Equilibrium Polyethylene Passive Sampling of Soil Gas VOC Concentrations: Modeling, Parameter Determinations, and Laboratory Testing.

The use of low-density polyethylene (PE) sheets as equilibrium passive soil gas samplers to quantify volatile organic compounds (VOCs) such as benzene, toluene, ethylbenzene, and xylenes, and chlorinated solvents ( trichloroethene and tetrachloroethene) in unsaturated subsurface environments was evaluated modeling and benchtop testing. Two methods were devised to quantify such VOCs in PE. Key chemical properties, including PE-water () and PE-air () partition coefficients and diffusivities in the PE (), were determined.

Relevance of the bioavailable fraction of DDT and its metabolites in freshwater sediment toxicity: New insight into the mode of action of these chemicals on Dictyostelium discoideum.

In this work, the toxicity of lake sediments contaminated with DDT and its metabolites DDD and DDE (collectively, DDX) was evaluated with widely used toxicity tests (i.e., Vibrio fischeri, Daphnia magna, Pseudokirchneriella subcapitata, and Lumbriculus variegatus) and with the social amoeba Dictyostelium discoideum, a model organism that is also suitable for studying pollutant-induced alterations at the molecular and cellular levels.