Peer Reviewed: Meeting the Scientific Needs of Ecological Risk Assessment in a Regulatory Context

Abstract

uring the past decade, the field of ecological risk assessment has progressed considerably. Advances have come from such international bodies as the Organisation for Economic Co-operation and Development (OECD), the World Health Organisation (WHO), the European and Mediterranean Plant Protection Organisation (EPPO), and the European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) (1-8). Risk assessments have played a critical role in the development of various regulations within the European Commission (EC) as well as in other parts of the world, including the United States, Canada, and Japan (9-17 ). But scientists and regulators are faced with three significant challenges: streamlining the risk-assessment process, quantifying risks in a spatially explicit manner, and acquiring the correct kind of environmental data to enable regulatory programs to effectively focus on future environmental protection activities.

Making Sense of Ecotoxicological Test Results: Towards Application of Process-based Models

“…One aim of the new EU chemicals policy is to generate more data on chemical properties while limiting animal testing (Christensen et al, 2003). There is hope that QSARs can be used to fill ecotoxicological data-gaps (Christensen et al, 2003;Bradbury et al, 2004), but QSARs for ecotoxicity suffer from the same drawbacks as NOEC, LC50 and ECx methods. A more promising direction might be to develop more efficient testing strategies and test designs, and to use these in combination with process-based analyses.…”

“…Apart from risk assessment situations where acute mortality is important (short-term exposure to high concentrations), this form of testing might be discarded altogether. As an alternative, efficient screening could be achieved by using a low default value for the PNEC (Bradbury et al, 2004). Chemicals for which predicted exposure levels remain well below this threshold would not need to be tested unless there are other considerations, such as structural similarity to known problematic chemicals.…”

Vision & strategy: Predictive ecotoxicology in the 21st century

“…Based on the best available and practical science and technology of its time, it is viewed by many as the ''gold standard'' by which all other approaches should be measured. Nevertheless, if we are to address the nuanced and diverse contaminant issues of the 21st century, our toxicity-testing paradigm must evolve [2][3][4][5][6]. In many respects, in vivo toxicity testing and the concept of ''one problem, one test'' [7], which purports to design a single definitive toxicity test for each adverse outcome, have proved unwieldy, particularly as the inventory of chemicals requiring assessment has grown.…”

“…As a result, only certain high-risk classes of chemicals have been subjected to intensive testing. For example, pesticides long have been subjected to significant amounts of testing and assessment under legislative requirements such as the U.S. Federal Insecticide, Fungicide and Rodenticide Act, whereas little or no toxicity data remain for a large percentage of the chemicals currently in commerce [2,3,8,9].…”

“…The classic example is pesticide registration in the United States and many other countries, where a defined battery of toxicity studies must be submitted to a regulatory authority, but the final risk assessment may be based on only the few most sensitive toxicity tests or endpoint responses. This suggests that efficiency could be improved by incorporating both mechanistic data that could focus testing [3][4][5] and bioinformatic approaches that more effectively integrate and use available data.…”