Food Safety and Environmental Stewardship Program

This work sought to characterize the effect of traditional Native American fish smoking methods on dietary exposure to PAHs and identify possible risks to human health. To this end, fresh spring-run Chinook salmon were purchased from Tribal fisherman and smoked using two commonly used smoking structures (tipi or shed) and two types of traditionally used woods (apple or alder). Salmon smoking events were carried out by Tribal researchers at the Confederated Tribes of the Umatilla Indian Reservation (CTUIR) in collaboration with Oregon State University Superfund Research Program (OSU SRP) researchers. For the purposes of exposure and risk assessment, all salmon samples were prepared as if to be eaten. Additionally, 20 non-smoked spring-run Chinook salmon were analyzed for background PAH content along with three commercially available smoked salmon.

Across all smoking methods, individual PAH loads ranged between < 2 – 3,800 μg/kg, where non-carcinogenic and carcinogenic PAHs accounted for 90% and 10% of the total PAH load respectively. It was found that neither smoking structure nor wood type accounted for differences in smoked salmon PAH content. However, PAH loads in traditionally smoked salmon were 40 – 430 times higher than PAH loads measured in fresh caught non-smoked salmon and commercial smoked salmon. Exposure to levels of carcinogenic PAHs measured in traditionally prepared smoked salmon could result in excess lifetime cancer risks between 1E-5 and 1E-4 at a daily consumption rate of 5 g/d and could approach 1E-2 at 300 g/d. Exposure to non-carcinogenic PAHs could result in hazard indexes of 0.005 at 5 g/d and approach 0.3 at 300 g/d. PAH levels present in smoked salmon prepared using traditional Native American methods potentially pose elevated cancer risks if consumed at high consumption rates over many years.

Study results are currently being evaluated in order to design a culturally specific message for the Tribes.