benzofurans and 2-2--4-4--5-pentachlorodiphenyl-ether

Soil samples from five contaminated sawmill sites in Sweden were characterized with respect to chlorophenols (CP), chlorinated phenoxy phenols (PCPP, hydroxylated chlorinated diphenyl ethers), chlorinated diphenyl ethers (PCDE), chlorinated dibenzofurans (PCDF) and chlorinated dibenzo-p-dioxins (PCDD). The composition of chlorinated compounds in the soil samples was compared to the composition of two preservatives commonly used in the Scandinavian wood impregnation industry: the 2,3,4,6-tetrachlorophenol preservative called Ky-5 and the pentachlorophenol preservative Dowicide G. The levels of CPs in the soil samples ranged from 0.1 to 4500 mgkg-1 d.w., PCPPs from <0.15 to 940 mgkg-1 d.w., PCDEs from <38 to 6800 microgkg-1 d.w., PCDFs from 7.4 to 18000 microgkg-1 d.w. and PCDDs from 9.9 to 35000 microgkg-1 d.w. The resulting WHO-TEQ of PCDD/Fs in the soil samples ranged from 0.14 to 3000 microgkg-1 d.w. Despite a wide range of concentrations the congener compositions were similar within tetrachlorophenate and pentachlorophenate contaminated soils respectively. The contamination at each sawmill site may be linked to the use of either a tetrachlorphenol preservative, e.g. Ky-5, or a pentachlorophenol preservative, e.g. Dowicide G. Best-fit calculations were used to compare the chlorinated phenol contents of the preservatives to those of the soil samples. This revealed a positive correlation between the hydrophobicity (logKow) of contaminants and the ratio of their levels in soil to preservatives. The relative abundance of the chlorinated compounds varied greatly between the five sites studied, suggesting that their transport parameters differ substantially.

Topics: Benzofurans; Chlorophenols; Dibenzofurans, Polychlorinated; Ethers; Hydrocarbons, Chlorinated; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Polymers; Soil; Soil Pollutants; Sweden; Wood

Sediment and chironomid samples were collected from a river in the vicinity of and downstream from a closed chlorophenol production plant, and they were analyzed for polychlorinated dibenzo-p-dioxins and furans (PCDD/F) and polychlorinated diphenyl ethers (PCDE). Bioaccumulation of these compounds from the sediments by the oligochaeta, Lumbriculus variegatus, and semipermeable membrane devices (SPMDs) was studied in a 28-d bioaccumulation test. The sum concentrations of PCDD/Fs and PCDEs in sediments varied spatially, peaking at the site below the production plant, but the congener composition remained fairly constant throughout the river. The sum concentrations of chironomids, oligochaetes, and SPMDs all varied independently of sediment concentrations. Both invertebrates accumulated more PCDEs, whereas PCDD/Fs dominated in sediments and SPMDs. Despite the variable sum concentrations, similarities were observed in concentrations and compositions of individual congeners. A significant correlation was found between sediments and oligochaetes, and between oligochaetes and chironomids, for both PCDD/Fs and PCDEs. These results suggest that bioaccumulation of PCDD/Fs and PCDEs in invertebrates is nonselective. Furthermore, the laboratory bioaccumulation tests seem to yield relevant results. The SPMDs were found to give good predictions of the PCDD/F concentrations of sediments and oligochaetes. For PCDEs, the estimates were slightly poorer, but still useful for preliminary concentration assessments.

Topics: Animals; Benzofurans; Chironomidae; Dibenzofurans, Polychlorinated; Environmental Exposure; Ethers; Geologic Sediments; Membranes, Artificial; Oligochaeta; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Reproducibility of Results; Rivers; Soil Pollutants; Tissue Distribution