Toxicity and composition of water-soluble fractions derived from neat creosote and creosote contaminated sediments

Creosote, a complex mixture of aromatic compounds (ACs), contaminates numerous sites in the US and elsewhere. A 48 h static renewal assay compared survival of the bay mysid, Mysidopsis bahia, exposed to water soluble fractions (WSFs) generated from two different sources: neat creosote and creosote contaminated sediments from a Virginia Super Fund site, where a facility producing creosote treated lumber was located. Both WSFs and parent materials from which the WSFs were generated (neat creosote and contaminated sediment) were analyzed using gas chromatography and mass spectrometry. LC50s (expressed in total identified AC) for the WSFs generated from neat creosote and sediment were: 180 ug/l and 700 ug/l, respectively. The creosote WSF contained > 70% low molecular weight nitrogen heterocyclics, which were below detectable limits in the sediment generated WSF. Nitrogen heterocyclics were also undetected in sediments, indicating that environmental losses of these compounds had occurred. This qualitative difference likely contributed to the neat creosote WSF`s four-fold greater toxicity.