This report is an outgrowth of the report, "Transport Factors in Fish: A Review and Evaluation of HEDR Project Columbia River Pathway Modeling and Dose Calculation Procedures," prepared by Deward E. Walker, Jr. (1995) (hereafter referred to as Walker) for the Hanford Environmental Dose Reconstruction Project (HEDR). From its beginning in 1987 to its completion in 1995, the HEDR Project progressed under the assumption that Native Americans living in the middle Columbia River region could have been exposed to higher levels of radiation than other sub-populations in the same areas. One of the results of the HEDR Project was a computer program, the Columbia River Dosimetry (CRD) model, for calculating the radiation dose an individual might have received as a result of exposure to radionuclide discharges into the Columbia River from the Hanford Nuclear Site in Richland, Washington. Our analysis applies the CRD model to three representative Native American fishermen using the Columbia River during the years of peak discharges from Hanford operations.

A difficult task in dose reconstruction is dietary recall from periods far in the past. Ethnographically derived estimates provide one answer to this problem (Walker 1967). Occasional fish buying records provide another (Walker 1992). This study employs a third approach in its reliance upon officially recorded fishing sites for a major Native American Tribe in the middle Columbia River area.

Purpose and Scope

The purposes of this study of Yakama Tribal fishing sites and radionuclide doses are twofold: first, to document Yakama Tribal fishing sites along the middle Columbia River from Bonneville Dam to McNary Dam (Zone 6) for the year 1967; second, to estimate radiation doses that Native American fishermen could have received as a result of radionuclide emissions from Hanford operations into the Columbia River between 1950 and 1971 based on number and locations of fishing sites. It does not evaluate radiation doses received by Tribal members from other pathways

This study presents previously unpublished Yakama Tribal fishing site locations along the middle Columbia River gathered by Walker and relates them to radionuclide doses resulting from Hanford operations between 1950 and 1971. Columbia River Native Americans are an important group to consider in making dose calculations because they were and continue to be significant users of the river and may have been exposed to higher levels of radionuclides than other groups previously studied. Prior to this report, two significant works have been published that address Native American exposures to radionuclides on the Columbia River (Hoffman et al. 1997; PNNL and CRCIA 1998). While these two reports provide valuable analyses and information on tribal exposures, they rely upon hypothetical representative individuals and do not fully reflect the exposure of Tribal fishermen to radionuclides in the Columbia River. This WRG report is the first test of the CRD model emphasizing ethnographically validated data concerning Native American fishermen and their activities on the Columbia River

We estimate the doses that could have been received as a result of radionuclide releases to the river from Hanford production reactors from 1950 to 1971 for three types of representative Native American fishermen using the Columbia River. These individuals are: a maximally exposed Native American (Maximum River User), a moderately exposed Native American (Median River User), and a minimally exposed Native American (Minimum River User). This report includes fishing and other activities only on the Columbia River. It does not include doses received from fishing on tributaries of the Columbia River

This study is unique because it relates the potential doses to these three representative individuals to fisherman profiles of known individuals using known fishing sites along the Columbia River in 1967. This has allowed us to analyze the effects of fishing site locations and number of fishing sites on radiation doses. This report does not calculate doses for specific individuals. Rather, we use Yakama Tribal fishermen and the number and locations of their fishing sites to construct a framework from which more specific doses can be determined in the future. The use of actual fishing site locations and fishermen profiles will also permit future assessment of the health consequences for Native American consumers of fish on the middle Columbia River.

Chapter 1 of this report presents the history of Hanford operations and of the Hanford Environmental Dose Reconstruction Project. Chapter 2 presents the principal sources of data used in our analysis. Chapter 3 presents the methodology used to map the Yakama Tribal fishing sites and calculate doses to Native American fishermen. Because it plays an integral part in our analysis, chapter 4 is devoted entirely to a detailed description of the Columbia River Dosimetry model. Chapter 5 discusses the results of our analysis. In this chapter we briefly review the results attained by Battelle, Pacific Northwest Laboratories and compare them to the results of our analysis. We describe the spatial distribution of the Yakama Tribal fishing sites and link the fishermen using those sites to the doses calculated for the three representative individuals. We limit our detailed discussion in this chapter to an analysis of the 21-year dose calculations only. Dose calculations for representative individuals using the fishing sites for 21-year and one-year periods may be found in Appendices C and D, respectively. Finally, chapters 6 and 7 discuss our results and present our conclusions and recommendations for further research. Our conclusions are summarized below:

Summary of Observations and Conclusions

1. Dose is a function of:
   1. location on river
   2. amount of river use (fish and water consumption, boating, swimming)
   3. duration of use (in months or years)
   4. period of use (use during years of peak releases leads to higher doses)
2. The 21-year cumulative doses are 25 to 35 times higher than the 1-year doses.
3. Doses to individuals using the river in river reach #4 (Snake River/Walla Walla: above river mile 285) were 25 percent to 30 percent higher doses than doses to individuals utilizing the river downstream.
4. The lower large intestine generally received higher doses than red bone marrow.
5. Consumption of resident fish is the largest contributor to total dose; this dose is 10 to 15 times higher than that received from eating salmon for one year and 10 times higher for 21 years of exposure. The variance depends on the amount of river use and fishing site locations.
6. Sodium-24 is the largest contributor to the external exposure dose. By reach 6, the contribution of Na-24 to the total EDE is negligible for the one-year period between January 1967 through December 1967.
7. Phosphorous-32 and Zn-65 contribute most to total EDE.
8. Sodium-24, As-76, and Np-239 become less important contributors to dose as one moves down river from reach 4 to reach 11.
9. Minimum river use individuals received an average 21-year cumulative dose from January 1950 through January 1970 of 117 mrem; median river use individuals received an average of 436 mrem; maximum river use individuals received an average of 916 mrem.
10. The average dose to a minimum river use individual in 1967 was 4 mrem; to a median river use individual was 16 mrem; to a maximum river use individual was 33 mrem.
11. Seventy percent of the Yakama Tribal fishermen in this study are categorized as minimum river users; 20 percent are categorized as median river users; 10 percent are categorized as maximum river users.
12. The number of Yakama Tribal fishing sites and fishermen is more highly concentrated in the section of the Columbia River between Bonneville Dam and John Day Dam (river reaches 7, 8, 9, 10, and 11). Therefore, a majority of Yakama Tribal fishermen could have been exposed to smaller doses than the few who fished closer to Hanford.
13. External exposures and consumption of drinking water become less important contributors to dose as one consumes more salmon and resident fish. This is independent of the river reach in which one fishes.
14. Consumption of resident fish and salmon become more important contributors to dose the farther from Hanford one fishes. External exposures and drinking water become less important with distance from Hanford. This is because the primary radionuclide that contributes to dose from external exposures, Na-24, decays rapidly and is largely dissipated by river reach 6.
15. The CRD model does not account for the consumption of fish skin, scales, bones, heads, and viscera that are consumed by Native Americans. Due to different bioaccumulation rates in these organs, the actual doses to Native Americans may be larger than can currently be estimated with the CRD model.
16. Not all fish produced in Yakama Tribal fisheries were ingested by the fishermen who caught them. Many were distributed throughout the Native American community at public gatherings, family events, and ceremonies. Many fish were sold at the market. Therefore, some Native American fishermen may have actually received less dose than calculated in this analysis

Recommendations For Further Research

There are a number of suggestions for additional research that would strengthen the conclusions reached in this report. First, the dietary and river use patterns of fifteen to twenty specific individuals should be used to validate the use of representative individuals. Ideally, these individuals should be selected from among the fishermen whose fishing sites were originally mapped in 1967.

The doses in this analysis include only the Columbia River pathway; they do not include the air pathway. Native American fishermen typically spent many hours outdoors throughout the year. They were exposed not only to radiation from the river pathway, but also to I-131 fallout from the air. Therefore, an effort should be made to combine the dose calculations from both the air and river pathways to arrive at a total radiation dose from the Hanford Site. Recent work by PNNL and CRCIA (1998) addresses the health risks associated with exposure to many of these additional pathways. The work in the PNNL and CRCIA report could be strengthened through the use of ethnographically validated, empirical data such as those found in our report.

More ethnographic work should be undertaken specifically to investigate the effects of fisherman behavior on dose during the period of Hanford operations. For example, how and with whom did fishermen share fish with others in the community; what methods of fish storage and preparation had the most impact on radiation dose; how did fishermen use multiple fishing sites over time.

In light of the fact that Native Americans regularly consume many parts of the fish ignored by the CRD model, bioconcentration factors for fish skin, scales, bones, viscera, and other parts should be developed and incorporated into the CRD model. This would do much to improve the accuracy of dose calculations for Native Americans who consume fish from the Columbia River. Although recent work by Hoffman et al. (1997) calculates doses based on modified bioconcentration factors from the HEDR Project, their modifications are arithmetic and do not incorporated the consumption of fish parts other than flesh, such as skin, scales, bones, and viscera.

Several decades have passed since the height of Hanford's radiation emissions, thus allowing enough time for development of radiation induced pathologies. We recommend that monitoring be initiated to watch for signs of increased diseases that may have resulted from exposure to radiation from Hanford operations. This recommendation runs counter to the findings of Hoffman et al. (1997). In fact, their work relies on the same ingestion rates for fish in the HEDR Project; the HEDR rates underestimate the doses received by Tribal fishermen. Had they used consumption rates and river use patterns representative of Tribal subsistence fishermen, and derived more accurate bioconcentration factors to reflect the Tribal practice of consuming fish parts other than flesh, their calculations would have resulted in higher doses and health risks.

Further, we recommend that particular attention be paid to Native Americans, such as the Wanapum Tribe, who regularly consumed resident fish taken from high exposure areas of the Columbia River between the Hanford Site and Priest Rapids. This part of the Columbia River was not modeled by the HEDR Project. Such persons were probably exposed to much higher levels of radiation than others who took their fish from further downstream. Similarly, tribal members who consumed fish that ascended the Yakima River, and perhaps the Walla Walla River, might also have received significant radiation doses.

Finally, we recommend that uncertainty analyses be performed on the results of the CRD model after supplemental data have been identified and incorporated into our Native American fishing model. Although the results obtained to date are compelling, an assessment of their precision would be a welcome addition.

The productivity of dipnet fishermen in the Wayam region of Celilo Falls is described. Central is an analysis of a body of information recorded by Joe Pinkham enumerating the fall chinook and steelhead catch for September 1945. The actual numbers of fish taken by 169 fishermen at the Wayam fishery suggest that certain conceptual refinements are necessary in the ongoing debate concerning tribal fish catch and fish consumption in the Plateau. Other suggestions for research include the desirability of developing more precise data from situations where direct historical observations have been made.

Dr. Walker conducted ethnographic and ethnohistoric research concerning the reserved treaty rights of the Yakama Indian Nation to use the public roads of the State of Washington. He provided depositions, responded to interrogatories, prepared reports, and gave testimony in trial in support of the Yakama Indian Nation.