Environmental Project, 988 – Multiple Chemical Sensitivity, MCS

Multiple Chemical Sensitivity, MCS

Annex B

Recommendations from three working groups under the NRC Workshop 1991 (Interagency report, 1998)

Clinical Evaluation working group:

Prospective longitudinal studies of exposure-based events are very important and should be performed.
A research priority should be the study of the adaptation - de-adaptation hypothesis, and the study should be pursued using an ECU. In addition, a second approach should evaluate individuals, over time, in their usual environment.
Selection of research subjects should be based on the specific hypothesis to be tested (e.g., symptom-based, exposure-based, and population-based).
Development of a database of chemicals, foods, drugs, and signs and symptoms reported to be associated with MCS is important.

Exposures and Mechanisms working group:

Studies should include a comprehensive history, including exposures, physical examination, and appropriate laboratory testing. Endpoints for response should include immunological, neurological, endocrinological, psychological, social, and other markers or measures.
Dose-response relationships should be examined.
Animal models should be developed that mimic the human syndrome.
Tissues obtained by biopsy and necropsy from patients, animals, and their controls should be evaluated for signs of pathologic change.

Epidemiology working group:

The magnitude of the problem caused by MCS in the general population should be determined.
Multi-centre, clinical case-comparison studies in occupational/environmental medicine clinics should be an early priority.
A broad set of symptom prevalences should be utilized that will allow flexible construction of a variety of case definitions.
Population-based methods, including construction of survey instruments, should be used to determine the basic descriptive epidemiology of certain multi-organ disorders that have been linked to MCS (e.g., systemic lupus erythematosus, scleroderma, multiple sclerosis, and somatization disorder).
Prompt studies of defined populations subjected to discrete and sudden chemical exposures should be enacted to assess the initiation and natural history of sensitivity syndromes involving environmental chemicals.
Normal ranges for new test modalities, including the sensitivity and specificity of screening techniques and biomarkers, should be determined.