Risk to human health related to the presence of perfluorooctane sulfonic acid and perfluorooctanoic acid in food

Abstract

The European Commission asked EFSA for a scientific evaluation on the risks to human health related to the presence of perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in food. Regarding PFOS and PFOA occurrence, the final data set available for dietary exposure assessment contained a total of 20,019 analytical results (PFOS n = 10,191 and PFOA n = 9,828). There were large differences between upper and lower bound exposure due to analytical methods with insufficient sensitivity. The CONTAM Panel considered the lower bound estimates to be closer to true exposure levels. Important contributors to the lower bound mean chronic exposure were 'Fish and other seafood', 'Meat and meat products' and 'Eggs and egg products', for PFOS, and 'Milk and dairy products', 'Drinking water' and 'Fish and other seafood' for PFOA. PFOS and PFOA are readily absorbed in the gastrointestinal tract, excreted in urine and faeces, and do not undergo metabolism. Estimated human half-lives for PFOS and PFOA are about 5 years and 2-4 years, respectively. The derivation of a health-based guidance value was based on human epidemiological studies. For PFOS, the increase in serum total cholesterol in adults, and the decrease in antibody response at vaccination in children were identified as the critical effects. For PFOA, the increase in serum total cholesterol was the critical effect. Also reduced birth weight (for both compounds) and increased prevalence of high serum levels of the liver enzyme alanine aminotransferase (ALT) (for PFOA) were considered. After benchmark modelling of serum levels of PFOS and PFOA, and estimating the corresponding daily intakes, the CONTAM Panel established a tolerable weekly intake (TWI) of 13 ng/kg body weight (bw) per week for PFOS and 6 ng/kg bw per week for PFOA. For both compounds, exposure of a considerable proportion of the population exceeds the proposed TWIs.

Influence of the geographical origin on substance concentrations in herring as basis for dietary exposure assessments

“…For the organic contaminants, the concentrations were low in fillets but high concentrations were found in fish liver increasing from north to south and from open sea to fjords in the North Sea area (Frantzen and Måge, ). PFAS concentrations were mostly below the limit of quantification (LOQ) in fillet and liver, for perfluorooctanoic acid the LOQ was 2.4 ng/g and for perfluoroctanesulfonic acid 1.8 ng/g, which was below the cut‐off values 10 ng/g and 14 ng/g used by EFSA for these two substances (Frantzen and Måge, ; EFSA CONTAM Panel, ,b). A similar study was done for Atlantic halibut and concentrations of mercury and organic contaminants in lean and fatty fillet parts increased from north to south and with fish length and weight (Nilsen et al., ).…”

“…In case of missing LOQs and LODs, they were replaced by zero before. Every sample investigated for PCDD/Fs and DL‐PCBs was analysed for all congeners and in this way no sample exclusion was needed for the calculation of sums (EFSA CONTAM Panel, ,b). To weigh the concentrations of the individual congeners according to their different toxicity and to convert the given unit to Toxic Equivalents (TEQ), PCDD/F and DL‐PCB lower and upper bound concentrations were multiplied with Toxic Equivalency Factors (TEF) (European Commission ) established by the World Health Organization (WHO) in 2005.…”

“…In these cases, country‐specific concentration data could help to refine dietary exposure estimates and to see differences related to the origin of consumed food. This is already highlighted by the European Food Safety Authority (EFSA), because Baltic herring is supposed to have higher PCDD/F and DL‐PCB concentrations than herring from other catching areas and for the consumption there could be a country‐specific focus on certain catching areas (EFSA CONTAM Panel, ,b). Different substance concentrations in herring for Norway and Germany could be due to different geographical origins, named ‘catching areas’ for fish.…”

“…EFSA evaluated PCDD/F and DL‐PCB concentrations using pooled European data mostly from Germany, France, Norway and Denmark between 2010 and 2016, and catching areas were not reported and might be mixed (EFSA CONTAM Panel, ,b). For most of the congeners, lower and upper bound mean and P95 concentrations from EFSA (2018) were higher than calculations using German Baltic Sea data.…”

“…Concentrations of PCDD/Fs and DL‐PCBs in herring vary by catching area and fishing season (Karl et al., ; Frantzen et al., ; Karl and Lahrssen‐Wiederholt, ) and concentrations in farmed salmon decrease if the feed composition is changed (Karl and Lahrssen‐Wiederholt, ). Fish and fishery products like herring and salmon from the Baltic region contain higher amounts of PCDD/Fs and DL‐PCBs than from other areas and therefore special recommendations for monitoring are given (European Commission ; EFSA CONTAM Panel, ,b).…”