Multiple-chemical sensitivity (MCS) is a disputed condition that is believed to result when chemicals or substances in the environment or in food disrupt the immune system, leading to nausea, respiratory problems, headaches, dizziness, rashes, fatigue and many other afflictions. Some people go to great extremes to eliminate hostile chemicals and synthetic materials from their lives, and even lining their homes with aluminium or moving to remote parts of the world.
The Environmental Health Center in Dallas treated 17,000 MCS patients between 1976 and 1988. Canada recognizes MCS and offers many social services to its victims. The Board on Environmental Studies and Toxicology of the National Academy of Sciences estimates that 15 percent [out-of-date statistics] of the population of the USA is sensitive to common household chemicals.
Chemical ecologists have never been able to demonstrate laboratory abnormalities in their patients, nor have they shown that their treatments have any particular efficacy. Patients in whom environmental illness have been diagnosed are much more likely to meet the criteria of a current of past psychiatric problem than a group of healthy people selected from the community -- in other words, they are suffering from a mental disorder. They were likely to be depressed, anxious, obsessive-compulsive or to display some other mental ailment.