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 food were used to determine time trends of organochlorine concentrations in adipose tissues from swine (4-8 months old) and bovines (non-dairy, 12-36 months) slaughtered between 1991 and 1997. Moreover, possible regional differences in concentrations were studied, as well as differences in concentrations depending on sex and age of the slaughtered animals. Multiple linear regression indicated that the concentrations of PCB, p,p'-DDE, HCB and alpha-HCH decreased by 4-17% per year, suggesting that the decline in organochlorine concentrations in the Swedish environment and biota reported during the 1970s-1990s also has occurred in meat-producing animals during the 1990s. The concentrations of PCB, DDE and HCB in bovines and PCB and DDE in swine were 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 animals. The organochlorine concentrations were higher in bovines than in swine, and declined faster in swine than in bovines. Moreover, the concentrations of CB 153 and p,p'-DDE were similar in bovines, but in swine the average concentrations of the two compounds differed two-fold. Apart from possible species differences in metabolism of organochlorines, this may be due to differences in the age at slaughter between swine and bovines, and differences in husbandry of the animals. In the latter case, swine are generally kept inside during their whole life span, whereas bovines are kept outside grazing during the summer period. Finally, a sex-dependent difference in concentrations was indicated in swine, but not in bovines. Our study shows that a lot of information can be 'extracted' from control program results.

Survey of consumption fish from Swedish waters for chlorinated pesticides and polychlorinated biphenyls.

In this survey eighty-seven samples of consumption fish comprising mainly of salmon, pike, eel, herring, whitefish, sea-trout, perch, pike-perch, mackerel, cod, flounder, plaice and sole collected between 1992-1993 have been analysed for the levels of chlorinated pesticides and polychlorinated biphenyls (PCBs). Considering the diversity in the sizes and assortment, locations, and time of catch, the samples are deemed to represent the normal fish variety available to the local people at various seasons of the year. Virtually all the samples contained CB-153 levels below the new established maximum limit of 0.1 mg/kg fresh weight. Results are compared with those obtained between 1985 and 1993. Neither the total PCB (on fat weight basis) nor CB 153 as a marker showed any clear trend for most of the fish species analysed, particularly for the short period 1991-1993. The pesticides, on the other hand, showed a rather good downward trend up till 1991; some of them seem to have virtually attained a steady state after 1991.

WHO collaborative breast feeding study. I. Organochlorine contaminants in individual samples of Swedish human milk, 1978--1979.

Individual samples of human milk collected in Uppsala at 3 months post-partum (18 samples) or 6 months post-partum (23 samples) were analysed for chlorinated insecticides and polychlorinated biphenyls (PCBs) by gas chromatography. The mean levels of the organochlorine compounds in the 3- and 6-month groups were similar. The mean content of DDE, the major metabolite of DDT, in all the samples was 54 micrograms/kg fresh weight (1.3 mg/kg on a fat basis) with a range of 8.4--220 micrograms/kg (0.49--3.0 mg/kg fat). The results confirm that the decline since 1967 in the levels of DDT and its metabolites in Swedish human milk reported by other authors is continuing. The levels of dieldrin and beta-hexachlorocyclohexane found are lower than those reported earlier in Sweden, whereas the levels of hexachlorobenzene are about the same. On the other hand, the levels of PCBs (mean 64 micrograms/kg, range 15--150 micrograms/kg, fresh weight, equivalent to 1.6 mg/kg, range 0.84--2.9 mg/kg, on a fat basis) are higher than those reported earlier in Swedish human milk. Although the calculated intake of the DDT complex (DDT + DDE + DDD) by some of the suckling infants exceeds the acceptable daily intake proposed by a FAO/WHO expert group, it does not constitute a reason for recommending any restrictions on breast feeding--for nutritional, immunological and other reasons it should be encouraged.