Pulmonary functionality among workers of a Central Italy waste-to-energy plant: a retrospective study

Background: We are observing a growing trend towards the use of waste incineration in waste-to-energy (WTE) plants in Italy. Various authors started to investigate their potential health effects, but without univocal outcomes. The aim of this study is to assess whether or not main pulmonary function indexes could be decreased in a group of workers employed in a municipal solid WTE plant located in Central Italy, and if there's a correlation between the levels of exposure to airborne pollutants and alterations in the pulmonary apparatus.

Methods: The study was conducted with a retrospective cohort approach. We reviewed data from clinical records of 58 waste-to-energy plant workers undergoing annual health surveillance in the period 2010-2015. We considered the exposure to airborne dust and the main parameters of respiratory function (FVC, FEV1, Tiffeneau Index and FEF 25-75%) at time zero and after a period of 5 years. We divided our study population into two groups: low (< 1 mg/m3) and high (> 1 mg/m3) exposure. We estimated odds ratios (OR) with 95% confidence interval (95% CI) adjusted for potential confounders.

Results: We observed a decrease in lung function parameters both in high and in low exposure group after a five-years exposure period. FEV1, FEV1/VC ratio and FEF 25-75% were worst in more exposed group, even if this difference resulted not significant at Wilcoxon test.

Conclusions: Active employee in WTE plants is associated to a non-significant worsening in the main parameters of lung function after 5 years exposure. Clinical significant of these variations need to be assessed.