L'Association pour la santé environnementale du Québec / Environmental Health Association of Québec

What are environmental sensitivities/multiple chemical sensitivities (MCS)?

Description of environmental sensitivities/multiple chemical sensitivities (MCS)

Nowhere to run, Nowhere to hide…

Environmental sensitivities/multiple chemical sensitivities (MCS) are a range of reactions to environmental factors, including chemicals, foods, and biological agents at levels of exposure tolerated by many people.

MCS is a painful, chronic, multi-system condition that can develop in people of all ages, often following either a single massive exposure or repeated low-level exposures to commonly used products, and chemicals commonly released into the environment.

Sufferers then become sensitized to substances in their everyday environment at levels well below what would be considered to be acceptable to “normal” people. Sensitivity reactions can be triggered by scented products (personal products, shampoo, antiperspirants, creams, cologne, clothes softener, etc.), cleaning products, laundry detergents, paints, petrochemicals, cigarette smoke, pesticides, pets, plants, solvents, molds, foods or additives, etc.

Possible symptoms include:

  • Nervous system – heightened sense of smell; difficulty concentrating and/or remembering; variability in mental processing; feeling dull, groggy or spacey; headache, pain, restlessness, hyperactivity, agitation, insomnia, depression, lack of coordination or balance, anxiety, seizures, tinnitus, fatigue, tension, confusion, memory loss, dizziness.
  • Upper Respiratory System – stuffy nose, itchy nose (the “allergic salute”), blocked ears, sinus stuffiness, pain, infections.
  • Lower Respiratory System – cough, wheezing, shortness of breath, heavy chest, asthma, frequent bronchitis or pneumonia.
  • Eyes – red, watery eyes; dark circles under eyes; pain in eyes, disturbed vision.
  • Gastrointestinal System – excessive salivation, heartburn, nausea, bloating, constipation, abdominal pain, diarrhea.
  • Endocrine System – fatigue, lethargy, blood sugar fluctuations.
  • Musculoskeletal System – joint and muscle pain in the extremities and/or back, muscle twitching, spasm or weakness, swollen limbs.
  • Cardiovascular System – Rapid or irregular heartbeat, cold extremities, high or low blood pressure.
  • Skin (Integumentary System) – flushing (whole body, or isolated, such as ears, nose or cheeks), hives, eczema, other rashes, itching.
  • Genitourinary System – frequency and urgency to urinate, painful bladder spasms.

Some factors which contribute to the development of MCS:

  • Exposure to chemicals such as solvents and pesticides, or biological contaminants such as mold.
  • Long-term exposure to low levels of hazardous substances. Chronic low-level exposure, at work and at home.
  • A single overwhelming exposure such as a chemical spill.

Social Impact

The effects of MCS can be overwhelming. Productive people may suddenly or gradually become unable to tolerate offices, homes, schools, hospitals, and public places. Employers, who may or may not be aware of the problem, may refuse to make the accommodations necessary to allow people affected to continue working in safety. Many people with sensitivities lose their jobs if they are not provided with the accommodations they need to work productively. Some become homeless. All too often, retirement savings are depleted, and debts are incurred in attempts to create safe living conditions and to fund the costs of treatment. Treatment of these problems can be expensive and difficult to obtain, and includes avoidance of offending agents.

Some people with MCS do improve after many years if they are able to find a safe environment in which to live and work, and if they can obtain (and afford) treatments that are both tolerable and effective for them. Sadly, despite skills and education, some people with MCS end up on social assistance. Many become socially isolated as they are forced to retreat from places and activities they love, and for some, the devastation extends to losing spouses, family and friends who may not believe that they are ill.

The disability may be invisible, but it is real. Like others with disabilities, people with MCS have special needs which include, but are not limited to: housing in a safe and tolerable environment so that their bodies can heal; well-tolerated, environmentally safe products available at a reasonable cost; self-help groups and a support system; tolerable meeting places; publicly funded treatments; safe hospitals, schools, and other public facilities; and accommodation in the workplace.

Like all Canadians, we are entitled to freedom from discriminatory treatment, which includes the right to accessible workplaces, accommodation and public facilities. Notably, environmental sensitivities/multiple chemical sensitivities have been recognized as a disability by the Canadian Human Rights Commission and many provincial human rights commissions.

The consequences of Non-Recognition

Life for the individual suffering from MCS becomes unbearable, especially in a world that relies so heavily on chemicals and electromagnetic radiation.

Simple things that one takes for granted such as a movie or an evening at the theater, dinner with a companion or banking and shopping for essentials becomes impossible.

Due to a lack of accommodation in the workplace, many end up unemployed or underemployed. This can result in poverty and homelessness due to a lack of healthy housing. Living and sleeping on a verandah, tent or in the car, does occur. Often the individual is constantly unwell because of exposures to products emanating from neighbouring apartments and it is common that people suffering from this condition are forced to move from place to place in an effort to find appropriate, healthy housing.

‘No place to run, no place to hide’ becomes a reality and unless the person is cared for with appropriate housing, treatment and compassion for the huge losses they have suffered, they experience isolation and exclusion from society.

Lack of proper information on the medical condition can also lead to family disintegration.

Lack of recognition, treatment and social services also causes physical, emotional and social harm. ASEQ-EHAQ is witness to the fact that there is a steady progression of breakdown in communication within social support systems, due to a lack of awareness and education, leaving the very ill individual on their own and susceptible to neglect and abuse.

Economic impacts

The costs of this medical condition are incalculable: increased health care costs of repeated visits with little if any improvements to show for it, lost opportunities (trained professionals are no longer in the workplace), caregivers are diverted from other work, social stress as families break up, loss of quality of life, etc.

A study done in 2000 shows that across Canada, there are billions in direct and indirect costs. These costs are related to:

  • Lost productivity
  • Lost opportunities
  • Decreased tax base
  • Avoidable health care costs
  • Disability payments

Kassirer J and Sandiford K. Socio-Economic Impacts of Environmental Illness in Canada. 15-11-2000. The Environmental Illness Society of Canada.
The Centers for Occupational and Environmental Health, University of California. GREEN CHEMISTRY: Cornerstone to a Sustainable California, January 2008. see:
There is evidence that taking care of this issue has a positive economic impact. The Nova Scotia Environmental Health Centre (NSEHC) reports that health care utilization for those diagnosed with MCS was almost twice the provincial average. This health care utilization decreased to normal after NSEHC treatment. (Fox et al, 2007)


Our external environment can become our internal environment. For this reason, we must insist on clean air, clean water and clean food.

Your indoor air quality will depend on what you put into it. It is therefore in the interest of your health to choose products with the least possible toxins for personal use, cleaning and maintenance. Be mindful of your humidity levels and ensure that there is adequate ventilation in order to prevent mould and decrease indoor pollution. For cases of mould infestation, contact a reliable company for testing and clean up. Educate yourself on the best possible manner to do this in order to protect your health.

If needed, research the best water purification system. Studies have shown that several man-made products including pharmaceuticals are showing up in tap water. Avoid storing your water in plastic containers. Glass, ceramic and stainless-steel containers are available for this purpose.

Organic food is one of the best investments for your health. Try freezing organic farm vegetables in the summer to tide you through the winter.

Prevention of MCS touches on all the choices we make in our lives. Take a look at what you use and how it impacts yourself, your neighbours and our little friends in the environment. As the saying goes: An ounce of prevention is worth a pound of cure

Help for people suffering from environmental sensitivities/multiple chemical sensitivities (MCS)

ASEQ-EHAQ receives many calls for help from people with environmental sensitivities. There is no comprehensive treatment center in Quebec for these people. Most conventional medical doctors have not been trained to recognize or treat MCS. Generally, hospitals are not equipped to accommodate people suffering from MCS, although health care is considered a universal right.

Ontario has a provincially funded and mandated, academically-affiliated Environmental Health Clinic at Women’s College Hospital in Toronto, which provides diagnosis, support and help for people suffering from MCS. In addition to conducting research, they hold workshops and teach in medical schools.

It is now time for Quebec to take care of the chemically injured.

If you, your family or friends have MCS, we urge you to contact us for assistance. We also need the talents and skills of those who are well, whether you are family or friends who wish to help, or you are simply concerned about the effects of the environment on human health.