Creating an Indoor Environmental Problem from a Nonproblem: A Need for Cautious Evaluation of Antibodies Against Hapten-Protein Complexes

An epidemic of illness in three schools in New York State occurred in early 1983. An epidemiological review of the problem led to the conclusion that some of the symptoms could have been explained by irritant reactions to boiler exhaust gases but that a major factor was likely public concern about environmental contamination and heightened awareness of common minor symptoms and of exacerbations of chronic illnesses. Diphenylmethane diisocyanate (MDI) from polyurethane insular ion had previously been suspected as a potential cause. An earlier investigation had found low levels of anti MDI-human serum albumin in a small number of subjects who did not have typical symptoms of identified MDI or other hypersensitivity syndromes. Similar antibodies were found in two of nine unaffected children in Chicago, who served as a comparison group. The identification of these antibodies, however, was inappropriately used to support the idea of a school contaminated with MDI in spite of the absence of detectable MDI in the environment. The availability of highly sensitive immunoassays should not be inappropriately used to accelerate the fear of environmental toxins when there is no clinical correlation.