Alameda County, Tecumseh, or Washington County cohorts could have an addition to follow-up surveys to probe for prevalence of conditions such as MCS.

Population based methods should also be used to determine the basic descriptive epidemiology of certain multi-organ conditions linked by some to MCS, such as SLE, scleroderma, MS and somatization disorder.

Epidemiology has an important role to play in supporting methods evaluation and development for test instruments used in clinical studies as well. Determination of normal ranges for new test modalities, establishing the sensitivity and specificity of screens and biomarkers, and the construction of survey instruments are examples where epidemiologic input is important and we recommend the inclusion of such expertise in these areas. The committee felt that the follow-up of a defined population subjected to a discrete and sudden chemical exposure (such as a spill or pesticide misapplication) would also be useful to assess the initiation of hypersensitivity to environmental chemicals and its natural history. It recommends that a protocol for evaluation and follow-up be developed and pre-tested and that resources be set aside for designated centers (e.g., environmental/occupational clinics) to respond rapidly in the event of an incident.