Search

This article describes the outcome and follow-up discussions of an expert group meeting (Amsterdam, October 9, 2009) on the applicability of toxicity profiling for diagnostic environmental risk assessment. A toxicity profile was defined as a toxicological "fingerprint" of a sample, ranging from a pure compound to a complex mixture, obtained by testing the sample or its extract for its activity toward a battery of biological endpoints. The expert group concluded that toxicity profiling is an effective first tier tool for screening the integrated hazard of complex environmental mixtures with known and unknown toxicologically active constituents. In addition, toxicity profiles can be used for prioritization of sampling locations, for identification of hot spots, and--in combination with effect-directed analysis (EDA) or toxicity identification and evaluation (TIE) approaches--for establishing cause-effect relationships by identifying emerging pollutants responsible for the observed toxic potency. Small volume in vitro bioassays are especially applicable for these purposes, as they are relatively cheap and fast with costs comparable to chemical analyses, and the results are toxicologically more relevant and more suitable for realistic risk assessment. For regulatory acceptance in the European Union, toxicity profiling terminology should keep as close as possible to the European Water Framework Directive (WFD) terminology, and validation, standardization, statistical analyses, and other quality aspects of toxicity profiling should be further elaborated., (Copyright © 2013 SETAC.)

The trait approach has already indicated significant potential as a tool in understanding natural variation among species in sensitivity to contaminants in the process of ecological risk assessment. However, to realize its full potential, a defined nomenclature for traits is urgently required, and significant effort is required to populate databases of species-trait relationships. Recently, there have been significant advances in the area of information management and discovery in the area of the semantic web. Combined with continuing progress in biological trait knowledge, these suggest that the time is right for a reevaluation of how trait information from divergent research traditions is collated and made available for end users in the field of environmental management. Although there has already been a great deal of work on traits, the information is scattered throughout databases, literature, and undiscovered sources. Further progress will require better leverage of this existing data and research to fill in the gaps. We review and discuss a number of technical and social challenges to bringing together existing information and moving toward a new, collaborative approach. Finally, we outline a path toward enhanced knowledge discovery within the traits domain space, showing that, by linking knowledge management infrastructure, semantic metadata (trait ontologies), and Web 2.0 and 3.0 technologies, we can begin to construct a dedicated platform for TERA science., (Copyright © 2010 SETAC.)

The magnitude of ecological damage caused by elevated phosphorus concentrations (C(P) ) in Dutch inland waters is expressed as the fraction of disappeared macroinvertebrate genera. We used field observations of species occurrence from 1980 to 2005 that were stored in the Limnodata Neerlandica to derive the presence of 867 aquatic macroinvertebrate genera in the water column of freshwater bodies with total phosphorus (P(tot) ) concentrations ranging from 0.001 to 40 mg/L. At concentrations > 0.3 mg/L, which is considered to cause nutrient enrichment of freshwater bodies, the disappeared fraction (DF) of macroinvertebrate genera can be described as a logistic function of the C(P) : DF = 1/(1 + 4.07/C( P)¹·¹¹). The logistic function suggests that half of the macroinvertebrate genera that potentially occur in the freshwater column in the Netherlands would disappear at a C(P)  = 3.5 mg/L. This field-based effect expression resembles the cumulative sensitivity distribution function for a toxic substance based on the species sensitivity distribution (SSD) concept and exposure data. Whereas an SSD for a toxic chemical is derived from laboratory sensitivity data for a small number of species, our DF is derived from field observations of many macroinvertebrate genera at numerous C(P) levels. By applying this damage function to measured phosphorus in the rivers Rhine, Meuse, and Scheldt, we found that the observed C(P) values in 1975 imply diversity losses of 15% for the Rhine and Meuse, and 20% for the Scheldt. For 2000, the calculated diversity losses are 3% (Rhine), 6% (Meuse), and 9% (Scheldt). The cumulative genera sensitivity distribution function for phosphorus from national freshwater monitoring data can be applied in various environmental screening systems, such as multistress impact assessment of surface waters, and in life cycle impact assessment of products., (Copyright © 2010 SETAC.)

The Water Framework Directive (WFD) of the European Union requires member states to attain a good ecological status for all water bodies by the year 2015. This implies that the bioecological protection endpoint itself is upfront, next to abiotic chemical quality standards, as tools to protect those endpoints. Within the requirements of the Directive, ecological status and abiotic conditions will be monitored extensively. Based on the analysis of the monitoring data, authorities are required to derive Programs of Measures (PoMs) for impacted sites. Optimization of these programs requires diagnosis, to provide site-specific or catchment-specific information on the causes of observed deviations from a good ecological status. This article shows one pilot analysis of monitoring data (Scheldt River, Belgium) compiled in the scope of the EU MODELKEY project. Ecological, ecotoxicological, and statistical models are combined to quantify local ecological impact magnitudes and to identify site-specific factors that are associated with those impacts. Results show significant ecological effects in terms of taxa loss at study sites, which are highly variable among sites, with variable combinations of environmental factors associated with those effects. The results of the diagnostic approach are discussed, which appear to be complementary to the assessment of chemical status required by the Directive. Both types of assessment are useful to assist in the derivation of optimized PoMs. In addition, it could be concluded that the acute toxic pressure parameter relates to reduced taxon abundance for more than half of the studied taxa and that this parameter relates to the fraction of taxa lost under field conditions. Finally, various lessons for the execution of monitoring programs are derived because the Scheldt (bio)monitoring data set has its weaknesses, although it can be seen as typical for current monitoring programs.

This study addresses the potential risks to the aquatic ecosystem posed by pesticides currently used in The Netherlands. The study used a novel method to predict aquatic exposure to pesticides based on a geographic information system (GIS) map of agricultural land use, comprising 51 crops used in open-canopy areas. Through the application of species-sensitivity distributions for aquatic organisms, in combination with rules for mixture-toxicity calculation, the modeled exposure results were transformed to risk estimates for aquatic species. The majority of the predicted risks were caused by pesticides applied to potato cropland, and approximately 95% of the predicted risk was caused by only 7 of the 261 pesticides currently used in The Netherlands. For risk verification, local toxic-risk estimates were compared with observed species composition in field ditches. The field verification study was not able to draw firm conclusions regarding the predicted impact of pesticide use on overall biodiversity. A toxicity-related shift from sensitive to more tolerant or opportunistic species could be observed for a few species.