Retrospective Modeling of NO2 and PM10 Concentrations over the Lyon Metropolitan Area (France), 1990–2010—Performance Evaluation, Exposure Assessment and Correlation between Pollutants

Abstract

Numerous cancers develop years after subjects have been exposed to chemical compounds. Thus, environmental epidemiological studies need to accurately reconstruct exposures over long periods. To estimate exposure to NO₂ and PM₁₀ concentrations, we modelled ground-level air concentrations, at very fine temporal (1 h) and spatial (10 m) resolutions, over a large European metropolitan area and at subject’s address of a French national cohort, for five different years (1990, 1995, 2000, 2005 and 2010). Model performances were assessed by comparing the annual modelled concentration against monitoring station measurements. As input data, we used background concentrations from a large-scale dispersion model. The relevance of our approach was assessed by comparing results in 2010, with a modelling using monitoring values as background data. The comparison with measurement data showed good performance of the model for the majority of the period, with a performance declined in 1990. Concentrations at the subject’s residence decreased by 45% for PM₁₀ and 38% for NO₂. The proportion of subjects exposed above the WHO recommendations declined from 100% to 50% for PM₁₀ and from 79% to 16% for NO₂. The results of this study would provide a reference for future models to assess chronic exposures to PM₁₀ and NO₂ on a larger scale.