Percorrer por autor "Ng, Chris Fook Sheng"
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- Associations of ambient exposure to benzene, toluene, ethylbenzene, and xylene with daily mortality: a multicountry time-series study in 757 global locationsPublication . Zhou, Lu; Xiong, Ying; Sera, Francesco; Vicedo-Cabrera, Ana Maria; Abrutzky, Rosana; Guo, Yuming; Tong, Shilu; Coelho, Micheline de Sousa Zanotti Stagliorio; Saldiva, Paulo Hilario Nascimento; Lavigne, Eric; Correa, Patricia Matus; Ortega, Nicolás Valdés; Osorio, Samuel; Roye, Dominic; Kyselý, Jan; Orru, Hans; Maasikmets, Marek; Jaakkola, Jouni J.K.; Ryti, Niilo; Pascal, Mathilde; Huber, Veronika; Breitner-Busch, Susanne; Schneider, Alexandra; Katsouyanni, Klea; Samoli, Evangelia; Entezari, Alireza; Mayvaneh, Fatemeh; Goodman, Patrick; Zeka, Ariana; Raz, Raanan; Scortichini, Matteo; Stafoggia, Massimo; Honda, Yasushi; Hashizume, Masahiro; Ng, Chris Fook Sheng; Alahmad, Barrak; Diaz, Magali Hurtado; Félix Arellano, Eunice Elizabeth; Overcenco, Ala; Klompmaker, Jochem; Rao, Shilpa; Carrasco, Gabriel; Seposo, Xerxes; Chua, Paul Lester Carlos; das Neves Pereira da Silva, Susana; Madureira, Joana; Holobaca, Iulian-Horia; Scovronick, Noah; Garland, Rebecca M.; Kim, Ho; Lee, Whanhee; Tobias, Aurelio; Íñiguez, Carmen; Forsberg, Bertil; Ragettli, Martina S.; Guo, Yue Leon; Pan, Shih-Chun; Li, Shanshan; Masselot, Pierre; Colistro, Valentina; Bell, Michelle; Zanobetti, Antonella; Schwartz, Joel; Dang, Tran Ngoc; Van Dung, Do; Gasparrini, Antonio; Huang, Yaoxian; Kan, HaidongBackground: The presence of benzene, toluene, ethylbenzene, and xylene isomers (BTEX) in the environment is of increasing concern due to their toxicity and ubiquity. Although the adverse health effects of BTEX exposure have been documented, robust epidemiological evidence from large-scale, multicountry studies using advanced exposure assessment methodologies remains scarce. We aimed to assess the association of short-term ambient exposure to individual BTEX components and their mixture with daily total, cardiovascular, and respiratory mortality on a global scale. Methods: Daily data on mortality, meteorological factors, and air pollution were collected from 757 locations across 46 countries or regions. Data on individual chemicals (ie, benzene, toluene, xylenes [summation of ethylbenzene, m-xylene, p-xylene, and o-xylene]) and the aggregate mixture (ie, BTEX) were estimated using a chemistry–climate model. We examined the short-term associations of each individual chemical as well as the BTEX mixture with daily total, cardiovascular, and respiratory mortality in a multicountry framework. Using a two-stage time-series design, we first applied generalised additive models with a quasi-Poisson distribution to obtain location-specific associations, which were subsequently pooled using random-effects meta-analysis. Two-pollutant models were used to assess the independent effects of BTEX after adjusting for co-pollutants (PM2·5, PM10, nitrogen dioxide, sulphur dioxide, ozone, and carbon monoxide). Additionally, we assessed the overall exposure–response curves with spline terms. Findings: An IQR increment of BTEX concentration on lag 0–2 days (3-day moving average of the present day and the previous 2 days) was associated with increases of 0·57% (95% CI 0·49–0·65), 0·42% (0·30–0·54), and 0·68% (0·50–0·86) in total, cardiovascular, and respiratory mortality, respectively. The corresponding effect estimates for an IQR increment in individual chemicals (benzene, toluene, and xylenes) were 0·38–0·61%, 0·44–0·70%, and 0·41–0·65%, respectively. The associations remained significant after adjusting for co-pollutants, with a general decline in magnitude, except for a slight increase after adjustment for ozone. The shape of the exposure–response curves for all pollutants and causes of death was almost linear, with steeper slopes at low concentrations and no discernible thresholds. Interpretation: This global study provides novel evidence linking short-term exposure to ambient BTEX, both individually and as a mixture, with increased daily total, cardiovascular, and respiratory mortality. Our findings underscore the need for comprehensive air pollution mitigation policies, including stringent controls on BTEX emissions, to protect public health.
- Geographical Variations of the Minimum Mortality Temperature at a Global ScalePublication . Tobías, Aurelio; Hashizume, Masahiro; Honda, Yasushi; Sera, Francesco; Ng, Chris Fook Sheng; Kim, Yoonhee; Roye, Dominic; Chung, Yeonseung; Dang, Tran Ngoc; Kim, Ho; Lee, Whanhee; Íñiguez, Carmen; Vicedo-Cabrera, Ana; Abrutzky, Rosana; Guo, Yuming; Tong, Shilu; Coelho, Micheline de Sousa Zanotti Stagliorio; Saldiva, Paulo Hilario Nascimento; Lavigne, Eric; Correa, Patricia Matus; Ortega, Nicolás Valdés; Kan, Haidong; Osorio, Samuel; Kyselý, Jan; Urban, Aleš; Orru, Hans; Indermitte, Ene; Jaakkola, Jouni J.K.; Ryti, Niilo R.I.; Pascal, Mathilde; Huber, Veronika; Schneider, Alexandra; Katsouyanni, Klea; Analitis, Antonis; Entezari, Alireza; Mayvaneh, Fatemeh; Goodman, Patrick; Zeka, Ariana; Michelozzi, Paola; de’Donato, Francesca; Alahmad, Barrak; Diaz, Magali Hurtado; De la Cruz Valencia, César; Overcenco, Ala; Houthuijs, Danny; Ameling, Caroline; Rao, Shilpa; Di Ruscio, Francesco; Carrasco, Gabriel; Seposo, Xerxes; Nunes, Baltazar; Madureira, Joana; Holobaca, Iulian-Horia; Scovronick, Noah; Acquaotta, Fiorella; Forsberg, Bertil; Åström, Christofer; Ragettli, Martina S.; Guo, Yue-Liang Leon; Chen, Bing-Yu; Li, Shanshan; Colistro, Valentina; Zanobetti, Antonella; Schwartz, Joel; Dung, Do Van; Armstrong, Ben; Gasparrini, AntonioBackground: Minimum mortality temperature (MMT) is an important indicator to assess the temperature-mortality association, indicating long-term adaptation to local climate. Limited evidence about the geographical variability of the MMT is available at a global scale. Methods: We collected data from 658 communities in 43 countries under different climates. We estimated temperature-mortality associations to derive the MMT for each community using Poisson regression with distributed lag nonlinear models. We investigated the variation in MMT by climatic zone using a mixed-effects meta-analysis and explored the association with climatic and socioeconomic indicators. Results: The geographical distribution of MMTs varied considerably by country between 14.2 and 31.1 °C decreasing by latitude. For climatic zones, the MMTs increased from alpine (13.0 °C) to continental (19.3 °C), temperate (21.7 °C), arid (24.5 °C), and tropical (26.5 °C). The MMT percentiles (MMTPs) corresponding to the MMTs decreased from temperate (79.5th) to continental (75.4th), arid (68.0th), tropical (58.5th), and alpine (41.4th). The MMTs indreased by 0.8 °C for a 1 °C rise in a community's annual mean temperature, and by 1 °C for a 1 °C rise in its SD. While the MMTP decreased by 0.3 centile points for a 1 °C rise in a community's annual mean temperature and by 1.3 for a 1 °C rise in its SD. Conclusions: The geographical distribution of the MMTs and MMTPs is driven mainly by the mean annual temperature, which seems to be a valuable indicator of overall adaptation across populations. Our results suggest that populations have adapted to the average temperature, although there is still more room for adaptation.
- Interactive effects of ambient fine particulate matter and ozone on daily mortality in 372 cities: two stage time series analysisPublication . Liu, Cong; Chen, Renjie; Sera, Francesco; Vicedo-Cabrera, Ana Maria; Guo, Yuming; Tong, Shilu; Lavigne, Eric; Correa, Patricia Matus; Ortega, Nicolás Valdés; Achilleos, Souzana; Roye, Dominic; Jaakkola, Jouni J.K.; Ryti, Niilo; Pascal, Mathilde; Schneider, Alexandra; Breitner, Susanne; Entezari, Alireza; Mayvaneh, Fatemeh; Raz, Raanan; Honda, Yasushi; Hashizume, Masahiro; Ng, Chris Fook Sheng; Gaio, Vânia; Madureira, Joana; Holobaca, Iulian-Horia; Tobias, Aurelio; Íñiguez, Carmen; Guo, Yue Leon; Pan, Shih-Chun; Masselot, Pierre; Bell, Michelle L.; Zanobetti, Antonella; Schwartz, Joel; Gasparrini, Antonio; Kan, HaidongObjective: To investigate potential interactive effects of fine particulate matter (PM2.5) and ozone (O3) on daily mortality at global level. Design: Two stage time series analysis. Setting: 372 cities across 19 countries and regions. Population: Daily counts of deaths from all causes, cardiovascular disease, and respiratory disease. Main outcome measure: Daily mortality data during 1994-2020. Stratified analyses by co-pollutant exposures and synergy index (>1 denotes the combined effect of pollutants is greater than individual effects) were applied to explore the interaction between PM2.5 and O3 in association with mortality. Results: During the study period across the 372 cities, 19.3 million deaths were attributable to all causes, 5.3 million to cardiovascular disease, and 1.9 million to respiratory disease. The risk of total mortality for a 10 μg/m3 increment in PM2.5 (lag 0-1 days) ranged from 0.47% (95% confidence interval 0.26% to 0.67%) to 1.25% (1.02% to 1.48%) from the lowest to highest fourths of O3 concentration; and for a 10 μg/m3 increase in O3 ranged from 0.04% (-0.09% to 0.16%) to 0.29% (0.18% to 0.39%) from the lowest to highest fourths of PM2.5 concentration, with significant differences between strata (P for interaction <0.001). A significant synergistic interaction was also identified between PM2.5 and O3 for total mortality, with a synergy index of 1.93 (95% confidence interval 1.47 to 3.34). Subgroup analyses showed that interactions between PM2.5 and O3 on all three mortality endpoints were more prominent in high latitude regions and during cold seasons. Conclusion: The findings of this study suggest a synergistic effect of PM2.5 and O3 on total, cardiovascular, and respiratory mortality, indicating the benefit of coordinated control strategies for both pollutants.
- Regional variation in the role of humidity on city-level heat-related mortalityPublication . Guo, Qiang; Mistry, Malcolm N.; Zhou, Xudong; Zhao, Gang; Kino, Kanon; Wen, Bo; Yoshimura, Kei; Satoh, Yusuke; Cvijanovic, Ivana; Kim, Yoonhee; Ng, Chris Fook Sheng; Vicedo-Cabrera, Ana M.; Armstrong, Ben; Urban, Aleš; Katsouyanni, Klea; Masselot, Pierre; Tong, Shilu; Sera, Francesco; Huber, Veronika; Bell, Michelle L.; Kyselý, Jan; Gasparrini, Antonio; Hashizume, Masahiro; Oki, Taikan; Abrutzky, Rosana; Guo, Yuming; de Sousa Zanotti Stagliorio Coelho, Micheline; Nascimento Saldiva, Paulo Hilario; Lavigne, Eric; Ortega, Nicolás Valdés; Correa, Patricia Matus; Kan, Haidong; Osorio, Samuel; Roye, Dominic; Indermitte, Ene; Orru, Hans; Jaakkola, Jouni J K.; Ryti, Niilo; Pascal, Mathilde; Schneider, Alexandra; Analitis, Antonis; Entezari, Alireza; Mayvaneh, Fatemeh; Zeka, Ariana; Goodman, Patrick; de'Donato, Francesca; Michelozzi, Paola; Alahmad, Barrak; De la Cruz Valencia, César; Hurtado Diaz, Magali; Overcenco, Ala; Ameling, Caroline; Houthuijs, Danny; Rao, Shilpa; Carrasco, Gabriel; Seposo, Xerxes; Madureira, Joana; Silva, Susana; Holobaca, Iulian-Horia; Acquaotta, Fiorella; Scovronick, Noah; Kim, Ho; Lee, Whanhee; Tobias, Aurelio; Íñiguez, Carmen; Forsberg, Bertil; Ragettli, Martina S.; Pan, Shih-Chun; Guo, Yue Leon; Li, Shanshan; Schneider, Rochelle; Colistro, Valentina; Zanobetti, Antonella; Schwartz, Joel; Van Dung, Do; Ngoc Dang, Tran; Honda, YasushiThe rising humid heat is regarded as a severe threat to human survivability, but the proper integration of humid heat into heat-health alerts is still being explored. Using state-of-the-art epidemiological and climatological datasets, we examined the association between multiple heat stress indicators (HSIs) and daily human mortality in 739 cities worldwide. Notable differences were observed in the long-term trends and timing of heat events detected by HSIs. Air temperature (Tair) predicts heat-related mortality well in cities with a robust negative Tair-relative humidity correlation (CT-RH). However, in cities with near-zero or weak positive CT-RH, HSIs considering humidity provide enhanced predictive power compared to Tair. Furthermore, the magnitude and timing of heat-related mortality measured by HSIs could differ largely from those associated with Tair in many cities. Our findings provide important insights into specific regions where humans are vulnerable to humid heat and can facilitate the further enhancement of heat-health alert systems.
- Seasonality of mortality under climate change: a multicountry projection studyPublication . Madaniyazi, Lina; Armstrong, Ben; Tobias, Aurelio; Mistry, Malcolm N.; Bell, Michelle L.; Urban, Aleš; Kyselý, Jan; Ryti, Niilo; Cvijanovic, Ivana; Ng, Chris Fook Sheng; Roye, Dominic; Vicedo-Cabrera, Ana Maria; Tong, Shilu; Lavigne, Eric; Íñiguez, Carmen; das Neves Pereira da Silva, Susana; Madureira, Joana; Jaakkola, Jouni J.K.; Sera, Francesco; Honda, Yasushi; Gasparrini, Antonio; Hashizume, Masahiro; Multi-Country Multi-City Collaborative Research NetworkBackground: Climate change can directly impact temperature-related excess deaths and might subsequently change the seasonal variation in mortality. In this study, we aimed to provide a systematic and comprehensive assessment of potential future changes in the seasonal variation, or seasonality, of mortality across different climate zones. Methods: In this modelling study, we collected daily time series of mean temperature and mortality (all causes or non-external causes only) via the Multi-Country Multi-City Collaborative (MCC) Research Network. These data were collected during overlapping periods, spanning from Jan 1, 1969 to Dec 31, 2020. We projected daily mortality from Jan 1, 2000 to Dec 31, 2099, under four climate change scenarios corresponding to increasing emissions (Shared Socioeconomic Pathways [SSP] scenarios SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5). We compared the seasonality in projected mortality between decades by its shape, timings (the day-of-year) of minimum (trough) and maximum (peak) mortality, and sizes (peak-to-trough ratio and attributable fraction). Attributable fraction was used to measure the burden of seasonality of mortality. The results were summarised by climate zones. Findings: The MCC dataset included 126 809 537 deaths from 707 locations within 43 countries or areas. After excluding the only two polar locations (both high-altitude locations in Peru) from climatic zone assessments, we analysed 126 766 164 deaths in 705 locations aggregated in four climate zones (tropical, arid, temperate, and continental). From the 2000s to the 2090s, our projections showed an increase in mortality during the warm seasons and a decrease in mortality during the cold seasons, albeit with mortality remaining high during the cold seasons, under all four SSP scenarios in the arid, temperate, and continental zones. The magnitude of this changing pattern was more pronounced under the high-emission scenarios (SSP3-7.0 and SSP5-8.5), substantially altering the shape of seasonality of mortality and, under the highest emission scenario (SSP5-8.5), shifting the mortality peak from cold seasons to warm seasons in arid, temperate, and continental zones, and increasing the size of seasonality in all zones except the arid zone by the end of the century. In the 2090s compared with the 2000s, the change in peak-to-trough ratio (relative scale) ranged from 0·96 to 1·11, and the change in attributable fraction ranged from 0·002% to 0·06% under the SSP5-8.5 (highest emission) scenario. Interpretation: A warming climate can substantially change the seasonality of mortality in the future. Our projections suggest that health-care systems should consider preparing for a potentially increased demand during warm seasons and sustained high demand during cold seasons, particularly in regions characterised by arid, temperate, and continental climates.
- Short term association between ozone and mortality: global two stage time series study in 406 locations in 20 countriesPublication . Vicedo-Cabrera, Ana M.; Sera, Francesco; Liu, Cong; Armstrong, Ben; Milojevic, A.i.; Guo, Yuming; Tong, Shilu; Lavigne, Eric; Kyselý, Jan; Urban, Aleš; Orru, Hans; Indermitte, Ene; Pascal, Mathilde; Huber, Veronika; Schneider, Alexandra; Katsouyanni, Klea; Samoli, Evangelia; Stafoggia, Massimo; Scortichini, Matteo; Hashizume, Masahiro; Honda, Yasushi; Ng, Chris Fook Sheng; Hurtado-Diaz, Magali; Cruz, Julio; Silva, Susana; Madureira, Joana; Scovronick, Noah; Garland, Rebecca M.; Kim, Ho; Tobias, Aurelio; Íñiguez, Carmen; Forsberg, Bertil; Åström, Christofer; Ragettli, Martina S.; Röösli, Martin; Guo, Yue-Liang Leon; Chen, Bing-Yu; Zanobetti, Antonella; Schwartz, Joel; Bell, Michelle L.; Kan, Haidong; Gasparrini, AntonioObjective: To assess short term mortality risks and excess mortality associated with exposure to ozone in several cities worldwide. Design: Two stage time series analysis. Setting: 406 cities in 20 countries, with overlapping periods between 1985 and 2015, collected from the database of Multi-City Multi-Country Collaborative Research Network. Population: Deaths for all causes or for external causes only registered in each city within the study period. MAIN OUTCOME MEASURES: Daily total mortality (all or non-external causes only). Results: A total of 45 165 171 deaths were analysed in the 406 cities. On average, a 10 µg/m3 increase in ozone during the current and previous day was associated with an overall relative risk of mortality of 1.0018 (95% confidence interval 1.0012 to 1.0024). Some heterogeneity was found across countries, with estimates ranging from greater than 1.0020 in the United Kingdom, South Africa, Estonia, and Canada to less than 1.0008 in Mexico and Spain. Short term excess mortality in association with exposure to ozone higher than maximum background levels (70 µg/m3) was 0.26% (95% confidence interval 0.24% to 0.28%), corresponding to 8203 annual excess deaths (95% confidence interval 3525 to 12 840) across the 406 cities studied. The excess remained at 0.20% (0.18% to 0.22%) when restricting to days above the WHO guideline (100 µg/m3), corresponding to 6262 annual excess deaths (1413 to 11 065). Above more lenient thresholds for air quality standards in Europe, America, and China, excess mortality was 0.14%, 0.09%, and 0.05%, respectively. Conclusions: Results suggest that ozone related mortality could be potentially reduced under stricter air quality standards. These findings have relevance for the implementation of efficient clean air interventions and mitigation strategies designed within national and international climate policies.
- Short term associations of ambient nitrogen dioxide with daily total, cardiovascular, and respiratory mortality: multilocation analysis in 398 citiesPublication . Meng, Xia; Liu, Cong; Chen, Renjie; Sera, Francesco; Vicedo-Cabrera, Ana Maria; Milojevic, Ai; Guo, Yuming; Tong, Shilu; Coelho, Micheline de Sousa Zanotti Staglior; Saldiva, Paulo Hilario Nascimento; Lavigne, Eric; Correa, Patricia Matus; Ortega, Nicolas Valdes; Osorio Garcia, Samuel; Kyselý, Jan; Urban, Aleš; Orru, Hans; Maasikmets, Marek; Jaakkola, Jouni J.K.; Ryti, Niilo; Huber, Veronika; Schneider, Alexandra; Katsouyanni, Klea; Analitis, Antonis; Hashizume, Masahiro; Honda, Yasushi; Ng, Chris Fook Sheng; Nunes, Baltazar; Teixeira, João Paulo; Holobaca, Iulian Horia; Fratianni, Simona; Kim, Ho; Tobias, Aurelio; Íñiguez, Carmen; Forsberg, Bertil; Åström, Christofer; Ragettli, Martina S.; Guo, Yue-Liang Leon; Pan, Shih-Chun; Li, Shanshan; Bell, Michelle L.; Zanobetti, Antonella; Schwartz, Joel; Wu, Tangchun; Gasparrini, Antonio; Kan, HaidongObjective: To evaluate the short term associations between nitrogen dioxide (NO2) and total, cardiovascular, and respiratory mortality across multiple countries/regions worldwide, using a uniform analytical protocol. Design: Two stage, time series approach, with overdispersed generalised linear models and multilevel meta-analysis. Setting: 398 cities in 22 low to high income countries/regions. Main outcome measures: Daily deaths from total (62.8 million), cardiovascular (19.7 million), and respiratory (5.5 million) causes between 1973 and 2018. Results: On average, a 10 μg/m3 increase in NO2 concentration on lag 1 day (previous day) was associated with 0.46% (95% confidence interval 0.36% to 0.57%), 0.37% (0.22% to 0.51%), and 0.47% (0.21% to 0.72%) increases in total, cardiovascular, and respiratory mortality, respectively. These associations remained robust after adjusting for co-pollutants (particulate matter with aerodynamic diameter ≤10 μm or ≤2.5 μm (PM10 and PM2.5, respectively), ozone, sulfur dioxide, and carbon monoxide). The pooled concentration-response curves for all three causes were almost linear without discernible thresholds. The proportion of deaths attributable to NO2 concentration above the counterfactual zero level was 1.23% (95% confidence interval 0.96% to 1.51%) across the 398 cities. Conclusions: This multilocation study provides key evidence on the independent and linear associations between short term exposure to NO2 and increased risk of total, cardiovascular, and respiratory mortality, suggesting that health benefits would be achieved by tightening the guidelines and regulatory limits of NO2.
- Short-Term Association between Sulfur Dioxide and Mortality: A Multicountry Analysis in 399 CitiesPublication . O’Brien, Edward; Masselot, Pierre; Sera, Francesco; Roye, Dominic; Breitner, Susanne; Ng, Chris Fook Sheng; de Sousa Zanotti Stagliorio Coelho, Micheline; Madureira, Joana; Tobias, Aurelio; Vicedo-Cabrera, Ana Maria; Bell, Michelle L.; Lavigne, Eric; Kan, Haidong; Gasparrini, Antonio; MCC Collaborative Research NetworkBackground: Epidemiological evidence on the health risks of sulfur dioxide (sulfur dioxide SO2) is more limited compared with other pollutants, and doubts remain on several aspects, such as the form of the exposure–response relationship, the potential role of copollutants, as well as the actual risk at low concentrations and possible temporal variation in risks. Objectives: Our aim was to assess the short-term association between exposure to sulfur dioxide SO2 and daily mortality in a large multilocation data set, using advanced study designs and statistical techniques. Methods: The analysis included 43,729,018 deaths that occurred in 399 cities within 23 countries between 1980 and 2018. A two-stage design was applied to assess the association between the daily concentration of sulfur dioxide SO2 and mortality counts, including first-stage time-series regressions and second-stage multilevel random-effect meta-analyses. Secondary analyses assessed the exposure–response shape and the lag structure using spline terms and distributed lag models, respectively, and temporal variations in risk using a longitudinal meta-regression. Bi-pollutant models were applied to examine confounding effects of particulate matter with an aerodynamic diameter of less than or equal to 10 micrometers≤10μm (particulate matter begin subscript 10 end subscriptPM10) and 2.5 micrometers2.5μm (particulate matter begin subscript 2.5 end subscriptPM2.5), ozone, nitrogen dioxide, and carbon monoxide. Associations were reported as relative risks (RRs) and fractions of excess deaths. Results: The average daily concentration of sulfur dioxideSO2 across the 399 cities was 11.7 micrograms per meter cubed11.7 μg/m3, with 4.7% of days above the World Health Organization (WHO) guideline limit (40 micrograms per meter cubed40 μg/m3, 24-h average), although the exceedances occurred predominantly in specific locations. Exposure levels decreased considerably during the study period, from an average concentration of 19.0 micrograms per meter cubed19.0 μg/m3 in 1980–1989 to 6.3 micrograms per meter cubed6.3 μg/m3 in 2010–2018. For all locations combined, a 10 microgram per meter cubed10-μg/m3 increase in daily sulfur dioxide SO2 was associated with an RR of mortality of 1.0045 [95% confidence interval (CI): 1.0019, 1.0070], with the risk being stable over time but with substantial between-country heterogeneity. Short-term exposure to sulfur dioxide SO2 was associated with an excess mortality fraction of 0.50% [95% empirical CI (eCI): 0.42%, 0.57%] in the 399 cities, although decreasing from 0.74% (0.61%, 0.85%) in 1980–1989 to 0.37% (0.27%, 0.47%) in 2010–2018. There was some evidence of nonlinearity, with a steep exposure–response relationship at low concentrations and the risk attenuating at higher levels. The relevant lag window was 0–3 d. Significant positive associations remained after controlling for other pollutants. Discussion: The analysis revealed independent mortality risks associated with short-term exposure to sulfur dioxideSO2, with no evidence of a threshold. Levels below the current WHO guidelines for 24-h averages were still associated with substantial excess mortality, indicating the potential benefits of stricter air quality standards.
