Effect of reduced food intake on toxicokinetics of halogenated organic contaminants in herring gull (Larus argentatus) chicks

The aim of the present study was to investigate how contaminant exposure and reduced food intake affect tissue distribution and biotransformation of halogenated organic contaminants (HOCs) in Arctic seabirds using herring gull (Larus argentatus) as a model species. Herring gull chicks were exposed for 44 d to cod liver oil containing a typical mixture of contaminants. Following exposure, food intake was reduced for a one-week period in a subgroup of the chicks. Polyclorinated biphenyls, organochlorine pesticides, and brominated flame retardants, as well as a wide range of hydroxy, methyl sulfone, and methoxy compounds were measured in liver, brain, and plasma samples. Additionally, phase I biotransformation enzyme activities and phase I and II messenger ribonucleic acid (mRNA) expression were investigated in the liver, brain, or both. Both contaminant exposure and reduced food intake had an increasing effect on the concentrations of HOCs and their metabolites. The HOC exposure and reduced food intake also led to increased 7-ethoxyresorufin-O-deethylation (EROD) activity, whereas mRNA expression of the biotransformation enzymes increased only following the reduced food intake. Tissue distribution of HOCs and their metabolites was not affected by either contaminant exposure or reduced food intake. In conclusion, the results indicate that biotransformation capacity and formation of HOC metabolites increase during reduced food intake. This finding supports the hypothesis that reduced food intake increases the susceptibility of Arctic animals to the effects of lipophilic HOCs. Environ. Toxicol. Chem. 2013;32:156164. (c) 2012 SETA

Chemical risk indicator scoping study : Scoping study to develop an indicator on the risk of chemicals on ecosystems

This scoping study outlines various options for methodologies that can underpin indicator(s) on the risk of (single/mixtures of) chemicals on various types of ecosystems, habitats and species. The aim of the indicator is to provide a sufficient and indicative level of information to contribute to risk governance. It can inform governmental institutions, non-governmental organizations and the general public on to what extent terrestrial ecosystems, habitats, or species, are put at risk by the occurrence of chemicals in the environment, as a consequence of human activities (e.g., farming). The report highlights the data required for the development of such an indicator and their availability through a review of existing databases. A case study illustrates the applicability of the indicator and the need for further development

Towards an alternative testing strategy for nanomaterials used in nanomedicine: Lessons from NanoTEST

In spite of recent advances in describing the health outcomes of exposure to nanoparticles (NPs), it still remains unclear how exactly NPs interact with their cellular targets. Size, surface, mass, geometry, and composition may all play a beneficial role as well as causing toxicity. Concerns of scientists, politicians and the public about potential health hazards associated with NPs need to be answered. With the variety of exposure routes available, there is potential for NPs to reach every organ in the body but we know little about the impact this might have. The main objective of the FP7 NanoTEST project (www.nanotest-fp7.eu) was a better understanding of mechanisms of interactions of NPs employed in nanomedicine with cells, tissues and organs and to address critical issues relating to toxicity testing especially with respect to alternatives to tests on animals. Here we describe an approach towards alternative testing strategies for hazard and risk assessment of nanomaterials, highlighting the adaptation of standard methods demanded by the special physicochemical features of nanomaterials and bioavailability studies. The work has assessed a broad range of toxicity tests, cell models and NP types and concentrations taking into account the inherent impact of NP properties and the effects of changes in experimental conditions using well-characterized NPs. The results of the studies have been used to generate recommendations for a suitable and robust testing strategy which can be applied to new medical NPs as they are developed. © 2015 Informa UK Ltd. All rights reserved: reproduction in whole or part not permitted