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Exposures in agricultural populations affecting respiratory health.

Doekes-G; Douwes-J; Dowling-K; Heederik-D; Kullman-G; Lawson-B; Nieuwenhuijsen-M; Olenchock-S; Seiber-J; Thorne-P
Am J Respir Crit Care Med 1998 Nov; 158(5):S4-S18
Farmers and other individuals involved in agriculture have potential inhalatory exposures to a very wide range of agents: inorganic dust from the soil; organic dust containing microorganisms, mycotoxins, or allergens; decomposition gases; pesticides; etc. These exposures occur when dealing with animals, harvesting, processing or storing grains or other plant matter, or when the soil, plants, or stables are treated with chemical agents such as pesticides and disinfectants. This section gives an overview of the scientific information available on exposure levels to these agents and the population exposed, the available (legal and other) health-based exposure standards to evaluate exposure to these agents in the work environment, and possibilities for exposure reduction. For most of the chemical agents, reliable standards exist for the evaluation of exposure to these agents, and exposure levels that occur in agricultural settings are reasonably well documented. For most biologic agents, a more limited insight exists. Analytical techniques for several biologic agents have become only recently available, and serious standardization issues have not been resolved. Generally accepted exposure limits are not available for most biologic agents. Nevertheless, it is clear from this document that farmers are often exposed to high levels of chemical and biologic agents, often above existing recommended limits. Preventive strategies have been developed for some specific exposures but are not widely available for most specific exposures.Agriculture involves a very wide variety of activities in diverse geographic and climatic settings. In small, often family-based farms, there may be little task separation, resulting in a wide range of potential occupational exposures for all involved. Swine farmers, for example, are exposed to animal danders, disinfectants, and other chemical substances, organic feed particulates, bacteria originating from feces, and such gases as NH3 emanating from manure. Exposure patterns may be cyclic, related to growth cycles of animals or to seasonal variations. Fruit growers' exposure to pesticides, for example, is concentrated in the summer months, the type of pesticide depending on crop type and climate. The exposure of farmers involved in the same or similar activities may also differ between countries, due to differences in climate as well as regional agricultural practices. Fruit farmers in northern countries may use more fungicides, because a humid climate encourages significant fungal growth, while farmers in southern areas may make greater use of insecticides. Dairy farmers experience higher exposures to dust and gases during the winter months, when most activities take place indoors and ventilation rates are reduced to effect energy conservation. In contrast to many occupational settings where exposures are relatively constant, farming involves a number of high-exposure tasks that, while performed infrequently, carry a high disease burden. Examples include grain bin clean out, manure pit cleaning, and silo uncapping. These examples illustrate farmers' exposure to a range of chemical and biologic agents and variable nature of these exposures in terms of time and place.
Agricultural-industry; Agricultural-workers; Agriculture; Occupational-diseases; Occupational-hazards; Occupational-health; Inhalation-studies; Respiratory-irritants; Hazards; Inhalation-studies; Inorganic-chemicals; Organic-dusts; Microorganisms; Mycotoxins; Fungi; Fungicides; Endotoxins; Allergens; Allergies; Gases; Chemical-composition; Pesticides; Disinfectants
Publication Date
Document Type
Journal Article
Funding Amount
Funding Type
Cooperative Agreement; Agriculture
Fiscal Year
Identifying No.
Issue of Publication
NIOSH Division
Source Name
American Journal of Respiratory and Critical Care Medicine
Performing Organization
University of California - Davis
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division