Accurate risk assessment of secondary poisoning by persistent organic pollutants (POPs) in top predators is possible but requires multidisciplinary input from wildlife ecology, ecotoxicology, and analytical chemistry. Because of the transfer of POPs up the food chain, traditional approaches to exposure assessment based on POPs in abiotic compartments or organisms low in the food chain can make the assessment of risk to top predators complicated. For more direct, accurate, and site-specific methods of assessing the risks of secondary poisoning of top predator by POPs, we classify 2 main approaches: diet based and tissue based. Exposure assessment via the diet-based approach requires samples of the predator's diet and measured concentrations in the prey items, realistic estimates of dietary composition, and ingestion rates. The even more direct, tissue-based approach uses measured POP concentrations in tissues of top predators to determine internal exposure coupled with tissue-based effect concentrations (or biological responses measured via biomarkers) to determine risk. The advantage of these methods is that uncertain estimates of POPs transfer to top predators from lower trophic levels are avoided. In practice, the availability of dose–response data and internal exposure–response relationships for POPs in top predators is limited, so these may have to be extrapolated from surrogate species. In this paper we illustrate and evaluate the potential of diet-based and tissue-based risk assessment approaches with case studies and demonstrate that appropriate methodologies significantly reduce the uncertainty in risk assessments of POPs.

The most likely entry pathways of veterinary pharmaceuticals to the environment are via slurry or manure from intensively reared animals to soil and via dung or urine from animals grazing on pasture. These pathways may result in contamination of surface water via runoff or leaching and drainage. Direct entry into water may occur by defecation by pasture animals or by companion animals. In addition, application of medicines for aquaculture is important for a limited number of veterinary medicinal products. For a large number of veterinary medicinal products, consistent data on the environmental risk have never been generated. In this project, a simple risk-based ranking procedure was developed that should allow assessing the potential for environmental risks of active substances of veterinary medicinal products. In the European Union approximately 2000 products containing 741 active substances were identified. In the prescreening step and in agreement with the technical guidelines released by the European Medicines Agency, 294 natural substances, complex mixtures, and substances with low expected exposure were exempted from the ranking procedure. For 233 active substances, sufficient information was collated on 4 exposure scenarios: Intensively reared animals, pasture animals, companion animals, and aquaculture. The ranking approach was performed in 4 phases: 1) usage estimation; 2) characterization of exposure to soil, dung, surface water, and aquatic organisms depending on exposure scenarios; 3) characterization of effects based on therapeutical doses; and 4) risk characterization, which is the ratio of exposure to effects (risk index), and ranking. Generally, the top-ranked substances were from the antibiotic and parasiticide groups of veterinary medicines. Differences occurred in the ranking of substances in soil via application to either intensively reared or pasture animals. In intensive rearing, anticoccidia, for example, are used as feed-administered medicines (feed additives) in comparatively large doses over a long time. For pasture animals, these substances are used less, if at all, and therefore receive lower ranks. Besides that, the risk indices for the aquatic compartment are large for substances used in aquaculture or applied to companion animals. In conclusion, the ranking scheme developed for this project provided a scientifically based and pragmatic means of assessing the relative priority of veterinary medicines for further detailed risk assessment. The outcome of this project will support pharmaceutical industries and competent authorities when seeking authorization for market applications of veterinary pharmaceutical products.

Current testing guidelines for pesticide registration for the protection of nontarget plants calls for the use of sterilized, standardized soil consisting of primarily sandy loam, loamy sand, loamy clay, or clay loam that contains up to 3% organic matter. Low organic matter soils can be difficult to manage in a greenhouse setting because when soils dry, they contract, causing impeded water infiltration, or when overwatered, poor drainage increases the chances of anaerobic conditions. The purpose of this study was to determine if the results for the vegetative vigor test differed when using either natural or artificial soils. The herbicide sulfometuron methyl was applied 14 d after emergence at 0.1 and 0.0032 of the suggested field application rate. Six plant species were tested, 4 of the common test species, Zea mays (corn), Glycine max (soybean), Avena sativa (oat), and Lactuca sativa (lettuce), and 2 native plants of the Willamette Valley, Oregon prairie, Bromus carinatus (California brome) and Ranunculus occidentalis (western buttercup). Herbicide application rate was the most significant factor in the experiment regardless of soil type. The different soils generally produced different results, even though the 2 native soils, one from Oregon and the other from Maryland, are both acceptable soils for the pesticide registration tests. The plants grown on artificial soil produced results generally between the Oregon and Maryland soil results. This study indicates that artificial soils may produce results similar to or more sensitive than soils currently used in the vegetative vigor test.

Ambient concentrations of metals in surface waters have become an important consideration when establishing water quality criteria and conducting risk assessments. This study sought to estimate amounts of copper that may be released into fresh and estuarine waters considering ambient concentrations, toxicity thresholds, and bioavailability. Cumulative distribution functions of ambient copper concentrations were compared statistically for individual sites within 14 surface waters of North America and Europe to identify differences among mean distribution variables (e.g., slopes, intercepts, and inflection points). Results illustrated that the majority of distributions among sites differed significantly. These differences illustrate the variability in ambient copper concentrations in surface waters due to geographic location, regional geology, and anthropogenic influence. Additionally, surface water quality data were used for streams and lakes in Chile, Europe, and North America (including 1 saltwater estuary) to estimate bioavailable copper concentrations in ambient surface waters (based on predictions using biotic ligand models). The amount of dissolved metal that could be added to surface waters without exceeding toxicity thresholds was calculated by subtracting ambient surface water concentrations from chronic (reproduction) no-observable-effect concentrations (NOEC) for Daphnia magna using the freshwater data and 48-h median-effect (normal shell development) concentrations (EC50) for Mytilus edulis using that for saltwater. Because ambient dissolved copper concentrations were, on average, only a small fraction (18%) of predicted effects threshold, an average of 14 ± 17 μg/L (±SD) of copper could be added before exceeding the D. magna chronic NOEC or the M. edulis EC50. However, several sites were identified as having ambient copper concentrations in excess of these toxicity thresholds. The risks posed by copper to sensitive indicator species in surface waters can now be readily computed to facilitate site-specific consideration of point and nonpoint sources of metal.

Since the onset of plutonium production at the US Department of Energy's Hanford Site, several hundred cubic meters of carbon tetrachloride (CCl₄) has been discharged to the soil column, resulting in a dispersed CCl₄ vapor plume in the subsurface. Inhalation of volatile organic chemicals could be an important exposure pathway for burrowing animals there. Historical levels of CCl₄ in soil pore gas exceeded the inhalation ecological screening level for CCl₄. Thus, the inhalation exposure pathway was evaluated with the use of artificial burrows deployed at locations that had elevated levels of CCl₄ in soil gas. Artificial burrows were designed on the basis of information available for Hanford Site fossorial wildlife. After installation, the artificial burrow atmosphere was sampled and analyzed for CCl₄ and its degradation products: chloroform, methylene chloride, and chloromethane. Sampling was repeated on 3 occasions to capture varying atmospheric conditions affecting exposure concentrations. CCl₄ was detected in the artificial burrows, and maximum exposures were observed during relatively low barometric conditions. The highest CCl₄ detections were still well below the inhalation-based ecological screening level and CCl₄ degradation products were never detected. This study shows that artificial burrows are an efficient method for obtaining relevant exposure data and illustrates the utility of directly measuring the medium for exposure under ecologically realistic conditions.

The impacts of land disturbance on streams have been studied extensively, but a quantitative mechanism of stream degradation is still lacking. Small changes in land use result in changes in physical and chemical characteristics in the stream, which significantly alter biotic integrity. The objective of this study was to quantify the mechanisms of aquatic ecosystem degradation in streams impacted by watershed urbanization. By quantifying the development level and the changes in the physical parameters of receiving streams, the effects of land use change can be illustrated in a conceptual model and evaluated using a traditional ecological risk assessment framework. Three 1st-order streams draining catchments undergoing varying stages of land development were examined in the upper Piedmont physiographic province of South Carolina, USA. A disturbance index was developed to quantify the changes in land use on a monthly basis. This normalized disturbance index (NDI) was quantitatively linked to an increase in the percentage of impervious cover, stormwater runoff, storm-event total suspended solid (TSS) concentrations, and the North Carolina biotic index (NCBI). The NDI was inversely related to a decline in habitat, median bed-sediment particle size, and benthic index of biotic integrity (BIBI). Unlike the percentage of impervious cover, the NDI facilitated the development of strategies for multiple scales of regulation. Predictive multivariate regressions were developed for storm-event TSS concentrations, the BIBI, and the NCBI. These regressions can be used to develop improved regulations for the effects of development and can lead to better implementation of best management practices, improved monitoring of land use change, and more sustainable development.

This study examines how pollutant linkage of contaminants will be influenced by predicted changes in precipitation and subsequent rainfall erosion of soils and spoils in the United Kingdom during the 21st century. Two contrasting regional climates were used in conjunction with 2 extreme emissions scenarios (low and high greenhouse gas emissions) to run the Revised Universal Soil Loss Equation 2 (RUSLE2) model for a case study that represents a high risk of pollutant linkage through water erosion. Results for the 2 scenarios and the 2 regions showed a significant and gradual increase in erosion rates with time as a consequence of climate change, by up to 32% for the southwest and 6.6% for the southeast regions by the 2080s. Revegetation of the site showed a dramatic reduction in predicted future amounts of sediment production and subsequent contaminant movement, well below existing levels. Limitations and future improvements of the methodology are discussed.

The types and quality of data needed to determine relationships between chronic whole effluent toxicity (WET) test results and in-stream biological condition were evaluated using information collected over a 1.5-y period from 6 different sites across the United States. A data-quality-objectives approach was used that included several proposed measurement quality objectives (MQOs) that specified desired precision, bias, and sensitivity of methods used. The 6 facilities used in this study (4 eastern and 2 western United States) all had design effluent concentrations >60% of the stream flow. In addition to at least quarterly chronic Ceriodaphnia dubia, Pimephales promelas (fathead minnow), and Selenastrum capricornutum (green algae) WET tests, other tests were conducted to address MQOs, including splits, duplicates, and blind positive and negative controls. Macroinvertebrate, fish, and periphyton bioassessments were conducted at multiple locations upstream and downstream of each facility. The test acceptance criteria of the US Environmental Protection Agency (USEPA) were met for most WET tests; however, this study demonstrated the need to incorporate other MQOs (minimum and maximum percent significant difference and performance on blind samples) to ensure accurate interpretation of effluent toxicity. More false positives, higher toxicity, and more “failed” (noncompliant) tests were observed using no-observed-effect concentration (NOEC) as compared to the IC25 endpoint (concentration causing ≥25% decrease in organism response compared to controls). Algae tests often indicated the most effluent toxicity in this study; however, this test was most susceptible to false positives and high interlaboratory variability. Overall, WET test results exhibited few relationships with bioassessment results even when accounting for actual effluent dilution. In general, neither frequency of WET noncompliance nor magnitude of toxicity in tests were significantly related to differences in biological condition upstream and downstream of a discharge. Periphyton assessments were most able to discriminate small changes downstream of the effluent, followed by macroinvertebrates and fish. Although sampling methods were robust, more replicate samples collected upstream and downstream of each facility were needed to increase detection power. In general, macroinvertebrate and periphyton assessments together appeared to be sufficient to address project objectives.

The number of products containing biocides is increasing at the same time as the number of available biocides is decreasing. Biocides are biologically active chemicals with a vast area of applications where demands for maintaining product quality by use of biocides presents a major challenge for developers striving to meet emerging environmental concerns and fulfilling criteria for eco-labeled consumer products. Tightening regulations have, however, led to stagnation in the current development of new biocide chemistries, and the “nontoxic poison” has yet to be formulated. Accordingly, the present article presents a critical overview of European Union regulation of biocides and their usage and of some of the future challenges for meeting demands for environmentally safe products and processes in which biocides are used. The Biocidal Product Directive, which is presently implemented, is one focus in the present article. Regulations of environmental, health, and safety (EHS) risk classifications and their role in the future development of biocide-containing products are also discussed. Studying the biocide dilemma may provide tools for the chemical industry as whole for proactive anticipation of the effect of emerging regulatory demands on product development.

Environmental assessment practices have not been as successful as they should be. We believe that this is in part because environmental assessors lack a clear and useful set of principles—that is, a theory of practice. We propose a theory that derives 19 principles from 3 axioms: 1) assessments inform environmental management decisions, 2) assessments are science based, and 3) management decisions accommodate multiple goals and constraints. The 1st axiom leads to principles that change the focus from good assessments to good decisions. The 2nd focuses assessments on the scientific needs of the decision maker rather than making policy judgments or consensus building. The 3rd axiom leads to integration across disciplines, scales, and types of evidence. This theory of assessment practice implies the need for a new framework for environmental assessment that is more integrative than existing frameworks and more focused on making decisions that resolve environmental problems. We believe that this theory of environmental assessment can lead to clear assessment practices that compel beneficial and confident environmental management.

Criteria for the quality of water and other media are often said to be risk based. However, the relationship between the process of criterion setting and risk assessment has not been clear. This article shows that the conventional framework for risk assessment may be easily modified to represent criterion development. The critical difference is that conventional risk assessments solve an exposure–response model for an expected exposure to estimate an effect, but criterion assessments solve the same model for a benchmark effect to estimate an upper limit to acceptable exposures. Hence, the critical step in criterion setting is the determination of an effect metric that can be modeled and that represents the environmental goal. The same process applies to equivalent assessments, such as deriving screening benchmarks and remedial goals.

In the United States, ambient aquatic life water quality criteria are derived using guidelines developed in 1985 that include a clear and consistent methodology using data from standard toxicity tests. The methodology from these guidelines has been successful, but a broader methodology is needed because some effects of pollutants do not lend themselves to conventional toxicity testing. Criterion assessment is proposed as that methodology. In criterion assessment, a specific environmental goal is translated into a measurable benchmark of effect that is used together with a modeled exposure–response relationship to estimate a range of exposures that will achieve the specific goal. The model of the exposure–response relationships and the benchmark effect are developed from field data and laboratory data using multiple analytical methods. Then the model is solved for the effect, thereby estimating the criterion, an upper threshold for acceptable exposures. The resulting candidate criteria are synthesized to select criteria and other benchmark values, such as remedial goals. The criterion assessment process is illustrated using the US Environmental Protection Agency Framework for Developing for Suspended and Bedded Sediments Water Quality Criteria, which recommends developing alternative candidate criterion values and then evaluating them to select a final criterion. Candidate criteria may be derived from models of field observations, field manipulations, laboratory tests, or empirical and theoretical models. Final selection of a criterion uses a weight-of-evidence comparison that engenders confidence because causal associations are confirmed on the basis of different assumptions, independent data sets, and varied statistical methods, thereby compensating for the concerns raised by individual studies and methods. Thus, it becomes possible to specify criteria for agents with biological or physical modes of action, as well as those with chemical modes of action, to best achieve environmental goals.

This article presents the development and results of Ozone Web—a near-real-time Web-based approach to communicate environmental information to policy makers, researchers, and the general public. In Ozone Web, ground-level ozone information from 750 air quality measurement stations across Europe is collected on an hourly basis, filtered, interpolated, and presented on zoomable maps and graphs. Compared with other environmental information initiatives, the main aspects of this Website is the allowance for user interactivity, free access to data, and high timeliness. Data are published 2 to 3 h after actual monitoring. In a response to the acute characteristics of air pollution, the basic principle is that up-to-date and accurate information about air pollution levels will help 1) citizens to protect their health, 2) policy makers in assessing the state of the environment, and 3) researchers in exchanging data and knowledge. Near-real-time information systems on the Web seem to be a valuable complement to future environmental reporting, and the European Environment Agency is currently investigating the requirements needed to extend the use of near-real-time data, including reporting on air pollutants other than ozone.