Exposure to endocrine-disrupting plasticisers and lung function in children and adolescents: A systematic review and meta-analysis

Exposure to endocrine-disrupting plasticisers (EDPs), such as phthalates and bisphenols, has been associated with reduced lung function in children and adolescents. However, the existing literature yields conflicting results. This systematic review and meta-analysis aimed to assess the epidemiologic evidence investigating the association between EDP exposure and lung function in children and adolescents. A comprehensive search of five databases identified 25 relevant studies. We employed a random-effects meta-analysis on spirometry measures. The effect size of interest was the change in lung function in standard deviation (SD) units resulting from a two-fold increase in exposure levels. We found that certain phthalates marginally reduced lung function in children. Forced expiratory volume in 1 s (FEV1) was reduced by a two-fold increase in mono-benzyl phthalate (MBzP) (beta = -0.025 SD, 95%CI: 0.042, -0.008), mono-ethyl-oxo-hexyl phthalate (MEOHP) (beta = -0.035 SD, 95%CI: 0.057, -0.014) and mono-carboxy-nonyl phthalate (MCNP) (beta = -0.024 SD, 95%CI: 0.05, -0.003). Forced vital capacity (FVC) was decreased by a two-fold increase in MBzP (beta = -0.022 SD, 95%CI: 0.036, -0.008) and MEOHP (beta = -0.035 SD, 95%CI: 0.057, -0.014) levels. A two-fold increase in MCNP levels was associated with lower FEV1/FVC (beta = -0.023 SD, 95%CI: 0.045, -0.001). Furthermore, a two-fold increase in MEOHP levels reduced forced mid-expiratory flow (FEF25-75) (beta = -0.030 SD, 95%CI: 0.055, -0.005) and peak expiratory flow (PEF) (beta = -0.056 SD, 95%CI: 0.098, -0.014). Notably, associations were more pronounced in males. Given the potential for reverse causation bias, the association between childhood exposure to EDPs and lung function remains uncertain. Overall, our meta-analysis showed small reductions in lung function with higher phthalate exposure. However, future studies are warranted in younger age groups.