WP9 Filling Critical Data Gaps in Ecological Risk Assessment
D137-140
1:20 PM - 4:40 PM, Wednesday
() Criteria for Ecological Risk Assessment at Vandenberg Air Force Base:Issues and Data Gaps.
Wilson, B1, Ambrose, R2, Faulkner, B1, Fry, D3, Johnson, M1, 1 University of California at Davis, Davis, California, USA2 University of California at Los angeles, Los Angeles, California, USA3 Stratus Consulting, Boulder, Colorado, USA
ABSTRACT- Disagreement between the California Department of Toxic Substances Control (DTSC) and Tetra Tech, the US Air Force contracting agency, regarding toxic reference values (TRVs) for contaminated sites on Vandenberg Air Force Base (VAFB) resulted in asking a third party to review the situation. The criteria of the committee appointed to review the selection of papers to derive TRVs included: (a) principles of good science, (b) dose/response studies, (c) dose levels of both effect and no effect, (d) sensitive life stages, (e) appropriate allometric factors,(f) consistent application of criteria, (g) scientifically justifiable end points (e.g. organ specific toxicity, growth, reproduction, development, mortality), (h) consideration of nutritional requirements when appropriate, and (i) papers from peer-reviewed publications. In most cases, several or more of these criteria were lacking in the studies that were selected by both parties. Both performed careful, in depth reviews, had excellent training and expertise, knowledge of the literature and of principles of risk assessment. Their differences in selection of TRVs were reflected in choices of critical papers or in differing interpretations of the results from the same papers, with different emphases on adverse effects on behavior, reproduction, morphology, and other endpoints. This led to TRVs from the two teams that differed greatly, often by orders of magnitude. The major issue that created this situation was the lack of studies that met the above listed criteria for the selection of TRVs, even for compounds that were of concern on a national level. In general, this lack of appropriate papers rendered the selection of TRVs virtually an arbitrary process for many compounds of concern. The need for more fundamental dose/response studies is the most critical and possibly the largest gap that needs to be filled in the current risk assessment process.
Key words: case example, risk assessment, toxic reference values, data gaps