Page 4 - Lake Roosevelt Forum 2020 Public Guide

Human Health Risk Assessment
EPA’s draft Human Health Risk Assessment (HHRA) estimates the nature and probability of adverse human health effects from being exposed to chemicals (primarily metal contaminants) of concern now or in the future. This is a key milestone in the ongoing Remedial Investigation/Feasibility Study (RI/FS). Based on the level of risk found, determinations will then be made regarding what, if any, type of additional cleanup or other actions are needed.
The Upper Columbia River (UCR) HHRA uses the results of site-specific investigations and information from the scientific literature regarding exposure and toxicology to assess potential health risks for individuals in the area. The lengthy period of investigation reflects the complexity of a site that is very large, has multiple contaminants being evaluated, and potential ways people can be exposed.
The population groups evaluated in the HHRA include residents, recreational visitors, outdoor workers, and members of the Colville Confederated Tribes and Spokane Tribe of Indians. This public guide focuses on HHRA findings for residents, recreational visitors and workers.
What the HHRA Does and Doesn’t Provide
DOES
• Estimate human health risks (cancer and non-cancer) from exposure to lead and other chemicals of concern.
• Provide the necessary information to assess whether further cleanup or other actions are needed.
• Use current EPA benchmarks to assess risk and assure a high degree of human health protection and risk prevention. For instance, triggering a cancer benchmark requires an estimated increase in lifetime cancer risk of at least a 1 in 10,000 among populations being exposed to the chemicals of concern under reasonable maximum exposure scenarios. By comparison,
Focal Areas for Human Health Risk Assessment
The desired result of investigating complex relationships between chemicals of concern, exposure pathways, and exposed populations is to establish a safe level of human contact with chemicals of concern.
the Washington Department of Ecology applies a cancer risk threshold of 1 in 100,000 for its cleanup evaluations.
DOES NOT
• Recommend whether or where further cleanup or other actions are needed. These decisions occur when EPA risk managers assess the results in the next phases of the RI/FS process.
• Suggest further precautionary measures or advisories to protect human health.
• Collect data based on blood or other medical test of individuals.
• Recommend or address other issues such as the buying or selling of property where concentrations of lead in soil may exceed benchmarks.
Chemicals (Contaminants) of Concern
INORGANIC
- Heavy metals such as
lead, arsenic, cadmium,
copper and zinc - Mercury
ORGANIC - PCBs
- Dioxins/Furans
Exposure Media
- Air
- Surface Water
- Soil
- Fish
- Plants
- Game
- Beach Sediment
- Mussels/Crayfish
- Amphibians/Reptiles
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Populations of Concern
- Residents
- Recreational Visitors
- Residents of Colville Indian Reservation
- Subsistence Lifestyles of the Colville Tribes and Spokane Tribe of Indians
- Outdoor Workers