Air Pollution and the Modification by Spatial Synoptic Classification on Mortality

Abstract

BackgroundKorean Peninsula has the distinct seasonal characteristics and the study on seasonality is relatively frequent compared to the relationship with synoptic classification (SSC). In the study, we aimed to investigate the modification effect between air pollution and SSC on mortality.MethodsDaily death data were collected through the Korean Statistics between 2000 and 2014 in Seoul, Korea. We conducted the time-series study using Poisson generalized linear models with an allowance of over-dispersion with seven distinctive SSC (Dry moderate [DM], Dry polar [DP], Dry tropical [DT], Moist moderate [MM], Moist polar [MP], Moist tropical [MT], and Transition [T]) and investigated the modification effects between the SSC and PM10 adjusting for other meteorological conditions, and time trend. The estimated effects were expressed as percentage changes in the risk with 95% confidence interval (CI) per interquartile range(IQR) increase in PM10 for daily non-accidental, cardiovascular-, respiratory-related mortality associated with exposure to PM10 at lag 0−4 according to the type of SSC.ResultsDaily PM10 level was greater in days [DM] (mean, 61.0 µg/m3) and [DT] (mean, 61.8 µg/m3) and the overall risk of mortality increase were observed in non-accidental [1.11% (95% CI 0.50%, 1.73%)], and cardiovascular [1.87% (95% CI 0.68%, 3.08%)] for PM10 IQR increase. In addition, we observed the mortality risk modified by SSC and increased effect was observed in [DM], [DT], [MM], [MT], and [T] in non-accidental and cardiovascular-related mortality. In particular, we observed the increased risk in [MT] regardless cause of death with non-accidental [1.86% (95% CI 1.02%, 2.70%)], cardiovascular [2.01% (95% CI 0.37%, 3.67%)], and respiratory [3.78% (95% CI 0.89%, 6.76%)].DiscussionThe application of SSC in the investigation of air pollution and short-term health effects assisted to understand the health risks in overall weather condition.