Geographical Differences in Dietary Exposure to Perfluoroalkyl Acids between Manufacturing and Application Regions in China

Abstract

Emissions of perfluoroalkyl acids (PFAAs) have increased in China over the past decade, but human exposure pathways are poorly understood. Here we analyzed 15 PFAAs in commonly consumed food items and calculated body weight normalized dietary intake rates (estimated dietary intake, EDIs) in an area with ongoing PFAA production (Hubei province; n = 121) and an urbanized coastal area (Zhejiang province; n = 106). Geographical differences in concentrations were primarily observed for perfluorooctanesulfonic acid (PFOS) and perfluorohexanesulfonic acid (PFHxS) in animal food items and short-chain PFAAs in vegetable food items. The average EDI of ∑PFAAs for adults in Hubei (998 ng kg day) was more than 2 orders of magnitude higher than that in Zhejiang (9.03 ng kg day). In Hubei province, the average EDI of PFOS for adults (87 ng kg day) was close to or exceeded advisory guidelines used in other countries indicating health risks for the population from long-term exposure. Yet, PFOS could only account for about 10% of the EDI of ∑PFAAs in the Hubei province, which was dominated by short-chain PFAAs through consumption of vegetables. The large contribution of short-chain PFAAs to the total EDIs in manufacturing areas emphasize the need for improved exposure and hazard assessment tools of these substances.

Risk to human health related to the presence of perfluoroalkyl substances in food

“…The maximum concentration of PFBA recorded in the Rhine/Meuse delta was 330 ng/L as estimated from the author's figure. Zhang et al (2017) reported on PFBA in food from a contaminated site and a site without known contamination. The concentration in legumes and leafy vegetables from the contaminated site was up to 200 and 1,000 ng/g ww, respectively, whereas the concentrations in the same vegetables from the noncontaminated site were 1 ng/g ww or lower.…”

“…Concentrations up to 0.80 ng/L, corresponding to a bioconcentration factor (related to concentration in ground water) of 0.072, were reported. Zhang et al (2017) report on PFHpA in food from a contaminated site and a site without known contamination. The authors calculated that the total daily intake by adults (fish liver not considered due to lack of data) from the contaminated site was 2.94 ng/kg bw per day and 0.003 ng/kg bw per day at the non-contaminated site.…”

Strategies for grouping per- and polyfluoroalkyl substances (PFAS) to protect human and environmental health

“…47 In regions where the soil is highly contaminated with short-chain PFAAs, human exposure from consumption of crops can become an important pathway. 49 A fundamental limitation of grouping according to bioaccumulation potential (B) is that for highly persistent chemicals, B may become less relevant if a high exposure is achieved via other pathways than uptake and accumulation within the body. It has been argued 50 that B is not a sufficient criterion for protecting against poorly reversible effects because the residence time of highly persistent chemicals in the environment is oen much greater than their residence time in humans and biota, which means that levels in organisms will be poorly reversible regardless of the magnitude of B.…”

Variety-Selective Rhizospheric Activation, Uptake, and Subcellular Distribution of Perfluorooctanesulfonate (PFOS) in Lettuce (Lactuca sativa L.)

“…Perfluorooctanesulfonate (PFOS) is one of the perfluoroalkyl sulfonic acids (PFSAs) widely used in industrial and commercial products, − resulting in ubiquitous occurrence in the environment. − Agricultural soil is an important sink of PFOS at concentrations up to ∼1.8 mg/kg, due to application of biosolids, usage of pesticides, irrigation of wastewater, and degradation of PFOS precursors . PFOS in agricultural soil can be absorbed and accumulated in the edible parts of crops, thereby causing PFOS intake in human bodies via food chain. , Vegetable consumption can contribute important PFOS intake in human bodies in some areas, similar to those through consumption of drinking water, eggs, meat, and seafood. ,, Once ingested, PFOS persists in a half-life of up to 5.4 years, posing severe threats to human health due to its potential toxicity to liver, kidney, nervous, and immune systems. , PFOS is among the most toxic PFSAs to the human body. , Therefore, the human health risk posed by PFOS contamination in edible crops has attracted worldwide attention. , PFOS and its salts have been listed in Annex B of the Stockholm Convention on Persistent Organic Chemicals in 2009 . More conservative tolerable daily intakes (TDIs) of PFOS have been proposed by different organizations, such as 20 ng/(kg·day) by the U.S. Environmental Protection Agency (EPA) in 2016 and 13 ng/(kg·week) by the European Food Safety Authority (EFSA) in 2018 …”

“…7,8 Vegetable consumption can contribute important PFOS intake in human bodies in some areas, similar to those through consumption of drinking water, eggs, meat, and seafood. 2,8,9 Once ingested, PFOS persists in a half-life of up to 5.4 years, 10 posing severe threats to human health due to its potential toxicity to liver, kidney, nervous, and immune systems. 2,8 PFOS is among the most toxic PFSAs to the human body.…”