Association between ambient air pollution and fatal stroke mortality in Songjiang District of Shanghai

Abstract

ObjectiveTo investigate the risk of fatal stroke mortality associated with short-term exposure to air pollution， and to determine the susceptible population.MethodsIn this study， daily stroke mortalities of adults between 2012 and 2014 in Songjiang District， Shanghai were collected. Time-stratified case-crossover approach was used to assess the association between daily concentrations of air pollutants and fatal stroke mortalities.ResultsThis study included 514 patients who died from acute strokes. The average concentrations during the study period were 77.45 μg·m-3 for PM2.5， 21.22 μg·m-3 for SO2， and 57.59 μg·m-3 for NO2. The fatal stroke mortality of adults under the age of 65 was found to be significantly associated with NO2. At the time of a Lag of 2 d and 03 d， a significantly higher risk of fatal stroke mortality in relation to NO2 exposure was observed， and the OR values of ischemic stroke mortality for people were 3.86 （1.53-9.75） and 5.83 （1.40-24.34） respectively. People over the age of 65 were more sensitive to increased PM2.5 concentrations， at the time of a Lag of 03 d， fatal strokes increased by 28% when PM2.5 levels increased. A significantly higher risk of fatal stroke mortality in relation to increase of NO2 concentration was observed among people who were overweight or obese.ConclusionA significantly higher risk of fatal stroke mortality is associated with the increase of PM2.5 and NO2. The results also suggest that the susceptible population should take additional precautions to avoid or reduce the risk of fatal strokes.

Keywords

• air pollution
• fatal stroke
• case cross-over design
• conditional logistic regression