Inorganic particles of agricultural origin

Our plain-English summary of Inorganic particles of agricultural origin, by K. Kay (Environmental Health Perspectives, 1974).

The study

• Author: K. Kay
• Journal: Environmental Health Perspectives
• Published: 1974;9:193-5
• Cited by: 1 article, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

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.

In plain English

This 1974 paper was a speculative commentary, not a study of people or new laboratory work. The author used U.S. Department of Agriculture production figures for 1965 to 1969 on mineral silicates used as dry carriers for pesticides. In 1969, about 374,000,000 lb of Fuller's earth, 107,000,000 lb of talc and soapstone, 55,000,000 lb of pyrophyllite, 51,000,000 lb of kaolin and 4,000,000 lb of bentonite were produced. The author singled out talc, soapstone and pyrophyllite combined, roughly 160,000,000 lb, as holding the potential cancer risk, because these minerals can contain anthophyllite, tremolite and chrysotile asbestos. The author noted that no one had apparently examined the asbestos content of pesticide preparations or the cancer experience of applicators. Citing a USDA figure that roughly 85% of pesticides are applied by air, the author reasoned that applicators and some nearby residents would inhale or swallow these carriers. The author concluded that it seemed reasonable to speculate this could create a cancer risk, at least locally. The author added that this could only be established by testing products, air, water and crops and by studying applicators and exposed residents.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Speculative commentary based on published U.S. production data and earlier studies by others; no new study of people or animals
• Who was studied: No people were studied. The paper used annual U.S. pesticide review data on production of mineral silicate pesticide carriers, 1965 to 1969, and discussed pesticide application personnel and nearby nonoccupational populations as potentially exposed groups
• Exposure: Mineral silicates used as dry carriers for pesticides (Fuller's earth, talc and soapstone, pyrophyllite, kaolin, bentonite, fireclay and stoneware clay). The author stated that talc, soapstone and pyrophyllite can contain anthophyllite, tremolite and chrysotile asbestos
• Main results:
  • U.S. production of pesticide carriers in 1969: about 374,000,000 lb of Fuller's earth, 107,000,000 lb of talc and soapstone, 55,000,000 lb of pyrophyllite, 51,000,000 lb of kaolin and 4,000,000 lb of bentonite
  • The author identified the combined talc, soapstone and pyrophyllite, roughly 160,000,000 lb, as the portion holding the potential cancer risk
  • The author noted that the asbestos content of trade pesticide preparations on mineral carriers, and the cancer experience of applicators, had apparently not been explored
  • Citing the U.S. Department of Agriculture, the author stated that roughly 85% of all pesticides are applied by air dissemination. The author reasoned that the carriers would be deposited in the lungs and stomachs of applicators and some nearby residents
• The authors' conclusion: The author concluded that it seemed reasonable to speculate that the yearly dissemination of vast quantities of talc, soapstone, and anthophyllite (as printed) in the United States may create a cancer risk, at least locally where pest control is carried out. The author stated that this could only be established by testing pesticide preparations for asbestos, sampling air, water and agricultural products, and studying cohorts of applicators and locally exposed residents
• Limitations the authors state:
  • The author described the paper as speculative
  • The author noted that particle size of the carriers and droplet size would influence how much mineral is deposited in the lung and gastrointestinal tract

Topics

Medical terms in this study, explained in our Lexicon: Silicate, Deposition, Anthophyllite, Tremolite, Chrysotile.

Related studies

• Increased risk of lung cancer in pesticide-exposed male agricultural workers — E. Barthel (1981)
• Inorganic particles in human tissues and their association with neoplastic disease — A.M. Langer (1974)
• Morphologic characterization of alveolar macrophages from subjects with occupational exposure to inorganic particles — T. Takemura, W.N. Rom, et al. (1989)
• Inorganic particle content of foods and drugs — W.V. Eisenberg (1974)
• Deposition pattern of inorganic particles at the alveolar level in the lungs of rats and mice — A.R. Brody, M.W. Roe (1983)
• Sialic acid mediates the initial binding of positively charged inorganic particles to alveolar macrophage membranes — J.E. Gallagher, G. George, et al. (1987)

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