Publications by authors named "Katrina Leigh"

Historically, ecological risk assessments have rarely included amphibian species, focusing preferentially on other aquatic (fish, invertebrates, algae) and terrestrial wildlife (birds and mammal) species. Often this lack of consideration is due to a paucity of toxicity data, significant variation in study design, uncertainty with regard to exposure, or a combination of all three. Productive risk assessments for amphibians are particularly challenging, given variations in complex life history strategies.

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Triclosan, an antimicrobial compound used in personal care products, occurs in the aquatic environment due to residual concentrations in municipal wastewater treatment effluent. We evaluate triclosan-related risks to the aquatic environment, for aquatic and sediment-dwelling organisms and for aquatic-feeding wildlife, based on measured and modeled exposure concentrations. Triclosan concentrations in surface water, sediment, and biota tissue are predicted using a fugacity model parameterized to run probabilistically, to supplement the limited available measurements of triclosan in sediment and tissue.

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Triclosan is an antimicrobial compound found in many consumer products including soaps and personal care products. Most triclosan is disposed of down household drains, whereupon it is conveyed to wastewater treatment plants. Although a high percentage of triclosan biodegrades during wastewater treatment, most of the remainder is adsorbed to sludge, which may ultimately be applied to land as biosolids.

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Cause-effect sediment-quality benchmarks for the protection of benthic invertebrates are needed for polychlorinated biphenyls (PCBs) to support predictive risk assessments and retrospective evaluations of the causes of observed sediment toxicity. An in-depth evaluation of PCB aquatic toxicity and organic carbon partitioning was conducted to predict sediment effect concentrations using the equilibrium partitioning (EqP) approach. This evaluation was limited to invertebrate toxicity data, because PCBs may exert toxicity to invertebrates and fish via different toxicological mechanisms.

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