Per- and polyfluoroalkyl substances (PFASs) were one of the priority substance groups selected in the European Human Biomonitoring Initiative HBM4EU. Several policy-questions on exposure and health effects were developed and addressed under the Scoping Document at the beginning of the research program, including an attempt to answer whether existing regulations on PFASs were sufficient to protect human health. These policy questions were addressed in the Scoping Document for PFASs1 at the beginning of the research program.

The HBM4EU project period coincided with growing awareness of the potentially harmful effects of PFAS exposures in the general population. As an example, in 2020 the European Food Safety Authority derived a new tolerable weekly intake (TWI) of 4.4 ng/kg bw per week, for the sum of PFOA, PFNA, PFHxS and PFOS (EFSA, 2020). The new TWI was derived on the basis of effects on the immune system, more specifically the reduction of antibody response after vaccination in children (Abraham et al., 2020). This TWI corresponds to a blood serum level of 6.9 μg/L in women of childbearing age, which would prevent the breastfed infant from exceeding 17.5 μg/L in serum; the reference point derived by EFSA. In this approach, EFSA assumed equal potency for the four substances as no studies were available to derive relative potency factors (RPFs) for human effects. The dietary exposure assessment performed by EFSA showed that large numbers of the EU-population exceeds the new TWI.

While most individuals are exposed to background-levels of PFASs, some populations living near contaminated sites are exposed at moderate, high or extremely high levels (Xu et al., 2020, 2021; Ingelido et al., 2018). The main sources of PFASs contamination at hotspots are (historical) PFASs production, which contaminated the soil and groundwater, or the use of PFASs containing products such as PFASs containing firefighting foams or PFASs contaminated biosolids applied as soil improving materials. The list of suspected PFASs contaminated sites in the EU is continuously growing. Occupational exposure to PFASs has only been investigated in a few studies (Olsen et al., 2007), such as in fluoropolymer manufacturing, firefighters when using aqueous film-forming foams (AFFF) or professional ski waxers (Langenbach and Wilson, 2021). However, PFASs have a wide range of applications; therefore, occupational exposure is expected to occur in other sectors as well (Langenbach and Wilson, 2021).

This publication synthesizes HBM4EU's activities, results and knowledge gained within the five years and half of HBM4EU and highlights how they may be used to inform science-based policy decisions on PFASs in Europe.