Human Health Risk Assessment at Sediment Cleanup Sites

1. Human Health Risk Assessment at Sediment Cleanup Sites Lon Kissinger, Office of Environmental Assessment, Risk Evaluation Unit, U.S. EPA Region 10 ELEC Sediment Conference, 4/22/2010

2. Why Conduct Sediment Human Health Risk Assessments? • Establish a need to take action. • Develop sediment cleanup levels that will protect human health.

3. Sediment Contaminant Exposures

4. Lower Duwamish Waterway Direct and Indirect Sediment Exposure Risks

5. Sediment Site Seafood Consumption Risk Assessment

6. Seafood Consumption Surveys: Considerations and Results

7. Possible Purposes of Seafood Consumption Surveys • Seafood consumption trends • Water body fishing pressures • Site specific seafood contaminant risks • Environmental regulation • Fish consumption advisories • Development of water quality criteria

8. Seafood types Seafood sources Seafood preparations Cooked or uncooked weights Survey timing Statistics/data handling (e.g. outliers, non-response, weighting, etc.) Inclusion of non-consumers Population (ethnicity, age, culture, economics) Presence of environmental contamination Factors to Consider in Interpreting Results

9. Methodologies for Key Pacific NW Surveys • Personal interviews of members of specific groups recording 24 hour and seasonal consumption. Interviews done by members of those groups. • Creel surveys involving field inspection of angler catch by individuals that may or may not be members of the angler’s community.

10. Creel vs. Personal Interview • Representative sample of population • Pilot testing • Language and literacy • Interview environment • Supporting materials • Trust • Geographic and temporal scope of survey

11. Relevant Seafood Consumption Surveys • National USDA Continuing Survey of Food Intakes by Individuals (CSFII) • Regional Surveys • A Fish Consumption Survey of the Umatilla, Nez Perce, Yakama, and Warm Springs Tribes of the Columbia River Basin, 1994 • A Fish Consumption Survey of the Tulalip and Squaxin Island Tribes of the Puget Sound Region, 1996 • Asian & Pacific Islander Seafood Consumption Study in King County Washington, 1999 • Fish Consumption Survey of the Suquamish Indian Tribe of the Port Madison Indian Reservation, Puget Sound Region, 2000

12. Seafood Consumption Rates

13. Seafood Consumption Rates

14. Regional Alaskan Seafood Harvest Rates

15. Issues in Assessing Seafood Contaminant Exposure. • How much seafood is consumed daily? • How many years is seafood consumed? • How much of the seafood consumed is affected by a source of contamination? • What to do with anadromous species? • How to address risks posed by consumption of different types of seafood that have varying contaminant levels?

16. EPA Region 10, August 2007 Framework for Selecting and Using Tribal Fish and Shellfish Consumption Rates for Risk-Based Decision Making at CERCLA and RCRA Cleanup Sites in Puget Sound and the Strait of Georgia North to the Canadian Border

17. Why was this Framework Developed? • Tribal members may consume greater quantities of seafood than the general population • Tribal members may hence have greater exposure to contaminants in fish • Limited data on tribal fish consumption • Need to adapt the available data to sites • Different people/different approaches

18. Framework Purpose To present a consistent and protective approach for EPA Region 10 staff to use when considering Tribal fish and shellfish consumption rates when working on toxic cleanup projects in Puget Sound and the Strait of Georgia north to the Canadian border

19. Consultation with Tribal Governments and the Framework • Application of the Framework is not, in any way, to affect a Tribe’s treaty rights. • “ To be applied in Consultation with Tribal Governments on a site-specific basis” • The Framework is a starting point for discussion. • Consultation begins during site investigation evaluation and continues through site study and remedy selection phases.

20. Geographic scope Basis for choice of tribal data set Seafood data set policy choice Consumption rates used Fraction from source Alternate scenarios Cultural impacts Resource switching Percentage of different seafood types consumed Duration of exposure Consideration of salmon Key Points of the Framework

21. Geographic Scope Framework applies to cleanup sites in Puget Sound and the Strait of Georgia up to the Canadian border EPA’s cleanup program addresses site related contamination - not all health risks

22. Reasonable Maximum Exposure and Seafood Consumption • The highest exposure that is reasonably expected to occur at a site • Exposure for current and future conditions • Is computed using a mixture of central tendency and upper bound values for various exposure parameters • Media contact rate, in this case seafood consumption, utilizes the 95th percentile contact rate

23. 95th Percentile Consumption Rate 95th percentile consumption rate

24. Basis for Choice of Tribal Data Set • It is difficult to decide whether Tulalip or Suquamish data are appropriate for a site risk assessment. • Needs to be protective, realistic • EPA proposing that key difference in rates is shellfish consumption which in turn relates to the quality/quantity of shellfish habitat • Not all habitat can sustain high levels of shellfish consumption.

25. Seafood Data Set Policy Choice • Large quantities of current or potential high quality shellfish habitat at a site lead to use of Suquamish consumption rates • Tulalip rates to be used at other sites • Tribal shellfish biologists key to evaluating habitat

26. Consumption Rate Values Used • Two tribal data sets available: • Tulalip: weight of seafood consumed per day • from PS: 6.8 oz (194 grams) • from PS: 3.4 oz (98 grams) without salmon • Suquamish: weight of seafood consumed per day • from PS: 1 lb 12 oz, (767 grams) • from PS: 1 lb 2 oz, (583 grams) without salmon

27. Fraction of Seafood Affected by Contamination • The same consumption rate would be used for small sites as well as big sites. • EPA assumes all of the fish and shellfish harvested from Puget Sound could be affected by releases from the site.

28. Alternate Tribal Scenarios Alternative rates may be included in the analysis: • At the request of a Tribe. • If the site falls within the exclusive U&A of a Tribe and that Tribe can document a seafood consumption scenario, then that Tribe’s scenario should be included.

29. Resource Switching • Regardless of the species present at a site, the overall consumption rate must be used. • The Framework’s position is that Tribes will substitute alternate species if desired species are not present at a site.

30. Percentage of Different Seafood Types Consumed • Starting point is the percentage of different seafood types specified in surveys used in the framework. • Different assumptions may be adopted.

31. Duration of Exposure • Exposure duration of 70 years • Higher than EPA default value of 30 years to account for Tribal lifestyles

32. Inclusion of Salmon • Inclusion of salmon in the overall consumption rate is dependent on site characteristics and the contaminants present. • Key question: “Do salmon acquire a body burden of contaminants that originate from the site?”

33. Impact of Contamination on Tribal Culture • EPA recognizes quantitative risk assessment does not address cultural impacts • Tribes may present information to EPA regarding impacts of contamination on tribal culture to inform decision makers

34. Application of Framework • Lower Duwamish Waterway and associated sites • ITT Rayonier • Puget Sound Naval Shipyard

35. Issues in Developing Risk Based Sediment Cleanup Levels • Sometimes difficult to relationships between biota and sediment contaminant levels in the field. • Background levels of bioaccumulative contaminants in the environment may exceed acceptable levels based on risk.

36. 1000 767 Background / Ambient Range in WA 194 17.5

37. Take Home Messages • Seafood consumption risk reduction goals can not be attained purely by remediation in urban areas. • In such cases, the goal should be maximum risk reduction considering background and source control • Aquatic biota monitoring following cleanup actions is essential to better understand relationships between contaminants in sediment and aquatic biota.