Chapter One


More Common Than You Think


What Is MCS and Who Gets It?

Five years ago, Jane’s workplace installed and glued down new carpeting. Following this she became ill with severe flu-like symptoms, headache, and nausea. She also developed bleeding ulcers and suffered from weight loss, confusion, forgetfulness, and ultimately, serious depression. She noticed she was becoming sensitive to odors from a variety of chemicals, but particularly formaldehyde. Within one hour of entering the workplace or of being exposed to new furniture, fabric or clothing stores, and some houses, she would develop the symptoms listed above.

As the carpet installation progressed and Jane experienced the above-described symptoms, she sent for a list of chemicals being used. Initially it made no sense to her that she suddenly became mentally unbalanced just because carpeting was installed. Yet, this seemed to be the opinion of a number of others. At the time, she received no testing or verification for her own conclusions, which were that the carpet itself was making her ill. She tried to tough it out, hold on to her job, and keep a “normal” life by tolerating the odors.

Each time she said to herself, “I will be okay—the smell is not that bad.” But her symptoms continued and even worsened, and she became frightened after she fell asleep while driving. Simple exposures to perfume and pest spray brought on such dire symptoms that she was forced to seek emergency medical treatment for vomiting and headaches. Unfortunately, just when Jane was dealing with these problems, she nearly died from a gas leak in her house. When the leak occurred and she felt faint, she attributed the symptoms to her usual sense of feeling unwell and tolerated them. Later, her daughter found her asleep in her bedroom with the entire house smelling strongly of propane. It took her two weeks to recover, after which she noticed she had become even more sensitive.

The propane heating system has now been removed from Jane’s house. In her attempt to avoid chemical exposures, she has sealed off all the plywood in the house, and she uses no scented products. She cannot tolerate the smell of her appliances, particularly new ones, and she can barely tolerate the natural smells of blooming flowers. Her joints are so inflamed and swollen that she can hardly use her hands. What sort of illness could cause such a myriad collection of symptoms?


What Is MCS?

Multiple chemical sensitivity (MCS) has also been referred to as chemical injury (CI), environmental illness (EI), chemical hypersensitivity, total allergy, and twentieth-century illness, among other names. There is some controversy about which name is most appropriate. Those who prefer the name “chemical injury” believe that the name should reflect a chemical cause for the problem. Those who prefer “environmental illness” believe that since patients often react to pollens, dust, molds, and animal dander, the broader term is more appropriate. Although I understand and agree with the arguments for using other terms, I will use the term “multiple chemical sensitivity” (MCS) when describing sensitivity to chemicals because it is used most often in the professional literature.


Defining MCS

Defining MCS has stirred its own controversy. Simply put, people seem to undergo some poorly understood systemic damage that causes them to react negatively to common chemicals in ambient air. Jane’s health has somehow changed such that she experiences violent—even life-threatening—illness from a number of chemicals that others seem to tolerate. Finding an “official” definition of MCS, however, is more complicated. Ashford and Miller (1998) propose an operational definition, claiming that an MCS patient “can be discovered by removal from the suspected offending agents and by re-challenge, after an appropriate interval, under strictly controlled environmental conditions.” For example, if Jane were removed from her work atmosphere, placed in a clean environment, given time to recover, and then experienced symptoms upon re-exposure to formaldehyde, by this definition she would be a chemically sensitive person.

A group of thirty-four researchers and clinicians with experience in the “study, evaluation, diagnosis, and/or care of adults and children with chemical sensitivity disorders” has published a consensus statement supporting a definition of MCS adapted from Nethercott, Davidoff, Curbow, et al. (1993). The consensus includes the following six criteria:

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 (added in 1999)

                (Multiple Chemical Sensitivity:  A 1999 Consensus)


Jane meets all of these criteria, assuming that no other medical explanation is found for her constellation of symptoms. Cullen (1987) would add that the problem must be initiated by one identifiable episode or event. However, some object to this criterion because not everyone with MCS can identify a single episode that caused their problem.


Describing MCS

The first comprehensive description of patients with MCS was by Theron Randolph, who was doing research on “allergic” reactions to chemicals as early as the 1950s. He was a loved mentor and friend of practitioners in environmental medicine, and a physician to people with MCS for many years. His book with Ralph Moss, An Alternative Approach to Allergies (1982), describes his practice, his theories, the symptoms he believed are caused by chemicals, and the chemicals that elicit those symptoms. Randolph traced some of his patients’ difficulties as they (and he) discovered their sensitivities to exhausts, cooking gas, perfumes, formaldehyde, and other chemicals. The book includes his patient questionnaire and many valuable case histories.

Chemicals eliciting illness in people with MCS fall into many classes, but often they are solvents. In Phase IV of my research, respondents rated pesticides, formaldehyde, fresh paint, new carpets, diesel exhaust, perfumes, and air fresheners as being particularly troublesome. (See Appendix A for more details.)


MCS and the Body

MCS symptoms can affect any bodily system, including respiratory, digestive, neurological, musculoskeletal, endocrinological, immunological, and others. Of the symptoms reported by respondents in a study of 191 MCS patients by the Canadian Ministry of Health (Report of the Ad Hoc Committee, 1985), forty-five affected the central nervous system, twenty-six were gastrointestinal, twelve were respiratory, eight were musculoskeletal, sixteen were genito-urinary, thirty-two affected the ear/nose/throat, seventeen concerned skin, and twelve were cardiovascular.

The five most common symptoms in my research were tiredness/lethargy, difficulty concentrating, muscle aches, memory difficulties, and long-term fatigue. This suggests overlap with chronic fatigue syndrome.

Sometimes symptoms caused by chemicals are more unusual or frightening. Some respondents reported experiencing memory loss, nervousness, bleeding from the lips, water retention, heart palpitations, hair loss, and other alarming reactions to exposures. The cerebral effects may be some of the most frightening and debilitating symptoms experienced, as described here: “I don’t know what triggers it, but I’m normally quiet and easygoing. Sometimes I have temper and anger management problems along with the feeling that I am really out of control.”

Another person said, “My symptoms are largely mental. I begin to have memory problems and can’t think, then my face turns red and I become very irritable. Also some slowing of my speech.”  

Because we know so little about MCS, nothing is known about the long-term effect of actually experiencing the reactions to chemicals. As one person said: “Who knows what harm is occurring in one’s head due to repeated migraines?”


Total Load

People with MCS may also demonstrate food, mold, pollen, and animal allergies/sensitivities that complicate life and increase the “total chemical load” on the person’s system. The concept of total load says that the body can tolerate only so many insults/exposures/stresses before they start to exact a heavy toll. The body is seen as “filling up” with exposures and stressors such that one’s daily ability to tolerate exposures may fluctuate depending on how many exposures already have been endured on that given day.

According to this concept, if you have food allergies and eat the foods that are triggering those allergies, you may have less tolerance for chemicals than you had just a week ago when your system was dealing with fewer assaults. Similarly, if it is hay fever season and you are already reacting to pollens, you may be less able to tolerate chemicals. Conversely, anything you can do to reduce your total load may help you give your body the time it needs to heal and thus increase your ability to face future exposures without falling apart.


MCS and Electromagnetic Frequencies

Sensitivities to electromagnetic frequencies (EMFs) also may complicate people’s lives, because high-tension wires, transmitters, and other large sources of electricity as well as electrical appliances emit electrical fields. According to Libby Kelly of the Council on Wireless Technology Impact, today in the world we face radio frequency radiation (RFR) that is 10,000 times the natural level that the earth creates, bombarding our bodies with continual outside electrical pollution (Public Exposure 2001). The United States legally allows exposures up to 500mHz, a high limit when compared with limits of other countries. Although there has been a call for adequate research on this matter, very limited financial resources are available, most controlled by the very telecommunications companies potentially affected by the findings. EMFs can alter the permeability of nerve cells in the brain, thereby affecting the levels and circulation of brain chemicals (neurotransmitters). Dr. Jerry Phillips, a biochemist and former researcher for Motorola, was employed to research for the telecom giant, and then advised not to publish his results: that electromagnetic fields created by cellular phones are unsafe for adults, with increasing risk to children and particularly to young children. Dr. Henry Lai, a professor of engineering at the University of Washington, has found that after radio frequency radiation exposure, animal DNA literally breaks up into pieces. Correlational studies suggest that proximity to RFR is associated with increased cancer rates (primarily leukemia, both child and adult), infertility, memory loss, lowered reaction time, DNA damage, immune system effects, a weakened blood-brain barrier, and sleeplessness (Pinsky 1995; Public Exposure 2001).

Per Sagabeck, a senior electronics engineer for Ericsson, has been sensitized to electrical fields, and is handicapped to the point that he must wear a stainless steel mesh suit to even go outside. According to Sagabeck, between 80 and 90 percent of employees from all over the world employed in his building developing electrical technology were diagnosed with electrosensitivity within one year. Legally recognized as a disability by the Swedish government, Sagabeck states “up to two percent of the Swedish population, or 180,000 people, may be electrosensitive” (Public Exposure 2001).

It is difficult to avoid these exposures because, even if people attempt to control EMFs in their homes, the proliferation of cell towers and radio towers threatens to make it almost impossible to live away from these magnetic fields. The towers are now being camouflaged as architectural features such as chimneys or church steeples or as evergreen trees or sorrel cacti. Electromagnetic sensitivities (EMS) can exist along with or apart from MCS, but often persons with EMS experience MCS as well.


MCS and Allergies

More than half of the people with chemical sensitivities in a study by Meggs, Dunn, Bloch, et al. (1996) also had common allergies, such as to dust, pollen, and weeds. In addition, food sensitivities can be a major obstacle:

“Sitting down to a meal was like dining in a minefield. Whether in a restaurant or at home, I would take one small bite, stop, and see if I reacted. If my breath didn’t stop, or my head didn’t pound, or my stomach didn’t rebel, I would eat a little more. I did this with every bite. Experience taught me not to bother with the water. I always reacted to that.”

                            —Forty-seven-year-old woman with MCS



One interesting and important dynamic to understand in relation to chemical sensitivity is that of adaptation. Randolph and Moss (1982) drew parallels to the addictive process in that the initial exposure to a chemical may actually cause an excitatory response. That is, you may actually feel temporarily better or more energized after an exposure when you are in the process of becoming sensitized to a chemical.

The workaholic, for example, who cannot leave the office, actually may be getting a temporary unhealthy “high” from a work exposure that excites the nervous system. However, as the exposure wears off (withdrawal), the person experiences the opposite reaction—that of energy depletion, and so forth. Over time, exposure to the chemical in question ceases to have the excitatory effect (much as alcohol does for the alcoholic), and the person feels poorly all of the time. At any one point in time we are involved in a number of cycles of exposure and withdrawal with all of the cycles overlapping. This is adaptation.

For example, you may be beginning to become sensitized to a new chemical in the workplace that makes you feel high. But this may be counterbalanced by a withdrawal reaction you are having due to not having eaten eggs for two days. You can see that with several cycles simultaneously overlapping, it would be impossible to tell exactly what is causing your reactions. This is why practitioners of environmental medicine have urged the construction of environmental hospital units, where patients can be tested for reactions in a clean environment after fasting for several days on pure water. This puts patients into a de-adapted state, and makes it more likely to pinpoint precisely what is causing their reactions. Patients are challenged (tested) with one substance or food at a time, and the substances most harmful to them can then be identified.


Induction and Triggering

Miller (1994) describes the two-stage process of induction (when the person develops a sensitivity to a substance) and triggering (when future exposures to the substance bring on negative reactions). Induction may be caused by one large exposure or by a series of low-level exposures, or possibly by severe stress or physical illness (although this cause is less clearly understood).

An international study of MCS found in at least three countries that all of the following were associated with the onset of the illness: organic solvents, pesticides, amalgam/mercury, formaldehyde, renovated buildings, paints/ lacquers, pentachlorophenol/wood preservative, and stress or psychological factors (Ashford, Heinzow, and Lutjen, et al. 1995). Scandinavian studies of “sick buildings” have found that being female, having preexisting asthma or rhinitis, having a history of atopy (allergy), working in particular job categories having the most exposures as part of the job, i.e., photocopying, visual display terminal use, and handling carbonless paper all increase the risk of developing symptoms in “sick buildings” (Ashford, Heinzow, and Lutjen, et al. 1995). Therefore, any preexisting vulnerabilities seem to “set us up” for chemical insult. One woman who had been sick with MCS for four years said:

“I had a minor case of asthma for about ten years and never really got too sick until they added the chemical methyl tertiary butyl ether to the gas tanks. As a result when it is used in Colorado from November to March, I develop asthma and bronchitis over and over. After five years of the irritation to my lungs I have chemical sensitivities. I am very bothered by pesticides, paint, perfumes, newspapers, copy machines, and hair sprays. I correspond with people in Alaska and Montana and they are having the same effects from the fuel.”

How Many People Have Environmental Sensitivities?

Four prevalence studies to date have looked at the incidence of MCS in the general population. In one study, Meggs et al. (1996), surveyed a representative rural household sample of people. This means that the population sample selected by the university represented as closely as possible the area population. Of 1,027 people, one-third reported chemical sensitivity, with the major incitants being perfumes, pesticides, cigarette smoke, and fresh paint. Chemical sensitivity without allergy was almost as common as allergy without chemical sensitivity (16 percent versus 18 percent), was present in all age, income, race, and education groups, and caused 3.9 percent of respondents to become ill every single day.

The New Mexico and California State Departments of Health also conducted population prevalence studies. In New Mexico, Voorhees (1999) found that 16 percent of people reported being sensitive to chemicals, 2 percent had been diagnosed with MCS, and 2 percent had lost a job or career because of the sensitivities. Neutra, Kreutzer, and Lashuay (1999) found that of a random sample of California adults, 15.9 percent of respondents reported being “allergic or unusually sensitive to everyday chemicals,” and 6.3 percent had been diagnosed with the problem.

The most recent prevalence studies have been done by Caress and Steinemann (2003) who found that 12.6% of a random sample of people from the Atlanta metropolitan area reported that they were “unusually sensitive to everyday chemicals like those in household cleaning products, perfume, detergents, insect spray and things like that” (p. 1491). About three percent had been medically diagnosed. According to these studies, chemical sensitivity seems to be fairly evenly distributed by age, educational level, marital status, job, and geographic location.

Another California Department of Health survey found that 3 percent of the people interviewed reported that they are unusually sensitive to electric appliances or power lines (Levallois, Neutra, Lee, and Hristova 2001). 

If approximately 4 percent of the U.S. population is becoming ill every day from chemicals, this extrapolates to over 11 million people having moderate to severe MCS, a formidable number of people to be ill without so much as an agreement as to what to call their condition. If 2 percent have lost their jobs because of the problem, then the productivity of five and a half million people has been compromised. If this many people are sick from chemicals, why is Jane receiving feedback that she has psychological problems?

At least two papers document MCS as a global concern. An international team of researchers found reports of chemical sensitivity in Denmark, Sweden, Norway, Finland, Germany, Holland, Belgium, the United Kingdom, and Greece (Ashford, Heinzow, Lutjen, et al. 1995). Cynthia Wilson (1995) compiled data that suggests that MCS is a global, albeit an unlabeled and insufficiently researched problem.


Who Gets Environmental Sensitivities?

Ordinary people get environmental sensitivities. Variables that increase your chances for developing MCS seem to be large single exposures to chemicals, low-level chronic exposures without adequate ventilation, being female, having a family history of chemical sensitivity, and other possible insults to your body that reduce its ability to detoxify chemicals, such as serious illness or damage to your enzyme systems. (Enzyme systems are important components of the body’s detoxification pathways.)

People from all walks of life develop MCS including professionals, office workers, homemakers, and farmers. My data sample contains large numbers of homemakers, clerical workers, students, teachers, and nurses. Other represented occupations include chemists, engineers, professors, hairdressers, and accountants. Having a “good job” does not protect you from getting MCS. In fact, more than half of those in my data sample who reported an initial known exposure that had damaged their health said that it had occurred in the work environment. For most people, MCS appears to be a long-term chronic condition. The volunteers in my sample had been sick with MCS for an average of fifteen years. For seven and a half of those years their problem was undiagnosed. (See Appendix A for the demographics, occupations, and other data from my research sample.)



Many study samples have been predominantly women. Caress and Steinemann (2003) reported that two-thirds of their chemically sensitive respondents (when adjusted for sample bias) were women. My samples have been about 80% women. Although no one knows for certain why women appear to be more susceptible to MCS, there are several hypotheses that may explain these percentages. Some simple explanations may be that women are physically smaller on average than men and, therefore, may be less able to metabolize chemicals. Women also have a greater total percentage of body fat, which stores chemicals. There is an enzyme called alcohol dehydrogenase that detoxifies not only carbohydrates, sugar, and alcohol, but also chemicals. Men have much more of this enzyme than do women (Freeza, Padova, Pozzato, et al. 1990; Rogers 1990). Also levels of butylcholinesterases, which scavenge chemicals, are lower in females over the age of ten than in males, and decline further in women over the age of thirty (Wilson 1997).

Our culture also encourages women to use many chemically-based cosmetics filled with hundreds of ingredients for which Material Safety Data Sheets (MSDS) say, “Do not inhale vapors” or “Avoid contact with skin.” Women are then exposed to one another’s fragrances in small working spaces.

Recent information about the importance of hormone mimickers may also explain some of the gender disparity. Many commonly used chemicals contain known estrogen blockers or mimickers (i.e., “xenoestrogens”), which may disrupt endocrine functioning in women differently than they do in men (Colborn, Dumanoski, and Myers 1997). These “xenoestrogens” may enter the body and activate estrogen receptors, thus simulating a high estrogen content in the body (mimicking), or may fill, but fail to activate, a receptor, thus disrupting the body’s estrogenic processes (blocking). Cynthia Wilson (1997) explains that the P450 enzyme system, which is responsible for removing toxins from the blood, can be inhibited or even inactivated by these estrogen-mimicking chemicals. Permissible levels for chemical exposure set by the Occupational Safety and Health Administration (OSHA) are based on young, healthy, 154-pound white men. Thus women, children, and minorities are probably not being adequately protected (Wilson 1997).

It is possible, however, that the gender difference in MCS is exaggerated as a result of using volunteer and medical samples. In Meggs et al.’s household population study (1996), the ratio was much smaller, with 24 percent of men and 39 percent of women reporting illness due to chemicals. Although still favoring women, this is a much smaller differential than has been found in other studies. It is also possible that women have better support networks, and thus find their way to studies or to medical treatment more easily.

Another possibility is that men may call their symptoms something else. In our culture we teach men that they must endure. A friend of mine returned home one day to find the man who had been hired to paint the inside of her house walking around in circles in her yard. When she asked him what was wrong he said that this “always happened” when he painted. This man probably did not use the term “MCS,” yet clearly, he was experiencing reactions to chemicals on a regular basis.

Whether or not EMS shows the same gender ratio as MCS is not certain at this point.



Race is certainly a variable in how much of a toxic load a person is expected to bear. Our industrial culture puts poor and minority people at risk for much greater exposures in their neighborhoods because of environmental racism. Minority groups inhabit neighborhoods close to polluting facilities after these neighborhoods have been depopulated by middle-class families who have improved their “standard of living” and moved to the suburbs. In other cases, minority neighborhoods are purposely targeted by industry for facilities that contaminate air, earth, and water because industry expects less resistance in communities where people have little political power, few resources, and are more desperate for jobs. The result is often serious illness, decimated communities, and the destruction of family life. Nowhere is this more evident than in the African-American communities in Louisiana between Baton Rouge and New Orleans, an area that has earned itself the name “Cancer Alley.” I am not aware of any MCS studies that have specifically surveyed African-American inhabitants of such areas. There were no African-American participants in my study, which drew heavily on persons from support groups. However, population studies have found that MCS affects persons from many racial backgrounds. Meggs et al. (1996) found that African-Americans reported MCS in the same percentages as Caucasians (33 percent).

Certainly, Native Americans also endure the level of contamination found in Cancer Alley. There are several reports that MCS is prevalent among Native Americans. The environmental contamination on reservations is high due to the presence of radioactivity, waste dump sites, pesticide use, contaminated water, and the high consumption of fish (which accumulate toxins in the food chain) (Hall 1994; Hansen and Lurie 1995). Factories have been and still are allowed to contaminate drinking water for Indian nations (Hall 1994), and radioactive dump sites are situated on their lands. These and other forms of industrial contamination take their toll on Native American health. Hansen and Lurie (1995) described the pesticiding of Lurie’s neighborhood on the Rosebud Reservation in Mission, South Dakota. The scenario is a chemically sensitive person’s worst nightmare with trucks repeatedly spraying malathion and leaving a sticky residue in the interiors of people’s homes and on their possessions (including food and clothing). Without air-conditioning, residents were forced to keep their windows open. Lurie and his pregnant wife were trying to detoxify their belongings and cope with their symptoms, which included splitting headaches for themselves and breathing difficulties for their two-year-old daughter, without even a fan. The spraying also sickened all fourteen neighbors who had been home on the night of the spraying. The sprayings continued with the mayor refusing to provide notification or to turn off the spray when the truck passed the Lurie home.

Clearly, we are all exposed to unsafe levels of many chemicals. Nonetheless, the less powerful and more oppressed members of the population are most at risk for harm from decisions made by those in power who subject them to unsafe substances. As Lois Gibbs says, “Pollution begins in the boardroom.”