Inorganic particles of agricultural origin.

Substantial quantities of mineral silicates are used as carriers for agricultural pest control agents. Most of this material is applied by air dissemination, either dry or as a droplet spray. Therefore, pulmonary and gastric deposition of the mineral carriers (and active agents) will occur among pesticide application personnel and some proportion of the general population in the vicinity of pest control operations-to the extent that particle size of the disseminated material is below the critical 5mum respirable diameter. Furthermore, ingestion of particulates deposited on food crops may be expected as well as mineral finding its way into drinking water supplies. It has been found that the silicates widely used in America can contain three forms of asbestos, anthophyllite, tremolite, and chrysolite. Of these, anthophyllite and chrysotile have been found associated with a neoplastic outcome after many years of exposure. It is therefore proposed that comprehensive mineralogical investigation of pesticide carriers is warranted, including epidemiological and clinical study of formulation and application personnel as well as exposed nonoccupational populations.