Ambient Nitrogen Dioxide and Hospitalizations of Full-Spectrum Respiratory Diseases:A National Case-Crossover Study

Few multicity studies have examined the acute effects of nitrogen dioxide(NO_(2))on respiratory disease(RD),especially its specific causes.This study aimed to investigate the associations between short-term exposure to NO_(2)and hospitalization of full-spectrum RDs in China.Hospitalization of 10 major categories and 40 cause-specific RDs were obtained from 20 provinces over the study period of 2013−2020.A time-stratified case-crossover study was conducted at the individual level to explore the associations between NO_(2)and RDs.NO_(2)was significantly associated with increased hospitalization of eight major RDs(acute upper respiratory infections,influenza and pneumonia,acute lower respiratory infections,upper respiratory tract diseases,chronic lower respiratory diseases,respiratory interstitium diseases,pleura diseases,and other respiratory diseases)and 18 specific causes of RDs,with the largest associations observed on lag 0−1 day.The effect estimates ranged from 0.75 to 4.09%per 10μg/m^(3)of NO_(2)exposure.The associations remained robust after controlling for copollutants.The concentration−response curves were mostly positive and linear.This nationwide study provides comprehensive information on the acute effects of NO_(2)on respiratory morbidity across the full spectrum,highlighting the need for caution with regard to this important traffic-related air pollutant in current pollution control programs.

Criteria air pollutants and hospitalizations of a wide spectrum of cardiovascular diseases: A nationwide case-crossover study in China

Few national studies have systemically examined the effects of criteria air pollutants on cardiovascular morbidity.This study aimed to investigate the associations between all criteria air pollutants and hospitalization of causespecific cardiovascular diseases(CVD)in China.We obtained data on CVD hospitalization events of four major categories and 12 specific diseases from 153 hospitals distributed in 20 provincial-level regions from 2013 to 2020.We adopted a time-stratified case-crossover study design using individual cases to capture the effect of short-term exposure to six criteria air pollutants on CVD hospitalizations,using conditional logistic regression models.More than 1.1 million CVD hospitalization events were included.The lag pattern exploration demonstrated the largest effect for six air pollutants on lag 0–1 day.PM_(2.5),PM_(10),NO_(2),and CO were significantly associated with increased hospitalization from ischemic heart diseases,cerebrovascular diseases,other heart diseases,and five specific causes of CVD.The effect estimates of NO_(2)were the most robust when adjusting for copollutants.The concentration-response curves were positive and linear for most pollutant–endpoint pairs(except for O_(3)),and these positive associations remained even below the 24-h levels recommended by WHO Air Quality Guidelines and China Air Quality Standards.This nationwide case-crossover study in China demonstrated that short-term exposure to multiple ambient air pollutants may significantly increase the risk of cause-specific CVD hospitalizations even under the most stringent air quality regulations,striking an alert for potential CVD patients against these environmental risk factors.

Short-term effects of fine particulate matter constituents on myocardial infarction death

Existing evidence suggested that short-term exposure to fine particulate matter(PM_(2.5))may increase the risk of death from myocardial infarction(MI),while PM_(2.5) constituents responsible for this association has not been determined.We collected 12,927 MI deaths from 32 counties in southern China during 2011–2013.County-level exposures of ambient PM_(2.5) and its 5 constituents(i.e.,elemental carbon(EC),organic carbon(OC),sulfate(SO_(4)^(2-)),ammonium(NH_(4)^(+)),and nitrate(NO_(3)^(-)))were aggregated from gridded datasets predicted by Community Multiscale Air Quality Modeling System.We employed a space-time-stratified casecrossover design and conditional logistic regression models to quantify the association of MI mortality with short-term exposure to PM_(2.5) and its constituents across various lag days.Over the study period,the daily mean PM_(2.5) mass concentration was 77.8(standard deviation(SD)=72.7)μg/m^(3).We estimated an odds ratio of 1.038(95%confidence interval(CI):1.003-1.074),1.038(1.013-1.063)and 1.057(1.023-1.097)for MI mortality associated with per interquartile range(IQR)increase in the 3-day moving-average exposure to PM_(2.5)(IQR=76.3μg/m 3),EC(4.1μg/m^(3))and OC(9.1μg/m^(3)),respectively.We did not identify significant association between MI death and exposure to water-soluble ions(SO_(4)^(2-),NH_(4)^(+)and NO_(3)^(-)).Likelihood ratio tests supported no evident violations of linear assumptions for constituents-MI associations.Subgroup analyses showed stronger associations between MI death and EC/OC exposure in the elderly,males and cold months.Short-term exposure to PM_(2.5) constituents,particularly those carbonaceous aerosols,was associated with increased risks of MI mortality.