Comment on "Determinants of PFOA Serum Half-Life after End of Exposure: A Longitudinal Study on Highly Exposed Subjects in the Veneto Region"

The paper by Batzella et al.1 considered 5,860 persons 14-52 years of age exposed to per- and polyfluoroalkyl substances (PFAS). The participants, residents of the Veneto Region in Italy, underwent two rounds of screening in the regional Health Surveillance Plan. The half-life results for perfluorooctanoic acid (PFOA) were simi-lar to those described in the Mid-Ohio Valley (United States) and in Ronneby (Sweden), where exposure was estimated for a smaller number of residents.2,3 The results pertain to a subset of individuals who underwent the second round of screening and, by definition, exclude all those who did not participate in the surveillance program.

The new results are important from a pharmacokinetic perspec-tive. They also indicate that some subpopulations are still being exposed, even after the commendable and timely implementation of double filtration with activated carbon in the aqueducts of the most highly contaminated area (known in the literature as Red Area A).4 We therefore believe far more research should address pathways of exposure beyond drinking water.

The paper presents new knowledge regarding the role of some lifestyle factors (obesity, alcohol consumption, smoking habits) in influencing the serum clearance process of PFOA. However, con-sumption of drinking water and food was not considered. Further investigation seems appropriate, given that a previous study showed that 50.9% of residents in the affected area consumed vege-tables from their own garden, 20.9% consumed their own animal products (mostly eggs and poultry), and 11.6% consumed water from private wells.4

There is already evidence that food and water consumption is an important source of PFAS exposure in this region: Biomonitoring studies carried out by Istituto Superiore di Sanità (ISS) about 2 years before the start of the first round of Health Surveillance Plan screening also showed higher serum concentrations of PFOA among 257 resi-dents who raised livestock for self-consumption and among 122 farmers and breeders who consumed beef from their own farmsteads.5,6 In an unpublished scenario analysis conducted by the ISS in 2019, the estimated adult daily intake of PFOA and perfluorooctane sulfonate (PFOS) was about 0:6 ng=kg=day and 1:7 ng=kg=day, respectively, among residents in Red Area A, based on drinking water doubly filtered with activated carbon and eating local food over anextended period.7 Elevated exposure to PFOA among those consuming vege-tables from their own garden was described in the Mid-Ohio Valley.8 Thus, ongoing exposure to PFOA and PFOS from sources other than tap water among residents in Red Area A cannot be ruled out. Residual excesses in daily intakes might influence the half-life of these congenersinsome subgroupsofthe affected population.

References

References

1. Batzella E, Rosato I, Pitter G, Da Re F, Russo F, Canova C, et al. 2024. Determinants of PFOA serum half-life after end of exposure: a longitudinal study on highly exposed subjects in the Veneto region. Environ Health Perspect 132(2):27002, PMID: 38306197, https://doi.org/10.1289/EHP13152.

2. Bartell SM, Calafat AM, Lyu C, Kato K, Ryan PB, Steenland K. 2010. Rate of decline in serum PFOA concentrations after granular activated carbon filtration at two public water systems in Ohio and West Virginia. Environ Health Perspect 118(2):222-228, PMID: 20123620, https://doi.org/10.1289/ehp.0901252.

3. Li Y, Fletcher T, Mucs D, Scott K, Lindh CH, Tallving P, et al. 2018. Half-lives of PFOS, PFHxS and PFOA after end of exposure to contaminated drinking water. Occup Environ Med 75(1):46-51, PMID: 29133598, https://doi.org/10.1136/oemed-2017-104651.

4. Pitter G, Da Re F, Canova C, Barbieri G, Zare Jeddi M, Daprà F, et al. 2020. Serum levels of perfluoroalkyl substances (PFAS) in adolescents and young adults exposed to contaminated drinking water in the Veneto region, Italy: a cross-sectional study based on a health surveillance program. Environ Health Perspect 128(2):27007, PMID: 32068468, https://doi.org/10.1289/EHP5337.

5. Ingelido AM, Abballe A, Gemma S, Dellatte E, Iacovella N, De Angelis G, et al. 2018. Biomonitoring of perfluorinated compounds in adults exposed to contami-nated drinking water in the Veneto region, Italy. Environ Int 110:149-159, PMID: 29108835, https://doi.org/10.1016/j.envint.2017.10.026.

6. Ingelido AM, Abballe A, Gemma S, Dellatte E, Iacovella N, De Angelis G, et al. 2020. Serum concentrations of perfluorinated alkyl substances in farmers living in areas affected by water contamination in the Veneto region (Northern Italy). Environ Int 136:105435, PMID: 31935559, https://doi.org/10.1016/j.envint.2019.105435.

7. Istituto Superiore di Sanità. Reparto di Chimica Tossicologica, Dipartimento Ambiente e Salute. 2017. Biomonitoraggio di sostanze Perfluoroalchiliche (PFAS) nella Regione Veneto. Risultati della determinazione della concentrazione di PFAS nel siero di operatori e residenti in aziende agricole e zootecniche. Roma, Italy: Istituto Superiore di Sanità. https://sian.aulss9.veneto.it/index.cfm?method= mys.apridoc&iddoc=3191 [accessed 2March 2024].

8. Steenland K, Jin C, MacNeil J, Lally C, Ducatman A, Vieira V, et al. 2009. Predictors of PFOA levels in a community surrounding a chemical plant. Environ Health Perspect 117(7):1083-1088, PMID: 19654917, https://doi.org/10.1289/ehp. 0800294.