By Dr. Stephen Barrett
Posted: Friday, January 1, 1999
ARTICLES
Publication Date: January 1, 1999
The notion of sensitivities to chemicals has broad appeal, even among persons who do not believe they have such a condition. Contributors to its appeal include environmental worries; concern about victimization; distrust of government, high technology, and standard medicine; and widespread interest in "alternative medicine."
"Multiple chemical sensitivity" refers to an ill-defined problem whose sufferers misinterpret physical responses to irritants or to stress as allergies or "toxicities" and behave abnormally. Clinicians who advocate the MCS diagnosis assert that chemicals present in the environment at extremely low levels are to blame. But no scientific tests have ever yielded evidence that MCS has an organic basis. Moreover, no major medical organization has acknowledged MCS as a clinical (objective) disease. Advocates of the MCS diagnosis do not pursue well-designed research to test their claims. Rather, they propagandize their claims through publications, talk shows, "support groups," lawsuits, and political maneuvering.
Clinical diseases that the biomedical community has acknowledged—coronary heart disease, diabetes, and rheumatoid arthritis, for example—relate to clear-cut patient histories, physical findings, and lab tests. In contrast, with MCS the range of symptoms is virtually endless; the onset can be abrupt or gradual and may or may not be linked to any specific exposure or causal factor; and symptoms can vary in intensity, can "come and go," and typically do not correspond to objective physical findings and laboratory findings. For these reasons, standard medical textbooks do not list MCS as a diagnosis; nor does the standard reference book that classifies medical conditions (International Classification of Diseases, Ninth Edition, Clinical Modification).
Seconding That Emotion
Medical scholars realized more than a century ago that fatigue, pressure in the head, inability to concentrate, irritability, and many other common symptoms could have an emotional basis. One doctor who understood this was John Noland MacKenzie, M.D., an ear, nose and throat specialist in Baltimore, Maryland. In 1886 he wrote about a 32-year-old woman who believed she was sensitive to many environmental factors, especially the scent of roses. The woman had bouts of depression and numerous other complaints, including impairment of mental ability, irritability, malaise, and sneezing. MacKenzie did not believe that rose pollen was responsible for the woman's symptoms. So he obtained a realistic artificial rose and, to remove potential allergens from it, cleaned it carefully. During the woman's next visit, he found that she felt she was unusually well. Then he produced the artificial rose, which had been behind a screen, and kept it in his hand as they talked. Almost immediately, the woman's eyes began tearing and became red and itchy; her throat became itchy; her nose became runny and its membranes swelled; and she became hoarse and short of breath. When MacKenzie revealed the deception to his patient, she appeared amazed, but within a few days she could smell real roses uneventfully.
In the 1980s, in Denver, Colorado, allergist John Selner, M.D., and psychologist Herman Staudenmayer, Ph.D., tested many patients who believed they were hypersensitive to workplace and residential chemicals at low levels. In one experiment they used an environmental chamber that enabled exposing each of 20 such patients, unawares, to specific chemicals at specific levels. In preliminary tests, when the patients were made aware of the exposures beforehand, they consistently reported symptoms they had been associating with chemical exposures. Then the patients were randomly exposed to: (1) chemicals to which they considered themselves sensitive; (2) the same chemicals masked by the odor of anise oil, cinnamon oil, lemon oil, peppermint spirit, or another substance; (3) the odorous substance used to mask the suspect chemical; or (4) clean air. After each test period, the patients were asked whether they thought they had been exposed to a suspect chemical or to clean air. The patients were monitored for objective signs (such as skin reactions). They were also asked to report any symptoms experienced during testing and during the following three days. None of the 20 patients demonstrated a response pattern that implicated the chemicals they considered responsible for their symptoms. Nearly all reported an absence of symptoms at least once when the suspect chemical was present. Most reported symptoms at least once when the suspect chemical was absent. It became clear that many of the subjects had been reacting not to the chemicals they considered at fault but to their own feelings about the test. Informing the patients of this helped recovery in some cases.
What Isn't MCS?
About 50 years ago allergist Theron G. Randolph, M.D., concluded that patients had become ill from exposures to substances at levels far below those that experts consider safe. He asserted that humankind's failure to adapt to modern manmade chemicals had resulted in a new form of chemical sensitivity. Over the years the condition he posited has been called "allergic toxemia," "cerebral allergy," "chemical sensitivity," "ecologic illness," "environmental illness," "immune system dysregulation," "total allergy syndrome," "20th century disease," "universal allergy," and other names that suggest various physical causal factors. "Multiple chemical sensitivity" is the favorite.
The complaints associated with these labels include chest pain, constipation, diarrhea, depression, dizziness, drowsiness, fatigue, forgetfulness, frequency of urination, headache, inability to concentrate or to think clearly, irritability, itchiness of the eyes and nose, lightheadedness, mental exhaustion (also called "brain fog" or "brain fag"), mood swings, muscle and joint pain, muscle incoordination, nasal stuffiness, rashes, sneezing, wheezing, stomach upset, swelling of various parts of the body, and tingling of fingers and toes. William J. Rea, M.D., who says he has treated more than 20,000 environmentally ill patients, has stated that such persons "may manifest any symptom in the textbook of medicine."
Most physicians who "diagnose" and treat MCS call themselves "clinical ecologists" or "specialists in environmental medicine." About 400 such doctors belong to the American Academy of Environmental Medicine, which Randolph founded in 1965 as the Society for Clinical Ecology. Most of its members are M.D.s and osteopaths. Clinical ecologists also figure in the American Academy of Otolaryngic Allergy, which Randolph helped to found in 1941. Clinical ecology has never been established as a medical specialty, is not advocated in any standard medical textbook, and is not a component of medical-school or specialty training programs. Environmental medicine is a component of the specialty of preventive medicine (public health) but does not embrace the theories and practices of clinical ecology. To avoid confusion, I refer to all self-styled "specialists in environmental medicine" who advocate such theories and practices as "clinical ecologists."
What Doesn't Trigger MCS?
Many proponents of the MCS concept depict the immune system as a barrel that continually fills with chemicals and overflows, whereupon symptoms arise. Some further claim that just one serious episode of infection, psychological stress, or chemical exposure can trigger "immune system dysregulation." Possible MCS-related stressors supposedly include practically any substance common in industrialized areas, for example: building materials; cedar closets; certain plastics; diesel exhaust; felt-tip pens; fragrances; fresh paint or tar; gas for cooking and heating; household cleansers; medications; newsprint; organic solvents and pesticides; permanent press and synthetic textiles; rubbing alcohol; tap water; tobacco smoke; urban air; and even electromagnetic forces. Proponents of the MCS diagnosis also assert:
* that a substance may be an adverse factor even if it has no effect alone, because different substances at low levels can augment or multiply one another's effects;
* that hypersensitivity develops when the "total body load" of physical and psychologic stresses exceeds one's tolerance; and
* that once the process of chemical sensitivity begins, new sensitivities can develop rapidly and from diminishingly low exposures.
These speculations clash with what is known in the fields of human physiology, pathology, toxicology, clinical medicine, and allergy and immunology. No known mechanism explains how chemicals at low levels, or how widely assorted chemicals, might interact adversely with numerous organ systems. Moreover, if the "total body load" concept were valid, low-level exposure to many unrelated chemicals (as well as infections and psychological stress) would have the same effects as high-level exposure to a single chemical—which is not so. The physiologic effects of chemicals are specific, and levels of exposure fix the development and severity of these effects.
Dubious Diagnosis
Clinical ecologists typically "diagnose" MCS in a large proportion of their patients. Their diagnostic evaluation usually involves taking an "ecological oriented history," performing a physical, and ordering lab tests. The history-taking procedure may include the patient's filling out a long questionnaire that focuses on dietary habits and exposure to environmental chemicals. The relevance of findings from physical exams to MCS is unclear, as no combination of such findings can validate a diagnosis of MCS. And findings from standard allergy tests are often normal in MCS patients.
The test clinical ecologists consider paramount is called "provocation—neutralization." During this procedure, the patient is asked to report any symptoms that develop after various substances under suspicion have been placed under the tongue or injected into the skin. If the patient reports symptoms, the test is considered positive, and the substance considered causal is administered in various concentrations until the symptoms are "neutralized." In addition, the clinical ecologist may prescribe other substances, such as hormones and food extracts, as "neutralizing" agents.
"Neutralization" superficially resembles the desensitization process that allergists use. But allergists test for—and treat their patients with substances that can elicit—measurable allergic reactions. In contrast, clinical ecologists base their diagnostic and treatment decisions on subjective responses. Many use tests related to immune function or to exposure to specific chemicals. Samples of blood, urine, body fat, and hair may be tested for various environmental chemicals. Blood may be tested to determine levels of immunoglobulins, other immune complexes, lymphocytes, and "antipollutant enzymes." Some of these tests lack both standardization and a protocol that has proved reliable. Moreover, it has not been demonstrated that any of these tests yields data that enable distinguishing persons with MCS.
Some treatments are based on blood tests that enable detecting chemicals in concentrations of parts per billion. Thus, clinically insignificant levels may be misinterpreted as evidence of unusual and harmful exposure. If any "toxin" level is deemed abnormal, the clinical ecologist may prescribe a "detoxification" or "purification" regimen to remove undesirable chemicals from the body. Such regimens may include exercise, "herbal wraps," massage, saunas, showers, megavitamin therapy, self-injection of "neutralizing" agents, and the use of devices for purifying air and water.
Researchers at the University of California conclusively debunked provocation—neutralization in the early 1980s. The test sites were the offices of the clinical ecologists who had been treating the subjects. During three-hour sessions, the patients received three injections of suspect food extracts and nine injections of normal saline (dilute salt water). Sixteen patients were tested once, and two were tested twice. In "nonblinded" trials, the patients reported symptoms whenever food extracts were injected, and they consistently reported an absence of symptoms when normal saline was injected. In double-blind trials, however, they developed symptoms with 16 (27%) of the 60 food-extract injections and with 44 (24%) of the 180 saline injections. The symptoms that accompanied the food-extract injections and those that accompanied the saline injections were identical and included: abdominal discomfort; aches in the legs; breathing difficulty; burning or watering of the eyes; chills; coughing; depression; disorientation; dizziness; dryness of the mouth; a feeling of fullness in or plugging of the ears; a feeling of tightness or pressure in the head; headache; intestinal gassiness or rumbling; nasal itching; nausea; nervousness; an odd taste; ringing of the ears; scratchiness of the throat; tingling of the face or scalp; and tiredness. The researchers thus demonstrated that the patients' symptoms were placebo effects; i.e., that the symptoms resulted from undergoing the experiment rather than from any chemical exposure.
They also debunked the claim that administering the offending substances at "neutralizing" doses can relieve the patient's symptoms: The responses to food-extract injections of each of the seven patients who had been "treated" during the experiment had been equivalent to their responses to saline injections.
Questionable Treatment
How clinical ecologists treat illness is as questionable as how they diagnose it. They usually emphasize avoidance of suspect substances and prescribe lifestyle changes that range from small alterations to sweeping transformations. For example, they generally instruct their patients to modify their diets and to avoid such items as aftershave; automobile exhaust; cigarette smoke; deodorants; scented shampoos; and carpets, clothing, and furniture that contain synthetic fibers. More extreme restrictions that clinical ecologists prescribe include wearing a charcoal-filter mask, using a portable oxygen device, staying home for months, relocating, quitting a job, and avoiding physical contact with members of one's family. Clinical ecologists also advise many patients to take vitamin, mineral, and other supplements. "Neutralization therapy," which is based on provocation—neutralization findings, may include the administration of extracts under the tongue or by injection.
Many experts have concluded that the basis of MCS is psychologic rather than physical. Many MCS patients suffer from an emotional problem termed "somatization disorder." This is characterized by persistent symptoms that no known medical condition can fully explain but that may require medical treatment. Some MCS patients are paranoids, who are prone to believe that their problems have external causes. Others suffer from agoraphobia, depression, panic disorder, or other anxiety states that induce physical reactions. Many patients are relieved when a clinical ecologist offers what they think they need and encourages them to participate actively in their recovery. But the "treatment" MCS patients receive may do them much more harm than good. ACSH scientific advisor Ronald E. Gots, M.D., Ph.D., president of the International Center for Toxicology and Medicine, in Rockville, Maryland, reviewed the medical records of more than a hundred MCS patients and concluded:
Unlike many alternative medical practices, the diagnosis of MCS begins a downward spiral of fruitless treatments, culminating in . . . withdrawal from society and condemning the sufferer to a life of misery and disability. . . . The diagnosis is far more disabling than the symptoms.
Political Action
To mandate that public places be designed or redesigned to accommodate variable and unpredictable individual responses is unfair. Yet MCS support groups have lobbied to persuade employers and government agencies to adopt policies that "accommodate employees and members of the public disabled by chemical barriers." Such groups have demanded:
* better ventilation systems;
* purchase of only the "least toxic/allergenic" building materials and office furniture, equipment, and supplies;
* prenotifying employees of any construction or remodeling in which an adhesive, carpet shampoo, floor wax, paint, or a solvent will be applied; and
* the proscribing of (a) air fresheners, (b) smoking in or near workplaces, (c) synthetic lawn chemicals near workplaces, and (d) except in emergencies, pesticides indoors.
Many MCS patients would have their workplaces completely odorless—without, for example, the scents of colognes and fragrant hygiene products. But attempts to accommodate persons who consider themselves sensitive to chemicals are often futile. The most publicized example of such futility is Ecology House, an eight-unit "safe house" in San Rafael, California. The U.S. Department of Housing and Urban Development (HUD) contributed $1.2 million toward the project's total cost of $1.8 million. A lottery decided which of 100 applicants around the U.S. would become tenants. Although the building was designed to be "free" of synthetic chemicals, most of the initial tenants said it sickened them.
Legal Mischief
Many people who say they have MCS have filed lawsuits claiming that exposure to environmental chemicals and particular foods has made them ill. Many of these suits allege that chemical exposures cause disease by injuring the immune system. This notion is maintained by professionals who misinterpret laboratory data so that the data look like evidence of a correlation between virtually any symptom and exposure to almost anything. Some plaintiffs have not complained of physical ills but rather have alleged that low-level exposure to environmental chemicals affected their immune systems and may eventually predispose them to cancer or to other diseases. Some plaintiffs have even sought damages for emotional distress that they've ascribed to an alleged toxic exposure.
Claims and lawsuits have also been filed to obtain workers' compensation and Social Security Disability benefits. Some courts have accepted MCS as a compensable occupational disease or a disability. But even a court that does not regard MCS as such may neglect causation and award benefits to a plaintiff it considers disabled by a somatization disorder or by another psychologic impairment.
Cumulative or high-level exposure to toxic chemicals can, of course, injure persons. But many MCS—related lawsuits rest on laboratory detection of insignificant traces of chemicals or on a small deviation from normal in some measure of immune function.
A 1993 U.S. Supreme Court decision strengthened the ability of judges to exclude unscientific testimony. Rule 702 of the Federal Rules of Evidence states that "expert testimony" is admissible if it is relevant and the witness is qualified by knowledge, skill, experience, training, or education. In Daubert v Merrell Dow the court upheld this rule and stated:
The trial judge must determine at the outset. . . . whether the expert is proposing to testify to (1) scientific knowledge that (2) will assist the trier of fact to understand or determine a fact in issue. This entails a preliminary assessment of whether the reasoning or methodology underlying the testimony is scientifically valid and of whether the reasoning or methodology properly can be applied to the facts in issue.
Since 1993 many judges have, on this basis, not permitted advocates of the MCS diagnosis to testify as experts.
Public Protection Is Needed
Meaningful research on the prevalence of a condition cannot be performed without clear-cut criteria for diagnosing it. None of the proposed definitions of "multiple chemical sensitivity" and its synonyms meets this standard. Yet hundreds of thousands of tax dollars have been wasted on such studies.
Meanwhile, clinical ecologists are emotionally and financially exploiting persons who think they have MCS. Moreover, dubious claims for disability benefits and damages burden insurance companies, employers, educational facilities, homeowners, other taxpayers, and, ultimately, all citizens. These problems can be reduced by establishing comprehensive, government-supported treatment programs that include environmental-chamber testing for chemical sensitivities. Whenever no chemical sensitivities are found, the psychologic nature of the problem can be clarified and the patient treated accordingly.
To protect the public, state licensing boards should scrutinize the practices of clinical ecologists and decide whether the overall quality of their patient care warrants permitting them to practice medicine. I believe that most of them should be delicensed.
ACSH scientific advisor Stephen Barrett, M.D., a retired psychiatrist, is board chairman of Quackwatch, Inc. His 1997 book, Chemical Sensitivity: The Truth About Environmental Illness, is available for $27 plus $2.50 postage from ACSH Books, P.O. Box 1747, Allentown, PA 18105.
(From Priorities, Vol. 11, No. 1)
