Multiple chemical sensitivity: treatment and followup with avoidance and control of chemical exposures.

Reducing unnecessary chemical exposures, particularly pesticides and other petrochemicals, shows promise for reducing illness episodes in the chemically sensitive. Because similar types of exposures have been associated with the onset of chemical sensitivity, such precautions could have wider preventive value for the rest of society as well. Many uses of chemicals have dubious social benefits, and reduced use should be achievable. The chemical industry will likely bitterly contest the reduced use of chemicals because it stands to lose substantial sales. Compensation and liability insurance carriers also stand to lose if the environment is found problematic, rather than individual psychology, for example. Professionals should also recognize conflicts of interest for the chemical and insurance industries by openly acknowledging funding sources for research. The author believes that research on chemical sensitivity that blames the psyche of the victim rather than the chemical will more likely be funded by the insurance or chemical industry than will other research. Study designs should be developed in an atmosphere removed from financial conflicts of interest. This means a substantially larger role for government funding of research on chemical sensitivity to avoid biasing the knowledge base by financially interested parties. The time is critical for government funding of research on chemical sensitivity because the illness is being defined and characterized. If preliminary research is flawed by improper design and focus, our understanding of the problem could be delayed for years.

Threshold limit values: historical perspectives and current practice.

A 1989 Occupational Safety and Health Administration standard mandates that workplace air concentrations be held below new permissible exposure limits for 376 substances. As more than 350 of these limits came from the 1987 list of "Threshold Limit Values" (TLVs), the medical basis of the TLVs is of direct importance to the health of millions of workers. However, the TLV development process has been gravely flawed by lack of scientific rigor, inadequate medical input, and lack of attention to financial conflicts of interest. The adoption by the Occupational Safety and Health Administration of many poorly supported values as permissible exposure limits reflects also the underutilization of industrial medicine in identifying health effects of exposures below the TLVs. It is thus the responsibility of the medical profession to act on the presumption that the TLV permissible exposure limits are unsafe limits until a sound underlying body of medical and scientific literature exists for the substances on the list. It is industry's responsibility to commit itself seriously to medical and exposure monitoring and to begin to remedy the knowledge deficit that exists about the less immediate health effects of most industrial materials.

Corporate influence on threshold limit values.

Investigations into the historical development of specific Threshold Limit Values (TLVs) for many substances have revealed serious shortcomings in the process followed by the American Conference of Governmental Industrial Hygienists. Unpublished corporate communications were important in developing TLVs for 104 substances; for 15 of these, the TLV documentation was based solely on such information. Efforts to obtain written copies of this unpublished material were mostly unsuccessful. Case studies on the TLV Committee's handling of lead and seven carcinogens illustrate various aspects of corporate influence and interaction with the committee. Corporate representatives listed officially as "consultants" since 1970 were given primary responsibility for developing TLVs on proprietary chemicals of the companies that employed them (Dow, DuPont). It is concluded that an ongoing international effort is needed to develop scientifically based guidelines to replace the TLVs in a climate of openness and without manipulation by vested interests.