Water pollution and diseases in fish (an epizootiologic survey).

Three watersheds, varying from highly polluted or moderately polluted to essentially pollution-free, were surveyed to determine the frequency of fish disease. Over a five year period, it was found that a relationship existed between the level of pollution and frequency of disease. The occurrence rates of microbial and oncogenic diseases increased similarly in relation to increases in pollution in the waters. Since the water systems studied provide recreational opportunities for man, it is suggested that catching and subsequent ingesting of diseased fish from these waters present a health hazard.