PCB and chlorinated pesticide concentrations in swine and bovine adipose tissue in Sweden 1991-1997: spatial and temporal trends

Results from the Swedish control programme regarding organochlorines in foo d were used to determine time trends of organochlorine concentrations in ad ipose tissues from swine (4-8 months old) and bovines (non-dairy, 12-36 mon ths) slaughtered between 1991 and 1997. Moreover, possible regional differe nces in concentrations were studied, as well as differences in concentratio ns depending on sex and age of the slaughtered animals. Multiple linear reg ression indicated that the concentrations of PCB, p,p'-DDE, HCB and a-HCH d ecreased by 4-17% per year, suggesting that the decline in organochlorine c oncentrations in the Swedish environment and biota reported during the 1970 s-1990s also has occurred in meat-producing animals during the 1990s. The c oncentrations of PCB, DDE and HCB in bovines and PCB and DDE in sc-vine wer e 1.4-3.8-fold higher in the southern parts of Sweden than in the northern parts of the country, indicating a regional difference in exposure of the a nimals. The organochlorine concentrations were higher in bovines than in sw ine, and declined faster in swine than in bovines. Moreover, the concentrat ions of CB 153 and p,p'-DDE were similar in bovines, but in swine the avera ge concentrations of the two compounds differed two-fold. Apart from possib le species differences in metabolism of organochlorines, this may be due to differences in the age at slaughter between swine and bovines, and differe nces in husbandry of the animals. In the latter case, swine are generally k ept inside during their whole life span, whereas bovines are kept outside g razing during the summer period. Finally, a sex-dependent difference in con centrations was indicated in swine, but not in bovines. Our study shows tha t a lot of information can be 'extracted' from control program results. (C) 2000 Elsevier Science B.V. All rights reserved.