EN
Samples of settled dust were collected in 14 animal houses and examined for the presence of bacterial endotoxin with the Limulus (LAL) test and the gas chromatography - tandem mass spectrometry (GC-MSMS) technique, based on the detection of 3- hydroxy fatty acids (3-OH-FAs) as chemical markers of the endotoxin lipopolysaccharide. The median concentrations of the endotoxin in dust determined with LAL test in sheep sheds, poultry houses, and horse stables were 15,687.5 µg/g, 8,081.8 µg/g, and 79.3 µg/g, respectively, while those determined with the GC-MSMS technique were 868.0 µg/g, 580.0 µg/g, and 496.0 µg/g, respectively. Statistical comparison of the results yielded with LAL test and GC-MSMS technique revealed a weak correlation between both methods. Fatty acids with 14-16 carbon chains (3-OH-C₁₄ and 3-OH-C₁₆) were predominant in the settled dust of the facilities under study. In conclusion, endotoxin in the concentrations detected in this study may present a respiratory hazard to both livestock animals and farm workers. Thus, the prevention measures aiming to lower the exposure to endotoxin in livestock facilities are highly desirable.