Toxicity of extracts from municipal wastewater to early life stages of Japanese medaka (Oryzias latipes) to evaluate removals of micropollutants by wastewater treatment.

Treatment of municipal wastewater reduces the concentrations of some pharmaceuticals and personal care products (PPCPs), hormones, and drugs of abuse. However, reduced concentrations of these micropollutants in wastewater may not correlate with reduced toxicity because transformations of micropollutants and/or the formation of disinfection by-products may generate toxic compounds. In the present study, we prepared extracts by solid phase extraction of samples collected from wastewater treatment plants (WWTPs) at various stages of treatment and tested these extracts for toxicity to early life stages of Japanese medaka (Oryzias latipes).

Biomarkers of oxidative stress and genotoxicity in livers of field-collected brown bullhead, Ameiurus nebulosus.

The objective of this investigation was to determine whether differences in a suite of biomarker assays in brown bullhead liver tissues could be detected and related to the pollution histories of two Ohio locations, one a reach of the Black River that had historically been severely impacted by the effluents of a coking plant, the other at Old Woman Creek, a freshwater estuarine research preserve. There were no gross differences in pathologies detectable in fish from either site, and the major difference found in bullheads at the two sites was in the relative liver weight (RLW). Differential responses of glutathione reductase, glutathione-S-transferase, Se-dependent glutathione peroxidase, Se-independent glutathione peroxidase, and oxidized glutathione have been reported between fish from contaminated and uncontaminated sites in other studies, but no such differences were observed in the present study.

Assessment of the effectiveness of composting for the reduction of toxicity and mutagenicity of explosive-contaminated soil.

Composting is being developed as an economical method for remediating explosive-contaminated soils and has been found to reduce the concentrations of target contaminants such as 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). However, whether environmental safety is improved by composting can be determined only by assessing the effects of the treated material on living organisms. In this study two bioassays, the Mutatox assay and the earthworm acute toxicity test, were used to evaluate the effectiveness of a pilotscale composting demonstration in reducing environmental hazard.