[Physical, chemical and biological study of dust from large-scale pig farms]

Dust deposition in 16 halls of two large pig-fattening farms with dry or wet feeding systems was analyzed. In the halls with wet feeding the samples contained maximally 28 dust particles up to 10 micron and 17 particles up to 5 micron per cm3 of air, in the halls with dry feeding 220 particles smaller than 10 micron and 205 particles smaller than 5 micron per cm3 of air. The total amino acid content in the dust deposition was 17.440 +/- 1.820 g per 100 g of sample and the content of nitrogen compounds (N X X 6.25, %), was 24.170 +/- 2.910. The contents of chemical elements were as follows (mg per kg): zinc 448 +/- 151; manganese 109.9 +/- 49.5; copper 40.5 +/- 12.1; lead 4.77 +/- +/- 4.79; chromium 1.64 +/- 1.47; cadmium 1.61 +/- 1.62; mercury 0.36 +/- 0.39. Chlorinated carbohydrates and triazine and diazine herbicides were present in the following amounts (mg per kg): HCB 0.0023 +/- 0.0021; Lindane 0.0058 +/- 0.0079; DDE 0.0048 +/- +/- 0.0024; DDT 0.0065 +/- 0.0015; Simazine 0.060 +/- 0.020; Atrazine 0.083 +/- 0.059; Prometryn 0.093 +/- 0.040; Chloridazon 0.036 +/- 0.008; Terbutryn 0.085 +/- 0.029. The content of aflatoxin B1 was 12.89 +/- 9.31 micrograms per kg and the maximum amount of polychlorinated biphenyls was 8 mg per kg. Nitrovin was found out only in the dust of two halls: 4.0 and 7.9 mg per kg. The dust deposition also contained 21 genera and species of moulds, six species of mites, numerous saprophytic bacteria and, in some cases, Staphylococcus aureus. For the time being, no viruses have been detected in the dust samples.