“…The hitherto obtained endotoxin concentrations in the poultry farm environment present a rather consistent picture of such pollution which in individual countries on different continents reaches the following values (adjusted from EU/ m 3 to ng/m 3 using 10 EU equal to 1 ng as conversion factor): in Switzerland (18.99-1,634.8 ng/m 3 ) [45], United Kingdom (0.02-76.2 ng/m 3 ) [67,68], The Netherlands (45.22-469.3 ng/m 3 ) [46,67], Denmark (116.6-139.7 ng/m 3 ) [67], Sweden (10-1,003 ng/m 3 ) [48,66], France (3.5-315.6 ng/m 3 ) [64], Germany (1.98-6,434.7 ng/m 3 ) [67,69], Korea (0.16-251 ng/m 3 ) [54][55][56]70], Iran (5.4-23.6 ng/m 3 ) [57], and the USA (13.5-1,360 ng/m 3 ) [49,51,67]. Endotoxin concentrations measured in earlier research by the authors of this study, performed in poultry houses in southern Poland, were at much higher levels (0.04-8,364 ng/m 3 ) [58] than those noted in the current study.…”