Social and ethical implications of claims for cancer hazards

Current data show that about 80% of human cancers can be traced to environmental causes. The majority of human cancers are associated with two main etiologic factors: smoking of cigarettes and diet, which account for most of the cancers in the respiratory tract, in the digestive tract, and in the endocrine sensitive and reproductive organs. The evidence for these multifactorial causes is both ipidemiologic and experimental. In recent years a number of lay and professional groups have expressed concern that the microcontaminants in our environment are responsible for cancer in man. Agitation, press releases, and statements before legislative and excutive government departments have made claims for cancer hazards which do not appear to rest on sound epidemiologic or experimental bases, yet these claims hav alarmed and indeed scared the public. Government agencies and industry have spent funds to investigate such claims. It appears that such actions not only divert valuable research funds and efforts into lines which do not seem to be fruitful in leading to a reduction in cancer risk for the main human cancers, but by falsely alarming the public, dilute serious efforts of cancer prevention with respect to the experimentally and epidemiologically established cancer risk.