Ostertag, SK, BA Tague, MM Humphries, SA. Tittlemier, HM Chan. 2009. Estimated dietary exposure to fluorinated compounds from traditional foods among Inuit in Nunavut, Canada. Chemosphere 75 (9):1165-1172.
The Inuit’s traditional diet of caribou, fish and whale contains more nonstick chemicals than store-bought foods, but the exposure poses minimal risk, say the study’s authors.
Traditional and locally harvested foods contribute more persistant, stain-repelling compounds to the native Inuit diet than packaged food that is imported and sold at the local stores, report researchers who analyzed and compared exposures from the two food sources.
The Inuit is the collective name for the native people living in the Arctic regions of North America. Because of their traditional diets and the cold environment they live in–and because, over time, persistent organic pollutants like these stain-repelling compounds are transported atmospherically to cold regions where they become more concentrated–, the Inuit are exposed to more persistant pollutants than people living in warmer climates.
In this study low concentrations of the perfluorinated compounds (PFCs) were measured in the traditional foods but they were more common in these than store bought foods. The estimated PFC exposure of the Nunavut Inuit studied is similar to levels measured in Canadians and Europeans. Yet, no universal health standards are set for PFC exposure, so the health impacts are unclear. Limited animals studies show some PFC types can cause tumors and affect development and reproduction .
The authors’ own risk assessments estimate that the dietary PFC exposure does not pose a health risk to the Inuit. Their conclusions are based on traditional toxicology results from animal studies and on a provisional acceptable intake for PFCs that is currently used in Germany to assess human health risks.
The samples analyzed in this study were collected in the late 1990s at a time when concentrations of some forms of PFCs in the Arctic environment were increasing. More recent work is showing declines of some types of PFCs in marine mammals and birds in the Arctic.
The authors caution, though, that levels of other PFCs continue to increase in animals that provide traditional foods. They suggest further studies are needed to assess health impacts.
PFCs have been used since the 1950s because they are very effective at repelling greases and water on furniture and clothing and at keeping food from sticking on pots and pans. They are also used in the manufacture of airplanes, adhesives, computers, cosmetics and cleaners.
Though some types of PFCs have been recently banned due to concerns over their persistence and accumulation in the environment and their global presence in humans and wildlife, production and use other PFCs continues. It is well known that these chemicals are in our air, drinking water and foods, but diet has recently been identified as the main route of exposure for humans.
Researchers analyzed many of the traditional foods eaten by Inuit living in the Canadian Arctic for 11 PFCs. Included were liver of ringed seal and caribou and meat of polar bear and beluga whale. They compared levels of PFCs in these traditional foods with previously reported PFC concentrations in foods purchased at grocery stores, including coffee, tea, bread, potatoes and meat (chicken, pork, beef and processed meats). People’s exposure estimates were based on published survey data detailing preferred foods eaten by Nunavut residents.
PFCs were found in 90 percent of the traditional foods analyzed (n=68) but these chemicals were at low levels (< 10 parts per billion) in all of the samples. In contrast, the same PFCs have been found in only 17 percent of samples of packaged store foods. Meats from the grocery store contain similar concentrations of PFCs as caribou and seal meats, but other traditional foods had higher concentrations of PFCs than any of the purchased foods. Primary sources of dietary PFCs were caribou meat, Arctic char, cookies, cheese, and beluga muktuk (skin and blubber).
Traditional foods represented a higher percentage of PFCs than market food for men, women and all age groups. As an example, caribou meat contributed between 43 and 75 percent of daily dietary PFC exposure. Older men – who eat more traditional foods – had the biggest exposures that were statistically higher than those for either younger men or women of the same age.