Organic dust exposure from compost handling: Response of an animal model.
Frazer-DG; Jones-WG; Petsonk-EL; Kullman-GJ; Barger-MW; Afshari-A; Jones-T; Castranova-V
Am J Ind Med 1993 Oct; 24(4):375-385
The pulmonary effects of a compost dust were studied in guinea-pigs. English-short-hair-guinea-pigs were exposed to 0 or 30 milligrams per cubic meter (m3) dust generated from leaf and wood compost for 4 hours. The dust concentration was chosen to simulate spore counts, 2x10(9) spores/m3, measured previously in dust clouds at a compost site where a landscape architect had developed acute respiratory symptoms after he had shoveled the compost. The effects on breathing rate were monitored for 18 hours by plethysmography. Selected animals were killed immediately and 18 hours after exposure and the lungs were removed and weighed. The degree of lung hyperinflation was determined by measuring the amounts of gas trapped in the lungs. The lungs were then lavaged. Lavagate total and differential cellularity was determined. The alveolar macrophages were isolated from the lavage fluid. The extent of spontaneous and opsonized zymosan stimulated superoxide-anion (O2-) release by the macrophages was determined. Compost dust caused a 17% increase in breathing rate immediately after exposure. The maximum increase, 36%, occurred 12 to 18 hours post exposure. The amount of trapped gas was increased by 120% immediately after exposure. The lungs were still hyperinflated by 53% 18 hours after exposure ended. Compost dust caused a 5.5 fold increase in lavagate granulocyte count immediately after exposure. By 18 hours post exposure, the granulocyte count was 16 times the control value. The concentrations of the other cell types were not significantly affected by dust exposure. Spontaneous O2- release by macrophages was not affected by dust exposure. Zymosan stimulated O2- release was increased by 65% after 18 hours. The authors conclude that exposure of guinea-pigs to the compost dust induces increases in breathing rate, airway obstruction, granulocyte infiltration, and stimulation of O2- release from alveolar macrophages treated with zymosan. These data indicate that guinea-pigs are a suitable model for assessing the effects of inhaled leaf and wood compost.
NIOSH-Author; Organic-dusts; In-vivo-studies; Wood-dusts; Laboratory-animals; Inhalation-studies; Pulmonary-function-tests; Lung-cells; Physiological-response; Respiratory-system-disorders; Airway-obstruction
American Journal of Industrial Medicine