Short-term risk assessment on mortality due to ambient particulate matter in Ningbo City

ObjectiveTo estimate the short-term risk on mortality attributable to ambient inhalable particulate matter (PM₁₀) in Ningbo City.

MethodsThe daily data on mortality, air pollution and meteorological factors were collected from 2011 to 2015 in Ningbo City. A time series study using a distributed lag non-linear model(DLNM)was used to estimate the excess risk, attributable number and fraction for the short-term effect of PM₁₀on mortality.

ResultsThe study showed that short-term exposure of ambient particulate matters were associated with an increased risk of daily mortality, and the effect had lags and persistence. A 10 μg/m³ increase of PM₁₀in lag 0~3 days was associated with a 0.35%(95%CI:0.16%~0.53%)increase in total mortality.From 2011 to 2015, the attributable number due to short-term exposure of PM₁₀ was 3972 (95%CI:1 877~6 032) for total mortality in Ningbo city, while the attributable fraction was 2.15% (95%CI:1.02%~3.27%).Compared with other diseases, more attributable deaths in respiratory mortality, with a fraction of 4.68%(95%CI:2.19%~7.03%)corresponding to 1 323 deaths (95%CI:619-1 990). The attributable risk for female and elderly were more than that for male and young people, respectively. If the daily concentration of PM₁₀ limits in 150 μg/m³ and 100 μg/m³, its corresponding attribute risk will decrease 25.45% and 53.07%.

ConclusionsThere is significant health impact attributable to short-term PM₁₀ exposure. More efforts should be devoted to reduction of air pollution immediately.