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

What Are Environmental Sensitivities?

Environmental sensitivities (ES) are a range of reactions to environmental factors including chemicals, foods, biological agents and electromagnetic radiation, at levels of exposure tolerated by many people.

It includes a range of overlapping chronic conditions such as Multiple Chemical Sensitivity (MCS) also known as environmental sensitivity/multiple chemical sensitivity (ES/MCS)

This condition is recognized as a disability by the Canadian Human Rights Commission.

Sufferers then become sensitised to substances or phenomena 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, paints, petrochemicals, cigarette smoke, pesticides, pets, plants, electromagnetic radiation, molds, foods or additives among other things.

Possible Symptoms Include

Nervous system

  • heightened sense of smell
  • difficulty concentrating and/or remembering
  • variability in mental processing
  • feeling dull, groggy or spacey
  • headache
  • restlessness
  • hyperactivity
  • agitation
  • insomnia
  • depression
  • lack of coordination or balance
  • anxiety
  • seizures
  • ringing in the ears
  • tension
  • confusion
  • dizziness

Upper Respiratory System

  • stuffy and/or itchy nose
  • blocked ears
  • infections

Lower Respiratory System

  • coughing
  • wheezing
  • shortness of breath
  • asthma
  • frequent bronchitis or pneumonia


  • 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


  • flushing (whole body, or isolated, such as ears, nose or cheeks)
  • hives
  • eczema and other rashes
  • itching

Genitourinary System

  • frequency and urgency to urinate
  • painful bladder spasms

Some Factors Which Contribute To The Development Of ES

  • Exposure to chemicals such as 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 environmental sensitivities 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 triggers.

Some people with sensitivities 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 sensitivities 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 all Canadians, we are entitled to freedom from discriminatory treatment, which includes the right to accessible workplaces, accommodation, and public facilities.

Over 1 Million Canadians Are Affected By An Increasing Health Condition, Multiple Chemical Sensitivity (MCS). See the statistics

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