| Abstrakt: |
Groundwater containing the process chemicals sulfolane (tetrahydrothiophene 1,1-dioxide) and diisopropanolamine (DIPA) has contaminated a wetland in the vicinity of a sour-gas natural gas processing facility. Of concern is the extent of which these contaminants are taken up by vegetation and the associated risk to wildlife that may eat the plants. All sampled wetland plants contained detectable levels of sulfolane and DIPA. Sulfolane was distributed predominantly in portions of the vegetation above the surface, such as sedges (Carex spp.) flower heads (e.g., 430 ± 80mgkg[SUP-1] wet tissue mass), whereas the levels of DIPA were more evenly distributed and generally lower throughout the plants (e.g., cattail (Typha latifilia) roots, 9.4±1.7 mg kg[SUP-1]; sedges flower heads, 16±3mgkg[SUP-1]). Sulfolane may, therefore, translocate to a greater extent than DIPA in wetland vegetation. A wide range of concentrations covering a factor of 10 was observed for both contaminants in plant tissue collected within close proximity (5-50 cm) of each other. The dose rates received by wildlife eating the plants will thus depend on which parts of specific plants are consumed. Site-specific factors, such as the heterogeneity in the levels of the contaminants, density and type(s) of biomass (e.g., roots, stem, leaves, berries) of specific vegetation in the wetland, must therefore be accounted for to properly assess the fate of sulfolane and DIPA in contaminated wetlands. [ABSTRACT FROM AUTHOR] |
