Short-term effects of ambient gaseous pollutants and particulate matter on daily mortality in Shanghai, China

Identification of the specific pollutants contributing most to the health hazard of the air pollution mixture may have important implications for environmental and social policies. In the current study, we conducted a time-series analysis to examine the specific effects of major air pollutants [particulate matter less than 10 microns in diameter (PM(10)), sulfur dioxide (SO(2)), and nitrogen dioxides (NO(2))] on daily mortality in Shanghai, China, using both single-pollutant and multiple-pollutant models. In the single-pollutant models, PM(10), SO(2), and NO(2) were found to be associated with mortality from both all non-accidental causes and from cardiopulmonary diseases. Unlike some prior studies in North America, we found a significant effect of gaseous pollutants (SO(2) and NO(2)) on daily mortality even after adjustment for PM(10) in the multiple-pollutant models. Our findings, combined with previous Chinese studies showing a consistent, significant effect of gaseous pollutants on mortality, suggest that the role of outdoor exposure to SO(2) and NO(2) should be investigated further in China.     

Associations between air pollution and mortality in Phoenix, 1995-1997

We evaluated the association between mortality outcomes in elderly individuals and particulate matter (PM) of varying aerodynamic diameters (in micrometers) [PM(10), PM(2.5), and PM(CF )(PM(10) minus PM(2.5))], and selected particulate and gaseous phase pollutants in Phoenix, Arizona, using 3 years of daily data (1995-1997). Although source apportionment and epidemiologic methods have been previously combined to investigate the effects of air pollution on mortality, this is the first study to use detailed PM composition data in a time-series analysis of mortality. Phoenix is in the arid Southwest and has approximately 1 million residents (9. 7% of the residents are > 65 years of age). PM data were obtained from the U.S. Environmental Protection Agency (EPA) National Exposure Research Laboratory Platform in central Phoenix. We obtained gaseous pollutant data, specifically carbon monoxide, nitrogen dioxide, ozone, and sulfur dioxide data, from the EPA Aerometric Information Retrieval System Database. We used Poisson regression analysis to evaluate the associations between air pollution and nonaccidental mortality and cardiovascular mortality. Total mortality was significantly associated with CO and NO(2) (p < 0.05) and weakly associated with SO(2), PM(10), and PM(CF) (p < 0. 10). Cardiovascular mortality was significantly associated with CO, NO(2), SO(2), PM(2.5), PM(10), PM(CF) (p < 0.05), and elemental carbon. Factor analysis revealed that both combustion-related pollutants and secondary aerosols (sulfates) were associated with cardiovascular mortality.     

气态污染物与上海市浦东新区居民心脑血管疾病死亡相关性的病例交叉研究

目的 评估气态污染物与浦东新区居民每日心脑血管疾病死亡的关联性,为制定相应的干预措施提供依据。方法 收集浦东新区2005年1月1日-2017年12年31日的气象因素、大气污染及居民心脑血管疾病死亡资料,采用时间分层-病例交叉研究的方法,评估气态污染物对浦东新区居民心脑血管疾病死亡的影响。结果 研究期间,上海市SO2与NO2的平均浓度分别为31.96μg/m3和45.21μg/m3。SO2与NO2与浦东新区居民心脑血管疾病死亡存在相关性。SO2与NO2的效应分别在滞后3d（lag3）与当日（lag0）强度最大,SO2浓度每上升10μg/m3,在滞后3d（lag3）时居民每日心脑血管疾病死亡将上升1.12%(95%CI:0.69%～1.56%);NO2浓度每上升10μg/m3,在当日居民每日心脑血管疾病死亡将上升0.85%(95%CI:0.40%～1.30%)。多污染物模型中,在控制了PM10与NO2的影响后,SO2的效应保持稳定,在控制了PM10与SO2的影响后,NO2的效应有所加强。结论 SO2与NO2浓度与每日浦东新区居民心脑血管疾病死亡存在相关性,其中SO2的效应在滞后3d影响最大,NO2在当日影响最大。     

Air pollution and daily mortality in Shanghai: a time-series study

In this study, the authors assessed the relationship between air pollution and daily mortality from June 2000 to December 2001 in Shanghai, the largest city in China. They used the generalized additive model to allow for the highly flexible long-term and seasonable trends, and for nonlinear weather variables. In the single-pollutant models, the authors found significant associations between concentrations of air pollutants (particulate matter less than 10 microm in aerodynamic diameter [PM10], sulfur dioxide [SO2], and nitrogen dioxide [NO2]) and daily mortality. An increase of 10 microg/m3 in PM10, SO2, and NO2 corresponded to a respective increase in relative risk of mortality from all causes of 1.003 (95% confidence interval [CI] = 1.001, 1.005), 1.014 (95% CI = 1.008, 1.020), and 1.015 (95% CI = 1.008, 1.022). In the multiple-pollutant models, the association between SO2 and daily mortality was not affected by the inclusion of other pollutants; for PM10 and NO2, however, the inclusion of other pollutants possibly weakened the effects between these 2 pollutants and mortality. This finding suggests that gaseous pollutants may be more important than particulate matter as indicators of health in Shanghai. The authors' analyses provided evidence that the current amounts of air pollution in Shanghai continue to adversely affect population health, and strengthen the rationale for limiting the quantities of pollutants in outdoor air.     

PM(10) exposure, gaseous pollutants, and daily mortality in Inchon, South Korea.

To evaluate the relative importance of various measures of particulate and gaseous air pollution as predictors of daily mortality in Inchon, South Korea, the association between total daily mortality and air pollution was investigated for a 20-month period (January 1995 through August 1996). Poisson regression was used to regress daily death counts on each air pollutant, controlling for time trends, season, and meteorologic influences such as temperature and relative humidity. Regression coefficients of a 5-day moving average of particulate matter less than or = to 10 microm in aerodynamic diameter (PM(10)) on total mortality were positively significant when considered separately and simultaneously with other pollutants in the model. PM(10) remained significant when the models were confined to cardiovascular or respiratory mortality. Sulfur dioxide (SO(2)) and carbon monoxide (CO) were significantly related to respiratory mortality in the single-pollutant model. Ozone exposure was not statistically significant with regard to mortality in the above models, and graphic analysis showed that the relationship was nonlinear. A combined index of PM(10), nitrogen dioxide, SO(2), and CO seemed to better explain the exposure-response relationship with total mortality than an individual air pollutant. Pollutants should be considered together in the risk assessment of air pollution, as opposed to measuring the risk of individual pollutants.     

石家庄市气态污染物与每日居民死亡人数的时间序列分析

目的 探讨石家庄市大气气态污染物SO2、NO2、O3-8 h和CO浓度与居民每日死亡人数之间的关系.方法 收集石家庄市2013—2016年每日死亡人数、大气污染物浓度、气象资料,采用广义相加时间序列模型,分析气态污染物浓度对死亡的影响,并按照性别、年龄进行分层分析.结果 大气SO2浓度每增加10μg/m3,人群非意外总...     

苏州市恶性肿瘤日死亡率与大气主要污染物的关系

[目的]探讨大气主要污染物对居民恶性肿瘤日死亡率的影响。[方法]收集2002～2007年苏州地区恶性肿瘤日死亡人数和大气中可吸入颗粒物（PM10）、二氧化硫（SO2）、二氧化氮（NO2）以及一氧化碳（CO）等污染物日平均浓度,经时间序列法平稳化后,再运用多元线性回归法进行相关性和确定性分析。[结果]（1）该地区居民恶性肿瘤日死亡率与7天前（1ag7）的大气中SO2、NO2及当日（1ag0）PM10平均浓度存在相关（P〈0．05）,其中S02和PM10每升高10μg/m^3,恶性肿瘤死亡的相对危险度（RR）和95％可信区间（Cl）分别为1．004（1．003～1．006,P〈0．01）和1．001（1．000～1．002,P〈0．05）,日死亡率分别上升0．44％（0．29％～0．60％）和0．10％（0．01％-0．19％）;而N02则呈负相关（P〈0．01）。（2）居民恶性肿瘤日死亡率与大气污染物日平均浓度存在线性回归（P〈0．05）,回归方程为：y=4．985＋3．963[SO2]-2．878[N02]＋0．577[PM10];模型预测的结果比较准确。（3）自变量SO2浓度标化后的偏回归系数为0．392,对应变量恶性肿瘤日死亡率的影响最大。[结论]该地区居民恶性肿瘤日死亡率与大气中SO2和PM10日平均水平呈正相关,与NO2则呈负相关;控制该地区SO2的污染水平可能有利于降低居民恶性肿瘤死亡率。     

Study on the association between ambient air pollution and daily cardiovascular and respiratory mortality in an urban district of Beijing

The association between daily cardiovascular/respiratory mortality and air pollution in an urban district of Beijing was investigated over a 6-year period (January 2003 to December 2008). The purpose of this study was to evaluate the relative importance of the major air pollutants [particulate matter (PM), SO2, NO2] as predictors of daily cardiovascular/respiratory mortality. The time-series studied comprises years with lower level interventions to control air pollution (2003-2006) and years with high level interventions in preparation for and during the Olympics/Paralympics (2007-2008). Concentrations of PM10, SO2, and NO2, were measured daily during the study period. A generalized additive model was used to evaluate daily numbers of cardiovascular/respiratory deaths in relation to each air pollutant, controlling for time trends and meteorological influences such as temperature and relative humidity. The results show that the daily cardiovascular/respiratory death rates were significantly associated with the concentration air pollutants, especially deaths related to cardiovascular disease. The current day effects of PM10 and NO2 were higher than that of single lags (distributed lags) and moving average lags for respiratory disease mortality. The largest RR of SO2 for respiratory disease mortality was in Lag02. For cardiovascular disease mortality, the largest RR was in Lag01 for PM10, and in current day (Lag0) for SO2 and NO2. NO2 was associated with the largest RRs for deaths from both cardiovascular disease and respiratory disease.     

某低污染区大气污染物对脑血管疾病死亡的影响

目的探讨低污染地区主要大气污染物对居民脑血管病死亡的影响。方法收集2002—2007年某地区脑血管病日死亡人数和主要大气污染物日平均浓度,经时间序列法平稳化序列后,再运用多元线性回归法进行相关性和确定性分析。结果①该地区大气中二氧化硫(SO2)、二氧化氮(NO2)、一氧化碳(CO)以及空气动力学直径10μm以下的可吸入颗粒物(PM10)日平均浓度与居民脑血管疾病死亡人数之间存在显著相关(P0.05),其中大气中SO2、NO2、CO浓度每升高10μg/m3,脑血管疾病死亡的相对危险度(OR)分别增加5.65%(95%CI,4.93%～6.37%)、1.03%(95%CI,0.24%～1.82%)和0.12%(95%CI,0.09%～0.14%),而PM10则呈显著负相关(P=0.00)。②居民日脑血管疾病死亡人数与大气污染物浓度存在线性回归(P0.05),回归方程为:^y=16.917+72.092(SO2)+26.190(NO2)-15.932(PM10)+2.062(CO)。③从标化后的偏回归系数可以得出,自变量SO2浓度对应变量脑血管疾病日死亡的影响最大。结论该地区居民脑血管病死亡与大气中SO2、NO2和呈正相关,存在线性回归,其中尤以SO2的影响最大,PM10则呈负相关;控制该地区SO2的污染水平是降低居民脑血管疾病死亡率的关键。     

大气颗粒物污染与脑卒中死亡的病例交叉研究

目的 评价大气颗粒物污染对人群脑卒中死亡的急性效应.方法 采用时间分层的病例交叉设计,分析杭州市2002-2004年间大气可吸入颗粒物(PM10)日平均浓度短期增加与人群每日脑卒中死亡的关系,同时分析其他气态污染物(NO2和SO2)的急性健康效应.结果共纳入9906例脑卒中死亡病例,粗死亡率约为83.54/10万.调整气象因素后,3 d内PM10、SO2和NO2日平均浓度每增加10μg/m3,人群脑卒中死亡则分别增加0.56%(95%CI:0.14%～0.99%)、1.62%(95%CI:0.26%～3.01%)和2.07%(95%CI:0.54%～3.62%).多污染物模型中未见有统计学意义的关联.敏感性分析结果显示进行缺失值填补后,单污染物模型中均有关联效应,多污染物模型中则无统计学意义的关联.结论大气颗粒物污染以及SO2和NO2污染物浓度短期升高均与脑卒中死亡增加存在一定关联.     

成都市大气颗粒物对居民心脑血管疾病死亡的急性影响研究

目的 探讨成都市大气颗粒物的急性暴露与居民每日心脑血管疾病死亡的关系。方法 收集2013-2015年成都市大气PM2.5、PM10、SO2和NO2的日平均浓度、气象因素(包括日平均气温和相对湿度)及心脑血管疾病日死亡数。采用广义相加模型(Generalized Additive Models,GAM)建立单污染物、多污染物模型,分析大气PM2.5、PM10浓度对居民心脑血管疾病日死亡数的影响。结果 大气污染物PM2.5、PM10浓度分别为75.9、119.7μg/m3,PM2.5高于GB3095-2012《环境空气质量标准》 二级标准。单污染物模型中,大气PM2.5(lag1)和PM10(lag01)浓度每增加10μg/m3,心脑血管疾病日死亡数分别增加0.29%(95%CI:0.01%~0.56%)和0.27%(95%CI:0.09%~0.45%)。PM2.5和PM10浓度与心脑血管疾病死亡的暴露反应关系基本呈线性。多污染物模型中,PM2.5和PM10单独或同时引入SO2、NO2时,对心脑血管疾病日死亡数的影响消失(P>0.05)。结论 成都市大气PM2.5和PM10浓度升高可能导致居民心脑血管疾病日死亡数增加。     

合肥市大气污染与肺炎门诊量的时间序列研究

目的探讨大气污染物SO_2、NO_2和PM_(2.5)浓度与合肥市滨湖医院肺炎日门诊量之间的关系。方法采用时间序列分析的广义相加Poisson回归模型,在控制长期趋势、星期几效应和气象因素等混杂因素的影响后,定量分析2014年安徽省合肥市大气污染物SO_2、NO_2、PM_(2.5)日均浓度与滨湖医院肺炎日门诊量的关系及滞后效应。结果单污染物模型中,在控制了长期趋势、星期几效应和气象因素的影响后,SO_2在滞后3、4、5 d(lag3、lag4、lag5)时对肺炎日门诊量的影响有统计学意义(P0.05),NO_2滞后2、3、4、5 d(lag2、lag3、lag4、lag5)时的影响有统计学意义(P0.01),PM_(2.5)滞后3、4 d(lag3、lag4)时的影响有统计学意义(P0.05);SO_2、NO_2、PM_(2.5)的滞后效应分别在lag3、lag2、lag4时最明显,当SO_2、NO_2、PM_(2.5)浓度每升高10μg/m~3时,肺炎日门诊量分别增加1.54%(95%CI:0.28%~2.81%),1.98%(95%CI:0.89%~3.08%)和0.28%(95%CI:0.06%~0.50%)。多污染物模型中,当模型中引入两种或两种以上的污染物后,各污染物对肺炎日门诊量的效应估计值均较单污染物模型降低,但并不改变各污染物与肺炎日门诊量之间的正向关联。结论合肥市大气污染物SO_2、NO_2、PM_(2.5)浓度升高可能引起医院肺炎日门诊量增加,且有一定的滞后效应。     

Is the association of airborne particles with daily deaths confounded by gaseous air pollutants? An approach to control by matching.

Although particulate air pollution has been associated with increased numbers of daily deaths in dozens of cities around the world, issues still remain about the association. Some have questioned the complex modeling used to control for season in Poisson regression or the role of gaseous air pollutants as potential confounders of the association. I examined the association between deaths and particulate matter with an aerodynamic diameter less than or equal to 10 microm (PM10) using a case-crossover design. In this approach, the pollution on the day of each death is contrasted with the pollution level on control days when the subject did not die. Season and gaseous air pollutants were controlled by matching. Control days were chosen within the same month of the same year to control for season, and matched on either sulfur dioxide (SO2; within 1 ppb), nitrogen dioxide (within 1 ppb), maximum ozone (within 2 ppb), or carbon monoxide (within 0.03 ppm). The analysis was conducted in 14 U.S. cities that have daily PM10 monitoring. After matching, there were about 400,000 deaths in each analysis. Results were combined across cities using a maximum likelihood method. PM10 was a significant predictor of mortality when controlling for gaseous air pollutants, with effect sizes ranging from a 0.45% increase per 10 microg/m3 increment of PM10 [95% confidence interval (CI), 0.12-0.79%] when matched on maximum hourly ozone levels, to a 0.81% increase per 10 microg/m3 increment of PM10 (95% CI, 0.47-1.16%) when matched on 24-hr average SO2.     

淮安市城区大气污染与呼吸系统疾病门诊量的时间序列分析

目的 探讨淮安市城区大气污染物对日呼吸系统疾病发生的急性影响,为呼吸系统疾病的早期预防提供科学依据。方法 收集淮安地区2015全年气象,环保及城区部分医疗机构呼吸系统疾病门诊量数据,采用Poisson分布广义相加模型(GAM)分析主要大气污染物(PM2.5、PM10、SO2、NO2)与呼吸系统疾病门诊量的关系。结果 (1)Spearman等级相关分析发现PM2.5、PM10、SO2和NO2与日呼吸系统疾病门诊量发生成正相关(P<0.01);(2)单污染物模型分析显示:PM2.5、NO2对日呼吸系统疾病门诊量的影响效应均在当日达到最大值,PM10、SO2对日呼吸系统疾病门诊量的影响效应分别在滞后第4天、滞后第3天达到最大值,且日浓度每升高10 μg/m3,对呼吸系统门诊量风险增加分别为0.26%(0.076%~0.44%),2.90%(2.20%~3.60%),0.26%(0.15%~0.38%)和2.40%(1.80%~3.00%);(3)多污染物模型分析显示:SO2与NO2在引入其他污染物时对日呼吸系统疾病门诊量影响均有所下降,且均具有统计学意义。结论 淮安市城区大气污染物(PM2.5、PM10、SO2、NO2)与呼吸系统疾病门诊量密切相关,并且SO2、NO2浓度增加更易增加呼吸系统疾病的发病风险。     

2014-2017年沈阳市细颗粒物对居民循环系统疾病死亡的影响

目的 探讨沈阳市2014-2017年大气PM2.5污染与居民循环系统疾病死亡之间的关系.方法 分析沈阳市2014-2017年PM2.5污染特征、气象特征以及居民循环系统疾病死亡水平,采用广义线性模型分析大气PM2.5对居民循环系统疾病死亡的影响.结果 循环系统疾病死亡人数与气压、大气PM2.5、PM10、SO2和03-...     

Coarse and fine particles and daily mortality in the Coachella Valley, California: a follow-up study

Many epidemiological studies provide evidence of an association between ambient particles, measured as PM10, and daily mortality. Most of these studies have been conducted in urban areas where PM10 is highly correlated with and dominated by fine particles less than 2.5 microm in diameter (PM2.5). Fewer studies have investigated impacts associated with the fraction of coarse mode particles (between 2.5 and 10 microm in diameter). In a previous study using data from 1989 through 1992 in the Coachella Valley, a desert resort and retirement area east of Los Angeles, we reported associations between PM10 and several different measures of mortality [Ostro B.D., Hurley S., and Lipsett M.J. Air pollution and daily mortality in the Coachella Valley, California: a study of PM10 dominated by coarse particles. Environ. Res. 1999: 81: 231-238]. In this arid environment, coarse particles of geologic origin are highly correlated with and comprise approximately 60% of PM10, increasing to >90% during wind events. This study was intended to repeat the earlier investigation using 10 years (1989-1998) of daily data on mortality and PM10. The last 2.5 years of data also included daily measures of PM2.5, allowing examination of size-specific impacts. To ensure adequate statistical power, we attempted to develop predictive models for both fine and coarse particles to use in analyses of the full 10-year period. An acceptable fit was found only for coarse particles, which were found to be a cubic function of PM10 (R2 = 0.95). Outcome variables included several measures of daily mortality, including all-cause (minus accidents and homicides), cardiovascular and respiratory mortality. Multivariate Poisson regression analyses using generalized additive models were employed to explain the variation in these endpoints, controlling for temperature, humidity, day of the week, season, and time, using locally weighted smoothing techniques. Pollution lags of up to 4 days were examined. Several pollutants were associated with all-cause mortality, including PM2.5, carbon monoxide and nitrogen dioxide. More consistent results were found for cardiovascular-specific mortality, for which associations were found for coarse particles (RR = 1.02; 95% C.I., 1.01-1.04), PM10 (RR = 1.03; 95% C.I., 1.01-1.05). None of the pollutants was associated with respiratory-specific mortality. Ozone was not associated with any of the mortality outcomes. These findings are generally consistent with those we previously reported for the Coachella Valley for the period 1989-1992, demonstrating associations between several measures of particulate matter and daily mortality in an environment in which particulate concentrations are dominated by the coarse fraction.     

Mortality and ambient fine particles in southwest Mexico City, 1993-1995.

++Epidemiologic studies have focused attention on the health effects of fine particulate air pollutants <2.5 microm in diameter (PM2.5). To further characterize the potential effects of fine particles, we investigated the relationship of air pollution to mortality in Mexico City during 1993-1995. The concentration of PM2.5 was measured on a 24-hr integrated basis; concentrations of NO2 and ozone were measured hourly and reduced to 24-hr means. Daily mortality was determined from death registration records, and Poisson regression was used to model daily death counts as a function of air pollutant levels on the same and previous days, while controlling for temperature and periodic cycles. Without taking other air pollutants into account, a 10 microg/m3 increase in the level of PM2.5 was associated with a 1.4% increase in total mortality, both on the current day and 4 days after exposure [95% confidence interval (CI), 0.2-2.5]. An equivalent increase in PM2.5 was also associated with somewhat larger excesses of deaths among people over 65 years of age and from cardiovascular and respiratory causes, which occurred after a lag of 4 days. The mean concentration of ozone over a 2-day period was associated with a 1.8% increase in mortality from cardiovascular diseases. NO2 was not consistently related to mortality. Fine particles had an independent effect on mortality when modeled simultaneously with other pollutants, and the association of ozone with cardiovascular mortality was strengthened after adjusting for NO2 and PM2.5. These results support previous findings that urban air pollution at current levels leads to excess mortality and suggest that fine particles may play a causal role in producing that excess.     

Ambient air pollution and respiratory emergency department visits

BACKGROUND: A number of emergency department studies have corroborated findings from mortality and hospital admission studies regarding an association of ambient air pollution and respiratory outcomes. More refined assessment has been limited by study size and available air quality data. METHODS: Measurements of 5 pollutants (particulate matter [PM10], ozone, nitrogen dioxide [NO2], carbon monoxide [CO], and sulfur dioxide [SO2]) were available for the entire study period (1 January 1993 to 31 August 2000); detailed measurements of particulate matter were available for 25 months. We obtained data on 4 million emergency department visits from 31 hospitals in Atlanta. Visits for asthma, chronic obstructive pulmonary disease, upper respiratory infection, and pneumonia were assessed in relation to air pollutants using Poisson generalized estimating equations. RESULTS: In single-pollutant models examining 3-day moving averages of pollutants (lags 0, 1, and 2): standard deviation increases of ozone, NO2, CO, and PM10 were associated with 1-3% increases in URI visits; a 2 microg/m increase of PM2.5 organic carbon was associated with a 3% increase in pneumonia visits; and standard deviation increases of NO2 and CO were associated with 2-3% increases in chronic obstructive pulmonary disease visits. Positive associations persisted beyond 3 days for several of the outcomes, and over a week for asthma. CONCLUSIONS: The results of this study contribute to the evidence of an association of several correlated gaseous and particulate pollutants, including ozone, NO2, CO, PM, and organic carbon, with specific respiratory conditions.     

Particulate matter,sulfur dioxide,and daily mortality in Chongqing,China

In 1995, daily mortality in a district of Chongqing, China, was analyzed from January through December for associations with daily ambient sulfur dioxide and fine particles (airborne particles with diameters less than or equal to 2.5 microm; PM2.5. The mean concentration of PM2.5 was 147 microg/m3 (maximum, 666 microg/m3), and that of SO2 was 213 microg/m3 (maximum, 571 microg/m3). On average, 9.6 persons died each day. We used a generalized additive model using robust Poisson regression to estimate the associations of mean daily SO2 and PM2.5 with daily mortality (on the same day and at lags up to 5 days) adjusted for trend, season, temperature, humidity, and day of the week. The relative risk of mortality associated with a 100 microg/m3 increase in mean daily SO2 was highest on the second lag day [1.04; 95% confidence interval (CI), 1.00-1.09] and the third lag day (1.04; 95% CI, 0.99-1.08). The associations between daily mortality and mean daily PM2.5 were negative and statistically insignificant on all days. The relative risk of respiratory mortality on the second day after a 100 microg/m3 increase in mean daily SO2 was 1.11 (95% CI, 1.02-1.22), and that for cardiovascular mortality was 1.10 (95% CI, 1.02-1.20). The relative risk of cardiovascular mortality on the third day after a 100 microg/m3 increase in mean daily SO2 was 1.20 (95% CI, 1.11-1.30). The relative risks of mortality due to cancer and other causes were insignificant on both days. The estimated effects of mean daily SO2 on cardiovascular and respiratory mortality risk remained after controlling for PM2.5.     

A comparison of mortality related to urban air particles between periods with Asian dust days and without Asian dust days in Seoul, Korea, 2000-2004

Recent papers have reported that Asian dust events have been associated with increased risks of all-cause mortality and rates of respiratory illness. The current study was designed to estimate the relative risk of mortality associated with Asian dust events. We used the daily counts of non-accidental deaths, air pollution and meteorological data in Seoul, Korea from 2000 to 2004. We divided all days during the study period into two groups according to the presence or absence of Asian dust events. For each group, we conducted time-series analysis to estimate the relative risk of total non-accidental death when the concentration of each air pollutant increased by the inter-quartile range (IQR). The average concentrations of every air pollutant on the days without a dust event were lower than those on the days with such an event. We found that the effect sizes of air pollution on daily death rates in the model without Asian dust events were larger than those in the model with Asian dust events, and were statistically significant for all air pollutants (PM(10), CO, NO(2), and SO(2)) except for O(3). Our results suggest that we are likely to underestimate the risk of urban air particles if we analyze the effect size of air pollution on daily mortality during Asian dust events. We hypothesize that the real health effect is much larger than previous results suggested.