Exposure to ambient fine particulate matter (PM2.5) is a major global health concern. Quantitative estimates of attributable mortality are based on disease-specific hazard ratio models that incorporate risk information from multiple PM2.5 sources (outdoor and indoor air pollution from use of solid fuels and secondhand and active smoking), requiring assumptions about equivalent exposure and toxicity. We relax these contentious assumptions by constructing a PM2.5-mortality hazard ratio function based only on cohort studies of outdoor air pollution that covers the global exposure range. We modeled the shape of the association between PM2.5 and nonaccidental mortality using data from 41 cohorts from 16 countries-the Global Exposure Mortality Model (GEMM). We then constructed GEMMs for five specific causes of death examined by the global burden of disease (GBD). The GEMM predicts 8.9 million [95% confidence interval (CI): 7.5-10.3] deaths in 2015, a figure 30% larger than that predicted by the sum of deaths among the five specific causes (6.9; 95% CI: 4.9-8.5) and 120% larger than the risk function used in the GBD (4.0; 95% CI: 3.3-4.8). Differences between the GEMM and GBD risk functions are larger for a 20% reduction in concentrations, with the GEMM predicting 220% higher excess deaths. These results suggest that PM2.5 exposure may be related to additional causes of death than the five considered by the GBD and that incorporation of risk information from other, nonoutdoor, particle sources leads to underestimation of disease burden, especially at higher concentrations.

https://www.pnas.org/content/pnas/115/38/9592.full.pdf

Global estimates of mortality associated with long-term exposure to outdoor fine particulate matter

Air Pollution and Cardiovascular Disease: JACC State-of-the-Art Review

The impact of air pollution on deaths, disease burden, and life expectancy across the states of India: the Global Burden of Disease Study 2017

Long-term exposure to PM and all-cause and cause-specific mortality: A systematic review and meta-analysis.

Outdoor air pollution is a major contributor to the burden of disease worldwide. Most of the global population resides in places where air pollution levels, because of emissions from industry, power generation, transportation, and domestic burning, considerably exceed the World Health Organization's health-based air-quality guidelines. Outdoor air pollution poses an urgent worldwide public health challenge because it is ubiquitous and has numerous serious adverse human health effects, including cancer. Currently, there is substantial evidence from studies of humans and experimental animals as well as mechanistic evidence to support a causal link between outdoor (ambient) air pollution, and especially particulate matter (PM) in outdoor air, with lung cancer incidence and mortality. It is estimated that hundreds of thousands of lung cancer deaths annually worldwide are attributable to PM air pollution. Epidemiological evidence on outdoor air pollution and the risk of other types of cancer, such as bladder cancer or breast cancer, is more limited. Outdoor air pollution may also be associated with poorer cancer survival, although further research is needed. This report presents an overview of outdoor air pollutants, sources, and global levels, as well as a description of epidemiological evidence linking outdoor air pollution with cancer incidence and mortality. Biological mechanisms of air pollution-derived carcinogenesis are also described. This report concludes by summarizing public health/policy recommendations, including multilevel interventions aimed at individual, community, and regional scales. Specific roles for medical and health care communities with regard to prevention and advocacy and recommendations for further research are also described.

https://acsjournals.onlinelibrary.wiley.com/doi/pdf/10.3322/caac.21632

Outdoor air pollution and cancer: An overview of the current evidence and public health recommendations.

Background: Cohort studies in North America and western Europe have reported increased risk of mortality associated with long-term exposure to fine particles (PM2.5), but to date, no such studies h...

/pdf/long-term-fine-particulate-matter-exposure-and-nonaccidental-5be82pl7y8.pdf

Long-term Fine Particulate Matter Exposure and Nonaccidental and Cause-specific Mortality in a Large National Cohort of Chinese Men.

Associations of long-term exposure to fine particulate matter and its constituents with cardiovascular mortality: A prospective cohort study in China.

Objective: To explore the effect of fine particulate matters with an aerodynamic diameter less than 2.5 μm (PM(2.5)) on daily cardiovascular disease mortality in seven cities of China. Methods: Daily average concentrations of PM(2.5), cardiovascular disease mortality data and environmental data were collected from January 1, 2013 to December 31, 2015 in seven cities of China, including Shijiazhuang, Haerbin, Shanghai, Wuhan, Guangzhou, Chengdu and Xi' an. We linked generalized additive model with Quasi-Poisson distribution to evaluate the association between daily concentrations of PM(2.5) and cardiovascular disease mortality at single-city level and multi-city level, after adjusting for the long-term and seasonal trend, as well as meteorological factors and the effect of " days of week" . Results: The single-pollutant model indicated that there were marked differences in association strength in these cities, among which the effect in Guangzhou was strongest. At multi-city level, a 10 μg/m(3) increase of PM(2.5) was associated with an increase of 0.315% (95%CI: 0.133%-0.497%) of daily cardiovascular disease mortality. From lag0 to lag2, the effect of PM(2.5) on cardiovascular disease mortality decreased, while it was strongest on lag01. In the two-pollutant model, the estimated effect decreased in all the cities with the adjustments of SO(2) or NO(2). The insignificant combined results suggested that PM(2.5) might have combined effect with other pollutants. Each 10 μg/m(3) increase of PM(2.5) was associated with increases of 0.371% (95%CI: 0.141%-0.600%) and 0.199% (95% CI: 0.077%-0.321%) of cardiovascular disease mortality in males and females, respectively. The effect of PM(2.5) on cardiovascular disease mortality increased with age and decreased with educational level, although the differences between different subgroups were insignificant. The dose-response relationship between PM(2.5) and cardiovascular disease mortality was non-linear and non-threshold, with a steeper curve at lower concentrations. Conclusion: The increases of PM(2.5) concentration can result in the increase of daily cardiovascular mortality.

Ruiming Liang

Papers

Long-term Fine Particulate Matter Exposure and Nonaccidental and Cause-specific Mortality in a Large National Cohort of Chinese Men.

Associations of long-term exposure to fine particulate matter and its constituents with cardiovascular mortality: A prospective cohort study in China.

Acute effect of fine particulate matters on daily cardiovascular disease mortality in seven cities of China