Effects of Two Insecticides on Survival, Growth and Emergence of Chironomus riparius Meigen

Effects of chlorpyrifos and cypermethrin on the survival, growth and emergence of Chironomus riparius were determined on a life-cycle study. Although neither cypermethrin nor chlorpyrifos affected larval survival or growth, a decrease in the number of emerged midges and in the number of females over males, as well as in female biomass, were found for both insecticides. The results from this study indicate that multiple biological endpoints and extended periods of exposure are needed in order to achieve a better screening of insecticide toxicity.FCT - SFRH/BM/8402/2002FCT - PTDC/BIABDE/72841/200

Making sense of ecotoxicological test results: towards process-based models.

Abstract The environmental risk of chemicals is rou-tinely assessed by comparing predicted exposure levels to predicted no-effect levels for ecosystems. Although pro-cess-based models are commonly used in exposure assessment, the assessment of effects usually comprises purely descriptive models and rules-of-thumb. The prob-lems with this approach start with the analysis of labora-tory ecotoxicity tests, because only a limited amount of information is extracted. Standard summary statistics (NOEC, ECx, LC50) are of limited use in part because they change with exposure duration in a manner that varies with the tested species and the toxicant. As an alternative, process-based models are available. These models allow for toxicity measures that are independent of exposure time, make efficient use of the available data from routine toxicity tests, and are better suited for edu-cated extrapolations (e.g., from individual to population, and from continuous to pulse exposure). These capabilities can be used to improve regulatory decisions and allow for a more efficient assessment of effects, which ultimately will reduce the need for animal testing. Process-based modeling also can help to achieve the goals laid out in REACH, the new strategy of the European Commission in dealing with chemicals. This discussion is illustrated with effects data for Daphnia magna, analyzed by the DEBtox model

Handbook of Environmental Chemistry

Human Health Risk Assessment (HHRA) and Environmental Risk Assessment (ERA) are well-established regulatory and scientific research fields that support regulatory decision-making in the European Union (EU) and are undergoing constant development. HHRA and ERA are crucial steps for reaching the objectives of Europe 2020, a strategy put forward by the Commission that sets out a vision of Europeâs social market economy for the twenty-first century. This chapter aims to describe the basic principles, the evolution and the future challenges of HHRA and ERA. The first part defines HHRA and ERA and describes the origins of risk assessment and management procedures at an international level. The precautionary principle has always been present in the European Union policies that aim to protect health and the environment. In the second part, current approaches that characterise risk assessment, such as the tiered approach, are presented. In the future, the implementation of recent scientific developments for the construction of integrated exposure scenarios models is of paramount importance to improve environmental and health risk assessment schemes. Moreover, the evaluation of uncertainties in the modelling inputs and outputs and the sensitivity analysis are two key elements to optimise current HHRA and ERA procedures