Revising Environmental Quality Standards: Lessons Learned.

An environmental quality standard (EQS) is a threshold value applied in regulatory monitoring for retrospective environmental risk assessment. However, an EQS may vary with time and between countries with shared water bodies, challenging coherent risk management. This study aimed to analyze the underlying reasons for changes in EQS values following a revision of previously derived EQSs for 62 substances.

The 2015 Annual Meeting of SETAC German Language Branch in Zurich (7-10 September, 2015): Ecotoxicology and environmental chemistry-from research to application.

This report provides a brief review of the 20th annual meeting of the German Language Branch of the Society of Environmental Toxicology and Chemistry (SETAC GLB) held from September 7th to 10th 2015 at ETH (Swiss Technical University) in Zurich, Switzerland. The event was chaired by Inge Werner, Director of the Swiss Centre for Applied Ecotoxicology (Ecotox Centre) Eawag-EPFL, and organized by a team from Ecotox Centre, Eawag, Federal Office of the Environment, Federal Office of Agriculture, and Mesocosm GmbH (Germany). Over 200 delegates from academia, public agencies and private industry of Germany, Switzerland and Austria attended and discussed the current state of science and its application presented in 75 talks and 83 posters.

Criteria for Reporting and Evaluating ecotoxicity Data (CRED): comparison and perception of the Klimisch and CRED methods for evaluating reliability and relevance of ecotoxicity studies.

Background: The regulatory evaluation of ecotoxicity studies for environmental risk and/or hazard assessment of chemicals is often performed using the method established by Klimisch and colleagues in 1997. The method was, at that time, an important step toward improved evaluation of study reliability, but lately it has been criticized for lack of detail and guidance, and for not ensuring sufficient consistency among risk assessors.

Results: A new evaluation method was thus developed: Criteria for Reporting and Evaluating ecotoxicity Data (CRED).

Erratum to: Criteria for Reporting and Evaluating ecotoxicity Data (CRED): comparison and perception of the Klimisch and CRED methods for evaluating reliability and relevance of ecotoxicity studies.

[This corrects the article DOI: 10.1186/s12302-016-0073-x.].

CRED: Criteria for reporting and evaluating ecotoxicity data.

Predicted-no-effect concentrations (PNECs) and environmental quality standards (EQSs) are derived in a large number of legal frameworks worldwide. When deriving these safe concentrations, it is necessary to evaluate the reliability and relevance of ecotoxicity studies. Such evaluation is often subject to expert judgment, which may introduce bias and decrease consistency when risk assessors evaluate the same study.

Acclimation of Chlamydomonas reinhardtii to ultraviolet radiation and its impact on chemical toxicity.

The toxicity of chemical pollutants can be modulated under stressful environmental conditions, such as increased temperature, salinity or ultraviolet radiation (UVR), due to the interaction of effects during simultaneous stressor exposure. However, organisms may acclimate to such conditions by activation of physiological and biochemical defence mechanisms. In sequential exposures, organisms acclimated to environmental stressors may display an increased sensitivity or co-tolerance towards chemical pollutants.

Multiple stressor effects in Chlamydomonas reinhardtii--toward understanding mechanisms of interaction between effects of ultraviolet radiation and chemical pollutants.

The effects of chemical pollutants and environmental stressors, such as ultraviolet radiation (UVR), can interact when organisms are simultaneously exposed, resulting in higher (synergistic) or lower (antagonistic) multiple stressor effects than expected based on the effects of single stressors. Current understanding of interactive effects is limited due to a lack of mechanism-based multiple stressor studies. It has been hypothesized that effect interactions may generally occur if chemical and non-chemical stressors cause similar physiological effects in the organism.

Ultraviolet radiation dose calculation for algal suspensions using UVA and UVB extinction coefficients.

Although the biological importance of ultraviolet light (UVR) attenuation has been recognised in marine and freshwater environments, it is not generally considered in in vitro ecotoxicological studies using algal cell suspensions. In this study, UVA and UVB extinction were determined for cultures of algae with varying cell densities, and the data were used to calculate the corresponding extinction coefficients for both UVA and UVB wavelength ranges. Integrating the Beer-Lambert equation to account for changes in the radiation intensity reaching each depth, from the surface until the bottom of the experimental vessel, we obtained the average UVA and UVB intensity to which the cultured algal cells were exposed.

GLK transcription factors coordinate expression of the photosynthetic apparatus in Arabidopsis.

Chloroplasts of photosynthetic organisms harness light energy and convert it into chemical energy. In several land plants, GOLDEN2-LIKE (GLK) transcription factors are required for chloroplast development, as glk1 glk2 double mutants are pale green and deficient in the formation of the photosynthetic apparatus. We show here that glk1 glk2 double mutants of Arabidopsis thaliana accumulate abnormal levels of chlorophyll precursors and that constitutive GLK gene expression leads to increased accumulation of transcripts for antenna proteins and chlorophyll biosynthetic enzymes.