[Evaluation and occurrence of high-risk pollutants in animal feed factories]

Concentrations of some hazardous pollutants were studied in dust deposit samples (n = 30) taken from the indoor equipment of two feed mixture plants (FMP) in Hodonín district in 1995 and 1996; the pollutants involved mercury, cadmium, lead, hexachlorobenzene (HCB), alpha and beta hexachlorocyclohexane (HCH), lindane (gamma HCH), DDT sum, DDT isomers, polychlorinated biphenyls (Delor 103, Delor 106, PCB indicator congeners). The statistically significantly higher (P < 0.01) average concentration of mercury (0.028 mg/kg) was recorded in dust depositions (n = 15) in FMP K. in comparison with FMP R. Increased concentrations of cadmium (more than 0.5 mg/kg) were determined in dust depositions in FMP K. in 1 sample (0.582 mg/kg), of lead (more than 5.0 mg/kg) in 1 sample (7.540 mg/kg), of HCB (more than 0.01 mg/kg) in two samples (0.034 and 0.036 mg/kg), of beta HCH (more than 0.005 mg/kg) in 4 samples (0.021; 0.022; 0.023 and 0.046 mg/kg), higher DDT sum (more than 0.05 mg/kg) were determined in FMP K. in 3 samples (0.072; 0.085 and 0.190 mg/kg) and of PCB sum (more than 0.05 mg/kg) in 4 samples (0.054; 0.059; 0.074 and 1.085 mg/kg). In comparison with FMP K., dust depositions (n = 15) in FMP R. showed the statistically significantly higher (P < 0.05) average concentration of lead (5.241 mg/kg). Increased concentrations of lead were determined in dust depositions in FMP R. in 7 samples (5.040; 5.230; 6.760; 7.590; 7.620; 8.450 and 15.650 mg/kg), of beta HCH in 7 samples (0.006; 0.008; 0.022; 0.024; 0.026; 0.029 and 0.049 mg/kg), higher DDT sum were recorded in 3 samples (0.053; 0.074 and 0.126 mg/kg) and higher PCB sum in 8 samples (0.057; 0.066; 0.101; 0.134; 0.164; 0.426; 0.821 and 1.202 mg/kg). The highest average concentration of hazardous pollutants in dust depositions (n = 30) in both feed mixture plants was determined in lead (4.122 mg/kg), in a descending order followed by PCB sum (0.151 mg/kg), cadmium (0.127 mg/kg), DDT sum (0.030 mg/kg), mercury (0.019 mg/kg), lindane (0.013 mg/kg), beta HCH (0.010 mg/kg), HCB (0.004 mg/kg and alpha HCH (0.001 mg/kg). Out of PCB indicator congeners, dust depositions contained the highest quantities of congener 138 (0.022 mg/kg), congener 180 (0.018 mg/kg) and congener 153 (0.015 mg/kg). Isomer p,p-DDT was dominant in dust depositions among DDT isomers (0.019 mg/kg). Dust depositions sampled from the indoor equipment of feed mixture plants are a promising indicator of produced feed mixtures contamination with hazardous pollutants. To seek sources of feed mixtures contamination is a permanent task of veterinary service.