Increased risk of respiratory diseases among people living close to municipal waste landfills

Abstract

Introduction: Nine municipal waste landfills have been operating in the Lazio region (Central Italy) for several decades. To evaluate their potential health effects, a population-based retrospective cohort study was conducted using dispersion modelling for exposure assessment. Methods: A cohort of residents within five km of landfills was enrolled (subjects resident on January 1, 1996 and those who subsequently moved into the areas until 2008) and followed for mortality and hospitalizations until December 31, 2012. Exposure assessment to the landfills (Hydrogen sulphide, H2S as tracer) was performed for each subject using a Lagrangian dispersion model. Information on several confounders was available (gender, age, socio-economic position, outdoor PM10 concentration, and distance from busy roads and industries). Cox regression analysis was performed (Hazard Ratios, HRs, 95% Confidence Interval, CI). Results: The cohort included 242,409 individuals. H2S exposure was associated with mortality from lung cancer and respiratory diseases (e.g. HR for increment of 1 ng/m3 H2S: 1.10, 95% CI 1.02-1.19; HR 1.09, 95% CI 1.00-1.19, respectively). There were also associations between H2S and hospitalization for respiratory diseases (HR=1.02, 95% CI 1.00-1.03), especially acute respiratory infections among children (0-14 years) (HR=1.06, 95% CI 1.02-1.11). Conclusions: Exposure to H2S, a tracer of airborne contamination from landfills, was associated with lung cancer mortality and with mortality and morbidity for respiratory diseases. The link with respiratory disease is plausible and consistent with previous studies while the association with lung cancer requires confirmation.