Environmental influences on the immune system and allergic reactions.

Environmental interactions with the immune system may result in two types of adverse outcomes: immunodeficiency and immunopathology. Serious immunodeficiency most commonly results from ionizing radiation or as a recognized side effect of iatrogenic drug therapy, usually cancer chemotherapy. At present there is little basis for believing that biologically significant suppression of immune competence in man results from more subtle interactions with environmental agents. On the other hand, environmentally triggered immunopathology is a source of considerable morbidity and mortality. Additional research is needed in the following areas: (a) basic mechanisms of immunopathological reactions; (b) development of methods for accurately implicating or excluding immunological mechanisms in the etiology of hypersensitivity states; (c) development of methods for assessing in advance the potential immunogenicity of new industrial chemicals and occupational allergens; (d) identification of the risk factors which predispose to immunopathological outcomes when individuals are exposed to sensitizing chemicals or other "natural" allergens.