Concentration-response curve and cumulative effects between ozone and daily mortality: an analysis in Wallonia, Belgium.

Many studies have shown an association between ozone and mortality. However, little data is available on the cumulative effects of ozone on health. A time-series analysis using a Poisson regression was used to measure the impact of ozone on non-traumatic mortality in Wallonia over the period 2000-2012. Initially, a single-lag model was tested. Then a distributed-lag non-linear model was used in order to verify the cumulative effects of ozone on mortality. Our study confirms the existence of an association between ozone and mortality. The linear model without threshold shows a higher sensitivity in persons aged 75 and over (ERR = 0.7, 95 % CI: 0.4; 1.0 %) compared to younger people (ages 25-74) (ERR = 0.2, 95 % CI: - 0.2; 0.6 %). Taking cumulative effects into account, men and women aged 25-74 have an ozone sensitivity equivalent to those over 75.