Historical Trend of Exposure to Perfluoroalkyl Surfactants PFOA, ADV, and cC6O4 and its Management in Two Perfluoroalkyl Polymers Plants, Italy.

OBJECTIVES

Perfluoroalkyl acid surfactants are used in the chemical industry for the synthesis of perfluoroalkyl polymers. In one Italian fluoropolymer plant and in the research and innovation center, two major perfluoroalkyl surfactants have been historically used: PFOA and ADV and a third, cC6O4 substituted PFOA from mid-2013. This work is summarizing occupational exposure to these chemicals in the period 2004-2021, assessed by biological monitoring. Moreover, taking advantage of the phasing out of PFOA, the elimination kinetics of PFOA in humans is investigated.

METHODS

Workers exposed to PFOA (from beginning of the sixties to 2013), ADV (since 1996), and/or cC6O4 (since 2012) in the production of fluoropolymers, in the synthesis, research, and analysis, were periodically surveyed from 2004, measuring the concentration of perfluoroalkyl acid surfactants in serum. Workers of the same plants, not directly exposed, were surveyed as well. Applying the first-order kinetics model, the half-life of PFOA was calculated.

RESULTS

809 Workers were investigated with measurements of PFOA (n = 3692), ADV (n = 4288) and cC6O4 (n = 2272) in serum. In the production plant, median PFOA ranged from 1900 to 14 µg/l from 2004 to 2021; median ADV ranged from 434 to 86 µg/l from 2011 to 2021. For cC6O4 the detection percentage ranged from 9 to 47%; in detected samples median cC6O4 ranged from 3 to 16 µg/l in the period 2013-2021. Adopted mitigation measurements included: the phasing out of PFOA, the improvement of the plastomer and elastomer post-treatments; the reinforcement of the staff involved in prevention. Decreasing trends were observed for all chemicals along years (P value for linear trend of means < 0.01). For PFOA, a half-life of 3.16 (95% CI 2.98-3.37) years was calculated.

CONCLUSIONS

In the study plants, several initiatives to reduce exposure and the risk associated with perfluoroalkyl surfactants were undertaken; results of biomonitoring show that they were effective, with a 5- to 136-fold reduction in the concentration of perfluoroalkyl compounds in the serum of workers.