Relationship between biodegradation and sorption of phthalate esters and their metabolites in natural sediments.

Regulatory evaluations of commercial chemicals in Canada, the United States, the European Union, and other countries aim to identify biodegradation rates of chemicals in natural soils and sediments. However, commonly used biodegradation testing methods are limited in their capacity to determine biodegradation rates under natural environmental conditions. As a result, widely varying biodegradation rates have been reported for many very hydrophobic substances.

Incorporation of 28-d Leptocheirus plumulosus toxicity data in a sediment weight-of-evidence framework.

A series of side-by-side trials were conducted to evaluate the variability of 28-d Leptocheirus plumulosus amphipod toxicity test data using existing and modified test protocols. One modification included examination of the influence of press-sieving on the sediment chemistry and the toxicity data. Press-sieving sediment did not reduce the variability in the toxicity data and also contributed uncertainty to the chemistry data.

Global geographic differences in marine metals toxicity.

Biochemical reaction rates, metabolic rates, and other rates of biological activity increase exponentially with temperature. It has thus been hypothesized that toxicity to chemical contaminants may increase from polar to temperate to tropical species; however, until recently, polar data to test this hypothesis were not available. This study examined differences in the acute sensitivities of marine invertebrates to four metals (Cu, Cd, Zn, Pb) for polar, temperate and tropical species; data deficiencies for polar regions prohibited comparisons using chronic end-points or other chemicals.