Mortality of workers exposed to tetrafluoroethylene (TFE) and perfluorooctanoic acid (PFOA) in a plant producing fluoropolymers in Italy, 1960-2024

Objective: Within a multicentre cohort study, mortality (1960-2008) had been evaluated of workers exposed to tetrafluoroethylene (TFE) and perfluorooctanoic acid (PFOA) employed (1960-1999) in a plant producing fluoropolymers in Piedmont, North-West Italy. Follow-up of this cohort was updated through 2024. Methods: Workers' job histories were merged with a semiquantitative job-exposure matrix to calculate cumulative exposure to TFE (still used) and PFOA (phased out in 2013). We calculated standardised mortality ratios (SMRs) and 95% CIs. Results: Among 505 male workers, there was high correlation between cumulative exposure to TFE and PFOA (Spearman's rho 0.57). SMRs (reference: regional rates) were elevated for lung cancer (SMR 1.43, 95% CI 0.95 to 2.16, 23 deaths) and non-Hodgkin's lymphoma (NHL, SMR 2.73, 95% CI 1.23 to 6.07, 6 deaths). Pleural cancer was also in excess (SMR 3.18 using national rates, 95% CI 1.02 to 9.84, 3 deaths). Mortality from leukaemia (three deaths) was not elevated. Lung cancer was not associated with length of employment or exposure. Three workers who died from liver, kidney and testis cancer had been exposed to TFE and unexposed to PFOA. NHL was positively associated with length of employment, time since first employment and exposure to TFE (all 6 deaths exposed, SMR 3.38, 95% CI 1.52 to 7.51 in unlagged analysis, excess confirmed in lagged analyses), while 3 were unexposed to PFOA. The NHL excess occurred among workers aged 65+ years last employed before 2000. Conclusions: This study found elevated mortality from NHL. The available evidence suggests an association with TFE rather than PFOA exposure, although exposure misclassification cannot be ruled out.