A framework for One Health research.

The need for multidisciplinary research to address today's complex health and environmental challenges has never been greater. The One Health (OH) approach to research ensures that human, animal, and environmental health questions are evaluated in an integrated and holistic manner to provide a more comprehensive understanding of the problem and potential solutions than would be possible with siloed approaches. However, the OH approach is complex, and there is limited guidance available for investigators regarding the practical design and implementation of OH research. In this paper we provide a framework to guide researchers through conceptualizing and planning an OH study. We discuss key steps in designing an OH study, including conceptualization of hypotheses and study aims, identification of collaborators for a multi-disciplinary research team, study design options, data sources and collection methods, and analytical methods. We illustrate these concepts through the presentation of a case study of health impacts associated with land application of biosolids. Finally, we discuss opportunities for applying an OH approach to identify solutions to current global health issues, and the need for cross-disciplinary funding sources to foster an OH approach to research.

Ecotoxicity of engineered nanoparticles to aquatic invertebrates: a brief review and recommendations for future toxicity testing.

Based on a literature review and an overview of toxic effects of engineered nanoparticles in aquatic invertebrates, this paper proposes a number of recommendations for the developing field of nanoecotoxicology by highlighting the importance of invertebrates as sensitive and relevant test organisms. Results show that there is a pronounced lack of data in this field (less than 20 peer-reviewed papers are published so far), and the most frequently tested engineered nanoparticles in invertebrate tests are C(60), carbon nanotubes, and titanium dioxide. In addition, the majority of the studies have used Daphnia magna as the test organism. To date, the limited number of studies has indicated acute toxicity in the low mg l(-1) range and higher of engineered nanoparticles to aquatic invertebrates, although some indications of chronic toxicity and behavioral changes have also been described at concentrations in the high microg l(-1) range. Nanoparticles have also been found to act as contaminant carriers of co-existing contaminants and this interaction has altered the toxicity of specific chemicals towards D. magna. We recommend that invertebrate testing is used to advance the level of knowledge in nanoecotoxicology through standardized short-term (lethality) tests with invertebrates as a basis for investigating behaviour and bioavailability of engineered nanoparticles in the aquatic environment. Based on this literature review, we further recommend that research is directed towards invertebrate tests employing long-term low exposure with chronic endpoints along with more research in bioaccumulation of engineered nanoparticles in aquatic invertebrates.