The release of Bisphenol A (BPA) from polycarbonate baby bottles into food and food simulants is reviewed in the perspective of the current intensive discussions on the risks of this substance. Potential factors that have been reported to influence the release of BPA are reviewed. Unlike most polymers polycarbonate is hydrolyzed under alkaline conditions by scale formation, residual alkaline detergents and boiled water. Data suggest that brushing of the bottle did not raise the release of BPA. Claims that used bottles release more BPA than new bottles and that mineral composition of the aqueous food simulant affect release could not be substantiated. There are indications that aminolysis of polycarbonate by milk and ethanolysis of polycarbonate by 50% ethanol might take place under relevant test conditions. The relatively few migration data following the test conditions of European food contact material legislation, comply with the specific migration limit. Two test conditions were identified that reflect real use and exposure, and might cause higher release of BPA compared to the test conditions of European food contact material legislation. Further detailed studies are necessary to verify whether these two exposure scenarios are more severe.

We studied the occurrence of halogenated organic compounds in soil air of rural areas. Chloroform appeared to occur in elevated concentrations compared to those in atmospheric air, while the concentrations of other chlorinated solvents were almost equal or lower than those in atmospheric air. We report conclusive evidence that chloroform is naturally produced from in situ Na37Cl enrichment field studies in soil top layers. The concentration of chloroform in soil air increased in deeper soil layers, but spiking of these soil layers by Na37Cl did not result in the formation of chloroform enriched with 37Cl. Bromodichloromethane shows similar concentration gradients in soil air as does chloroform. It seems also to be formed naturally in soil, even although this could not be confirmed by the Na37Cl enrichment field studies, because of the low concentration levels encountered. No detectable concentrations of chlorodibromomethane and bromoform in soil air were observed. In situ enrichment of a soil top layer by KBr showed that soil has the potential to form chlorodibromomethane and bromoform naturally. The formation mechanisms of the trihalomethanes are discussed, and a hypothesis is given to explain the natural formation in the soil top layer and the concentration gradients in soil air.

The natural formation of 4-MCP, 24/25-and 26-DCP, and 245-TrCP was detected in four selected areas of a rural Douglas fir forest where the humic layer was spiked in situ with a solution of Na 37 Cl and covered by an enclosure, after 1 year of incubation. Chlorinated phenols (CP) can be formed naturally from organic matter and inorganic chloride by either de novo synthesis or chloroperoxidase (CPO)catalyzed chlorination. The natural CP congeners were found to be present in high concentrations in soil compared to the other congeners, except for 245-TrCP which was present in a relatively low concentration. This study did not reveal which source, natural or anthropogenic, caused the observed concentrations. Some 20 chlorinated dibenzop-dioxins and dibenzofurans (CDD/F) were found to be formed naturally in soil of the Douglas fir forest; the formation of three 2,3,7,8-substituted congeners, 2378-TeCDD, 12378-PeCDD, and 123789-HxCDD, deserves special attention. A formation mechanism has been proposed which starts from naturally formed CP congeners and which probably involves peroxidase mediation. Chlorination of CDD/F congeners by the CPO-mediated reaction cannot be ruled out, but seems to be less likely due to the absence of several predicted congeners.

No abstract

No abstract