Agricultural dust isn't as serious a potential health problem as previously thought, according to an Agricultural Research Service scientist who has found a more accurate way to measure dust pollution from agricultural operations.

Agricultural engineer Michael Buser and colleagues at the ARS Cropping Systems Research Laboratory in Lubbock, Texas, have found that it is more accurate to use total suspended particulate (TSP) samplers to obtain a total concentration of dust, followed by a lab analysis of the sampling filter. The analysis determines particle-size distributions, as well as the percentage of the dust sample's total mass that is made up of smaller dust particles.

Buser evaluated U.S. Environmental Protection Agency (EPA) air samplers and found they tend to overestimate the amount of fine particles in agricultural dust. EPA has a network of ambient air samplers in place across the United States. To measure dust from an individual operation, a region's air quality agency may require the use of “stack” samplers.

Buser found that both types of samplers are very accurate for urban dust, which has a high proportion of fine dust particles. But they fall short when measuring agricultural dust, in which larger, less harmful particles tend to predominate.

As awareness grows regarding the human health dangers posed by fine dust particles, so does air quality regulation by federal and state governments. Farmers face the prospect of having to get air pollution permits before plowing.

Read more about this dust-sampling research in the May issue of Agricultural Research magazine, available online at: http://www.ars.usda.gov/is/AR/archive/may04/dust0504.htm