Miller 's Congressional Testimony
on Chemical Intolerance
DCH Congressional Testimony, November 3, 1999 .
CAPITOL HILL HEARING TESTIMONY
Senate Commerce, Science and Transportation
Manufacturing and Competitiveness, Machine Tool Industry
Committee on Veterans' Affairs Subcommittee on Benefits
United States House of Representatives Invited Testimony
by Claudia S. Miller, M. D., M. S. Environmental and
Occupational Medicine Department of Family Practice
October 26, 1999.
DR. CLAUDIA S. MILLER, MD
Department of Family Practice
The University of Texas Health Science Center at San Antonio
7703 Floyd Curl Drive, San Antonio, Texas 78229-3900
Telephone: (210) 567-7760; Fax: (210) 567-7764;
DR. CLAUDIA S. MILLER, MD
I have been asked to explain how physicians who see sick
Gulf War veterans can observe the same or similar symptoms
and interpret them as either undiagnosed illness or
Even when doctors apply monikers [names or titles] to
these patients' illnesses, like depression, migraine headaches,
asthma, irritable bowel, or fibromyalgia, these monikers
do not explain why these veterans are sick.
Most have symptoms involving several organ systems
simultaneously. For them there is no unifying diagnosis
offered, no etiology specified, and no disease process
In truth, all of these veterans are undiagnosed because
what we are dealing with is an entirely new mechanism
of disease not covered by standard medical diagnoses
one which presents itself symptomatically as different
conditions to different specialists.
The rheumatologist observing diffuse muscle pain
The neurologist hearing head pain and nausea diagnoses
The pulmonologist finding airway reactivity diagnoses
The psychiatrist seeing chronic malaise diagnoses depression.
The gastroenterologist noting GI complaints diagnoses
irritable bowel syndrome.
Some private practitioners diagnose multiple chemical
sensitivity, or MCS, which is not a diagnosis in itself,
but rather just another manifestation of the underlying
So what is at the core of this myriad of symptoms that
has come to be called "Gulf War Syndrome?"
What is the underlying disease process?
The key is in the new-onset intolerances
these diseases share.
Over the past six years, I have served as a consultant to the
VA's Referral Center for Gulf War Veterans in Houston.
The vast majority of the veterans there reported multiple
new intolerances since the War.
Among the first 59 patients,
78% reported new onset chemical intolerances;
40% experienced adverse reactions to medications;
78% described new food intolerances;
66% reported that even a can of beer made them feel ill;
25% became ill after drinking caffeinated beverages;
and 74 % of smokers felt sick if they smoked an extra
cigarette or borrowed someone else's stronger brand.
More than half reported new intolerances in all three
categories -- chemical inhalants, foods, and drugs or
One mechanic said that before the Gulf War his idea of
the perfect perfume was WD-40. Since the war, WD-40
and a host of other chemicals make him feel ill.
Many veterans no longer fill their own gas tanks because
the gasoline vapors make them "spacy" or sick. Some won't
drive because they become disoriented in traffic and they
fear causing an accident. Or they can't find their cars,
forget where they are going or get lost in once familiar
One VA study found excess motor vehicle deaths among Gulf
veterans and interpreted this as possible increased risk-
taking behavior (Kang and Bullmann, 1996).
What the veterans tell me is that they get confused, go
off the road, mistake the accelerator for the brake, and have
trouble judging stopping distances when they are exposed to
gasoline, diesel exhaust, or freshly tarred roads.
Researchers at the Robert Wood Johnson Medical School
in New Jersey and at the University of Arizona have noted
similar multi-system symptoms and intolerances to
common chemicals, foods, and drugs among the veterans
(Fiedler et al, 1996; Bell et al, 1998).
And a CDC study found that ill Gulf War veterans reported
more chemical intolerances than healthy veterans (Fukuda et
These studies are confounded by a phenomenon called "masking,"
which occurs when people become intolerant to many different
things (Miller and Prihoda, 1999a).
As they go through a day, symptoms triggered by fragrances,
hairspray, vehicle exhaust, foods and medications pile up
so they feel sick most of the time.
No one cause can be isolated because there's too much background
noise, and patients often underestimate the number of exposures
that affect them.
This problem is not altogether new.
German researchers described similar intolerances in
chemical weapons workers after World War II (Spiegelberg, 1961).
Nearly 20 percent of agricultural workers on a California
registry for organophosphate pesticide poisoning
(Tabershaw and Cooper, 1966) reported that even a
"whiff" of pesticide made them sick with symptoms
like those of the Gulf War veterans, as did dozens of
government workers a decade ago, after the EPA headquarters
became a "sick building" following remodeling (EPA, 1989).
Similar outbreaks of chemical intolerances have been
reported in more than a dozen countries (Ashford et al, 1995).
These observations suggest that we may
indeed be dealing with
an entirely new mechanism for disease, one which has been
referred to with the acronym "TILT", or "Toxicant-induced
Loss of Tolerance" (Miller, 1996, 1997, 1999).
Any one toxicant appears capable of initiating this process.
TILT involves two steps, initiation and triggering (Ashford and
(1) First, a single acute or multiple low-level exposures to
a pesticide, solvent or other chemical causes loss of
tolerance in a subset of those exposed;
(2) Thereafter, very low levels of common substance
can trigger symptoms -- not only chemicals, but various foods,
medications, alcoholic beverages and caffeine.
Symptoms involve several organ systems. These intolerances are
the hallmark of TILT, just as fever is the hallmark symptom
of infectious diseases.
Over the past several years, the finger has been pointed at a
number of potential causes for Gulf War Syndrome -- everything
from the oil shroud to pesticides, vaccinations, and pyridostigmine
What set off the Gulf War Veterans? The answer is "all of the
above." Exposure to any one or any combination of these toxicants
may, in fact, be capable of causing a general breakdown in
tolerance that can result in a plethora of beguiling symptoms.
We do not know exactly how this breakdown in tolerance occurs.
We do know that rats with nervous systems sensitive to
organophosphate pesticides are also intolerant of diverse
drugs and have increased gut permeability which in humans
is associated with food intolerance (Overstreet et al, 1996).
This suggests the breakdown might involve the cholinergic
nervous system, which regulates processes throughout the body.
How can these people be helped? No one knows -- yet. The
biggest obstacle is the symptoms themselves, which serve
as red herrings, diverting attention away from the central
What we do know is that Gulf War veterans, who have come to
recognize what sets them off and then avoid these triggers,
tend to improve.
We need to apply this understanding to the diagnosis and
treatment of other such veterans.
The first thing that needs to be done is to set up unmasking
studies in which sick Gulf War veterans can be isolated from
the exposures that are setting them off.
This can be achieved by putting them in a special environmentally
controlled hospital unit (Miller, 1997; Miller et al, 1997).
Once we get them to baseline, we can reintroduce things like
caffeine, perfumes, various foods, etc., and identify some
of the things that cause their flare-ups.
With avoidance, it is hoped that they, too, can improve.
This combined diagnostic-therapeutic approach would eliminate
much of the confusion that is the focus of this hearing.
There is no simple answer to Gulf War illness.
No single toxicant is likely to have caused it. But if we
concentrate less on the original toxicants and more on the
underlying disease mechanism, I believe we can make progress
in understanding why these people are sick and what we can
do to help them.
Agency for Toxic Substances and Disease Registry
(1994). Proceedings of the Conference on low level exposure
to chemicals and neurobiologic sensitivity.
Tox. Ind. Health 10(4/5):25.
Ashford, N., Heinzow, B., Lütjen, K., Marouli,
C., Mølhave, L.,
Mönch, B., Papadopoulos, S., Rest, K., Rosdahl, D., Siskos, P.,
and Velonakis, E. (1995). Chemical sensitivity in Selected
European Countries: An Exploratory Study.
Ergonomia Ltd., Athens, Greece.
Ashford, N., and Miller, C. (1998).
Chemical Exposures: Low
Levels and High Stakes. New York, Wiley & Sons.
Bell, I., Walsh, M., Gross, a., Gersmeyer, j.,
Schwartz, g., and
Kanof, P. (1997). Cognitive Dysfunction and Disability in Geriatric
Veterans with Self-Reported Intolerance to Environmental Chemicals.
J. Chronic Fatigue Syndrome. 3(3):15- 42.
Environmental Protection Agency (EPA) (1989).
Report to Congress
on Indoor Air Quality, Volume II, Assessment and Control of Indoor
Fiedler, N., Kipen, H., Natelson, B., and Ottenweller,
Chemical Sensitivities and the Gulf War: Department of Veterans
Affairs Research Center in Basic and Clinical Science Studies of
Regulatory Tox. Pharmacol. 24: S129-S138.
Fukuda, K., Nisenbaum, R., Stewart, G., Thompson,
W., Robin, L.,
Washko, R., Noah, D., Barrett, D., Randall, B., Herwaldt, B., Mawle,
A., and Reeves, W. (1998). Chronic multi-system illness affecting
Air Force veterans of the Gulf War.
JAMA 280: 981-988.
Kang, H., and Bullman, T. (1996).
Mortality among U.S. Veterans
of the Persian Gulf War.
New Engl. J. Med. 335(2a):1498-1504.
Miller, C. (1996).
Chemical Sensitivity: Symptom,
or Mechanism for Disease?
Tox. 11: 69-86.
Miller, C. (1997).
Toxicant-Induced Loss of
An Emerging Theory of Disease?
Environ. Health Perspect. 105 (Suppl. 2): 445-453.
Miller, C. (1999). Are We on the Threshold
of a New Theory
of Disease? Toxicant-induced Loss of Tolerance and its Relationship
to Addiction and Abdiction
Tox. Ind. Health. 15:284-294.
Miller, C., and Prihoda, T. (1999a).
A Controlled Comparison
of Symptoms and Chemical Intolerances Reported by Gulf War Veterans,
Implant Recipients and Persons with Multiple Chemical Sensitivity.
Tox. Ind. Health 15:386-397.
Miller, C., and Prihoda, T. (1999b).
The Environmental Exposure
and Sensitivity Inventory (EESI): A Standardized approach for
measuring Chemical Intolerances for Research and Clinical Applications.
Tox. Ind. Health 15:370-385.
Miller, C., Ashford, N., Doty, R., Lamielle, M.,
Otto, D., Rahill, A.,
and Wallace, L. (1997). Empirical Approaches for the Investigation
of Toxicant-Induced Loss of Tolerance.
Environ. Health Perspect. 105 (Suppl. 2): 515-519.
Overstreet, D., Miller, C., Janowsky, D.,
and Russell, R. (1996).
Potential Animal Model of Multiple Chemical Sensitivity with
Tox. 111: 119-134.
Spiegelberg, V. (1961).
Schden nach Einwirkung Synthetischer Gifte.
In Wehrdienst und Gesundeir, Vol. III. Darmstadt: Wehr
und Wissen Verlagsgessellshaft (1961).
Tabershaw, I., and Cooper, C. (1966).
Sequelae of Acute
Organic Phosphate Poisoning
J. Occup. Med. 8:5-20.
Claudia S. Miller, M.D.,
M.S., is an Associate Professor
in Environmental and Occupational Medicine in the Department
of Family Practice of the University of Texas Health Science
Center at San Antonio. Board-certified in Allergy/Immunology
and Internal Medicine, she holds a Masters degree in Public Health/
Her research interests include the health effects
of low level
chemical exposures, pesticides, indoor air pollution, and
Gulf War veterans illnesses.
Dr. Miller has held appointments to several federal
committees, including the National Advisory Committee on
Occupational Safety and Health, the National Toxicology Program
Board of Scientific Counselors, and the Department of Veterans
Affairs Persian Gulf Expert Scientific Advisory Committee.
She is co-author of the WHO-award-winning New Jersey
on Chemical Sensitivity and a professionally acclaimed book,
Chemical Exposures: Low Levels and High Stakes.
Other support related to these proceedings: Dr.
Miller has served
as a consultant to the Houston VA Regional Referral Center for
Gulf War Veterans since 1993. She is also principal investigator
on a study of neurobehavioral sensitization funded by the Office
of Naval Research.
Committee on Veterans' Affairs Subcommittee on
-- Dr. Claudia Miller's Invited Testimony
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