A consortium of world-class scientists from both academia and industry has been assembled to assess the risks to wild animals and humans posed by environmental exposure to pharmaceuticals. Their expertise will be supplemented by an advisory group consisting of representatives of all stakeholders. This project will concentrate on two classes of human pharmaceuticals, namely antibiotics and anti-cancer drugs, because there are good reasons for thinking that these could be of particular concern. In order to conduct sound risk assessments, including providing estimates of uncertainty, it will be necessary to obtain accurate data on both exposure concentrations and effects levels. Hence, new data on both environmental concentrations and effects on aquatic organisms will be produced during the project. The comparative sensitivities of embryos and adults will be determined, and used to reduce uncertainty in the risk assessments. The stable transformation products of the selected pharmaceuticals will also be investigated. All stakeholders and beneficiaries will be represented in the project, so that results are rapidly and reliably transferred to all interested parties. A prototype web-based classification system will be developed during the project with the intention of enabling all EU citizens to make their own informed decisions about the risk posed by human pharmaceuticals to their health and to the health of the environment. The results will able EU regulators and policy makers to make better informed decisions on the issue of pharmaceuticals in the environment.