Electrostatic dust collectors compared to inhalable samplers for measuring endotoxin concentrations in farm homes

Paired electrostatic dust collectors ( EDC s) and daily, inhalable button samplers ( BS ) were used concurrently to sample endotoxin in 10 farm homes during 7‐day periods in summer and winter. Winter sampling included an optical particle counter ( OPC ) to measure PM 2.5 and PM 2.5–10 . Electrostatic dust collectors and BS filters were analyzed for endotoxin using the kinetic chromogenic Limulus amebocyte lysate assay. Optical particle counter particulate matter ( PM ) data were divided into two PM categories. In summer, geometric mean (geometric standard deviation) endotoxin concentrations were 0.82 EU /m 3 (2.7) measured with the BS and 737 EU /m 2 (1.9) measured with the EDC . Winter values were 0.52 EU /m 3 (3.1) for BS and 538 EU /m 2 (3.0) for EDC s. Seven‐day endotoxin values of EDC s were highly correlated with the 7‐day BS sampling averages ( r  = 0.70; P  <   0.001). Analysis of variance indicated a 2.4‐fold increase in EDC endotoxin concentrations for each unit increase of the ratio of PM 2.5 to PM 2.5–10 . There was also a significant correlation between BS and EDC s endotoxin concentrations for winter ( r  = 0.67; P  <   0.05) and summer ( r  = 0.75; P  <   0.05). Thus, EDC s sample comparable endotoxin concentrations to BS , making EDC s a feasible, easy to use alternative to BS for endotoxin sampling.