Environmental properties and effects of nonionic surfactant adjuvants in pesticides: a review

A method to integrate benchmark dose estimates with genomic data to assess the functional effects of chemical exposure.

For reliable environmental risk assessment of pollutants, knowledge on the effects at different levels of biological organisation is needed During the early days of biomarker research in environmental studies approximately two decades ago, biochemical biomarkers were considered as the most promising tool for such purposes Among these, three enzymes have often been studied: catalase (CAT), glutathione S-transferase (GST) and cholinesterase (ChE) However, despite their intensive research, their measurements in invertebrates have not been commonly applied in environmental risk assessment (ERA) or for regulatory purposes In the present review, we summarise our past experiences in biochemical biomarker research in two crustacean species: water flea Daphnia magna and terrestrial isopod Porcellio scaber This is to orientate their use and to provide recommendations for the use of novel biomarkers in environmental studies, such as proteomic or genomic responses We assessed the intrinsic properties of biochemical biomarkers CAT, GST and ChE in the D magna and the isopod P scaber It was found that they are not in agreement with the expectations that were previously given for their use in environmental studies To advance their use in environmental risk assessment, we suggest that based on their properties, their role should be more specifically defined ERA includes several distinct steps, among them hazard identification, effect assessment and finally risk characterisation, each of which requires a different type of toxicity data We recommend that the use of biochemical markers is most appropriate for hazard identification because this is a procedure whose purpose is to characterise the potential hazard of the substance in question and is more flexible in terms of using different tools Furthermore, our results imply that biochemical markers are not always more sensitive than whole-organism responses, as was anticipated Their sensitivity depends on the mode of action, duration of exposure and test species Therefore, we suggest that combining both a battery of biomarkers from different levels of biological organisation and an array of biomarkers within a single level could identify hazard adequately The lesson learnt from biochemical biomarkers in environmental studies utilizing crustacean model species is that, for successful application of each group of biomarkers, their intrinsic properties are needed to be known before an (eco)toxicity study is designed We suggest that a substantial body of experience obtained with biochemical biomarkers should be exploited to new emerging biomarkers in environmental studies in order to facilitate their application The future of biomarkers lies in a combination of traditional biochemical and new-generation biomarkers The latter are not only a potential replacement for existing biomarkers but will also provide new knowledge which might encourage renewed research and development of traditional biomarkers For research purposes, complete ecotoxicity information should include contributions from molecular fingerprint of an organism, as well as whole organism, population and ecosystem responses Still, the type of biomarkers used for routine purposes will depend on their reproducibility, their ease of use, robustness, affordability of the methodology and the type of chemicals, organisms and ecosystem of interest

Biochemical biomarkers in environmental studies—lessons learnt from enzymes catalase, glutathione S-transferase and cholinesterase in two crustacean species

Toxicogenomics in risk assessment : Applications and needs

Environmental and Health Assessment of Substances in Household Detergents and Cosmetic Detergent Products

Several experiments were designed to examine the acute toxicity of surfactants toDaphnia. Specific tests were designed to develop comparisons between existing acute toxicity data for fish and similar data forDaphnia, and to provide data on the effects of various environmental factors on resultant toxicity of surfactants toDaphnia.
 Acute toxicity data for a series of homologous linear alkyl benzene sulfonates (LAS) demonstrate increases of up to one order of magnitude in toxicity for each increase of two alkyl carbons. LC 50's obtained withDaphnia magna are similar to those obtained with bluegills,L. Macrochirus. Comparative tests withD. magna andD. pulex indicate no statistical differences in 48-hr LC 50 values for three anionic and two nonionic surfactants. A 50 mg/L concentration of suspended, naturally-occurring kaolin significantly reduced the toxicity of longer chain length LAS homologs and had no effect on nonionic surfactant toxicity. In tests with variable hardness concentrations, the acute toxicity of LAS toD. magna is a combined function of both culture and test water hardness. The toxicity of a nonionic surfactant toD. magna was higher in soft water and was not affected by culture water hardness levels. Unlike previously published data for fish, the results of acute toxicity tests withD. magna cultures previously exposed to 0.4 mg/L LAS for periods up to seven generations indicated no significant difference in LAS susceptibility compared to simultaneously tested unexposed controls.

Acute toxicity studies of surfactants to Daphnia magna and Daphnia pulex.

The Genomic Revolution: What Does It Mean for Risk Assessment?

The first sequencing of a complete organism genome occurred in 1995. Since then there has been an explosion of information, with a new organism being sequenced nearly every week. This rapid development of genomics is providing unparalleled opportunities in toxicology, ecology, and risk assessment. This paper provides an overview of some possible applications of this new information in ecological and human risk assessment.

William E. Bishop

Papers

Acute toxicity studies of surfactants to Daphnia magna and Daphnia pulex.

The Genomic Revolution: What Does It Mean for Risk Assessment?

The genomic revolution: what does it mean for human and ecological risk assessment?