What is Multiple Chemical Sensitivity (MCS) ?

MCS is the acronym for Multiple Chemical Sensitivity; it is also called Environmental Illness. It is a negative reaction to chemicals/toxins in your environment, as well as foods or water. The EPA defines MCS as a condition in which a person reports a sensitivity or intolerance to a number of chemicals and other irritants at very low concentrations. People with MCS react to things in their environment that many others do not. MCS can involve multiple symptoms in multiple areas of the body. It is a symptom of a body overloaded with toxins, and a weakened immune system with the inability to process toxins as it should.

Dr. Theron G. Randolph, past professor of Northwestern University Medical School first described MCS in the 1950’s, where he considered it a 20th century disease. Throughout his 60 year medical career, he saw more than 20,000 patients and co founded the American Academy of Environmental Medicine. Dr. Randolph was diagnosing patients with allergies/ sensitivities to chemicals ten years before Rachel Carson published Silent Spring, which discussed the health risks imposed by living in an ever increasing toxic world. He was a man ahead of his time.

I’ve actually known people whose doctors said that this illness was all in their head. So I like to remind them that in the 1930’s-1950’s many doctors believed asthma to be a psychosomatic illness. Psychoanalysts thought that patients with asthma should be treated for depression, and that children who wheezed, were not showing signs of physical illness, but were actually displaying a suppressed cry for their mother. It wasn’t until the 1960’s that people started coming around. But one of the reasons MCS is controversial in the medical community is that medical experts have not found a consistent cause, clear cut test, or treatment for MCS. But as many of us with MCS know, this is not an illness that fits into a box.

MCS symptoms vary from individual to individual, based on their exposure, their overall health, and level of toxicity. One aspect of MCS that is understood by conventional medicine is sensitization. Sensitization is a true allergic reaction to a chemical or pollutant within the body of mast cells and IgE antibodies. Once sensitized to a particular irritant, another exposure to even a tiny amount of the irritant (even parts per million-ppm-or parts per billion-ppb can cause an extreme allergic reaction. (Note: one ppm=0.0001 percent.) These low levels of irritants go virtually undetected to the average person. But people with MCS have an acute sensitivity to anything from dry cleaned clothes, perfume, detergents, carpets, cleaning products, smoke, paper, and new furniture to name a few. What is interesting is that what bothers one person, may not be an issue for another, which again is why it is so hard for the medical community to grasp the concept of MCS. You can have a dozen people in a room, who are all exposed to the same thing, and each will have a different reaction.

Before we had high tech equipment to measure air quality, coal miners used canaries in the mines to determine the safety of the air. Canaries are very sensitive to methane and carbon monoxide, and these little birds will sing and chirp all day long. But if the carbon monoxide levels got to high, they would have difficulty breathing and stop singing, so miners would know that the gas levels in the mines were getting too high and they had to get out quickly. Why do I bring this up? Because individuals with MCS are modern day canaries. They can alert the modern world to the hazards of many modern products. Research by the California Dept. of Health estimates that up to 34% of Americans report symptoms of chemical sensitivity. Of this number up to 80% also have chronic fatigue syndrome; 65% have fibromyalgia, and over 85% have digestive and immune disorders. (cite: by Dr. Gloria Gilbere, Kootenai Valley Times.)

For many individuals living in a modern world with its many conveniences is a joy. For those with MCS it can be a nightmare. While some may find air fresheners and fabric softeners pleasant, those with MCS live in dread of coming in contact with the toxic chemicals used in the manufacturing of those products, due to the reactions these chemicals will cause. With repeated exposures to these toxins, the body becomes weaker, and the individual’s health will decline.


MCS symptoms can include, but are not limited to:

Anxiety Attacks


Body aches

Burning and / or itching skin

Burning and/or stinging eyes



Extreme fatigue/lethargy


Heart palpitations

Muscle cramps

Poor memory and concentration (brain fog)


Sleeping difficulties

Sore throat / cough

Tingling/Numbness/Burning around lips









Detoxify or Die by Dr. Sherry Rogers

I Was Poisoned by my Own Body by Dr. Gloria Gilbere

Silent Spring by Rachel Carson

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