Global distribution of perfluorochemicals (PFCs) in potential human exposure source–A review

Highlights

• Neutral PFCs are dominant in indoor air and dust.

• Dietary PFC exposure is mostly through fish, shellfish and meat consumption.

• Well water and tap water contain relatively higher PFC concentrations than other types of drinking water.

Abstract

Human exposure to perfluorochemicals (PFCs) has attracted mounting attention due to their potential harmful effects. Breathing, dietary intake, and drinking are believed to be the main routes for PFC entering into human body. Thus, we profiled PFC compositions and concentrations in indoor air and dust, food, and drinking water with detailed analysis of literature data published after 2010. Concentrations of PFCs in air and dust samples collected from home, office, and vehicle were outlined. The results showed that neutral PFCs (e.g., fluorotelomer alcohols (FTOHs) and perfluorooctane sulfonamide ethanols (FOSEs)) should be given attention in addition to PFOS and PFOA. We summarized PFC concentrations in various food items, including vegetables, dairy products, beverages, eggs, meat products, fish, and shellfish. We showed that humans are subject to the dietary PFC exposure mostly through fish and shellfish consumption. Concentrations of PFCs in different drinking water samples collected from various countries were analyzed. Well water and tap water contained relatively higher PFC concentrations than other types of drinking water. Furthermore, PFC contamination in drinking water was influenced by the techniques for drinking water treatment and bottle-originating pollution.

Introduction

Perfluorochemicals (PFCs) are a family of man-made compounds with strong CF bonds. Due to their unique properties, they are commonly used in consumer products and industrial processes, such as protective coatings of carpets and furniture, paper and cloth coatings, Polytetrafluoroethylene products, and fire-fighting foams (Ahrens and Bundschuh, 2014, Clara et al., 2008, Paul et al., 2009, Route et al., 2014). They have been widely detected in drinking water (Hoffman et al., 2011, Post et al., 2009, Thompson et al., 2011), air (Fromme et al., 2015, Goosey and Harrad, 2012, Karaskova et al., 2016, Piekarz et al., 2007), and human blood (Bjerregaard-Olesen et al., 2016, Ehresman et al., 2007, Karrman et al., 2007, Wu et al., 2017, Yeung et al., 2006), urine (Genuis et al., 2013, Jurado-Sanchez et al., 2014), breast milk (Barbarossa et al., 2013, So et al., 2006, Tao et al., 2008a, Tao et al., 2008b, Thomsen et al., 2010), nails(Li et al., 2012, Li et al., 2013, Liu et al., 2011) and hairs (Alves et al., 2015, Krol et al., 2013, Martin et al., 2016, Rodriguez-Gomez et al., 2017). Many studies also have reported that PFCs may be associated with human diseases, such as urine acid, thyroid diseases, peroxisome proliferation, asthmatic, liver tumor, hyperuricemia, pediatric atopy, chronic kidney disease, behavioral disorders, and immune toxicity (Bloom et al., 2010, Dong et al., 2013, Gump et al., 2011, Lopez-Espinosa et al., 2011, Wang et al., 2011a). As a result, the production and regulation of PFCs have attracted public attention. In 2000, 3M first announced a global phase-out of its products containing C6, C8, and C10 PFCs and replaced them with shorter C4 PFC (e.g., perfluorobutane sulfonic acid or PFBS) products. Eight major PFC manufacturers joined the United States Environmental Protection Agency (USEPA) 2010/15 PFOA Stewardship Program in 2006 to work towards the elimination of long-chain perfluoroalkyl carboxylic acids (PFCAs) and their potential precursors by 2015. In addition, perfluorooctane sulfonate (PFOS) and perfluorooctane sulfonyl fluoride (POSF) related compounds were listed under Annex B of the Stockholm Convention in 2009 (Wang et al. 2009). C11–C14 PFCAs, perfluorooctanoic acid (PFOA) and ammonium perfluorooctanoate (APFO) were recognized as vPvB chemicals (very persistent and very bioaccumulative), and included in the Candidate List of Substances of Very High Concern under the European chemicals regulation in 2012–2013. The different regulations of PFCs have led to varieties in production and time or region-dependent environmental distributions of PFCs.

Since PFCs are extremely persistent and associated with some human diseases (Costa et al., 2009, Dallaire et al., 2009, Gallo et al., 2012, Sakr et al., 2007, Stein et al., 2009), the biomonitoring of human exposure to PFCs has become increasingly important. It has been suggested that food sources, drinking water, and airborne sources are main PFC exposure routes for humans (D'Eon and Mabury, 2011, D'Hollander et al., 2010a, Enault et al., 2015, Harada et al., 2005, Tittlemier et al., 2007), although the contribution from each source remains unclear. Thus, it is critical to profile PFC concentrations in these potential exposure sources from time to time, which will be useful for evaluation of health effects induced by PFCs. Although numerous studies have been published on the monitoring and exposure of PFCs (Butenhoff et al., 2006, De Felip et al., 2015, Hoelzer et al., 2008, Landsteiner et al., 2014), only a limited number of reviews have been done to outline these research data, especially within the recent five years. Earlier reviews included Houde et al. (2006) and Lau et al. (2007), which summarized the biological monitoring of PFCs in wildlife and humans, discussed possible sources, and identified knowledge gaps. Trudel et al. (2008) assessed and modeled consumer exposure to PFOS and PFOA from a variety of environmental and product-related sources. Fromme et al. (2009) published a review on PFC monitoring data in environmental media relevant to human exposure. They outlined PFC concentrations in indoor and ambient air, house dust, drinking water, and food, as well as human biomonitoring data in blood, breast milk, and human tissues, and proposed that the consumption of highly contaminated fish products may substantially increase PFC body burdens. Kantiani et al. (2010) reviewed PFCs and other emerging contaminants in food, but focused more on methods used for detecting and quantifying PFCs. The review by D'Hollander et al. (2010a) suggested that PFC data in human diet and indoor dust were relatively scarce compared to those published in fish and drinking water. Domingo (2012) summarized PFC concentrations in foodstuffs and human dietary exposure to these compounds, as well as human biomarkers from different countries. However, PFC concentrations in different foodstuffs were only added in the discussion without detailed analysis. Wang et al. (2015) reviewed the sources, multimedia distribution and health risks of PFCs in China and suggested that terrestrial food (meat) contributed 93.2% of PFOA to human exposure, while seafood contributed 78.9% of PFOS. Several articles reviewed human exposure to PFOS, especially PFOS isomers, and provided definitive insights into the role of “precursor exposure” (Chen et al., 2009, Houde et al., 2006, Kovarova and Svobodova, 2008, Lau et al., 2007, Lindstrom et al., 2011, Mercier et al., 2011, MiraIles-Marco and Harrad, 2015). All these reviews are valuable for the establishment of biomonitoring and human exposure profiles for PFCs. As mentioned previously, the regulations on PFC production may lead to spatial and temporal changes of PFC concentrations and compositions in environmental media. Furthermore, journal articles related to human exposure to PFCs and health effects have increasingly emerged in recent six years. Thus, a systematic analysis of PFC concentrations in food, drinking water, and indoor air and dust is critically needed.

In this study, we reviewed recent studies on PFCs in potential sources (e.g. air, food and drinking water) related to human exposure. We outlined the occurrences of different PFC congeners/isomers in indoor air and dust, foodstuffs (e.g., vegetables, dairy products, beverages, eggs, meat and meat products, fish, and shellfish), and drinking water. Based on these data, we aimed to profile spatial distributions of PFCs in our surrounding environment and establish a good baseline for human exposure risk assessment.