Sponsoring Section/Society: ENAR
Session Slot: 10:30-12:20 Wednesday
Estimated Audience Size: 60-80
AudioVisual Request: Two Overheads
Session Title: Affecting Policy through Environmental Statistics
Session Organizer: Ryan, Louise M. Harvard University
Address: DFCI, 44 Binney Street, Boston Ma 02115
Phone: 617-632-3602
Fax: 617-632-2444
Email: ryan@jimmy.harvard.edu
Session Timing: 110 minutes total (Sorry about format):
Chair - 5 minutes First Speaker - 25 minutes (including 3 minutes questions) Second Speaker - 25 minutes Third Speaker - 25 minutes Discussant - 15 minutes Floor Discusion - 15 minutes
Session Chair: Young, Linda J. University of Nebraska
Address: Department of Biometry U of Nebraska Lincoln NE 68583-0712
Phone: 402 472 2903
Fax: 402 483 2392
Email: biom025@unlvm.unl.edu
1. Dose-Rate Considerations in Risk Assessment: Statistical Models and Policy Implications
Williams, Paige L., Dept. of Biostatistics, Harvard School of Public Health
Address: Biostatistics, 677 Huntington Avenue Boston Ma 02115
Phone: (617) 432-3872
Fax: (617) 432-2832
Email: paige@hsph.harvard.edu
Abstract: Regulatory agencies have become increasingly aware of the need to develop standards for a wider range of exposure conditions relevant for toxicity endpoints, particularly varying lengths of exposure. The strategy for comparing responses among exposures of different durations has often relied on a conjecture proposed by Haber (1924) that response levels should be equivalent for any constant multiple of dose times duration, i.e., whenever the cumulative exposure remains constant. More flexible statistical models have been developed for assessing joint effects of dose and duration, yet these typically require larger and more complex study designs. Current default approaches for setting regulatory standards in the context of dose-rate exposures will be reviewed, and implications of more flexible approaches on regulatory policy will be addressed.
2. Mechanistic Modeling in Environmental Policy: Challenges for Statistics
Portier, Christopher J., NIEHS
Address: NIEHS PO Box 12233 MD A3-06 Research Triangle Park, NC 27709
Phone: 919 541 4999
Fax: 919-541-1479
Email: portier@niehs.nih.gov
Abstract: There is now underway a concerted effort by the regulatory community to "improve" decisions about environmental health risks through the use of "mechanistic models" explaining the relationship between exposure and risk. The benefit from the use of these models is an increased linkage of a broad array of data sources and the u se of historical understanding of the etiology of a toxicity in the formulation of the model. However, these efforts result in a difficult task for statisticians i n terms of definition (what constitues "mechanistic modeling" as compared to an al ternative), parameter estimation (identifiability, likelihood construction, varian ce estimation, etc) and in validation of a highly complicated modeling scheme. Th is talk addresses some of these concerns and suggests avenues of research for stat isticians to improve the use of ``mechanistic models'' in risk assessment.
3. Regulating the Effects of Commercial Salmon Net Fisheries on Protected Seabirds
Conquest, Loveday L., Associate Dean And Professor, College Of Ocean & Fishery Sciences Univ. Of Washington
Address: Box 3355645 Seattle WA 98195-5645
Phone: 206 543 1708
Fax: 206 543 6263
Email: conquest@cqs.washington.edu
Melvin, Edward F., University of Washington, Washington Sea Grant Program
Abstract: In developing regulations for fishing gear and fishing techniques that reduce the accidental entanglement of endangered seabirds, we compared entanglement rates and fish catch rates in different types of salmon fishnets, and across different times of day. We used loglinear models to analyze both bird entanglement and fish catch data. Results indicate that seabird entanglement and salmon catch rates vary significantly among fishnet types and times of day. Particular patterns of variation were specific to the type of bird being investigated. Common Murres and Rhinoceros Auklets responded differently (in terms of entanglement rates) to different types of nets, and depending upon the time of day. This can be problematic when trying to devise fishing regulations across a broad array of circumstances. Fishing policy changes based on our work involve use of visual net barriers, acoustic pingers for fishnets, and daytime only fishing to reduce endangered seabird bycatch by commercial salmon fishing boats.
Discussant: Ross, N. Phillip Director for the Center for Environental Statistics, USEPA
Address: 401 M Street, SW Room 3101 Mail Stop 2163 Washington DC 20450
Phone: 202 260-5244
Fax: 202 260-8550
Email: ross.np@epamail.epa.gov
List of speakers who are nonmembers: None