Sensitivity to chemicals. By sensitivity we mean symptoms or signs related to chemical exposures at levels tolerated by the population at large that is distinct from such well recognized hypersensitivity phenomena as IgE-mediated immediate hypersensitivity reactions, contact dermatitis, and hypersensitivity pneumonitis.
Sensitivity may be expressed as symptoms and signs in one or more organ systems.
Symptoms and signs wax and wane with exposures. It is not necessary to identify a chemical exposure associated with the onset of the condition. Preexistent or concurrent conditions, e.g. asthma, arthritis, somatization disorder or depression, should not exclude patients from consideration.
The selection of subjects for research protocols will depend on the specific hypotheses to be tested. Identifiable populations include but are not restricted to:
Symptom or sign based: Patients with reactivity to environmental chemicals, either through serf-reporting or meeting case selection criteria.
Disease based: Patients with specific diseases that are suspected to be caused by or exacerbated by chemical exposures.
Exposure based: Groups characterized by a common exposure, such as workers at a specific factory, occupants of a particular building, or residents of a contaminated community.
Population based: Groups such as school children or a random community sample.
Appropriate comparison groups should be chosen in each case.
Research design and methods should be chosen as appropriate for each hypothesis. However, a minimum uniform data base across these groups needs to be developed which shall include the items in Table One. Specialized evaluations need to be developed for investigating specific hypotheses as listed in Table Two. It is beyond the scope of this committee to develop these in detail.
A research priority will be the study of the adaptation-deadaptation hypothesis, and this study must be conducted at an early stage because the outcome of this investigation will influence future study design. An environmental control unit, a clinical research unit in which subjects are housed for the control of exposures to foods and chemicals, should be developed to study the adaptation-deadaptation hypothesis. Other possible uses of units would include control of exposures and challenging subjects ha a well-defined environment. Use of this modality will be very complex, and its indications and use must be researched and tested in detail. Other modalities of testing such as challenge chamber studies will have utility, and also must be studied in detail.
Prospective longitudinal studies of exposure based events are very important and should be performed.