irritant and
allergic; and sarcoidosis.
NAS reviewed five studies of combustion products and esophageal
cancer, and concluded that no consistent association was observed in
those studies.
NAS reviewed six studies of combustion products and stomach cancer.
Two of the studies reported an increased risk for stomach cancer, but
the method used to assess exposure was limited and there were no
adjustments for confounders.
Studies of exposure to combustion products and colon cancer
reported positive associations for exposure to some combustion
products, but not to others. Further, a number of the positive findings
were limited, due to their large confidence intervals. NAS found that
the evidence of an association was inadequate because of the small
number of studies available.
With regard to rectal cancer, NAS found the studies' results were
inconsistent, and the number of studies was small. NAS also noted that
any
[[Page 50860]]
positive studies failed to include at least one high-quality study
supported by an adequate exposure assessment.
NAS noted only one relevant study that evaluated exposure to
combustion products and hepatic cancer. Although associations were
noted for some occupations, there were few cases with relevant
exposure, and the study did not consider all pertinent risk factors.
The four reviewed studies of combustion-product exposure and
pancreatic cancer generally did not provide evidence of an association.
One study found an association between exposure to coal combustion
products and increased risk of pancreatic cancer, but it did not find a
link between nine other types of combustion products and pancreatic
cancer.
Studies regarding melanoma addressed exposure to combustion
products but their reliability is limited because they failed to adjust
for exposure to sunlight, a major risk factor for melanoma. Overall,
the studies did not report significant findings of association for most
types of exposure. Two studies found isolated effects of specific
exposures (propane exhaust and being a traffic administrator,
respectively) that were not among the major exposures considered by
NAS.
NAS reviewed three studies concerning nonmelanoma skin cancer and
combustion products. The studies generally did not report statistically
significant findings of an association. NAS found that for the more
common type of nonmelanoma skin cancer (basal cell carcinoma), the
findings were largely negative. Two of the studies stated findings
regarding squamous cell carcinoma, with one finding a statistically
significant association for one type of exposure (diesel fumes), but
not others, and one study finding no association.
The two studies involving female breast cancer and exposure to
combustion products essentially had negative results.
Of the two reviewed studies regarding exposure to combustion
products and male breast cancer, one did not find an association
between PAH exposure and male breast cancer, and the other, although
reporting a positive association, was limited by its method of exposure
assessment.
NAS reviewed three studies regarding exposure to fuels or
combustion products and cervical, endometrial, uterine, or ovarian
cancer, and found that they provided inadequate support for an
association.
NAS reviewed four prostate cancer studies that measured the
relationship between occupations having potential for exposure to
combustion products or PAHs or having more rigorously derived estimates
of exposure to such agents and prostatic cancer. Although the studies
reported several positive associations, NAS noted that the results were
not consistently positive. For example, one study showed results
contrary to a dose-response relationship, while another study showed an
increased risk in firefighters and railroad workers but not in other
transportation or trucking workers.
Testicular cancer studies did not provide enough relevant data to
draw any sort of conclusion about exposure to fuels or combustion
products and testicular cancer.
Data on combustion products and brain cancer (nervous system
cancers) were too sparse to determine whether an association exists.
Three studies of ocular melanoma reported increased, but imprecise,
risks of ocular melanoma in occupations related to transportation. The
reliability of these studies is limited by their small size, lack of
statistical significance, and lack of adequate exposure assessment.
Although some studies of exposure to combustion products and kidney
cancer suggested a possible association based on job title, NAS found
that the results were not consistently positive, with some studies
showing no increased risk. Further, the results of some studies showing
positive associations were limited by considerations of statistical
significance and other factors.
Studies on non-Hodgkin's lymphoma (NHL) had no firmly positive
findings. In the study with the most objective exposure assessment,
there was no indication of an association with any of the fuels or
their combustion products.
The studies regarding Hodgkin's disease (HD) were limited by their
small numbers of cases and the nonspecificity of their exposure
assessments. Further, the three primary studies reviewed by NAS showed
findings of no association.
NAS reviewed ten studies concerning multiple myeloma and exposure
to combustion products. Three of the studies the NAS found to be among
the most sizable or significant reported only marginally increased
risks and are just barely suggestive of an association. Other studies
showed no association, and yet other studies are limited due to
imprecise estimates of increased multiple-myeloma risk in association
with exhaust exposure and concerns regarding exposure assessments. NAS
concluded that the literature overall provided insufficient evidence of
an association.
NAS reviewed six studies of leukemia and exposure to combustion
products. Four of the studies showed no findings of a statistically
significant increased risk. In the other two studies, the apparent
associations were related to separate types of leukemia, and the
authors of the studies noted that any increase in leukemia risk was
difficult to attribute specifically to exhaust because of concurrent
exposure to fuels and benzene. The exposure assessments in all the
studies were based on information from sources of questionable
reliability (personal interviews or medical records) or had a low
degree of specificity for combustion products.
NAS reviewed two studies regarding myelodysplastic syndromes and
exposure to combustion products. One study found no significant
evidence of an association. The other study found stable evidence of an
association for the not particularly substance-specific occupation of
machine operator. Further, the reliability of that study is limited
because the analyses by researchers were rudimentary and failed to
adjust for possible confounders when the information was available.
As noted above in section III.A.2, NAS found limited/suggestive
evidence of an association between exposure to combustion products
during pregnancy and preterm birth. NAS similarly found limited/
suggestive evidence of an association between exposure to combustion
products during pregnancy and low birth weight or intrauterine growth
retardation. However, NAS also found that there was inadequate/
insufficient evidence of an association between combustion products
exposure at any specific point during pregnancy (such as the first
trimester) and these reproductive effects. Although several of the
studies NAS reviewed reported results for exposure at different stages
of pregnancy, there were no consistent findings as to whether the risks
were greater with exposure early or late in pregnancy. Additionally,
none of the studies completely controlled for the significant risk
factor of smoking during pregnancy.
One study of an association between maternal exposure to air
pollutants and the risk of birth defects reported relationships between
certain cardiac defects and increasing exposure to CO and O3. NAS
discussed two studies that examined the association between paternal
employment as a firefighter and the risk of cardiac birth defects. One
of the studies found no evidence of an association, while the other
found some evidence that certain cardiac defects were associated with
paternal employment as a firefighter. Both studies had limitations due
to size,
[[Page 50861]]
potential confounding and/or inadequate information about duration of
paternal firefighting. In a study of maternal or paternal exposures
among residents of Rotorua, New Zealand, a city with high geothermal
exposure to hydrogen sulfide, no excess birth defects were reported in
comparison with residents in the rest of New Zealand.
NAS discussed eleven studies of the association between combustion-
products exposure and childhood cancers, including acute lymphocytic
leukemia, leukemia, neuroblastoma, and brain cancer. All of the studies
were limited by their inability to validate employment history and by
the lack of details on specific assessments of exposure to combustion
products. The exposure groups were broad and included many diverse
occupations where exposure to other chemicals was noted in addition to
combustion products. Six of the studies found no association between
combustion products exposure and the studied childhood cancers. One
study reported general findings of associations for a variety of
childhood cancers, while the remaining four studies contained mixed
findings, reporting positive associations for certain types of cancers.
All of the studies on neurobehavioral effects and combustion-
product exposure suffered from significant methodological limitations.
Several Gulf War studies reported positive relationships between self-
reported exposure and self-reported neuropsychologic, cognitive, or
mood symptoms or multiple unexplained symptoms, but the lack of
objective measurement of exposure limits the reliability of those
findings. Among two non-veteran studies reporting positive findings for
certain neurobehavioral effects, one study did not have a control
group, and the other had serious limitations, especially in subject
selection.
NAS identified no studies showing an association between
combustion-products exposure and post-traumatic stress disorder (PTSD).
Although several studies addressed the prevalence of PTSD among
firefighters, the result is most likely attributable to the hazardous
nature of the job rather than exposure to combustion products. Only a
few Gulf War studies have examined whether self-reported combustion-
product exposure was related to PTSD as an outcome measure, and none
has found such a relationship. None of the studies with objectively
measured oil-well fire smoke examined PTSD as an outcome measure.
Regarding nervous system disease subgroupings (or individual
nervous system diseases), NAS excluded studies involving only overbroad
and nonspecific health outcomes and focused on individual neurologic
diseases or subgroupings of nervous-system diseases. Only two
identified studies examined nervous-system subgroupings in relation to
combustion-products exposure. One study found exposure-response
relationships with nervous-system subgroupings in a hospital discharge
survey. The limitation of this study was assignment of exposure
(residence only) and potential for exposure misclassification. The
other study did not find a relationship between combustion product
exposure and multiple sclerosis. No other studies of nervous system
subgroups or the individual diseases met NAS's criteria for inclusion.
Although NAS reviewed several studies of Multiple Chemical
Sensitivity (MCS) in Gulf War veteran or civilian samples, those
studies provided relatively little evidence that MCS was associated
with combustion-products exposure in service. Several studies involved
questionnaires on which veterans or civilians self-reported that
exposure to certain combustion products (e.g., tobacco smoke, car
exhaust) are among the factors that can trigger their symptomatology.
However, NAS noted that most of the studies did inquire as to the first
onset of symptoms. Further, the studies generally were limited by
methodologic concerns, including self-reported exposures and symptoms
and the possibility of recall bias.
Although the studies reviewed by NAS indicated a probable
relationship between long-term (over 1 year) exposure to combustion
products and chronic bronchitis, a key unresolved issue was whether
shorter-term exposures (less than 1 year) can cause the condition. NAS
found inadequate published data that addressed the effect of shorter
term combustion-product exposures (less than 1 year) on the risk of
developing chronic bronchitis. Even if it could be shown that long-term
exposure to combustion products caused chronic bronchitis, it might be
expected to cease after exposure without long-term health consequences.
NAS found inadequate published data to evaluate the natural history of
chronic bronchitis after cessation of exposure to combustion products.
A study found that mortality due to emphysema was not considerably
increased among workers exposed to diesel exhaust. This result was
found after adjustments for the effects of smoking were made. Likewise,
a study of veterans exposed to oil-well fires also did not find a
relationship with emphysema. Other studies that included emphysema in
the analysis were methodologically inadequate.
NAS did not identify any high-quality studies that evaluated the
effect of exposure to combustion products on the risk of chronic
obstructive pulmonary disease (COPD), as defined by objective evidence
of irreversible airflow obstruction with spirometry. Several studies of
biomass-smoke exposure used measures of airflow obstruction but had
methodologic limitations that precluded clear conclusions about the
connection between combustion exposure and COPD.
There was relatively consistent epidemiologic evidence of the
relation between ischemic heart disease (including myocardial
infarction) and long-term exposure to fossil-fuel combustion products,
including motor-vehicle exhaust and combustion-derived fine particulate
matter. However, the increased risk was small in absolute terms, and
there was no adequate epidemiologic evidence to support the role of
relatively short exposures (similar to that experienced in the Gulf
War), followed by an exposure-free period, and then development of
ischemic heart disease events. Accordingly, NAS found inadequate/
insufficient evidence to determine whether an association exists
between short-term exposure (less than 2 years) to combustion products
and the development of ischemic heart disease after an exposure-free
period of months or years.
Rashes were frequently reported by Gulf War veterans, but only one
study of Gulf War veterans searched for relationships between
dermatitis and self-reported exposure during the Gulf War. No exposure
to combustion products or any other self-reported exposure was related
to dermatitis, defined as rashes, eczema, or skin allergies.
NAS identified three epidemiologic studies on the relationship
between occupational or residential exposure to fires and sarcoidosis,
all of which had significant methodologic limitations. One study had
numerous limitations, such as inadequate description of how the cases
without biopsy confirmation were diagnosed and the lack of control for
employment history (besides farming), recall bias, and lack of
measurement of pollutant concentrations. The authors noted that
sarcoidosis could be associated with a component of wood-burning or
wood-
[[Page 50862]]
handling, namely contact with smoke, ash, wood particles, or wood
molds. Another study was limited by the lack of specific exposure
assessment and of analysis of duration or frequency of exposure to
combustion products. There was no control for potential confounders,
such as race or familiar aggregation of sarcoidosis. In addition, there
was no way to determine the role of combustion products or exposure to
other toxicants, allergens, or infectious agents. The third study was
limited by the small sample, the low statistical power, the lack of a
risk estimate for firefighters versus police officers, the lack of
exposure assessment for combustion products, and the lack of assessment
of coexposures to other chemicals in the workplace.
Based on the information and analysis in the NAS report, the
Secretary has determined that there is insufficient credible evidence
to conclude that there is a positive association between exposure to
combustion products and esophageal cancer; stomach cancer; colon
cancer; rectal cancer; hepatic cancer; pancreatic cancer; melanoma;
nonmelanoma skin cancer; female breast cancer; male breast cancer;
female genital cancers (cervical, endometrial, uterine, and ovarian
cancers); prostatic cancer; testicular cancer; nervous system cancers;
ocular melanoma; kidney cancer; non-Hodgkin's lymphoma; Hodgkin's
disease; multiple myeloma, leukemia; myelodysplastic syndromes; preterm
births (based on exposure during any specific time period during
pregnancy, such as the first trimester); low birth weight and
intrauterine growth retardation (based on exposure before gestation or
during any specific period during pregnancy, such as the first
trimester); specific birth defects, including cardiac effects (with
maternal or paternal exposure before conception or maternal exposure
during early pregnancy; all childhood cancers identified, including
acute lymphocytic leukemia, leukemia, neuroblastoma, and brain cancer;
neurobehavioral effects; post-traumatic stress disorder; nervous system
disease subgroupings (or individual nervous system diseases); MCS
symptoms; chronic bronchitis (less than 1 year of exposure); emphysema;
chronic obstructive pulmonary disease; ischemic heart disease or
myocardial infarction (less than 2 years of exposure); dermatitis-
irritant and allergic; and sarcoidosis. Further, as explained in
section IV of this notice, VA does not consider the combustion-products
exposures underlying the NAS findings to be exposures ``associated
with'' the 1991 Gulf War. Therefore, a presumption of service
connection is not warranted for any such illness based upon exposure to
combustion products during service in the Gulf War.
B. Hydrazines
1. Limited/Suggestive Evidence of an Association
NAS found limited/suggestive evidence of an association between
exposure to hydrazines (monomethylhydrazine ``MMH,'' and unsymmetrical
(1,1-)dimethylhydrazine ``UDMH'') used as rocket propellants, and lung
cancer. This conclusion was based primarily on one high-quality study,
as discussed below.
An occupational study of a U.S. cohort of aerospace workers engaged
in testing rockets using hydrazine fuel demonstrated an association
between hydrazine exposure and risk of lung cancer. Several sources of
potential confounding, including sex and radiation exposure, were
controlled by study design. Other potentially confounding variables
were controlled in multivariate analysis, including age, pay type, and
time since hire or transfer. Although the smoking status of most
workers was unknown, there was indirect evidence that smoking did not
confound the results.
Two other studies of lung cancer were limited by small sample size
and inadequate study power. In addition, another study was limited by
its failure to control for coexposure to other carcinogenic substances,
including asbestos and PAHs. The lack of internal control subjects and
the lack of information on smoking constitute major limitations for
both studies. Consequently, there was inadequate evidence to evaluate
the consistency of the association between hydrazine and lung cancer
beyond the study of the U.S. cohort.
NAS stated in its report that U.S. military personnel could have
been exposed to UMDH during Operation Desert Storm if UMDH was used as
a rocket fuel in Scud missiles launched by Iraq and the U.S. military
personnel were in the vicinity of the Scud missiles when they
disintegrated. However, NAS stated that hydrazines were apparently not
used in Scud missiles during the 1991 Gulf War even though Iraq had
apparently experimented with UDMH as a rocket fuel. NAS further stated
that it was not aware of any other potential use of hydrazines that
could have resulted in exposure of U.S. service personnel.
Based on information and analysis in the NAS report and from DoD,
VA does not consider exposure to hydrazines to be exposures
``associated with'' the 1991 Gulf War. Please see section IV for
further detail. Therefore, a presumption of service connection is not
warranted for lung cancer based upon exposure to hydrazine during
service in the 1991 Gulf War.
2. Inadequate/Insufficient Evidence
NAS found inadequate/insufficient evidence between hydrazines and
hematopoietic and lymphopoietic cancers; digestive tract cancers;
pancreatic cancer; bladder cancer; kidney cancer; emphysema; ischemic
heart disease or myocardial infarction; and hepatic disease.
NAS noted that relatively few studies existed concerning the health
effects of hydrazine exposure, and that lung cancer was the only health
outcome represented in all three cohort studies reviewed by the
committee. NAS further noted that individual findings in those studies
also reported somewhat increased mortality from cancer at sites other
than the lung (hematopoietic and lymphopoietic, bladder and kidney,
digestive tract, and pancreas) and from two noncancer conditions
(emphysema and ischemic heart disease). NAS concluded, however, that
the few available studies do not provide adequate or consistent
evidence of an association between exposure to hydrazines and any of
those other health outcomes.
Based on the information and analysis in the NAS report, the
Secretary has determined that there is insufficient credible evidence
to conclude that there is a positive association between exposure to
hydrazines and hematopoietic and lymphopoietic cancers; digestive tract
cancers; pancreatic cancer; bladder cancer; kidney cancer; emphysema;
ischemic heart disease or myocardial infarction; and hepatic disease.
Further, as explained in section IV of this notice, VA does not
consider exposure to hydrazines to be exposures ``associated with'' the
1991 Gulf War. Therefore, a presumption of service connection is not
warranted for any such illness based upon exposure to hydrazine during
service in the 1991 Gulf War.
C. Fuels--Inadequate/Insufficient Evidence
NAS found inadequate/insufficient evidence of an association
between exposure to fuels and cancers of the oral cavity and
oropharynx; cancers of the nasal cavity and nasopharynx; esophageal
cancer; stomach cancer; colon cancer; rectal cancer; hepatic cancer;
pancreatic cancer; laryngeal cancer; lung cancer; melanoma; nonmelanoma
skin cancer; female breast
[[Page 50863]]
cancer; male breast cancer; female genital cancers (cervical,
endometrial, uterine, and ovarian cancers); prostatic cancer;
testicular cancer; nervous system cancers; kidney cancer; bladder
cancer; Hodgkin's disease; non-Hodgkin's lymphoma; multiple myeloma;
myelodysplastic syndromes; adverse reproductive or developmental
outcomes (including infertility, spontaneous abortion, childhood
leukemia, CNS tumors, neuroblastoma, and Prader-Willi syndrome);
peripheral neuropathy; neurobehavioral effects; MCS symptoms;
nonmalignant respiratory disease; chronic bronchitis; asthma;
emphysema; dermatitis-irritant and allergic; and sarcoidosis.
NAS reviewed five studies regarding cancer of the oral cavity and
oropharynx and fuels. NAS found that the three occupational cohort
studies it reviewed each had limited statistical power and were
therefore uninformative. NAS further concluded that the two case-
control studies it reviewed failed to report any consistent
relationship between fuel exposure and cancers of the oral cavity and
oropharynx.
NAS found little information available on exposure to fuels and
cancers of the nasal cavity and nasopharynx, and that the two studies
it reviewed failed to provide convincingly positive findings.
NAS found that studies of an association between fuel exposure and
esophageal cancer were few and results were inconsistent and inadequate
to support an association. Some of the studies were unreliable because
they analyzed esophageal cancer and stomach cancers together, and NAS
therefore could not determine which specific cancer type may have been
associated with fuel exposure. Other studies showed no evidence of
association.
NAS also found that studies of an association between fuel exposure
and stomach cancer were inconsistent and inadequate to support an
association. As noted above, some of the studies were unreliable
because they analyzed esophageal cancer and stomach cancers together in
relation to fuel exposure and NAS could not determine which specific
cancer type may have been associated with fuel exposure. Other studies
showed no evidence of association.
NAS found that the studies concerning fuel exposure and colon
cancer provided no consistent evidence of an association. Although some
studies showed increased risk of colon cancer, the increases were
modest and the confidence intervals in several instances included the
null. Three studies analyzed colon cancer and rectal cancer together
and, therefore, NAS could not determine whether exposure to fuels may
have been associated with a specific type of cancer.
NAS found that the studies reporting positive associations between
fuels and rectal cancer were not consistent and the number of studies
was small. Furthermore, the positive studies failed to include at least
one high-quality study supported by an adequate exposure assessment.
Some studies found no evidence of association between fuel exposure and
rectal cancer.
NAS noted only one relevant study that evaluated exposure to fuels
and hepatic cancer in which there were few cases with relevant
exposure, and the study did not consider all pertinent risk factors.
NAS found only two relevant studies on the risk of pancreatic
cancer posed by fuel exposure. One study found no association. The
other study reported an association, but the results were imprecise,
due in part to a large confidence interval that included the null.
NAS found that the results regarding exposure to fuels and
laryngeal cancer were inconsistent. Two studies reviewed by NAS
reported a modest increase in the risk of laryngeal cancer associated
with exposure to fuels, but the reliability of those findings is
limited because the exposures in both studies were self-reported.
Another study reported an increased, but imprecise, risk of laryngeal
cancer in vehicle mechanics, but found no increase in garage and
gasoline-station workers.
NAS found the results of studies of fuel exposure and lung cancer
risk were inconsistent. One study reported an association between
kerosene and crude-oil exposure and squamous-cell lung cancer, between
diesel-fuel exposure and nonadenocarcinoma, and between heating-oil
exposure and oat-cell lung cancer. Two studies did not find an
association in workers most likely to have been exposed to fuels.
The studies examined by NAS addressing melanoma and exposure to
fuels were not adjusted for sun exposure, a major risk factor for
melanoma, and the workers--particularly the exploration, drilling, and
pipeline workers--may have received considerable sun exposure while
performing their jobs. But the one case-control study with fairly
reliable exposure analysis did not support an association in workers
likely to have been exposed to fuels.
Of the available epidemiologic studies regarding nonmelanoma skin
cancer that met NAS's criteria, one study reported one borderline
association between fuel exposure and squamous-cell carcinoma. The
other two reports reviewed by NAS had methodologic limitations and did
not provide reliable evidence of an association. For the more common
type of nonmelanoma skin cancer (basal cell carcinoma), the findings
were largely negative.
NAS reviewed three studies concerning fuel exposure and female
breast cancer. One study found no increased risk of breast cancer,
while the other two found only an insignificant increase in risk.
NAS found no studies assessing the possible relationship of male
breast cancer to fuel exposure alone. NAS reviewed one study that
reported a positive finding regarding combined exposure to fuels and
combustion products and male breast cancer. NAS found, however, that
the method used to assess exposure in that study was limited.
NAS reviewed three studies concerning fuel exposure and female
genital cancers. The studies failed to provide any significant evidence
of an association between exposure to fuels and cervical, endometrial,
uterine, or ovarian cancer.
NAS reviewed several studies regarding an association between fuel
exposure and prostatic cancer. Only one of those studies reported a
positive association between a fuel-related exposure and prostatic
cancer. That study found an association between exposure to diesel fuel
and prostate cancer, but did not find significant evidence of an
association for other types of fuel exposure. The other reports
reviewed by NAS were negative for any association.
Only one study addressed the association between fuel exposure and
testicular cancer, and it found no evidence of an association. NAS
concluded that there was not enough relevant data to draw any sort of
conclusion about exposure to fuels and testicular cancer.
Several studies reported sporadic associations between fuel
exposure and nervous system cancers (brain cancer), but the results
were limited by several factors, including wide confidence intervals
that include the null. In some studies, the increased risk was found
only among workers likely to have lesser fuel exposure, while no
increased risk was seen among workers likely to have greater fuel
exposure. None of the studies could be considered a high-quality study
supported by an adequate
[[Page 50864]]
exposure assessment. Additionally, some studies found no evidence of
association.
No key study that was positive for an association between exposure
to fuels and kidney cancer was identified. NAS found the uniformly
negative results of a study of a comprehensive sample of renal cell
carcinoma cases in the petroleum industry with excellent exposure
assessment to be compelling.
NAS reviewed several studies concerning fuel exposure and bladder
cancer. Several of the studies found no evidence or no significant
evidence of an association. Other studies provided evidence of a
relationship between fuel exposure and bladder cancer, but the
relationship was not consistently increased in any study with a
detailed and specific exposure assessment. The positive findings in
some studies were further limited by the methods used to estimate
exposure and the difficulty in segregating fuel exposure from
combustion-product exposure in some instances.
Regarding Hodgkin's disease, the studies were limited by their
small numbers of cases and the nonspecificity of their exposure
assessments. Of the five studies reviewed by NAS, two found no evidence
of an association between fuel exposure and Hodgkin's disease, one
found an insignificant increase only among males. The other two studies
showed evidence of an association, but were limited by wide confidence
intervals and the lack of any relationship to a specific job or
duration of employment.
Studies on non-Hodgkin's lymphoma had no firmly positive findings.
The most well conducted studies showed no evidence of association.
NAS found no consistent relationship between exposure to fuels and
multiple myeloma in the studies reviewed. Most studies reported no
association.
NAS reviewed two studies that showed evidence of an association
between myelodysplastic syndrome and exposure to petroleum-related
substances. However, a significantly larger study using similar methods
and procedures failed to produce consistent results. The larger study
reported only a modest increased risk, with confidence intervals
including the null, and did not find any evidence of a dose-response
relationship with duration or intensity of exposure.
NAS determined that it was difficult overall to reach conclusions
on the epidemiologic studies of adverse reproductive outcomes and
exposure to fuels. The assessment of findings was limited by the small
number of studies available on each health outcome, the possibility of
recall bias, and the lack of specificity of exposure to the agents of
concern in this report. NAS found no adequate studies regarding the
relationship between fuel exposure and female infertility. NAS found
one study concerning fuel exposure and male fertility, and that study
showed no effect on sperm measures among persons exposed to jet fuels.
NAS found only one study on fuel exposure and spontaneous abortion. The
study showed a significant increase in spontaneous abortion among women
living in an area where water used for drinking, cooking, and bathing
was contaminated by nearby oil fields, however, the finding was
potentially limited by recall bias and methods of estimating exposure.
NAS identified one study showing an increased risk of childhood
leukemia in the offspring of men exposed to petroleum for 1,000 days or
more before conception, and one study showing an increased risk of
childhood leukemia based on maternal exposure to fuels during
pregnancy. The latter study was potentially limited by recall bias,
interviewer bias, control-selection procedures, and lack of validation
for other risk factors. NAS noted that three other occupational studies
showed no relationship between parental employment in a field involving
fuel exposure and childhood leukemia. With respect to childhood cancers
of the central nervous system, NAS identified one study showing no
increase in neuroblastoma based on maternal exposure to fuels during
pregnancy, but moderate increases based on paternal exposures. The
study authors were unable to distinguish between paternal exposures
occurring before or after conception. Another study showed an increased
risk of neuroblastoma based on maternal or paternal exposures, although
the study authors noted several limitations on the interpretation of
the data, including bias, chance, and self-reporting of exposure
information. NAS noted that two studies showed a possible association
between parental exposure to hydrocarbons and the occurrence of Prader-
Willi Syndrome in offspring, although neither study collected
information on potential confounders. A third study found no
association between exposure to hydrocarbons and Prader-Willi Syndrome
in offspring. In view of the minimal and indeterminate data, NAS
concluded that there was inadequate/insufficient evidence of an
association between parental fuel exposure and adverse reproductive or
developmental outcomes.
Regarding neuropathy, NAS reviewed two studies, in which certain
neurological symptoms were more prevalent among subjects with higher
exposures to jet fuels, while other neurological symptoms were either
not increased or were more prevalent among controls. NAS concluded
that, although certain symptomatic differences were apparently related
to exposure, there were no objective measures to support a relationship
between jet-fuel exposure and neuropathy. The limitations of the
studies included small samples and the lack of internal nonexposed
groups of controls.
Regarding neurobehavioral effects, NAS found that several studies
of Gulf War veterans found a relationship between the veterans' self-
reported fuel exposure and their self-reported neuropsychologic,
cognitive, or non-specific symptoms, but that these studies provided
weak evidence of any relationship, due to recall bias. NAS also
discussed a study of increased neurologic and cognitive abnormalities
among persons who engaged in ``petrol-sniffing,'' but found those
results inconclusive because the effects were most likely due to
exposure to lead rather than the fuels themselves.
NAS found that studies of MCS in Gulf War veteran or civilian
samples generally provided relatively little evidence that MCS was
associated with fuel exposure in service. Several studies involved
questionnaires on which veterans or civilians self-reported that
exposure to fuels are among the factors that can trigger their
symptomatology. The studies generally were limited by methodologic
concerns, including self-reported exposures and symptoms and the
possibility of recall bias. Further, NAS noted that most of the studies
did not address the factors relating to the first onset of symptoms as
distinguished from subsequent recurrence of symptoms. The only study
addressing first onset was an occupational study that incorporated
objective exposure measurement and found a relationship between
symptoms of MCS and fuel exposure. However, because the study was
limited by the small sample and lack of a matched control group of
workers, NAS found that it did not meet the criteria for a primary
study that could support an association.
Regarding respiratory diseases, the studies generally did not
report specific respiratory disease outcomes and exposure assessment,
so it was difficult to reach a conclusion as to a relationship between
respiratory disease outcomes and exposure to fuels. However, NAS noted
that most of the studies it reviewed showed
[[Page 50865]]
standardized mortality ratios of 1.0 or less in study populations,
showing no increased risk of death due to nonmalignant respiratory
disease, asthma, chronic bronchitis, or emphysema in populations
exposed to fuels.
Regarding irritant contact dermatitis, many fuels (for example,
gasoline and kerosene) were generally acknowledged skin irritants, as
indicated by the studies reviewed by NAS. Irritant contact dermatitis
was evident soon after exposure but usually disappeared soon after
removal of the irritant. There are few epidemiologic studies, however,
of exposure to fuels and irritant and allergic contact dermatitis.
Accordingly, NAS concluded that there was inadequate/insufficient
evidence of an association between fuel exposure and chronic irritant
and allergic contact dermatitis after cessation of exposure.
The NAS report does not identify any studies concerning the
possible relationship between exposure to fuels and sarcoidosis.
However, NAS concluded, presumably based on the absence of relevant
studies, that there is inadequate/insufficient evidence of an
association between fuel exposure and sarcoidosis.
Based on the information and analysis in the NAS report, the
Secretary has determined that there is insufficient credible evidence
to conclude that there is a positive association between exposure to
fuels and cancers of the oral cavity and oropharynx; cancers of the
nasal cavity and nasopharynx; esophageal cancer; stomach cancer; colon
cancer; rectal cancer; hepatic cancer; pancreatic cancer; laryngeal
cancer; lung cancer; melanoma; nonmelanoma skin cancer; female breast
cancer; male breast cancer; female genital cancers (cervical,
endometrial, uterine, and ovarian cancers); prostatic cancer;
testicular cancer; nervous system cancers; kidney cancer; bladder
cancer; Hodgkin's disease; non-Hodgkin's lymphoma; multiple myeloma;
myelodysplastic syndromes; adverse reproductive or developmental
outcomes (including infertility, spontaneous abortion, childhood
leukemia, CNS tumors, neuroblastoma, and Prader-Willi syndrome);
peripheral neuropathy; neurobehavioral effects; Multiple Chemical
Sensitivity symptoms; nonmalignant respiratory disease; chronic
bronchitis; asthma; emphysema; dermatitis-irritant and allergic; and
sarcoidosis. Therefore, a presumption of service connection is not
warranted for any such illness based upon exposure to fuels during
service in the 1991 Gulf War.
D. Nitric Acid--Inadequate/Insufficient Evidence
NAS found inadequate/insufficient evidence between nitric acid and
stomach cancer; melanoma; lymphopoietic cancers; pancreatic cancer;
laryngeal cancer; lung cancer; bladder cancer; multiple myeloma; and
cardiovascular diseases.
Generally, on the basis of NAS's review of the epidemiologic
evidence, no available studies directly examined the association
between exposure to nitric acid and long-term human health effects.
Most studies were able only to investigate the health effects of nitric
acid in combination with other strong inorganic acids, such as sulfuric
acid, or other known carcinogens such as asbestos: that is, an
independent assessment of nitric acid exposure was impossible because
workers were exposed simultaneously to such mixtures. As a result, the
health effects associated with exposure to nitric acid alone cannot be
assessed.
It appears that NAS stated conclusions with respect to nitric acid
and nine disease categories because certain studies state findings with
respect to those disease categories in populations that potentially
were exposed to a group of carcinogens that may have included nitric
acid. As explained above, however, NAS concluded that the existing data
are not sufficiently specific to nitric acid and, therefore, do not
provide reliable evidence of an association between exposure to nitric
acid and the occurrence of any disease.
Based on the information and analysis in the NAS report, the
Secretary has determined that there is insufficient credible evidence
to conclude that there is a positive association between exposure to
nitric acid and stomach cancer; melanoma; lymphopoietic cancers;
pancreatic cancer; laryngeal cancer; lung cancer; bladder cancer;
multiple myeloma; and cardiovascular diseases. Therefore, a presumption
of service connection is not warranted for any such illness based upon
exposure to nitric acid during service in the 1991 Gulf War.
IV. VA Response to the National Academy of Sciences Report
In order to facilitate action on the 2004 update report from NAS,
VA established the 2005 Gulf War Health Effects Task Force to consider
and develop recommendations for the Secretary of Veterans Affairs. The
Task Force consisted of top Departmental officials, specifically the
Under Secretaries for Health and Benefits, the General Counsel, and the
Assistant Secretary for Policy and Planning. The review provided the
basis for the Secretary's determination regarding health outcomes
related to service in the Gulf War.
A. 1991 Gulf War Hazard Exposure Data
Although the statutes necessarily contemplate that NAS would
evaluate non-veteran studies concerning the health effects of various
exposures, they also require NAS to attempt to relate its findings to
the actual experiences of Gulf War veterans.
For example, Public Law 105-277, Sec. 1603(e)(1)(B) directs NAS to
evaluate and summarize ``the increased risk of the illness among human
or animal populations'' including but not limited to Gulf War veterans.
Public Law 105-368, Sec. 101(c)(1)(C) directs NAS to ``identify the
illnesses * * * for which there is scientific evidence of a higher
prevalence among populations of Gulf War veterans when compared with
other appropriate populations of individuals.'' The statute goes on to
require that for each illness NAS finds to be more prevalent in Gulf
War veterans or to be associated with a possible Gulf War hazardous
exposure, NAS ``shall determine (to the extent available scientific
evidence permits) whether there is scientific evidence of an
association of that illness with Gulf War service or exposure during
Gulf War service to one or more agents, hazards, or medicines or
vaccines.'' Public Law 105-368, Sec. 101(e)(1).
Public Law 105-368, Sec. 101(e)(1)(E), (F) directs NAS to consider
``in any case where information about exposure levels is available,
whether the evidence indicates that the levels of exposure of the
studied populations were of the same magnitude as the estimated likely
exposures of Gulf War veterans; and * * * whether there is an increased
risk of illness among Gulf War veterans in comparison with appropriate
peer groups.''
Congress further provided that ``[i]n conducting the review and
evaluation * * * [NAS] shall * * * assess the latency period, if any,
between service or exposure to any potential risk factor (including an
agent, hazard, or medicine or vaccine [reviewed]) * * * and the
manifestation of such illness.'' Public Law No. 105-368, Sec.
101(c)(3).
Determinations concerning the increased risk of illness among Gulf
War veterans, as well as the latency periods for manifestation of
illness, necessarily require consideration of the degree and the
duration of exposure to the relevant environmental hazards. Findings
based on non-veterans dwelling in cities or
[[Page 50866]]
typical civilian occupational studies may not necessarily support
findings specific to Gulf War service because of differences in the
magnitude and duration of exposure between these groups.
NAS concluded in its report that it was essentially unable to
respond to Congress' charge to relate their literature-based health
findings to the actual exposure magnitude and duration for Gulf War
veterans. NAS explained:
To estimate the magnitude of risk of a particular health outcome
among Gulf War veterans, the committee would need to compare the
rates of disease or other health effects in veterans exposed to the
putative agents with the rates in those who were not exposed. That
would require information about the specific agents to which
individual veterans were exposed and about their doses. However,
there is a paucity of data regarding the agents and doses to which
individual Gulf War veterans were exposed. * * * Because of the lack
of various kinds of data on veterans, the committee could not
extrapolate from the exposures in the studies it reviewed to the
exposures of Gulf War veterans. Therefore, it could not determine
the likelihood of increased risk of adverse health outcomes among
Gulf War veterans due to exposure to the agents examined in this
report.
``Gulf War and Health, Volume 3. Fuels, Combustion Products, and
Propellants,'' pp.16-17 (December 20, 2004).
NAS further noted that the studies it reviewed often ``included
people whose exposures had been over a lifetime (such as to air
pollution in their communities) or included workers employed in a
particular industry over many years.'' NAS stated: ``In contrast, the
exposures of veterans in the Persian Gulf were of relatively short
duration with varying intensity. Therefore, the exposures experienced
during the Gulf War might only approximate the exposures described in
the occupational and environmental literature reviewed in this
report.'' ``Gulf War and Health, Volume 3. Fuels, Combustion Products,
and Propellants,'' p. 17 (December 20, 2004).
As such, NAS was unable to relate their health findings to the
actual exposures experienced by Gulf War veterans. However, some
relevant data is available.
1. Gulf War Exposure to Combustion Products
In its September 2000 report, ``Environmental Exposure Report: Oil
Well Fires'' the Department of Defense (DoD) summarized its
investigations on exposure of Gulf War veterans to oil-well-fire smoke
and related combustion products during the 1991 Gulf War. The report
describes how from January through late February 1991, retreating Iraqi
forces set fire to more than 600 Kuwaiti oil-wells, creating huge
columns of smoke. These fires were brought under control within 9
months.
The report concludes that, although the oil-well fires produced
smoke plumes, the actual exposure to combustion products of U.S.
service members in that region was generally unremarkable. Furthermore,
unlike many Gulf War environmental hazards of concern, the results of
extensive monitoring efforts by various agencies for air pollutants and
combustion products from the 1991 Gulf oil-well fires are available to
support the report's conclusions about such exposure. The report also
concludes that some individual veterans who were near the oil-well
fires could have been exposed to high levels of large particulates,
primarily as material deposited directly to skin or clothing rather
than through inhalation.
According to the report,
For about eight months immediately after the ground war, U.S.
and international organizations conducted comprehensive air
monitoring to characterize the contaminants of concern and, by
measuring their relative concentrations in the atmosphere, lay the
groundwork for assessing their likely short- and long-term impacts
to human health and the environment. * * * Ground-level and
airborne-based monitoring platforms collected numerous samples. The
U.S. Army Environmental Hygiene Agency conducted the most
comprehensive monitoring program, including taking more than 4,000
samples.
In general, the monitoring results were consistent among the
various organizations involved. * * * the maximum observed
concentrations of air contaminants, other than particulate matter,
were similar to levels found in U.S. suburbs and generally lower
than those found in large urban areas. Overall, * * * monitoring
data show the pollutant concentrations present in the environment,
particularly in areas where U.S. troops and civilians were located,
fell below NIOSH [National Institute for Occupational Safety and
Health], OSHA [Occupational Safety and Health Administration], or
ACGIH [American Conference of Government Industrial Hygienists]
recommended exposure limits for hazardous substances in the
workplace.
The DoD report states:
At the time of the destruction, the medical and environmental
community feared exposure to the fires would result in catastrophic
acute and chronic health effects. However, the fires' high
combustion efficiency, the nature and amount of the smoke's
contaminants, the lofting effect created by solar heating, and the
local wind and weather conditions combined to reduce the fires'
impact on military and civilian populations.
Results of air monitoring studies indicated, except for
particulate matter, air contaminants were below levels established
to protect the health of the general population. However, there were
self-reports by a number of veterans who complained of acute
symptoms they allege were a result of their proximity to the burning
oil wells.
The DoD report points out that exposures to the fires by U.S.
service members were quite short compared to civilians dwelling in U.S.
cities exposed to urban ``smog'' and indoor air pollution, or workers
exposed to engine exhaust: ``Fortunately, the time period during which
military and civilian populations were subjected to the fires'
pollution was relatively short.''
Nevertheless, some 1991 Gulf War troops apparently reported various
short-term adverse health symptoms that could have been related to
exposures to oil fire smoke. The report characterized these as follows:
``Several troops reported significant short-term exposures to oil fire
smoke, soot, and unburned oil, usually after having been totally
enveloped in oil-well-fire fallout. At times troops reported being
soaked with unburned oil.'' ``Several monitoring sites observed high
levels of airborne particulates, sand, and soot. Analysis of samples,
however, indicated the particles were mostly sand-based materials
typical for this region of the world. In the particulate matter
samples, PAH and toxic metal concentrations were low.'' Finally,
``[w]hile smoke plumes occasionally touched the ground, enveloping
nearby personnel, few were in those areas for extended periods of
time.''
DoD's finding that the oil-well fires did not result in significant
unique exposures has been confirmed by several other sources. The
Presidential Advisory Committee on Gulf War Veterans' Illnesses noted
that, while the oil well fires were burning, numerous U.S. and
international agencies performed extensive air monitoring; these groups
included a U.S. Interagency Air Assessment team comprised of scientists
from the Environmental Protection Agency, the National Oceanographic
and Atmospheric Administration, and the Department of Health and Human
Services; and a group of scientists from twelve countries engaged in a
data-collection effort overseen by the World Meteorological
Organization. The Presidential Advisory Committee stated that ``[a]ll
groups found that levels of nitrogen oxides, carbon monoxide, sulfur
dioxide, hydrogen sulfide, other pollutant gases, and [PAHs] were lower
than anticipated and did not exceed those seen in urban air in a
typical U.S. industrial city.'' Presidential Advisory Committee on Gulf
War Veterans' Illnesses: Final Report (Washington, DC:
[[Page 50867]]
U.S. Government Printing Office, December 1996). The Presidential
Advisory Committee further noted that biological samples taken from
persons deployed in the vicinity of the oil-well fires generally
revealed lower levels of volatile organic compounds (VOCs), polycyclic
aromatic carbons, and lead than in reference populations located
elsewhere, except in the case of firefighters, who had significantly
elevated levels of VOCs in comparison to the reference population.
NAS's finding linking oil-well-fire smoke and lung cancer was based
primarily on studies of workers exposed to engine exhaust on the job
and to civilians exposed to ``smog'' and indoor air pollution from
heaters and stoves in the cities in which they dwelled. Health effects
from these relatively long-term exposures may not be relevant to
effects from short-term but intense exposures experienced by some
veterans of the 1991 Gulf War who became heavily covered with fallout
from oil well fires.
Apart from the oil-well fires, exposure to combustion products
could also have occurred through more routine operations that involve
burning fuels. The 1996 Final Report of the Presidential Advisory
Committee stated that ``[o]perating the vehicles and machinery used in
the Gulf War involved exposure to petroleum-based material,'' and that
``[p]etroleum fuels also were used for burning wastes and trash, dust
suppression, and fueling stoves and tent heaters. The Presidential
Advisory Committee stated that ``none of these uses is unique to the
Gulf War,'' but that such uses probably led to increased petroleum
vapor and combustion product exposures. With respect to the use of
heaters, the Committee noted that ``[b]urning leaded fuels indoors
without proper ventilation--e.g., heaters in tents--could have caused
increased lead exposure,'' and that ``[k]erosene heaters, widely used
in the United States, also could have been significant sources of
exposure to nitric oxides, sulfur dioxide, inorganic combustion gases,
carbon monoxide, and particles when used with inadequate ventilation.''
2. Gulf War Exposure to Hydrazine Rocket Propellants
In January 2005, VA's Under Secretary for Health formally requested
DoD's Assistant Secretary of Defense for Health Affairs to provide all
available information about possible exposures of U.S. service members
to hydrazine rocket fuels during the 1991 Gulf War. DoD's response in
an April 8, 2005, letter from the Assistant Secretary of Defense was
that the best available information indicated it was unlikely there was
any exposure to hydrazine among U.S. military personnel in the Gulf.
U.S. missiles and other munitions did not employ hydrazine during the
Gulf War. Also, investigations indicated Iraq had not switched to
hydrazine as a propellant for Scud missiles. Accordingly, there was no
basis upon which to conclude that U.S. veterans of the Gulf War were
exposed to hydrazine from either U.S. or Iraqi missiles.
A very small number of personnel working with the U.S. Air Force F-
16 aircraft might have had minimal exposure to hydrazine. F-16 aircraft
are equipped with a sealed tank (bottle) of hydrazine as an emergency
propellant to be employed in the event of engine stall. When employed,
the hydrazine is consumed. F-16 squadrons deployed with spare bottles
during the Gulf War. If used, the bottles would have been returned to
the U.S., Europe, or Turkey to be refilled and shipped back. The Air
Force has long been keenly aware of the potential health hazards of
hydrazine, so refilling operations are conducted in a manner consistent
with the strictest of occupational health standards.
DoD's August 1999 report, ``Information Paper: Inhibited Red Fuming
Nitric Acid,'' concluded that the rocket fuel used by Iraqi forces in
Scuds and several smaller missiles during the 1991 Gulf War was a type
of kerosene and red fuming nitric acid (also known as IRFNA). DoD
states that apparently Iraq had experimented with hydrazine rocket
fuels including UDMH, however, it concluded that these fuels were not
used during that conflict:
The missile fuel that Iraq used in its older Soviet systems was
a specially refined kerosene-like substance (called kerosene in the
literature). Some improved missiles used UDMH in combination with
IRFNA. The Soviet Union used UDMH in their Scuds, but we have no
evidence that Iraq used UDMH.
Therefore, it is unlikely that any U.S. service members were exposed to
hydrazine rocket fuels during the 1991 Gulf War.
B. VA Determination on Combustion Products and Hydrazines
Based upon the evidence currently available, VA has determined that
a presumption of service connection is not warranted at this time for
any disease based upon an association with exposure to combustion
products or hydrazines during service in the Gulf War. This
determination is based on the conclusion that current evidence does not
establish that service in the Gulf War entailed exposures to combustion
products that were unique to Gulf War service when compared to other
military and civilian populations and that could be expected to produce
the increased risk of adverse health effects based on the findings set
forth in the NAS report. The best evidence currently available
indicates that hydrazines were used in limited circumstances during the
Gulf War and that hydrazine exposure generally would not have occurred.
With respect to combustion products, although the 1991 oil well fires
were the product of a unique event, the best evidence currently
available indicates that they did not result in combustion-products
exposures that were unique in kind or degree when compared to exposures
incurred generally by other military and civilian populations as the
result of ambient air pollution, vehicle exhaust, and other means.
Currently available evidence further indicates that other potential
means of exposure to combustion products, such as through proximity to
vehicles, aircraft, or the use of fuel-based heaters, did not differ
significantly in the Gulf War from similar exposures occurring in other
military and civilian populations generally.
In the absence of unique exposures associated with Gulf War service
that could be correlated to the increased risks of health effects
discussed in the NAS report, a generally applicable presumption of
service connection is not warranted based on exposure to combustion
products or hydrazines in the Gulf War. The governing statute requires
VA to establish presumptions when the Secretary determines that an
illness is associated with exposure to substances or hazards ``known or
presumed to be associated with service in the Southwest Asia Theater of
operations during the Persian Gulf War.'' 38 U.S.C. 1118(b)(1)(B)(i).
VA has determined that hydrazines were used during the 1991 Gulf
War only under extremely limited conditions, and, therefore, hydrazines
are not substances or hazards ``associated with'' service in the 1991
Gulf War. Consequently, VA need not establish a presumption of service
connection for any disease identified in the NAS report as associated
with such exposure.
VA has determined that combustion products, the prevalence and use
of which in the Gulf War did not differ significantly from the
prevalence and use of such substances in other military and civilian
populations, are not substances or hazards ``associated with'' service
in the 1991 Gulf War, because they are not unique to such service.
Consequently, VA need not establish presumptions of service connection
for
[[Page 50868]]
any of the eight diseases that NAS associated with exposure to
combustion products in its report.
This approach is similar to that taken in our notice concerning the
2002 NAS report on insecticides and solvents. Public Law 105-277
specifically directed NAS to consider combustion products, fuels, and
propellants among the substances to which veterans may have been
exposed in their service in the 1991 Gulf War. The statute does not
specifically identify these agents as substances ``associated with''
such service. Although Congress directed NAS to consider them in its
reports, the language and structure of the statute indicates that
Congress delegated to VA the responsibility for determining, based on
NAS reports and other available information, whether such substances
were ``associated with'' Gulf War service for the purpose of
establishing presumptions under the statute.
We conclude that the statutory phrase ``associated with service in
the Armed Forces in the Southwest Asia theater of operations during the
Persian Gulf War'' is most reasonably construed to refer to a
relationship between the substance or hazard and the specific
circumstance of service in the Southwest Asia theater of operations
during the Persian Gulf War, as distinguished from features of military
or civilian life in general that are not unique to service in the Gulf
War. The phrase ``associated with'' clearly connotes a direct
relationship, and the requirement that the substance or hazard be
associated with service at a particular time and place indicates an
intent to distinguish between substances and hazards associated with
general military or civilian life and those unique to service at the
specified time and place. If civilian and military populations are
commonly exposed to a substance, we believe it would be unreasonable to
conclude that the substance is ``associated with'' service in the
Persian Gulf during the Gulf War merely because it was present during
such service. We do not believe that Congress intended VA to establish
presumptions for the known health effects of all substances common to
military or civilian life. Rather, the requirement that the substance
be ``associated with'' Gulf War service makes clear that VA's task is
to focus on the unique exposure environment in the Persian Gulf during
the Persian Gulf War.
This reading of the statutory language comports with the clear
purpose of both Public Law 105-277 and Public Law 105-368. Both
statutes reflect the Government's commitment to addressing the unique
health issues presented by Gulf War veterans, by establishing a process
for identifying diseases and illnesses that may be associated with Gulf
War Service. It is by now well known that many Gulf War veterans have
reported a variety of similar symptoms that cannot presently be
identified with a known diagnosis or cause and that were not considered
``diseases'' for the purposes of the statutes generally authorizing VA
to pay compensation for service-connected disability or death due to
disease or injury. Congress responded initially to that situation by
authorizing VA to pay compensation for ``undiagnosed illness'' in such
veterans. The process established by Public Law 105-277 and Public Law
105-368 reflects a further effort to bridge the existing gaps in
medical and scientific knowledge and to ensure that Gulf War veterans
may obtain compensation for diagnosed or undiagnosed illnesses that may
have been caused by the unique exposures or hazards of service during
the Gulf War. Establishing presumptions of service connection for
illnesses associated with exposures or hazards specifically related to
Gulf War service obviously would further that objective. In contrast,
establishing presumptions of service connection for the exclusive
benefit of Gulf War veterans based solely on the well-known health
effects of exposures shared in common with the general veteran
population would not significantly further the purposes of those
statutes. Moreover, establishing such presumptions would create
significant inequities in the veterans' benefits system that Congress
could not have intended.
Public Law 105-277 requires VA to establish presumptions of service
connection, when the statutory requirements are met, exclusively for
veterans who served in the Southwest Asia theater of operations during
the Persian Gulf War. If the statute were construed to require
presumptions based on exposure in the Persian Gulf War to substances to
which other veterans serving at other times and places are commonly
exposed at similar levels, it would raise significant concerns of
fairness and reasonableness. For example, veterans exposed or
presumably exposed to combustion products during the Gulf War might be
entitled to presumptive service connection for certain diseases
associated with such exposure, while veterans who served stateside and
had equal or greater combustion product exposure would not be entitled
to presumptive service connection for those diseases. The fact that
most service members, and most civilians, routinely incur some degree
of background exposure to the substances NAS considered further
underscores the arbitrariness that would attach to establishing
presumptions for a limited class of veterans based on such common
exposures. Apart from the fact that it is generally unnecessary to
establish presumptions of service connection for health effects that
are well documented in the medical literature, establishing
presumptions applicable only to a small percentage of the veteran
population potentially exposed to the relevant substances would have
significant adverse effects on the veterans benefits system. Providing
by statute and regulation for the disparate treatment of similarly
situated veterans would substantially undermine confidence in the
objectivity and fairness of the veterans benefits system. Additionally,
establishing different adjudicative rules for the claims of similarly
situated veterans without any reasoned basis for the distinction would
undoubtedly cause confusion to the VA personnel responsible for
deciding claims, as well as to veterans and their representatives in
presenting and supporting their claims.
We do not believe that Congress intended VA to establish
presumptions unique to Gulf War veterans based on the well-known health
effects of exposures common to military and civilian life outside the
Gulf War theater of operations. As explained above, the language and
purpose of Public Law 105-277 and Public Law 105-368 indicate that
Congress did not intend such a result, and we believe it is reasonable
to presume that Congress did not intend arbitrary or unfair
distinctions. We note that statutes generally must be construed to
avoid serious constitutional concerns. See Edward J. DeBartolo Corp. v.
Florida Gulf Coast Building & Construction Trades Council, 485 U.S.
568, 575 (1988). We cannot say it is beyond Congress' power to
establish presumptions exclusively for Gulf War veterans based on
exposures not known to differ significantly from service outside the
Gulf War. However, the apparent unfairness, in our view, of that result
supports the conclusion that Congress did not intend such a result.
We recognize that Public Law 105-277 and Public Law 105-368 both
required NAS to consider the health effects of exposure to fuels,
combustion products, and propellants as part of its investigations of
illnesses potentially associated with Gulf War service. However, the
direction to consider those substances does not compel the
[[Page 50869]]
conclusion that those substances, considered in isolation, are
themselves agents ``known or presumed to be associated with service in
the Southwest Asia theater of operations during the Persian Gulf War''
for purposes of VA's duty to establish presumptions of service
connection. Section 1603 of Public Law 105-277 describes the scope of
NAS' inquiry. Section 1603(c)(1) directs NAS to ``identify the
biological, chemical, or other toxic agents, environmental or wartime
hazards, or preventive medicines or vaccines to which members of the
Armed Forces who served in the Southwest Asia Theater of operations
during the Persian Gulf War may have been exposed by reason of such
service.'' Section 1603(d) of that statute provides that, in
identifying substances to which Gulf War veterans ``may have been
exposed,'' NAS will consider, among other things, oil fire byproducts.
In contrast, section 1602 of Public Law 105-277 does not direct the
Secretary to establish presumptions of service connection for the
health effects of every substance to which Gulf War veterans ``may have
been exposed,'' but requires presumptions only for the health effects
of exposure to substances known or presumed to be ``associated with''
service in the Gulf War. Congress used different language in section
1602 and 1603 of Public Law 105-277, and we must conclude that the
different language was intended to have different meanings. See Bank of
America National Trust & Savings Ass'n v. 203 N. LaSalle St.
Partnership, 526 U.S. 434, 450 (1999); Russello v. United States, 464
U.S. 16, 23 (1983). Congress reasonably defined the scope of NAS'
inquiry broadly, to include consideration of all substances to which
veterans may have been exposed during the Gulf War, irrespective of
whether the exposures were unique to Gulf War service or common to all
service. In defining VA's regulation-writing obligations, however,
Congress reasonably required VA to establish presumptions of service
connection only for the health effects of substances that are
``associated with'' Gulf War service. As noted above, that limitation
furthers Congress' purpose of establishing presumptions for the unique
health concerns of Gulf War veterans and also avoids the inequity of
establishing presumptions exclusively for Gulf War veterans based on
exposures that are common to most veterans.
Our conclusion that the hydrazines and combustion products in
question, in isolation, cannot at this time be determined to be
``associated with'' Gulf War service is not intended to suggest that
they are irrelevant to further investigations of Gulf War veterans'
health or that they may not in any circumstance form the basis for
presumptions of service connection under Public Law 105-277. In the
event future evidence links any illnesses to a combination of exposures
associated with Gulf War service, whether or not including exposure to
fuels, combustion products, and propellants, VA may establish
presumptions of service connections for such illnesses pursuant to
Public Law 105-277.
This determination also in no way prevents veterans from obtaining
service connection for the health effects discussed in the NAS report
where the potential for above-normal exposures was present in service.
Under established current procedures, VA develops and considers
evidence concerning events or aspects of service that may contribute to
the incurrence of an illness. Accordingly, if a veteran's occupation in
service, such as a firefighter or mechanic, entailed above-normal
exposure to combustion products, VA will give due consideration to that
unique exposure in determining whether service connection is warranted
for a health effect known to be associated with such exposure.
Similarly, if a veteran served in a role that may have involved
exposure to hydrazines, VA will evaluate that factor in determining
whether service connection is warranted for a disease associated with
such exposure. These standards apply to claims by veterans of any
period of service, and are not dependent upon any presumption of
service connection. A presumption of service connection is not needed
for the purpose of establishing a link between exposure to combustion
products or hydrazines and any disease identified in the NAS report as
associated with such exposures, because those health effects are
generally well known and, in any event, the NAS report itself provides
significant additional evidence of such an association. Accordingly,
the determination not to establish a generally applicable presumption
based on the NAS report will not preclude the grant of benefits to any
individual whose service entailed the type of exposure NAS found to be
associated with an increased risk of disease incurrence.
V. Conclusion
After careful review of the findings of the 2004 NAS report, ``Gulf
War & Health Vol. 3: Fuels, Combustion Products, and Propellants,'' and
other pertinent information including reports from DoD on potential
exposure of U.S. service members, the Secretary has determined that the
scientific evidence presented in the 2004 NAS report and other
information available to the Secretary indicates that no new
presumption of service connection is warranted for any of the illnesses
described in the 2004 NAS report.
Approved: August 21, 2008.
James B. Peake,
Secretary of Veterans Affairs.
[FR Doc. E8-19971 Filed 8-27-08; 8:45 am]
BILLING CODE 8320-01-P