Pesticides and Non-Hodgkin's Lymphoma1

The incidence of non-Hodgkin's lymphoma (NHL) has increased over 50% in the last IS years. This paper reviews the possible role of pesticides in this increase. While small increases in risk of NHL among farmers have been observed in general occupational surveys, recent studies focusing on specific pesticides have observed much larger risks. Frequent use of phenoxyacetic acid herbicides, in particular, 2,4-dichlo rophenoxyacetic acid, has been associated with 2to 8-fold increases of NHL in studies conducted in Sweden, Kansas, Nebraska, Canada, and elsewhere. Canine malignant lymphoma has also been associated with dog owner use of 2,4-dichlorophenoxyacetic acid and commercial lawn pesticide treatments. There are much fewer data linking NHL to other types of pesticides, but triazine herbicides, organophosphate insecti cides, fungicides, and fumigants have also been associated with in creased risk of NHL. Pesticide exposures are not limited to agricultural populations but are widespread in the general population through use on lawns, golf courses, rights-of-way, and elsewhere. Since the use of pes ticides, particularly phenoxy herbicides, has increased dramatically pre ceding and during the time period in which the incidence of NHL has increased, they could have contributed to the rising incidence of NHL.