Table 1

Annual average exposure to dust, organic dust components, and ammonia in the farming population (n = 1614) stratified by type of farm production

AgentExposure level†
AllLivestock tending‡
1 type⩾2 types
GM = geometric mean; GSD = geometric standard deviation.
†Geometric mean if not otherwise stated
‡Comparisons between groups by t test for unequal variance. All comparisons were significant at p<0.001 except *p<0.05.
§Not measured, set to 0 because sources of ammonia were lacking.
¶Exposure levels of farmers tending one type of livestock.
Total dust (mg/m3)
Fungal spores (106/m3)*3.4*
Bacteria (106/m3)9.23.7111.61223666.11116
Endotoxins (103 EU/m3)284.3473.439776.0264674
Ammonia (ppm)