Page 8 - Lake Roosevelt Forum 2020 Public Guide

Human Health Risk Assessment
Upper Columbia Valley Cancer and Non-Cancer Risk
A range of metalloids and other chemicals found in the Upper Columbia River Site were evaluated for cancer and non-cancer risks. These represent contaminants other than lead.
For both residents and recreational visitors, no results exceeded EPA’s cancer benchmark. This means there is less than a 1-in-10,000 chance of a person being sufficiently exposed to one or more chemicals that can trigger cancer.
When evaluating possible human exposure to chemicals at the 588 residential decision units (soil sampling areas):
• No individual chemical exceeded the benchmark for non-cancer risk.
• When summing the exposure risk by target
organ for all chemicals except those from fish consumption, only one decision unit exceeded the non-cancer benchmark for children.
Non-cancer Benchmark Exceedances
• When summing the exposure risk, by target organ for all chemicals including fish consumption:
• Non-cancer benchmarks for children exposed to non-lead chemicals were marginally exceeded for developmental and nervous systems, and skin/hair/nails systems.
• Developmental and nervous system effects are driven by methylmercury, and skin/hair/ nail system effects are driven by thallium. Both occur due to fish consumption.
• As shown in the graphic, the number of exceedances differed by fish species.
• As shown in the section summarizing fish consumption findings, this is consistent with exceedances of non-cancer benchmarks for children consuming fish. To safely consume fish, follow the Washington Department of Health Fish Advisory (see pages 10-11).
for Children When Risks are Summed Across All Chemicals Except Lead
When the effect of fish consumption is included, non-cancer benchmarks for children are marginally exceeded due to exposure from methylmercury and thallium.
Fish Consumption
linked to exceedance of non-cancer benchmark
Developmental System
Nervous System
Skin/Hair/Nails Systems
Reproductive System
Cardiovascular System
0
0
0
0
White Sturgeon
0
588 of 588 DU
18 of 588 DUs
Whitefish
588 of 588 DUs
588 of 588 DUs
588 of 588 DUs
0
0
0
Burbot
588 of 588 DUs
588 of 588 DUs
438 of 588 DUs
0
0
0
Smallmouth Bass
588 of 588 DUs
588 of 588 DUs
588 of 588 DUs
0
0
0
Walleye
0
588 of 588 DUs
588 of 588 DUs
0
2 of 588 DUs
9 of 588 DUs
8
Sucker
To safely consume fish, follow the Washington Department of Health Fish Advisory (see pages 10-11). Healthy Choice Limit Caution
588 of 588 DUs
588 of 588 DUs
BODY ORGAN WITH NON-CANCER HEALTH RISK
578 of 588 DUs
Based on Soil Sampling of 588 Decision Units (DUs). DUs represent residential soil sampling areas in the Upper Columbia Valley.
588 of 588 DUs
0
Endocrine System
Kokanee
219 of 588 DUs
588 of 588 DUs
Northern Pike
Rainbow Trout
0
0
588 of 588 DUs
588 of 588 DUs
0
0
0
577 of 588 DUs
588 of 588 DUs
0
0
0
0
0
0
0