Multiple Chemical Sensitivity (MCS)


By P. Casanova


MCS stands for Multiple Chemical Sensitivity. It is often called MCSS for Multiple Chemical Sensitivity Syndrome, or E.I., for Environmental Illness. None of the titles address the cause(s) of the disease, but only describe the symptom of chemical sensitivity (obviously).

For over 50 years, MCS sufferers have commonly been dismissed and misdiagnosed as having a mental/emotional disorder. Some have even been viewed as "fakes". They've been fired from and forced to quit their jobs; forced to live in tents in the woods, their cars, or wander streets homeless despite financial situations; and often forced to have no social interaction. Some cannot pump the gas for their cars or even put on the heaters in the car without becoming ill. They cannot go grocery shopping, go malls, movie theaters, or even to their friends' homes without becoming ill.

Some of them cannot even read the newspaper because of the ink. Children and teens with the condition cannot go to school without becoming ill. Many of sufferers end up getting divorced, losing their friends and family (due to being perceived as "too weird"), and end up living alone without any help. Many end up committing suicide.

On average, sufferers see 6 or more doctors that refer to them as being "stressed", before receiving the proper diagnosis. Medical and scientific literature, particularly from the last decade, offers a large amount of data on the nature of the condition. Despite the data, MCS is still not entirely recognized as even existing. In addition, there are biased scientists and organizations that are actually trying to prevent further research from even taking place, let alone being used to form policies to reasonably accommodate the sufferers.


In 1999, 89 clinicians and researchers reached a consensus definition for MCS. The MCS criteria, which are nearly the same as those proposed by Cullen, are as follows:

1. "The symptoms are reproducible with [repeated chemical] exposure."

2. "The condition is chronic."

3. "Low levels of exposure [lower than previously or commonly tolerated]

result in manifestations of the syndrome."

4. "The symptoms improve or resolve when the incitants are removed."

5. "Responses occur to multiple chemically unrelated substances."

6. "Symptoms involve multiple organ systems."

See "Multiple Chemical Sensitivity: A 1999 Consensus":  and "Chemical Poisoning, Abraham Lincoln, and Flashdarks" by Bonnye Matthews.


A review of medical/ scientific literature on the subject will show that MCS can occur on a biological basis, and that it can also occur on a psychogenic basis (I describe the model for such later on).

Martin Pall reported that MCS is associated with, and may even be caused by elevated levels of nitric oxide/ peroxynitrite-The elevated levels of such are said to lead to neural sensitization. As seen next, both parts of the theory find strong evidence.


1. Several organic solvents thought to be able to induce MCS, formaldehyde, benzene, carbon tetrachloride and certain organochlorine pesticides all induce increases in nitric oxide levels.

2. A sequence of action of organophosphate and carbamate insecticides is suggested, whereby they may induce MCS by inactivating acetylcholinesterase and thus produce increased stimulation of muscarinic receptors which are known to produce increases in nitric oxide.

3. Evidence for induction of inflammatory cytokines by organic solvents, which induce the inducible nitric oxide synthase (iNOS). Elevated cytokines are an integral part of a proposed feedback mechanism of the elevated nitric oxide/peroxynitrite theory.

4. Neopterin, a marker of the induction of the iNOS, is reported to be elevated in MCS.

5. Increased oxidative stress has been reported in MCS and also antioxidant

therapy may produce improvements in symptoms, as expected if the levels of the oxidant peroxynitrite are elevated.

6. In a series of studies of a mouse model of MCS, involving partial kindling and kindling, both excessive NMDA activity and excessive nitric oxide synthesis were convincingly shown to be required to produce the characteristic biological response [in other words, if the nitric oxide production is blocked, then MCS is blocked. At least in animals anyway].

7. The symptoms exacerbated on chemical exposure are very similar to the chronic symptoms of CFS (1) and these may be explained by several known properties of nitric oxide, peroxynitrite and inflammatory cytokines, each of which have a role in the proposed mechanism.

8. These conditions (CFS, MCS, FM and PTSD) are often treated through intramuscular injections of vitamin B-12 and B-12 in the form of hydroxocobalamin is a potent nitric oxide scavenger, both in vitro and in vivo.

9. Peroxynitrite is known to induce increased permeabilization of the blood brain barrier and such increased permeabilization is reported in a rat model of MCS.

10. 5 types of evidence implicate excessive NMDA activity in MCS, an activity known to increase nitric oxide and peroxynitrite levels.


The above is taken from "Multiple Chemical Sensitivity - The End of Controversy" by Dr. Martin L. Pall, Professor of Biochemistry and Basic Medical Sciences, Washington State University.

I very strongly recommend that you review the essay, as it explains the mechanism of MCS very clearly and gives supporting evidence for it.

EEGs and P300:

Donald Dudley, M.D., studied twenty patients with MCS (under Cullen's definition) and discusses his research in the book "Defining Multiple Chemical Sensitivity", by Bonnye L. Matthews (1998). Auditory and visual P300 were influenced "significantly" when the olfactory system was stimulated with chemicals that had six or fewer carbon fragments. The patients were exposed to perfume, felt tip pen, and other everyday chemicals in an everyday amount. Left and right P300 auditory were greatly decreased upon chemical exposure. Though the visual P300 was not decreased to the same degree (but decreased none the less), there was a significant change in waveform quality that caused two patients to have occipital seizures. In other words, the brain waves of MCS sufferers go haywire upon being exposed to chemicals they are sensitive to. This is not the work of "psychological" disorders. (See Defining Multiple Chemical Sensitivity by Bonnye Matthews, pg. 24, summary of "MCS: Trial by Science")

NOTE: According to Dudley, the olfactory system sends signals to every part of the brain and uses excitatory amino acids in neuro-transmission.

In 1996, Bell reported abnormal EEGs in MCS sufferers, which was disrupting their sleep. See "Biomarkers of MCS" by Albert Donnay.

If EEGs become synchronized, coma can occur. This has occurred in a few MCS cases.


A tool used by Nuclear Medicine Specialists is the SPECT brain scan. SPECT stands for Single Photon Emission Computerized Tomography.

Rather than show brain structure like CAT or MRI scans, SPECT scans show functioning of the brain. "Perfusion impairment" means there is a decrease in the flow of blood.

2A. Neurotoxicologist Dr. Gunnar Heuser performed before and after SPECT brain scans in many MCS patients. The patients were scanned after chemical avoidance, and were then scanned again after being exposed to perfume. His research findings are as follows: MCS patients generally have a decreased flow of blood to the brain, which becomes further decreased upon exposure to perfumes (see Defining Multiple Chemical Sensitivity pgs. 27-30 and a response to the Interagency report by Ann McCampbell, M.D.)

2B. Nuclear Medicine specialist Dr. Theodore Simon, who trained at Harvard, and his colleagues conducted over 1,500 SPECT scans on MCS patients. 90% of these patients showed brain abnormalities and deterioration in brain function that increased upon chemical exposure. The changes that took place upon chemical exposure were "very different from the changes associated with psychiatric disease."

2C. Dr. Gerald H. Ross (M.D., C.C.F.P., D.I.B.E.M., D.A.B.E.M., F.A.A.E.M., F.R.S.M., Past President of the American Academy of Environmental Medicine), in a documentary, discusses before and after SPECT brain scans: MCS patients were scanned in a clean environment and then scanned after being exposed to a substance that by history they report being sensitive to, "in an amount that's an everyday experience ('s not as if they're sniffing glue)." MCS patients have abnormal brain functioning. After the patients were exposed to a substance they were sensitive to a "profound" deterioration in brain function took place. The area in which this function deterioration is present correlates with the brain-related symptoms reported by the MCS sufferers. (See MCS documentary "Multiple Chemical Sensitivity[:] How Chemical Exposures May Be Affecting Your Health," directed by Allison Johnson) Dr. Ross, MD. is board certified in both Family and Environmental Medicine, and is a Fellow of England's Royal Society of Medicine. In addition he has treated over one thousand patients with MCS. He is quite far from a "quack." These MCS brain abnormalities are not found in normal controls. (See "Response to Errors Prevalent in the Understanding of Environmental Illness" by Dr. Gerald H. Ross [M.D., C.C.F.P., D.I.B.E.M., D.A.B.E.M., F.A.A.E.M., and F.R.S.M. Past President, of the American Academy of Environmental Medicine])



PET scans were used to discover the roll of a specific gene in Alzheimer's Disease. PET scans are very accurate at showing brain function and metabolism. PET stands for Positron-Emission-Tomography. Function abnormalities on PET scans show up as holes in the brain that one medical scientist refers to as "function holes." Dr. Gunnar Heuser, M.D., Ph.D., FAC.P has also performed before and after PET scans. According to his studies, PET scans reveal that the brain stem, hypothalamic, and limbic areas of the brain are harmed by chemical exposures. In regards to radioactive glucose uptake, these areas of brain become hypermetabolic upon chemical exposure to a degree that resembles "focal seizure activity." Dr. Heuser wrote, "Since the limbic system contributes emotional reactions and interpretations to sensory input, and since patients with amygdaloid (the amygdala is part of the limbic system) seizures can develop panic and related attacks during an amygdaloid seizure, our data appear to explain the emotional instability during a reaction to chemicals. The previously mentioned structures also serve memory and cognitive as well as neuroendocrine and autonomic nervous system functions, all of which can be deranged in a patient with MCS." The limbic area of the brain is where the nervous, endocrine and immune systems interact.

See "The Role of the Brain and Mast Cells in MCS" by Gunnar Heuser, M.D., Ph.D., FACP ; "PET Scanning - Alzheimer's Disease".



Auditory and visual evoked potentials are "a measure of the ray at which nerves transmit messages from the eyes and ears to the brain", and are not influenced by emotional factors. Donald's 20 patients were having serious, non-allergic reactions to everyday chemicals on a biological basis. I must ask, what condition did they have? SPECT and PET scans are very accurate and valid tools: "S.P.E.C.T. and P.E.T. can clearly be used to delineate functional abnormalities of the brain regardless of the cause" (Ethical clinical practice of functional brain imaging, Society of Nuclear Medicine Brain Imaging Council, J Nucl Med 1996, 37, 1256-9).

Doesn't it strike you as very bizarre that hundreds of MCS sufferers would consistently have decreased blood flow to the same areas of the brain, if each one were simply experiencing a psychological disorder. That would be one fascinating coincidence. In addition, the brain functioning of the MCS sufferers improved after going on a detoxification plan. Also, 90% of Simon's MCS patients showed the brain dysfunction, not 100%. If Simon's observations were tainted, then wouldn't he have had it so ALL (100%) of his patients showed brain damage? It doesn't make sense to question his research and say that he is biased, and that his studies are tainted. He is a qualified, independent researcher specializing in Nuclear medicine.

Furthermore, in regards to PET scans, if an area of the brain does not receive the glucose, it's because that part of the brain is not working properly, or at all. PET studies on MCS patients with a control group show that, in general, the limbic area of MCS sufferer's brains is not working properly. This has not been found in control groups.

In addition, research by Gary Schwartz, Ph.D., has shown that brain abnormalities occur when the patients are unaware of the chemical's presence. That's at least "blinded." Although this does not show the cause of the disease, it does show that chemicals actually are the cause of symptoms. This is important to know since it is often claimed that "there is no evidence that chemicals actually trigger the symptoms in MCS."

NOTE: FRMI brain scans are probably the best to have done, yet are less frequently done in MCS. In the few times they've been performed in MCS, abnormalities appeared.


70% of the Mayo Clinic's MCS patients tested positive for disorders of porphyrin metabolism. Many of Grace Ziem's (M.D.) MCS patients tested positive for multiple blood enzyme deficiencies, including ALA-D, PBG-D, UPG-D (Ziem 1997). In 1996 Heuser discovered that some MCS sufferers had a disorder of mast cells. In 1987 Schwartz reported that during reactions, some MCS sufferers had variably abnormal serum tryptase.

[NOTE: In the overlapping disease FM(S), fibromyalgia (syndrome), it is reported that some of the sufferers have an excess of mast cells, as well as elevated levels of nitric oxide.]

Martin Pall has written papers on the above, stating that nitric oxide is known to stimulate mast cells and may be able to slow the porphyrin pathway, causing the changes of such reported in MCS.

See "Biomarkers of MCS" by Albert Donnay; "The Role of the Brain and Mast Cells in MCS" by Gunnar Heuser, M.D., Ph.D., FACP, at; "Defining Multiple Chemical Sensitivity," pgs 31-58; and Irene Ruth Wilkenfeld's response to the interagency MCS draft report.


In 1999 an Etobicoke teenager named Dilnaz Panjwani performed double blind studies that revealed and confirmed a biomarker for MCS, sufficient enough to serve as a diagnostic test for MCS, FM, and CFS. The double blind studies showed that MCS sufferers have an excess of a metabolite (2, 3-diphosphoglycerate) that prevents the bloodstream from delivering oxygen to cells, tissues, and organs. The symptoms include severe fatigue, muscle inflammation, weakness, brain fog, and "complete debilitation."The US Military invited Panjwani to use her "simple" blood test in military research. For more information see "Teenager Makes Scientific Breakthrough"; and "Teenager's discovery termed a medical breakthrough" By Latafat Ali Siddiqui.


In a MCS documentary, William J. Meggs, M.D. discussed the data on asthma and its relationship to chemicals. There is a type of asthma, which most MCS sufferers have, that Meggs refers to as "chemical irritant asthma". This type of asthma works as follows: When certain chemicals (typically solvents and perfumes) are inhaled they bind to the neurons in the airways and produce inflammation, which leads to an asthma attack. It's an impressive documentary. Speakers include Meggs, Ashford, Miller, Ross, and Heuser.

I am unaware of whether or not Meggs was referring to RADS: Reactive Airways Dysfunction Syndrome, which was described by Brooks in 1985 and is caused by a massive exposure to chemicals, which leads to airway sensitization. From that point on, low level exposures to common chemicals - perfumes, detergents, etc - result in airway constriction. This is a known, accepted and recorded phenomenon of sensitization, resulting in chemical intolerance of the airways. In the second edition of their scholarly book, Ashford and Miller put forth the argument from logic that if such sensitization can occur in the airways due to chemical exposure, then why could not such sensitization occur in the Central Nervous System [AKA, MCS]? (See Ashford and Miller's book, 2nd edition, pg. 9)

NOTES: The ALA and AMA both state that perfumes are triggers of asthma. In fact, statistics show there is a higher incidence of asthma among persons who live near perfume manufacturing areas. I am writing a paper on the formulas of perfumes and how they relate to public health, which will be more detailed with many references.


MCS is accepted as a biological disease by "4 Canadian Federal Agencies"; "6

Canadian Provincial Agencies"; "8 Federal Court Decisions"; "13 Local Government Agencies, Commissions, Councils & Departments"; "14 State Workers' Comp. Board Decisions"; "20 State Court Decisions"; "22 Federal Government Agencies, Commissions, Institutes & Departments"; and "23 State Government Agencies, Commissions, Legislatures & Departments" (Donnay) -- including the Department of Housing and Urban Development, Social Security Administration and the Americans with Disability Act [of July 26, 1990]. Go to and for more information.

Dr. Gerald H. Ross [M.D., C.C.F.P., D.I.B.E.M., D.A.B.E.M., F.A.A.E.M., F.R.S.M. Past President of the American Academy of Environmental Medicine, May 2000; Fellow of England's Royal Society of Medicine] describes the growing body of evidence for MCS's physical causation in his May 2000 essay "Response to Errors Prevalent in the Understanding of Environmental Illness". Ross was invited to a meeting on MCS by the American Chemical Society. There he presented his research on MCS patients and brain damage. He noted that about 75% of all the speakers there presented data that supported a physical origin of MCS, while the other 25% presented, for the most part, opinions that MCS is psychological.

From 1952 to 1997 there were 425 published articles on MCS (Excluding articles in the Journal of Clinical Ecology). Of these, 59 discuss both perspectives, 25 are research protocols, 104 support the psychogenic view, and 231 of the papers present data supporting a physical origin of MCS. Almost all of the psychogenic papers were written before 1993. As of 1999, there had been 609 published peer-reviewed articles on MCS. Of these, 311 present data supporting a physical origin while 137 present findings (mostly opinionated) of psychological origin. This gap is continuing to grow. To argue that those 311 pro-MCS articles, which show or discuss physical/ biological abnormalities in MCS patients and, again, exclude articles in the Journal of Clinical Ecology, were all tainted/ biased is absolutely ludicrous.

"It amazes me that in spite of all these publications on MCS, that some people continue to loudly proclaim that [it] is a non-existent illness" writes Ross, who later writes that people who say there is a "lack of evidence" in regards to "the prevalence and organic origins of chemical sensitivity are completely at odds with the weight of evidence and opinion in the published medical and scientific literature." Skeptical position statements on MCS by the American Academy of Allergy and Immunology and American College of Occupational and Environmental Medicine are in direct opposition to the majority of actual [solid] research on MCS and fail to even take such into account. Thus, skepticism from such authorities is irresponsible and unwarranted. [NOTE: I recently wrote to the American Academy of Allergy and Immunology and shared with the Annals' Editor-in-Chief a small piece of the literature showing consistent biological abnormalities in MCS. As I write, 3/20/2003, he is still reviewing the letter.]

In 1995, the California Medical Association had been aware of the MCS literature and reclassified its anti-MCS position statement of 1985 as "a historical document only". Likewise, the American College of Physicians now has no position statement on MCS (which in my opinion is also irresponsible).

In 1994 a MCS consensus was reached by the U.S. Environmental Protection Agency, U.S. Consumer Product Safety Commission, American Lung Association, and American Medical Association, which stated that "[MCS] should not be dismissed as psychogenic, and a thorough workup is essential." In 1999, another consensus, which involved 89 clinicians and researchers (whose MCS definition I quoted from earlier), was reached which agreed with the one in 1994.



There are data showing that some people who believe they have MCS actually have a psychogenic disorder. I call it "psychogenic chemical sensitivity," or PCS. I hope this is the title given to the phenomenon in question. An example of how this can occur is as follows: A young person (say age 6 or so) is molested, raped, or undergoes some other traumatic event. However let's say that during that traumatic event, there was a perfume scent in the air.Later on in life, when that person smells perfume or fragrance similar to the smell present during the trauma, then the person may have a sub-conscious reaction to the smell, which is then manifested physically. For such people, some form of therapy that goes into the sub-conscious would most likely be beneficial. (See Ashford and Millers' book, "Chemical Exposures - Low Levels and High Stakes", 2nd edition, pgs. 221-222) When Chemical Intolerance is not MCS: Chemicals are known to worsen eczema so if a person only has a skin reaction to chemicals, but is unaffected in other organs/systems, then it is not MCS. And some people have chemical irritant asthma, but not MCS. People who believe they have MCS need to have challenge testing done. There are imaging and blood tests that can be done in alleged MCS cases under challenge conditions. There are other challenge tests to do as well, if necessary. If the results are positive, then the person most likely really does have MCS. Stephen Barrett is aware of this fact but has not once countered it.


Stephen Barret wrote, "With these, however, the range of symptoms is virtually endless and typically does not correlate with physical findings or science-based laboratory tests." (See ) Barrett can be contacted at Clearly, Barrett is either dishonest, or alarmingly ignorant of scientific literature. Professor Ashford wrote, "People don't read the literature... 'The science isn't there' means 'I haven't read it.'.... You don't need ironclad evidence when a variety of disparate compass needles are all pointing in the same direction. In my 30 years in the area of environmental health, I see that in no case have we been wrong about environmental problems. The problem either got worse, or the evidence became stronger. Only the most robust environmental and occupational problems ever get noticed: That's why we've never been wrong." (Ashford, who has a degree in chemistry, is an environmental scientist who serves as a public health advisor for the United Nations.)

In summary, although the etiology of chemical sensitivity is not known for certain (though Pall's theory has more evidence supporting it than any other theory on MCS, with possible exception of the Carbon Monoxide theory advocated by Donnay), there are clear and abundant enough data to confirm the existence of chemical sensitivity on a biological basis. Excluding clinical ecologists, the majority of researchers who actually study MCS believe it does exist on a biological basis or at least that it can. Claims to the contrary are no longer justifiable. MCS "skepticism" is no longer a respectable opinion as it ignores the vast majority of medical/ scientific data. Indeed, the scientific literature unquestionably shows that there are two groups of chemically sensitive sufferers: In group #1, there is a genuine sensitivity to -or intolerance of-- chemicals on a biological basis, which may lead to psychiatric problems if the limbic area of the brain is affected (in most cases it is). In group #2, the sufferers react to chemicals on a psychogenic basis, often due to an early childhood trauma.

There may also be cases where the sufferer is reacting to chemicals on both a biological and psychogenic basis (i.e., subconsciously reacting due to a trauma, but also due to biological mechanisms). "Etiologies for these conditions can be wholly physical, wholly psychological, or varying combinations of the two", write Ashford and Miller. (See their book, 2nd edition, pgs. 221-222) An analogy can be drawn from a recent study on food allergies. In the study, many people who reacted to chocolate and thought they were allergic only reacted to the food when they thought it was chocolate (placebo study). It is well known that food allergies exist, but it is now also known that many people have reactions to foods on a psychological basis. MCS skeptics commonly ignore the data on group #1, and focus entirely on group #2. This is made clear in the articles written by the MCS skeptic Michael Fumento. He appears to be unaware of a great deal of data that contradict his generalized conclusions. Fumento is on record as referring to MCS sufferers and advocates as "fragrant-phobic fruit cakes" (see ).

Whenever someone asks me what MCS is I usually try to define it in an understandable way: A condition in which the sufferer is extremely sensitive to various chemicals, usually man-made, and reacts to such whether being aware of the chemicals' presence or not (to distinguish from psychological sensitivity). Sufferers are often 1,000 times more sensitive to --or intolerant of-- chemicals than average people are. Symptoms are often chronic and occur in response to, and are worsened by chemicals and often include anxiety and depression.


There are seven major studies that are used to show MCS is a psychogenic condition. In these seven studies, there were a total of 334 patients studied. However, no more than thirty-three of these patients actually had MCS. In five of the studies, none of the patients had MCS. Of the remaining two, in one study, eighteen out of forty-one had MCS, and in the other study no more than fifteen out of fifty-three had MCS. Thus, it is fair to state that the studies have nothing to do with the real MCS, since it was not studied. (See Defining Multiple Chemical Sensitivity, pgs 111-130)

Since no consistent laboratory abnormalities were found, these studies have been used to say that there are no consistent laboratory abnormalities found in MCS patients, despite the fact that these seven studies did not involve MCS patients. Due to these seven studies, policies were made denying accommodations to people with MCS, more anti-MCS essays were written, and millions of MCS sufferers have been left in the dark to suffer with their disease without the medical support they deserve.

I am trying to keep this letter as brief as possible, but if you would like me to list the seven studies and go into detail on them, please do not hesitate to ask me.

Ann McCampbell wrote detailed essay titled "MULTIPLE CHEMICAL SENSITIVITIES UNDER SIEGE" at .Dr. Ronald E. Gots testifies in court against MCS. He is depended on more than any other person is to discredit MCS. Yet, he is one of the most under qualified doctors to speak on MCS.

Gots said that MCS "defies classification as a disease. It has no consistent characteristics, no uniform cause, no objective or measurable features. It exists because a patient believes it does and a doctor validates that belief." -- A comment known to be inaccurate as it ignores the data on emission tomography brain scans, ERPs, porphyrin metabolism, etc. Gots likes to focus on the fact that the cause of MCS has not yet been proven and that the mechanisms are unknown (though this may change due to Pall's research). That is not a rational approach: MS (Multiple Sclerosis) has no known "uniform cause", nor even a diagnostic laboratory test (I believe MCS now does however), yet those would not be excuses to deny its harsh biological reality.

Ashford and Miller talk about Gots' earlier work in 95 and 96. Gots wrote, "[e]verything that is known about MCS to date strongly suggests behavioral and psychogenic explanations for symptoms." Ashford and Miller said Gots' statement was "unjustifiable," and that, "Even if he were correct about the absence of physiological evidence (and he is not), the presence of psychological problems in patients is not proof of psychological causation.

The work of Fiedler et al. (1992), and that of Simon et al. (1990, 1993) amply demonstrate that there are MCS patients with no premorbid or subsequent psychological problems" (pg. 280). They go on to describe Gots' work of 95 and 96 as "recycled opinion."

In his 1998 book, "Chemical Sensitivity: The Truth About Environmental Illness", co-written with Stephen Barret, Gots wrote (admitted that), "people do exist who are very sensitive to various micro-organisms, noxious chemicals, and common foods." [Emphasis added] He then goes on to say that "there is no scientific evidence that an immunologic basis exists for such a symptom pattern." [Emphasis added]

Donald Dudley, M.D., wrote, "Multiple chemical sensitivity has none of the characteristics of an immunologic disease, and as long as immunologic criteria are required as proof of its [MCS's] existence, it will be seen as a non-disease." MCS is not an immunologic disease, yet Gots and Barret require the criteria of such for proof of MCS -- but MCS does not meet the criteria of an immunologic disease, hence, they conclude that MCS is non-existent. That is poor judgement on the their part, as it is a flawed scientific approach. This is the exact same method used by other "skeptical doctors" to discount MCS. So much for "objective."

Dr. Gots has never treated a patient with MCS. He is trained in pharmacology, and neither he, nor Barret have any training or certification in toxicology. I bring this up because Gots is often introduced as being "a Toxicologist."

In addition, Gots and Barrett have not actually done any peer-reviewed studies on MCS. They only offer their interpretations on anti-or-non-MCS studies, and completely ignore peer-reviewed publications that contradict them. That is not in line with scientific integrity.

Despite this, Barrett finds it necessary to write anti-MCS essays on his "Quack Watch" web site. And Gots, well he's the head of the "Environmental Sensitivities Research Institute" (ESRI)-- an Institute whose contributors and board members consist of pesticide manufacturers; representatives from The Cosmetic, Toiletry, and Fragrance Association; and other industry dominated representatives. Those representatives each pay Gots 10,000 dollars per year. This is not conspiracy theory or speculation. I am simply listing the financial conflicts of interest since ESRI almost always fails to do so. (See Ashford and Miller, 2nd edition, pg.279) Believing what Gots says about MCS is like believing a representative from the Tobacco Industry saying "there exist no data that show cigarettes are unsafe." Thus, the MCS "skeptics" have managed to twist the data that show groups #1 and #2, and make it appear as though there is only group #2."They [MCS sufferers] have lost health, careers, financial resources, friends, family, and some have committed suicide because the pressure upon them was too great. This while the media makes of them a laughingstock and doctors play word games and chase geese. The barbaric treatment afforded these people is ignorant, unethical, and amoral", writes Matthews.



Multiple Chemical Sensitivity: A 1999 Consensus. Arch Environ Health

54:147-149. By Bartha, L., W. Baumzweiger, D.S. Buscher, T. Callender, K.A. Dahl, A.L. Davidoff, A. Donnay, S.B. Edelson, B.D. Elson, E. Elliott, D.P. Flayhan, G. Heuser, P.M. Keyl, K.H. Kilburn, P. Gibson, L.A. Jason, J. Krop, R.D. Mazlen, R.G. McGill, J. McTamney, W.J. Meggs, W. Morton, M. Nass, L.C. Oliver, D.D. Panjwani, L.A. Plumlee, D.J. Rapp, M.B. Shayevitz, J. Sherman, R.M. Singer, A. Solomon, A. Vodjani, J.M. Woods, and G. Ziem.. - started in 1989, ended in 1999

"Multiple Chemical Sensitivity: A Spurious Diagnosis" by Stephen Barrett, M.D.; (Questionable integrity) The Interagency Workgroup on Multiple Chemical Sensitivity, August 24, 1998 (the report can be read online at

Responses to the above report at; "Defining Multiple Chemical Sensitivity" by Bonnye E. Matthews. The book has chapters by 5 highly qualified Doctors. Also her online essay "Chemical Poisoning, Abraham Lincoln, and Flashdarks" at;

"Multiple Chemical Sensitivities (MCS): What It Is, What It Is Not, And how It Is Manifested" by Dr. Sheila Bastien, Ph.D.;

"MCS - A Medical Perspective" by Dr. Mark Donohoe, MB BS;

"Multiple Chemical Sensitivity (MCS)" by Rabin Prusty, MSCE:;


"Multiple Chemical Sensitivity [:] How Chemical Exposures May Be Effecting Your Health", MCS documentary Directed by Alison Johnson;

"Understanding & Accommodating People with Multiple Chemical Sensitivity in Independent Living" by Pamela Reed Gibson, Ph.D. James Madison University;

"A Brief Overview of MCS" by Cynthia Wilson at;

"Multiple Chemical Sensitivity: Potential Role for Neural Sensitization" by Barbara A. Sorg;

"The Role of the Brain and Mast Cells in MCS" by Gunnar Heuser, M.D., Ph.D., FACP at;

"Response to Errors Prevalent in the Understanding of Environmental Illness" by Dr. Gerald H. Ross, M.D., C.C.F.P., D.I.B.E.M., D.A.B.E.M., F.A.A.E.M., F.R.S.M., Past President, American Academy of Environmental Medicine: (I strongly recommend visiting that site);

"The MCS Debate: A Medical Streetfight" by Eric Nelson, The Free Press (Quote: "a growing body of evidence and literature - rarely cited by the proponents of psychological explanations for MCS - indicates that neurotoxic chemicals can irreversibly disrupt the central nervous system.")

"Corporate Manipulation of Scientific Evidence Linking Chemical Exposures to Human Disease: A Case in Point -- Cigarette Science at Johns Hopkins" by The Alexander Law Firm and Alexander, Hawes & Audet, LLP.

"Porphyria - Another Connection with Multiple Chemical Sensitivities" by Linda A. Thompson, M. Div.

"Comprehensive Protocol for Evaluating Disorders of Porphyrin Metabolism in Chemically Sensitive Patients" by Albert Donnay, MHS, and Grace Ziem, MD, DrPH;

"ENZYMATIC INFLUENCES causation of BRAIN CELL DAMAGE" by Dr Brian E. Goble Ph.D., Professor Physiological Toxicologist:;

"Testing for Toxic Metal- and Chemical-Induced Porphyrinuria" by Carl P. Verdon, Ph.D., Terry A. Pollock, M.S. and J. Alexander Bralley, Ph.D., C.C.N.

"Porphyria-How Modern Chemicals Trigger the Vampire Disease" by Hart Brent:;

"Integrated Defense System Overlaps as a Disease Model: With Examples for Multiple Chemical Sensitivity" by S.C. Rowat

"Multiple Chemical Sensitivity" by Heidi M. Hawkins, MAc, LAc

"Multiple Chemical Sensitivities" by the U.S. Department of Labor Occupational Safety & Health Administration


"Water and Health" by W.J. Rea, MD

"Pesticides & brain-function changes in a controlled environment" by William J. Rea, MD, FACSCDirector Environmental Health Center-Dallas, Dallas, TX, Joel R. Butler, PhDCNorth Texas State University, Denton, TX, John L. Laseter, PhDCCenter for Bio-Organic Studies of the University of New Orleans

"Multiple Chemical Sensitivity - The End of Controversy" by Dr. Martin L. (Marty) Pall, Professor of Biochemistry and Basic Medical Sciences, Washington State University, at

"Multiple Chemical Sensitivity Syndrome" by Michael K. Magill, M.D., and Anthony Suruda, M.D., M.P.H.

"Multiple Chemical Sensitivity (Environmental Illness)" by Stephen B. Edelson, M.D., F.A.A.F.P., F.A.A.E.M.

"Dubious Allergy-Related Practices: Clinical Ecology and the Feingold Diet" by William T. Jarvis, Ph.D.

"Chemical Exposures-Low Levels and High Stakes", second edition, by Nicholas Ashford, Ph.D. (United Nations Public Health advisor with a degree in chemistry) and Claudia Miller, M.D.