Percorrer por autor "Chen, Kai"
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- Ambient carbon monoxide and daily mortality: a global time-series study in 337 citiesPublication . Chen, Kai; Breitner, Susanne; Wolf, Kathrin; Stafoggia, Massimo; Sera, Francesco; Vicedo-Cabrera, Ana M.; Guo, Yuming; Tong, Shilu; Lavigne, Eric; Matus, Patricia; Valdés, Nicolás; Kan, Haidong; Jaakkola, Jouni J.K.; Ryti, Niilo R.I.; Huber, Veronika; Scortichini, Matteo; Hashizume, Masahiro; Honda, Yasushi; Nunes, Baltazar; Madureira, Joana; Holobâcă, Iulian Horia; Fratianni, Simona; Kim, Ho; Lee, Whanhee; Tobias, Aurelio; Íñiguez, Carmen; Forsberg, Bertil; Åström, Christofer; Ragettli, Martina S-; Guo, Yue-Liang Leon; Chen, Bing-Yu; Li, Shanshan; Milojevic, Ai; Zanobetti, Antonella; Schwartz, Joel; Bell, Michelle L-; Gasparrini, Antonio; Schneider, AlexandraBackground: Epidemiological evidence on short-term association between ambient carbon monoxide (CO) and mortality is inconclusive and limited to single cities, regions, or countries. Generalisation of results from previous studies is hindered by potential publication bias and different modelling approaches. We therefore assessed the association between short-term exposure to ambient CO and daily mortality in a multicity, multicountry setting. Methods: We collected daily data on air pollution, meteorology, and total mortality from 337 cities in 18 countries or regions, covering various periods from 1979 to 2016. All included cities had at least 2 years of both CO and mortality data. We estimated city-specific associations using confounder-adjusted generalised additive models with a quasi-Poisson distribution, and then pooled the estimates, accounting for their statistical uncertainty, using a random-effects multilevel meta-analytical model. We also assessed the overall shape of the exposure-response curve and evaluated the possibility of a threshold below which health is not affected. Findings: Overall, a 1 mg/m3 increase in the average CO concentration of the previous day was associated with a 0·91% (95% CI 0·32-1·50) increase in daily total mortality. The pooled exposure-response curve showed a continuously elevated mortality risk with increasing CO concentrations, suggesting no threshold. The exposure-response curve was steeper at daily CO levels lower than 1 mg/m3, indicating greater risk of mortality per increment in CO exposure, and persisted at daily concentrations as low as 0·6 mg/m3 or less. The association remained similar after adjustment for ozone but was attenuated after adjustment for particulate matter or sulphur dioxide, or even reduced to null after adjustment for nitrogen dioxide. Interpretation: This international study is by far the largest epidemiological investigation on short-term CO-related mortality. We found significant associations between ambient CO and daily mortality, even at levels well below current air quality guidelines. Further studies are warranted to disentangle its independent effect from other traffic-related pollutants.
- Impact of population aging on future temperature-related mortality at different global warming levelsPublication . Chen, Kai; de Schrijver, Evan; Sivaraj, Sidharth; Sera, Francesco; Scovronick, Noah; Jiang, Leiwen; Roye, Dominic; Lavigne, Eric; Kyselý, Jan; Urban, Aleš; Schneider, Alexandra; Huber, Veronika; Madureira, Joana; Mistry, Malcolm N; Cvijanovic, Ivana; MCC Collaborative Research Network; Gasparrini, Antonio; Vicedo-Cabrera, Ana MOlder adults are generally amongst the most vulnerable to heat and cold. While temperature-related health impacts are projected to increase with global warming, the influence of population aging on these trends remains unclear. Here we show that at 1.5 °C, 2 °C, and 3 °C of global warming, heat-related mortality in 800 locations across 50 countries/areas will increase by 0.5%, 1.0%, and 2.5%, respectively; among which 1 in 5 to 1 in 4 heat-related deaths can be attributed to population aging. Despite a projected decrease in cold-related mortality due to progressive warming alone, population aging will mostly counteract this trend, leading to a net increase in cold-related mortality by 0.1%-0.4% at 1.5-3 °C global warming. Our findings indicate that population aging constitutes a crucial driver for future heat- and cold-related deaths, with increasing mortality burden for both heat and cold due to the aging population.
- Ozone-related acute excess mortality projected to increase in the absence of climate and air quality controls consistent with the Paris AgreementPublication . Domingo, Nina G.G.; Fiore, Arlene M.; Lamarque, Jean-Francois; Kinney, Patrick L.; Jiang, Leiwen; Gasparrini, Antonio; Breitner, Susanne; Lavigne, Eric; Madureira, Joana; Masselot, Pierre; Silva, Susana das Neves Pereira da; Sheng Ng, Chris Fook; Kyselý, Jan; Guo, Yuming; Tong, Shilu; Kan, Haidong; Urban, Aleš; Orru, Hans; Maasikmets, Marek; Pascal, Mathilde; Katsouyanni, Klea; Samoli, Evangelia; Scortichini, Matteo; Stafoggia, Massimo; Hashizume, Masahiro; Alahmad, Barrak; Diaz, Magali Hurtado; De la Cruz Valencia, César; Scovronick, Noah; Garland, Rebecca M.; Kim, Ho; Lee, Whanhee; Tobias, Aurelio; Íñiguez, Carmen; Forsberg, Bertil; Åström, Christofer; Ragettli, Martina S.; Guo, Yue Leon; Pan, Shih-Chun; Colistro, Valentina; Bell, Michelle; Zanobetti, Antonella; Schwartz, Joel; Schneider, Alexandra; Vicedo-Cabrera, Ana M.; Chen, KaiShort-term exposure to ground-level ozone in cities is associated with increased mortality and is expected to worsen with climate and emission changes. However, no study has yet comprehensively assessed future ozone-related acute mortality across diverse geographic areas, various climate scenarios, and using CMIP6 multi-model ensembles, limiting our knowledge on future changes in global ozone-related acute mortality and our ability to design targeted health policies. Here, we combine CMIP6 simulations and epidemiological data from 406 cities in 20 countries or regions. We find that ozone-related deaths in 406 cities will increase by 45 to 6,200 deaths/year between 2010 and 2014 and between 2050 and 2054, with attributable fractions increasing in all climate scenarios (from 0.17% to 0.22% total deaths), except the single scenario consistent with the Paris Climate Agreement (declines from 0.17% to 0.15% total deaths). These findings stress the need for more stringent air quality regulations, as current standards in many countries are inadequate.
- Rainfall events and daily mortality across 645 global locations: two stage time series analysisPublication . He, Cheng; Breitner-Busch, Susanne; Huber, Veronika; Chen, Kai; Zhang, Siqi; Gasparrini, Antonio; Bell, Michelle; Kan, Haidong; Royé, Dominic; Armstrong, Ben; Schwartz, Joel; Sera, Francesco; Vicedo-Cabrera, Ana Maria; Honda, Yasushi; Jaakkola, Jouni J.K.; Ryti, Niilo; Kyselý, Jan; Guo, Yuming; Tong, Shilu; de’Donato, Francesca; Michelozzi, Paola; Coelho, Micheline de Sousa Zanotti Staglior; Saldiva, Paulo Hilario Nascimento; Lavigne, Eric; Orru,Hans; Indermitte, Ene; Pascal, Mathilde; Goodman, Patrick; Zeka, Ariana; Kim, Yoonhee; Diaz, Magali Hurtado; Arellano, Eunice Elizabeth Félix; Overcenco, Ala; Klompmaker, Jochem; Rao, Shilpa; Palomares, Alfonso Diz-Lois; Carrasco, Gabriel; Seposo, Xerxes; das Neves Pereira da Silva, Susana; Joana Madureira; Holobaca, Iulian-Horia; Scovronick, Noah; Acquaotta, Fiorella; Kim, Ho; Lee, Whanhee; Hashizume, Masahiro; Tobias, Aurelio; Íñiguez, Carmen; Forsberg, Bertil; Ragettli, Martina S.; Guo, Yue Leon; Pan, Shih-Chun; Osorio, Samuel; Li, Shanshan; Zanobetti, Antonella; Dang, Tran Ngoc; Dung, Do Van; Schneider. AlexandraObjective: To examine the associations between characteristics of daily rainfall (intensity, duration, and frequency) and all cause, cardiovascular, and respiratory mortality. Design: Two stage time series analysis. Setting: 645 locations across 34 countries or regions. Population: Daily mortality data, comprising a total of 109 954 744 all cause, 31 164 161 cardiovascular, and 11 817 278 respiratory deaths from 1980 to 2020. Main outcome measure: Association between daily mortality and rainfall events with return periods (the expected average time between occurrences of an extreme event of a certain magnitude) of one year, two years, and five years, with a 14 day lag period. A continuous relative intensity index was used to generate intensity-response curves to estimate mortality risks at a global scale. Results: During the study period, a total of 50 913 rainfall events with a one year return period, 8362 events with a two year return period, and 3301 events with a five year return period were identified. A day of extreme rainfall with a five year return period was significantly associated with increased daily all cause, cardiovascular, and respiratory mortality, with cumulative relative risks across 0-14 lag days of 1.08 (95% confidence interval 1.05 to 1.11), 1.05 (1.02 to 1.08), and 1.29 (1.19 to 1.39), respectively. Rainfall events with a two year return period were associated with respiratory mortality only, whereas no significant associations were found for events with a one year return period. Non-linear analysis revealed protective effects (relative risk <1) with moderate-heavy rainfall events, shifting to adverse effects (relative risk >1) with extreme intensities. Additionally, mortality risks from extreme rainfall events appeared to be modified by climate type, baseline variability in rainfall, and vegetation coverage, whereas the moderating effects of population density and income level were not significant. Locations with lower variability of baseline rainfall or scarce vegetation coverage showed higher risks. Conclusion: Daily rainfall intensity is associated with varying health effects, with extreme events linked to an increasing relative risk for all cause, cardiovascular, and respiratory mortality. The observed associations varied with local climate and urban infrastructure.