Constructed wetlands for mitigation of nonpoint agricultural runoff have been assessed for their ability to decrease potential toxicity from associated contaminants. After a simulated runoff event, constructed wetlands positioned in series were used to measure the effects of the organophosphate insecticide diazinon. Water, sediment, and plant samples from five sites were analyzed for diazinon c...

An important final step in development of an acute biotic ligand model for silver is to validate predictive capabilities of the biotic ligand model developed for fish and invertebrates. To accomplish this, eight natural waters, collected from across North America, were characterized with respect to ionic composition, pH, dissolved organic carbon, and sulfide. Tests were conducted with the clado...

A probabilistic risk assessment was conducted to evaluate the likelihood and ecological significance of potential toxic effects of diazinon in the Sacramento-San Joaquin system. Diazinon, an organophosphorus insecticide, is used in the Sacramento-San Joaquin River Basin as a dormant spray on almonds and other tree crops, as well as for other agricultural and urban applications. Diazinon and oth...

Wetland ecosystems have reduced ambient levels of various organic and metallic compounds, although their effectiveness on agricultural pesticides is not well documented. Five stations within each of two 10 x 50 m constructed wetlands (two vegetated, two nonvegetated) were selected to measure the fate and effects of methyl parathion (MeP). Following a simulated storm event (0.64 cm of rainfall),...

Propanil (3',4'-dichloropropionanilide) is one of the world’s most widely used rice herbicides, and it is extensively used in Arkansas, the leading rice producer in the United States (Webster and Gunnel1 1992). On average, the United States has applied approximately five kg/ha/year to about 70-100% of rice hectareacreage for the past two decades (US EPA 1987; Schlenk and Moore 1993). Arkansas, ...

The risk to adjacent aquatic systems posed by leachates from scrap tires used in engineering applications has not been characterized adequately. Toxicity testing, toxicity identification evaluation (TIE), and groundwater modeling were used to determine the circumstances under which tire shreds could be used as roadbed fill with negligible risk to aquatic organisms in adjacent water bodies. Elev...

The biocide, glutaraldehyde, is a potential environmental contaminant due to its widespread use in medical applications, off-shore oil extraction, and pulp mill processing. It has also been proposed as a candidate for treating the ballast water of vessels, which could result in a substantial increase in environmental release. To assess the potential for environmental impacts associated with glu...

The individual filtering rates of the cladocerans in Creteil Lake were measured in the daytime with 14C-labeled ChZorella during a seasonal survey. This mesotrophic, shallow, polymictic lake is characterized by small algae (~25 wrn) and cladocerans (< 1.3 mm). Multiple regression models were established for each genus and for all the cladocerans. Body length alone explained from 44 to 57% of th...

The main objectives of this work were to establish the behaviour of a ceria nanopowder in different ecotoxicological media commonly used in standardized aquatic ecotoxicity tests and consequently to assess the acute and chronic ecotoxicity in two microinvertebrates: Daphnia magna and Ceriodaphnia dubia and in a freshwater green algae: Pseudokirchneriella subcapitata. Different approaches to dis...