Multiple Chemical Sensitivities (MCS) - Questions and Answer

Q. What is multiple chemical sensitivities (MCS)?
A.  MCS is a condition in which physical and behavioral symptoms are induced by minor chemical exposure(s).  It has been recognized by a few physicians for a long time, and has been called a number of different terms: ecological or environmental illness, chemical sensitivities, total allergy syndrome, and twentieth century illness -- to name a few.  The characteristics shared by all who have this condition are that symptoms may be provoked by exceedingly small amounts of chemicals, and that the severity of the symptoms seems not to be typically dose-related -- a very small amount can produce a severe reaction. Although the exact cause of MCS remains unknown, according to one medical researcher, it is "...the result -- direct, indirect or cumulative -- of exposure to the increasing number of chemicals in our food, water, air and drugs." (H.J.Roberts, MD, (May 1990) Jour. Florida Medical Assn.)

Q. Who has MCS? What makes people susceptible to it?
A. No one knows for sure, but there is good reason to believe that other conditions that make people vulnerable to effects from chemicals -- such as pre-existing chronic illness, allergy, pregnancy, being elderly or an infant or child -- may promote vulnerability to chemical-induced illness.  Stress states or stress conditions may play a role. Other contributing factors may exist as well, such as poor nutrition, or genetic determinants that are at present unknown.  At different points over a life-time, many people experience some or all of these conditions, which indicates varying susceptibility in the population at any given time.

Q. Does that mean that anyone can get MCS?

A. Some believe so.  Others say that, until we can be certain in targeting those who are apt to develop this condition, it is prudent for everyone to take steps to reduce their exposures to chemicals.

Q. How many people have MCS?

A. No one knows. Thousands have been diagnosed, but many more may have it but be undiagnosed or misdiagnosed.  The problem isn't always obvious at the outset.  Many people gradually get worse over a period of years, accumulating seemingly unrelated symptoms for which they receive separate treatments.  Only after MCS is diagnosed do many people realize that chemicals can provoke symptoms and that exposure avoidance can restore well-being and reduce or eliminate the need for symptomatic drug treatment. Thus, there may be many, many people who have the problem but have not yet accurately identified it. The National Academy of Sciences speculated in 1987 that about 15% of the population may have increased sensitivity to chemicals, but did not provide documentation for this estimate at that time.  Subsequently, the chairman of the 1987 NAS workshop revealed that this figure was based on occupational studies of hypersensitivity to chemicals where the hypersensitivity was considered immunologic in origin (Lebowitz 1990)." (Ashford 1991).

Q. How many chemicals cause problems? Which ones are they? 
A. It may not be a question of  "how many" or even a question of "which ones."  Some problem chemicals have been identified. Formaldehyde is present in a formidable array of common products.    The volatile organic compounds in car exhaust, dry cleaning chemicals and consumer products (air fresheners, disinfectants, polishes, varnishes and the like -- as well as grooming aids) are examples of chemicals that are nearly ubiquitous in the modern world.  Everyone is exposed, and people with MCS have trouble with them.  But there are other chemicals that are almost unique to certain workplaces that can also induce sensitivity.  Although in February 1990 the 10 millionth chemical was registered, there  are said to be "only" about 60,000 chemicals in use, and of  these, only a handful of chemicals to which everyone is exposed.  Sheer numbers may not be as important as the ubiquity of some chemicals.

Q. Who treats MCS?
A. At the moment the condition is poorly understood and is being treated in only a few occupational health clinics and by practitioners of environmental medicine.  Many who have (or suspect they have) MCS may have to travel long distances to get appropriate diagnosis and treatment.  

Q. Why do so few doctors choose to treat MCS? 
A. There are a number of reasons. Perhaps the most important one is that, according to the National Academy of Sciences (NAS) Institute of Medicine (IOM), one reason why more doctors don't treat occupationally or environmentally induced illnesses is because they have little or no training in occupational and environmental medicine.  Since they have no training, it's not surprising that they fail to diagnose and treat these illnesses. In 1988, most doctors trained in occupational and environmental medicine were not in clinical practice, but were in academia or in industrial settings. Some medical schools didn't teach these disciplines at all. In their report, the IOM suggested that physicians learn about these illnesses in continuing education programs and in the years since their report, such programs in occupational and environmental medicine have become more common.

Q. Aren't chemicals tested for safety before they are allowed to be sold?
A. Not exactly. Their benefits are weighed against their risks. Until recently, the only health effects known for chemicals in the environment had to do with toxicity, cancer, birth defects, and reproductive hazards.  Since the capacity to sensitize was not looked for prior to approval of these chemicals for release into the market, it was not found. Recently there has been less talk about product safety and more talk about "risk assessment models," "risk/benefit analysis," and "negligible risk." These concepts replace the simple concepts of safe and unsafe. They also acknowledge that some products that are in wide use may not be safe per se, because safety is not an achievable state of affairs.  There is always some risk that any chemical could pose a health threat to a uniquely susceptible individual. The problem that MCS poses in this conceptual framework is that MCS has not been figured into the risk side of the risk/benefit ratio.  For those with MCS, this means that many products in wide use and assumed to be "safe" by consumers are most likely "unsafe" for those with MCS -- and for those at risk for developing MCS.

Q. Are all chemicals harmful?  Are pesticides especially dangerous? Why do applicators say they're safe?

A. It's probably too sweeping a generalization to say that all chemicals are harmful, or that all chemicals are equally harmful.  What can probably be claimed responsibly is that some people may react to just about anything, synthetic or natural. 

As for pesticides, there has been a long-standing problem with misleading safety claims made   about them.  Although the General Accounting Office repeatedly reported to Congress that some people are sensitive to pesticides and that all pesticides present some risk to people, the pesticide manufacturers and applicators have persisted in claiming that their products are "safe."  The Environmental Protection Agency has not devoted resources to discovering who is making these claims, and the Federal Trade Commission has failed to pursue professional applicators making false safety claims. It's not that there are no rules on the books, but they are not being enforced. Tight budgets account for some of the inaction, as does a lack of personnel trained to recognize the scope of the potential threat to public health.  There also seems to be a bit of inter-agency miscommunication.

Q.  Are "environmentally sound" or "green" products safe for those with MCS?

A.  Remember, there are no "safe" products in the absolute sense.  However, it's encouraging to see widespread interest in reducing chemical use.  But we need to make sure that "green" products aren't simply cosmetic solutions papering over fundamental problems. We also need be on guard for false and misleading claims.  For those simply concerned with reducing chemical use, a phoney “green” product may be difficult to detect.  But for those with MCS, a phoney “green” product may create serious health problems.

Q. Does that mean you’re anti-technology?

A.  No, it means we are pro RESPONSIBLE technology.  We are also for informed choice. That means better labeling and honesty on the part of regulators about what is and is not known about health risks associated with products, including consumer products containing chemicals and chemical residues.