[1] They often have a background in the field of allergy or otorhinolaryngology, and the theoretical approach is derived in part from classic concepts of allergic responses, first articulated by Theron Randolph and developed by Richard Mackarness.
[2] Clinical ecologists support a cause-and-effect relationship for non-specific symptoms reported by some people after low-dose exposure to chemical, biologic, or physical agents.
[1] Although some of the mainstream medical community continue to reject these claims, the concept is gaining some recognition under the modern and more clearly articulated classification of environmental medicine.
If wanted, they may obtain an extralegal certification or membership from the unregulated private organization American Academy of Environmental Medicine upon payment of a fee.
The pragmatic determination of MCS includes four elements: (1) the syndrome is acquired after a documentable environmental exposure that may have caused objective evidence of health effects; (2) the symptoms are referable to multiple organ systems and vary predictably in response to environmental stimuli; (3) the symptoms occur in relation to measurable levels of chemicals, but the levels are below those known to harm health; and (4) no objective evidence of organ damage can be found.
Several National Academy of Sciences workshops and Research Councils into Gulf War syndrome have validated the idiosyncratic effect low chemical exposure on sensitized individuals.