Levels of Perfluorochemicals (PFCs) and Their Predictors in the Ethnically Diverse Biomonitoring Exposures Study (BEST) Cohort in California

BACKGROUND:  Perfluorochemicals (PFCs) are used to make a wide variety of consumer products resistant to grease, water, and stains. They persist in the environment and have been detected in people worldwide. The available scientific data suggest a link between exposure to certain PFCs and developmental effects and decreased fertility. One of these, perfluorooctanoic acid (PFOA), has also been identified as a carcinogen. Suspected routes of exposure to PFCs among adults are diet and the use of PFC-containing products. To investigate how PFC exposure may vary across demographic subgroups, we measured levels of PFCs in a sample of adult members of Kaiser Permanente Northern California living in California’s Central Valley as part of the Biomonitoring Exposure Study (BEST).

METHODS:  Participants were recruited in 2013, with an oversampling of Hispanics and Asians and Pacific Islanders (APIs). A self-administered questionnaire, available in English and Spanish, captured demographic, lifestyle, and dietary information. Blood levels of 11 PFCs were analyzed in 337 participants at the California Department of Toxic Control Laboratory by online SPE-HPLC-MS/MS analysis. We computed descriptive statistics of PFC concentrations, and geometric means were compared across demographic subgroups. We also compared our results to the Centers for Disease Control and Prevention National Health and Nutrition Examination Survey (NHANES). We identified factors that predicted elevated levels of exposure using multivariate linear regression.

RESULTS:  Of the 11 PFCs measured, seven were detected in more than 82% of the BEST cohort. Levels were generally lower than the 2011-12 NHANES comparison group. Univariately, levels in BEST increased with age and education level; they also varied by race/ethnic group, years living in the U.S., and country of birth. Preliminary results from multivariate linear regression revealed increased age as a significant predictor for all PFCs. Other predictors, which varied by PFC, were higher education level, living in the U.S. for 25 years or more, higher consumption of fresh fish and seafood, male sex, and API race/ethnicity. 

CONCLUSIONS:  This is one of the first studies to provide PFC levels for a racially/ethnically diverse adult cohort in California. It supports previous research showing a relationship between fish consumption and elevated levels of some PFCs (e.g., Perfluoroundecanoic acid). Additionally, results suggest populations that may be more highly exposed to PFCs, which can inform future investigations.