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- Liu, Cong, et al.
(author)
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Coarse particulate air pollution and daily mortality : a global study in 205 cities
- 2022
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In: American Journal of Respiratory and Critical Care Medicine. - : American Thoracic Society. - 1073-449X .- 1535-4970. ; 206:8, s. 999-1007
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Journal article (peer-reviewed)abstract
- RATIONALE: The associations between ambient coarse particulate matter (PM2.5-10) and daily mortality is not fully understood at a global scale.OBJECTIVES: To evaluate the short-term associations between PM2.5-10 and total, cardiovascular, and respiratory mortality across multiple countries/regions worldwide.METHODS: We collected daily mortality (total, cardiovascular, respiratory) and air pollution data from 205 cities in 20 countries/regions. Concentrations of PM2.5-10 were computed as the difference between inhalable and fine particulate matter. A two-stage time-series analytic approach was applied, with over-dispersed generalized linear models and multilevel meta-analysis. We fitted two-pollutant models to test the independent effect of PM2.5-10 from co-pollutants (fine particulate matter, nitrogen dioxide, sulfur dioxide, ozone, and carbon monoxide). Exposure-response relationship curves were pooled and regional analyses were conducted.MEASUREMENTS AND MAIN RESULTS: A 10 μg/m3 increase in PM2.5-10 concentration on lag 0-1 day was associated with increments of 0.51% (95% confidence interval [CI]: 0.18%, 0.84%), 0.43% (95%CI: 0.15%, 0.71%) and 0.41% (95%CI: 0.06%, 0.77%) in total, cardiovascular, and respiratory mortality, respectively. The associations varied by country and region. These associations were robust to adjustment by all co-pollutants in two-pollutant models, especially for PM2.5. The exposure-response curves for total, cardiovascular, and respiratory mortality were positive, with steeper slopes at lower exposure ranges and without discernible thresholds.CONCLUSIONS: This study provides novel global evidence on the robust and independent associations between short-term exposure to ambient PM2.5-10 and total, cardiovascular and respiratory mortality, suggesting the need to establish a unique guideline or regulatory limit for daily concentrations of PM2.5-10.
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| 2. |
- Masselot, Pierre, et al.
(author)
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Differential mortality risks associated with PM2.5 components : a multi-country, multi-city study
- 2022
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In: Epidemiology. - : Wolters Kluwer. - 1044-3983 .- 1531-5487. ; 33:2, s. 167-175
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Journal article (peer-reviewed)abstract
- BACKGROUND: The association between fine particulate matter (PM2.5) and mortality widely differs between as well as within countries. Differences in PM2.5 composition can play a role in modifying the effect estimates, but there is little evidence about which components have higher impacts on mortality.METHODS: We applied a two-stage analysis on data collected from 210 locations in 16 countries. In the first stage, we estimated location-specific relative risks (RR) for mortality associated with daily total PM2.5 through time series regression analysis. We then pooled these estimates in a meta-regression model that included city-specific logratio-transformed proportions of seven PM2.5 components as well as meta-predictors derived from city-specific socio-economic and environmental indicators.RESULTS: We found associations between RR and several PM2.5 components. Increasing the ammonium (NH4+) proportion from 1% to 22%, while keeping a relative average proportion of other components, increased the RR from 1.0063 (95%CI: 1.0030-1.0097) to 1.0102 (95%CI:1.0070-1.0135). Conversely, an increase in nitrate (NO3-) from 1% to 71% resulted in a reduced RR, from 1.0100 (95%CI: 1.0067-1.0133) to 1.0037 (95%CI: 0.9998- 1.0077). Differences in composition explained a substantial part of the heterogeneity in PM2.5 risk.CONCLUSIONS: These findings contribute to the identification of more hazardous emission sources. Further work is needed to understand the health impacts of PM2.5 components and sources given the overlapping sources and correlations among many components.
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