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Abstract: Background: Both temperature and particulate air pollution are associated with increased death risk. However, whether the effect of particulate air pollution on mortality is modified by temperature remains unsettled. Methods: A stratified time-series analysis was conducted to examine whether the effects of particulate matter less than 10μm in aerodynamic diameter (PM10) on mortality was modified by temperature in eight Chinese cities. Poisson regression models incorporating natural spline smoothing functions were used to adjust for long-term and seasonal trends of mortality, as well as other time-varying covariates. The bivariate response surface model was applied to visually examine the potential interacting effect. The associations between PM10 and mortality were stratified by temperature to examine effect modification. Results: The averaged daily concentrations of PM10 in the eight Chinese cities ranged from 65μg/m3 to 124μg/m3, which were much higher than in Western countries. We found evidence that the effects of PM10 on mortality may depend on temperature. The eight-city combined analysis showed that on “normal” (5th–95th percentile) temperature days, a 10-μg/m3 increment in PM10 corresponded to a 0.54% (95% CI, 0.39 to 0.69) increase of total mortality, 0.56% (95% CI, 0.36 to 0.76) increase of cardiovascular mortality, and 0.80% (95% CI, 0.64 to 0.96) increase of respiratory mortality. On high temperature (>95th percentile) days, the estimates increased to 1.35% (95% CI, 0.80 to 1.91) for total mortality, 1.57% (95% CI, 0.69 to 2.46) for cardiovascular mortality, and 1.79% (95% CI, 0.75 to 2.83) for respiratory mortality. We did not observe significant effect modification by extreme low temperature. Conclusions: Extreme high temperature increased the associations of PM10 with daily mortality. These findings may have implication for the health impact associated with both air pollution and global climate change. [Copyright &y& Elsevier]

Abstract: Controversy remains regarding the relationship between various metrics of ozone (O3) and mortality. In China, the largest developing country, there have been few studies investigating the acute effect of O3 on death. We used three exposure metrics of O3 (1-hour maximum, maximum 8-hour average and 24-hour average) to examine its short-term association with daily mortality in Suzhou, China. We used a Generalized Additive Model (GAM) with penalized splines to analyze the mortality, O3, and covariate data. We examined the association by season, age group, sex and educational level. We found that the current level of O3 in Suzhou is associated with death rates from all causes and cardiovascular diseases. Among various metrics of O3, maximum 8-hour average and 1-hour maximum concentrations seem to be more strongly associated with increased mortality rate compared to 24-hour average concentrations. Using maximum 8-hour average, an inter-quartile range increase of 2-day average O3 (lag 01) corresponds to 2.15% (95%CI, 0.36 to 3.93), 4.47% (95%CI, 1.43 to 7.51), −1.85% (95%CI, −6.91 to 3.22) increase in all-cause, cardiovascular, and respiratory mortality, respectively. The associations between O3 and daily mortality appeared to be more evident in the cool season than in the warm season. In conclusion, maximum 8-hour average and 1-hour maximum concentrations of O3 are associated with daily mortality in Suzhou. Our analyses strengthen the rationale for further limiting levels of O3 pollution in the city. [Copyright &y& Elsevier]

Abstract: Evidence concerning the health risks of coarse particles (PM10-2.5) is limited. There have been no multi-city epidemiologic studies of PM10-2.5 in developing Asian countries. We examine the short-term association between PM10-2.5 and daily mortality in three Chinese cities: Beijing, Shanghai, and Shenyang. PM10-2.5 concentrations were estimated by subtracting PM2.5 from PM10 measurements. Data were analyzed using the over-dispersed generalized linear Poisson models. The average daily concentrations of PM10-2.5 were 101μg/m3 for Beijing (2007–2008), 50μg/m3 for Shanghai (2004–2008), and 49μg/m3 for Shenyang (2006–2008). In the single-pollutant models, the three-city combined analysis showed significant associations between PM10-2.5 and daily mortality from both total non-accidental causes and from cardiopulmonary diseases. A 10-μg/m3 increase in 1-day lagged PM10-2.5 was associated with a 0.25% (95% CI: 0.08 to 0.42) increase in total mortality, 0.25% (95% CI: 0.10 to 0.40) increase in cardiovascular mortality, and 0.48% (95% CI: 0.20 to 0.76) increase in respiratory mortality. However, these associations became statistically insignificant after adjustment for PM2.5. PM2.5 was significantly associated with mortality both before and after adjustment for PM10-2.5. In conclusion, there were no statistically significant associations between PM10-2.5 and daily mortality after adjustment for PM2.5 in the three Chinese cities. [Copyright &y& Elsevier]

Abstract: Ambient carbon monoxide (CO) is an air pollutant primarily generated by traffic. CO has been associated with increased mortality and morbidity in developed countries, but few studies have been conducted in Asian developing countries. In the China Air Pollution and Health Effects Study (CAPES), the short-term associations between ambient CO and daily mortality were examined in three Chinese cities: Shanghai, Anshan and Taiyuan. Poisson regression models incorporating natural spline smoothing functions were used to adjust for long-term and seasonal trend of mortality, as well as other time-varying covariates. Effect estimates were obtained for each city and then for the cities combined. In both individual-city and combined analysis, significant associations of CO with both total non-accidental and cardiovascular mortality were observed. In the combined analysis, a 1mg/m3 increase of 2-day moving average concentrations of CO corresponded to 2.89% (95%CI: 1.68, 4.11) and 4.17% (95%CI: 2.66, 5.68) increase of total and cardiovascular mortality, respectively. CO was not significantly associated with respiratory mortality. Sensitivity analyses showed that our findings were generally insensitive to alternative model specifications. In conclusion, ambient CO was associated with increased risk of daily mortality in these three cities. Our findings suggest that the role of exposure to CO and other traffic-related air pollutants should be further investigated in China. [Copyright &y& Elsevier]

Abstract: Few studies exist in China examining the association of ambient air pollution with morbidity outcomes. We conducted a time-series analysis to examine the association of outdoor air pollutants (PM10, SO2, and NO2) with hospital outpatient and emergency room visits in Shanghai, China, using 3years of daily data (2005–2007). Hospital and air pollution data were collected from the Shanghai Health Insurance Bureau and Shanghai Environmental Monitoring Center. Using a natural spline model, we examined effect of air pollutants with different lag structures including both single-day lag and multi-day lag. We examined effects of air pollution for the warm season (from April to September) and cool season (from October to March) separately. We found outdoor air pollution (SO2 and NO2) was associated with increased risk of hospital outpatient and emergency room visits in Shanghai. The effect estimates varied for different lag structures of pollutants’ concentrations. For lag 3, a 10μg/m3 increase in concentration of PM10, SO2 and NO2 corresponded to 0.11% (95%CI: −0.03%, 0.26%), 0.34% (95%CI: 0.06%, 0.61%) and 0.55% (95%CI: 0.14%, 0.97%) increase of outpatient visit; and 0.01% (95%CI: −0.09%, 0.10%), 0.17% (95%CI: 0.00%, 0.35%) and 0.08% (95%CI: −0.18%, 0.33%) increase of emergency room visit. The associations appeared to be more evident in the cool season than in the warm season. In conclusion, short-term exposure to outdoor air pollution was associated with increased risk of hospital outpatient and emergency room visits in Shanghai. Our analyses provide evidence that the current air pollution level has an adverse health effect and strengthen the rationale for further limiting air pollution levels in the city. [Copyright &y& Elsevier]