Donnez / Donate


Diagnosis of environmental sensitivities

Environmental sensitivities are a range of reactions to environmental factors including chemicals, sales view foods, biological agents and electromagnetic radiation, at levels of exposure tolerated by many people. It encompasses a range of overlapping chronic conditions such as Multiple Chemical Sensitivity (MCS) and Electromagnetic Sensitivity. Environmental sensitivities frequently contribute to illnesses such as Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) and Fibromyalgia (FM).
Taking an Exposure History (CH2OPD2)

In 1999, group of physicians and researchers published the criteria for diagnosis of MCS.

Case Criteria – 1999 Consensus on Multiple Chemical Sensitivity (MCS)

  • Symptoms are reproducible.
  • The condition is chronic.
  • Low levels of exposure (lower than previously or commonly tolerated) result in symptoms.
  • Symptoms improve or resolve when incitants are removed
  • Responses occur to multiple chemically unrelated substances.
  • Symptoms involve multiple organ Systems.

Reference: 1999 Consensus on Multiple Chemical Sensitivity. Archives of Environmental Health, May/June 1999, Vol. 54, No. 3, based on: J. R. Nethercott, L. L. Davidoff, B. Curbow. “Multiple Chemical Sensitivities Syndrome: Toward a Working Case Definition.” Arch Environ Health, 1993; 48:19–26.

Read more about the 1999 consensus ->

chevalThese diagnostic criteria were then validated by University of Toronto researchers, who also determined additional symptoms common in people with MCS.

  • Having a stronger sense of smell than others.
  • Difficulty concentrating.
  • Feeling dull or groggy.
  • Feeling spacey.

Reference: McKeown-Eyssen, G. E., C. J. Baines, L. M. Marshall, et al. “Multiple Chemical Sensitivity:
Discriminant Validity of Case Definitions.” Arch Environ Health, 2001; 56(5):406–12

Diagnostic Checklists –Ontario College of Family Physicians (go to Environmental Health Committee and scroll down (

Also noted commonly in the international medical literature:

  • Onset of ES most commonly reported after acute exposure to pesticides, solvents
  • Pain and fatigue may be severely disabling
  • If exposures are constant, sensitivities may be “masked” and not recognized until…

The Tipping Point

Cumulative contamination leads to tipping points. For example:

  • we are surpassing the environmental tipping point with climate change
  • human body burden and cellular/organ injuries build up over time

Multiple exposures can cause multiple effects, but until overloaded, a person may not feel ill

Sensitivities to various substances are individual, but may “spread” to more types of exposures.