Assessing short-term impacts of PM2.5 constituents on cardiorespiratory hospitalizations: Multi-city evidence from China

Association between ambient fine particulate matter constituents and mortality and morbidity of cardiovascular and respiratory diseases: A systematic review and meta-analysis

Existing studies have explored the associations between short-term or long-term exposures to PM2.5 constituents and mortality and morbidity outcomes related to all-causes, natural causes and the cardiopulmonary system, but the results are still inconclusive. To explore the associations between short-term and long-term exposures to ambient PM2.5 constituents with mortality and morbidity outcomes of all-cause, natural, cardiovascular and respiratory diseases. We comprehensively searched PubMed, Embase, Web of Science and Scopus electronic databases to identify studies until 28, August 2023. We estimated the pooled relative risk (RR) with 95 % confidence interval (CI) using random-effect models. Then we explored potential sources of heterogeneity across different studies by subgroup and meta-regression analysis. A total of 67 articles were included in the meta-analysis. We found that short-term exposures to PM2.5 carbon-containing constituents (black carbon and organic carbon) and metal iron showed the most consistent associations with the eight health outcomes among different PM2.5 constituents. Meanwhile, only long-term exposures to nitrate ions and silicon in PM2.5 showed significant positive associations with cardiovascular and natural mortality outcomes. Additionally, subgroup and meta-regression analyses highlight that geographical region and age group are primary sources of heterogeneity. The current meta-analysis reveals potential key PM2.5 constituents associated with elevated risk of mortality and morbidity of cardiovascular and respiratory diseases. Thus, greater attention should be directed toward establishing exposure limits for specific PM2.5 constituents to protect public health and alleviate the associated burden of diseases.

Hospital admissions attributable to reduced air pollution due to clean-air policies in China

The Air Pollution Prevention and Control Action Plan (APPCAP) is considered to be the most stringent air pollution control policy in China implemented since 2013. This policy is a milestone in China to mitigate serious air pollution. However, health benefits attributable to reduced fine-particulate air pollution after the implementation of the APPCAP have not been quantitatively estimated on a PM2.5 constituent-specific and morbidity cause-specific basis. Here we conducted a nationwide case-crossover study based on hospital admission records in 292 Chinese cities during 2013-2017. Compared with 2013, the annual average concentrations of PM2.5 and black carbon (BC) in 2017 decreased by 28.61% and 20.35%, respectively. As a result, the average relative reductions in annual attributable fractions of nine major cause-specific hospital admissions associated with PM2.5 and BC were 30.00% and 21.14%, respectively, among which annual attributable fraction for depression showed the largest reduction. Nationally, cities with higher reductions in PM2.5 and BC were found to have higher absolute reductions in annual hospital admission attributable fractions associated with PM2.5 and BC, and geographic inequality in health benefits still existed. Our study highlights the substantial wide-ranging health benefits of reduced PM2.5 and BC levels following the nationwide implementation of the APPCAP in China.

Impact of Emission Standards on Fine Particulate Matter Toxicity: A Long-Term Analysis in Los Angeles

This study examines long-term trends in fine particulate matter (PM2.5) composition and oxidative potential in Los Angeles based on data from the University of Southern California's Particle Instrumentation Unit, with chemical composition retrieved from the EPA's Air Quality System (AQS). While regulatory interventions have reduced PM2.5 mass concentration and primary combustion-related components, our findings reveal a more complex toxicity pattern. From 2001 to 2008, the PM2.5 oxidative potential, measured via the dithiothreitol (DTT) assay, declined from ~0.84 to ~0.16 nmol/min/m3 under stringent tailpipe controls. However, after this initial decline, PM2.5 DTT stabilized and gradually increased from ~0.35 in 2012 to ~0.97 nmol/min/m3 by 2024, reflecting the growing influence of non-tailpipe emissions such as brake/tire wear. Metals, such as iron (Fe, ~150 ng/m3) and zinc (Zn, ~10 ng/m3), remained relatively stable as organic and elemental carbon (OC and EC) declined, resulting in non-tailpipe contributions dominating PM2.5 toxicity. Although PM2.5 mass concentrations were effectively reduced, the growing contribution of non-tailpipe emissions (e.g., brake/tire wear and secondary organic aerosols) underscores the limitations of mass-based standards and tailpipe-focused strategies. Our findings emphasize the need to broaden regulatory strategies, targeting emerging sources that shape PM2.5 composition and toxicity and ensuring more improvements in public health outcomes.

The effects of PM2.5 components on the cardiovascular disease admissions in Shanghai City, China: a multi- region study

BACKGROUND

The burden of cardiovascular disease (CVD) is severe worldwide. Although many studies have investigated the association of particulate pollution with CVD, the effect of finer particulate pollution components on CVD remains unclear. This study aimed to explore the effect of five PM2.5 components ([Formula: see text], sulfate; [Formula: see text], nitrate; [Formula: see text], ammonium; OM, organic matter; BC, carbon black) on CVD admission in Shanghai City, identify the susceptible population, and provide clues for the prevention and control of particulate pollution.

METHODS

Daily PM2.5 components data during 2013-2019 in three districts of Shanghai were obtained from Tracking Air Pollution in China. We obtained CVD daily admissions data from relevant departments of Tongji Hospital, including basic information (sex, age, time of admissions, ICD code of root cause of admissions, etc.). First, generalized additive model (GAM) and distributed lag non-linear (DLNM) model were used to evaluate the individual effects of PM2.5 components on CVD admission in three districts of Shanghai. Then, the three regions were pooled for analysis using either a random-effects model or a fixed-effects model.

RESULTS

Overall, all five PM2.5 components had significant effects on CVD admission risk. BC and OM were strongly associated with daily CVD admissions, with increasing interquartile range of the concentrations, the maximum values of cumulative RR (95% CI) were 1.318 (95%CI: 1.222-1.415) and 1.243 (95%CI: 1.164-1.322), respectively. The elderly (≥ 65 years old) was more sensitive to the four PM2.5 components than the young population. [Formula: see text] and BC were strongest associated with CVD admissions in the elderly than in younger people, with increasing interquartile range of the concentrations, the maximum cumulative RR (95% CI) was 1.567 (95% CI: 1.116-2.019) and 1.534 (95% CI: 1.104-1.963), respectively.

CONCLUSIONS

This study found that five PM2.5 components were significant risk factors for CVD admissions and specific CVD diseases in Shanghai City. The elderly were susceptible to [Formula: see text],[Formula: see text], OM, and BC.

Differential effects of fine particulate matter constituents on acute coronary syndrome onset

Fine particulate matter has been linked with acute coronary syndrome. Nevertheless, the key constituents remain unclear. Here, we conduct a nationwide case-crossover study in China during 2015-2021 to quantify the associations between fine particulate matter constituents (organic matter, black carbon, nitrate, sulfate, and ammonium) and acute coronary syndrome, and to identify the critical contributors. Our findings reveal all five constituents are significantly associated with acute coronary syndrome onset. The magnitude of associations peaks on the concurrent day, attenuates thereafter, and becomes null at lag 2 day. The largest effects are observed for organic matter and black carbon, with each interquartile range increase in their concentrations corresponding to 2.15% and 2.03% increases in acute coronary syndrome onset, respectively. These two components also contribute most to the joint effects, accounting for 31% and 22%, respectively. Our findings highlight tailored clinical management and targeted control of carbonaceous components to protect cardiovascular health.

Associations between short-term exposure to airborne carbonaceous particles and mortality: A time-series study in London during 2010-2019

Exposure to ambient particulate matter (PM) has been identified as a major global health concern; however, the importance of specific chemical PM components remains uncertain. Recent studies have suggested that carbonaceous aerosols are important detrimental components of the particle mixture. Using time-series methods, we investigated associations between short-term exposure to carbonaceous particles and mortality in London, UK. Daily counts of non-accidental, respiratory, and cardiovascular deaths were obtained between 2010 and 2019. For the same period, daily concentrations of carbonaceous particles: organic (OC), elemental (EC), wood-burning (WC), total carbon (TC) and equivalent black carbon (eBC) were sourced from two centrally located monitoring sites (one urban-traffic and one urban-background). Generalized additive models were used to estimate the percentage change in mortality risk associated with interquartile range increases in particulate concentrations. Lagged effects up to 3 days were examined. Stratified analyses were conducted by age, sex, and season, separate analyses were also performed by site-type. For non-accidental mortality, positive associations were observed for all particle species at lag1, including statistically significant percentage risk changes in WC (0.51% (95%CI: 0.19%, 0.82%) per IQR (0.68 μg/m3)) and OC (0.45% (95%CI: 0.04%, 0.87% per IQR (2.36 μg/m3)). For respiratory deaths, associations were greatest for particulate concentrations averaged over the current and previous 3 days, with increases in risk of 1.70% (95%CI: 0.64%, 2.77%) for WC and 1.31% (95%CI: -0.08%, 2.71%) for OC. No associations were found with cardiovascular mortality. Results were robust to adjustment for particle mass concentrations. Stratified analyses suggested particulate effects were greatest in the summer and respiratory associations more pronounced in females. Our findings are supportive of an association between carbonaceous particles and non-accidental and respiratory mortality. The strongest evidence of an effect was for WC; this is of significance given the rising popularity of wood-burning for residential space heating and energy production across Europe.

Ambient PM2.5 Chemical Composition and Cardiovascular Disease Hospitalizations in China

Little is known about the impacts of specific chemical components on cardiovascular hospitalizations. We examined the relationships of PM2.5 chemical composition and daily hospitalizations for cardiovascular disease in 184 Chinese cities. Acute PM2.5 chemical composition exposures were linked to higher cardiovascular disease hospitalizations on the same day and the percentage change of cardiovascular admission was the highest at 1.76% (95% CI, 1.36-2.16%) per interquartile range increase in BC, followed by 1.07% (0.72-1.43%) for SO42-, 1.04% (0.63-1.46%) for NH4+, 0.99% (0.55-1.43%) for NO3-, 0.83% (0.50-1.17%) for OM, and 0.80% (0.34%-1.26%) for Cl-. Similar findings were observed for all cause-specific major cardiovascular diseases, except for heart rhythm disturbances. Short-term exposures to PM2.5 chemical composition were related to higher admissions and showed diverse impacts on major cardiovascular diseases.

The relative contribution of PM2.5 components to the obstructive ventilatory dysfunction-insights from a large ventilatory function examination of 305,022 workers in southern China

BACKGROUND

The new round of WHO/ILO Joint Estimates of the Work-related Burden of Disease assessment requires futher research to provide more evidence, especially on the health impact of ambient air pollution around the workplace. However, the evidence linking obstructive ventilatory dysfunction (OVD) to fine particulate matter (PM2.5) and its chemical components in workers is very limited. Evidence is even more scarce on the interactive effects between occupational factors and particle exposures. We aimed to fill these gaps based on a large ventilatory function examination of workers in southern China.

METHODS

We conducted a cross-sectional study among 363,788 workers in southern China in 2020. The annual average concentration of PM2.5 and its components were evaluated around the workplace through validated spatiotemporal models. We used mixed-effect models to evaluate the risk of OVD related to PM2.5 and its components. Results were further stratified by basic characteristics and occupational factors.

FINDINGS

Among the 305,022 workers, 119,936 were observed with OVD. We found for each interquartile range (IQR) increase in PM2.5 concentration, the risk of OVD increased by 27.8 (95 % confidence interval (CI): 26.5-29.2 %). The estimates were 10.9 % (95 %CI: 9.7-12.1 %), 15.8 % (95 %CI: 14.5-17.2 %), 2.6 % (95 %CI: 1.4-3.8 %), 17.1 % (95 %CI: 15.9-18.4 %), and 11 % (95 %CI: 9.9-12.2 %), respectively, for each IQR increment in sulfate, nitrate, ammonium salt, organic matter and black carbon. We observed greater effect estimates among females, younger workers, workers with a length of service of 24-45 months, and professional skill workers. Furthermore, it is particularly noteworthy that the noise-exposed workers, high-temperature-exposed workers, and less-dust-exposed workers were at a 5.7-68.2 % greater risk than others.

INTERPRETATION

PM2.5 and its components were significantly associated with an increased risk of OVD, with stronger links among certain vulnerable subgroups.

Nonlinear proinflammatory effect of short-term PM2.5 exposure: A potential role of lipopolysaccharide

The association between PM2.5 (particulate matter ≤ 2.5 µm) short-term exposure and its health effect is non-linear from the epidemiological studies. And this nonlinearity is suggested to be related with the PM2.5 heterogeneity, however, the underlying biological mechanism is still unclear. Here, a total of 38 PM2.5 filters were collected continuously for three weeks in winter Beijing, with the ambient PM2.5 varying between 10 and 270 µg/m3. Human monocytes-derived macrophages (THP-1) were treated with PM2.5 water-soluble elutes at 10 µg/mL to investigate the PM2.5 short-term exposure effect from a proinflammatory perspective. The proinflammatory cytokine tumor necrosis factor (TNF) induced by the PM2.5 elutes at equal concentrations were unequal, showing the heterogeneity of PM2.5 proinflammatory potentials. Of the various chemical and biological components, lipopolysaccharide (LPS) showed a strong positive association with the TNF heterogeneity. However, some outliers were observed among the TNF-LPS association. Specifically, for PM2.5 from relatively clean air episodes, the higher LPS amount corresponded to relatively low TNF levels. And this phenomenon was also observed in the promotion tests by treating macrophages with PM2.5 elutes dosed with additional trace LPS. Gene expression analysis indicated the involvement of oxidative-stress related genes in the LPS signaling pathway. Therefore, a potential oxidative-stress-mediated suppression on the PM2.5-borne LPS proinflammatory effect was proposed to be accounted for the outliers. Overall, the results showed the differential role of LPS in the heterogeneity of PM2.5 proinflammatory effects from a component-based perspective. Future experimental studies are needed to elucidate the signaling pathway of LPS attached on PM2.5 from different air quality episodes.

Determinants of Knowledge, Attitudes, Perceptions and Behaviors Regarding Air Pollution in Schoolchildren in Pristina, Kosovo

Air pollution poses a significant public health challenge, and Kosovo, a low-middle-income country in the Balkan peninsula, suffers from particularly poor air quality, especially around the area of the capital Pristina. The availability of accurate and timely information is crucial in mitigating the adverse effects of air pollution. This study aimed at evaluating the knowledge, attitudes, behaviors, and perceptions (KAPB) related to poor air quality in Pristina's low-middle schools. Furthermore, the study explored the connections between these factors and socio-demographic and health attributes and provided valuable inputs for the development of future strategies and policies in air pollution mitigation. Regression analysis provided insights into how these various factors interacted with KAPB scores. The results revealed limited knowledge about air pollution sources and risks among pupils, with insufficient awareness of reliable information sources. While attitudes were generally positive, they declined with higher grade levels. Parental education significantly influenced knowledge and attitudes, and better health correlated with more positive attitudes. Perceptions of air pollution risks were influenced by grade, gender, and parental education, with better-educated parents associated with improved perceptions. Overall behavior scores increased with higher levels of parental education. Understanding the factors that shape pupils' responses to air pollution is critical for strategy and policy development. These findings can guide strategies to enhance environmental awareness and promote healthy behavior, helping address the pressing issue of air pollution in the country.

Ambient PM2.5 Components Are Associated With Bone Strength: Evidence From a China Multi-Ethnic Study

CONTEXT

The relationship between the components of particulate matter with an aerodynamic diameter of 2.5 or less (PM2.5) and bone strength remains unclear.

OBJECTIVE

Based on a large-scale epidemiologic survey, we investigated the individual and combined associations of PM2.5 and its components with bone strength.

METHODS

A total of 65 906 individuals aged 30 to 79 years were derived from the China Multi-Ethnic Cohort Annual average concentrations of PM2.5 and its components were estimated using satellite remote sensing and chemical transport models. Bone strength was expressed by the calcaneus quantitative ultrasound index (QUI) measured by quantitative ultrasound. The logistic regression model and weighted quantile sum method were used to estimate the associations of single and joint exposure to PM2.5 and its components with QUI, respectively.

RESULTS

Our analysis shows that per-SD increase (μg/m3) in 3-year average concentrations of PM2.5 (mean difference [MD] -7.38; 95% CI, -8.35 to -6.41), black carbon (-7.91; -8.90 to -6.92), ammonium (-8.35; -9.37 to -7.34), nitrate (-8.73; -9.80 to -7.66), organic matter (-4.70; -5.77 to -3.64), and soil particles (-5.12; -6.10 to -4.15) were negatively associated with QUI. In addition, these associations were more pronounced in men, and people older than 65 years with a history of smoking and chronic alcohol consumption.

CONCLUSION

We found that long-term exposure to PM2.5 and its components may lead to reduced bone strength, suggesting that PM2.5 and its components may potentially increase the risk of osteoporosis and even fracture. Nitrate may be responsible for increasing its risk to a greater extent.

Long-term exposure to the components of fine particulate matters and disability after stroke: Findings from the China National Stroke Screening Surveys

BACKGROUND

Long-term exposure to ambient fine particulate matter (PM2.5) has been linked to an increased risk of stroke. However, the effect of long-term exposure to PM2.5 and its major components on the functional disability of stroke patients remains unclear.

METHODS

Based on China National Stroke Screening Survey data obtained from 2013 to 2019, we conducted a national multicenter longitudinal study of the associations of long-term exposure to PM2.5 and its components with the risk of disability after stroke in China. Post-stroke disability was assessed using the modified Rankin scale (mRS), which ranges from 0 to 5, with higher scores indicating greater disability. Long-term exposure to PM2.5 and its five components [sulfate (SO42-), nitrate (NO3-), ammonium salt (NH4+), organic matter (OM), and black carbon (BC)] was determined based on average concentrations during the 3 years preceding mRS administration according to the geographic coordinates of residential communities, using state-of-the-art estimates from multiple sources. We used a fixed-effect model to evaluate the associations between mRS scores and PM2.5 exposure, with adjustment for multiple covariates.

RESULTS

Every 10 µg/m3 increase in PM2.5 was associated with a 0.019 (95% confidence interval, 0.003, 0.036) increase in mRS score, but the effect was not significant after adjusting for all covariates [0.016 (95% CI, -0.003, 0.032)]. For PM2.5 components, each IQR (7.92 µg/m3) increment in OM exposure was associated significantly with 0.062 (95% CI, 0.013, 0.111) increment in the mRS score. A significant association was observed between SO42- exposure and the mRS score [0.057 (95% CI, 0.003, 0.112), per IQR: 6.28 µg/m3]. However, no significant association was found with BC, NO3-, or NH4+ exposure. Furthermore, the nonlinear curves were observed for the exposure-response relationship between PM2.5 exposure and the mRS score.

CONCLUSION

Greater PM2.5 exposure increased the mRS score and was associated with post-stroke functional disability among stroke patients. However, different chemical components showed unequal neurotoxic effects, and long-term exposure to OM and SO42- may play a more important role.

SYNOPSIS

This study reports fine particulate matter at higher concentrations damages the functional ability among specific stroke patients, and PM2.5 components have different neurotoxicities.

The life expectancy benefits on respiratory diseases gained by reducing the daily concentration of particulate matter to attain different air quality standard targets: findings from a 5-year time-series study in Tianjin, China

The short-term effects of particulate matter (PM) on years of life lost (YLL) have been confirmed by several studies; however, little attention has been paid to the effects of PM on life expectancy from respiratory diseases (RD), especially at the city level. A generalized additive model (GAM) was used to assess the associations between daily PM and YLL of the RD and chronic obstructive pulmonary diseases (COPD) in Tianjin from 2015 to 2019. Then the daily avoidable YLL, attributable fraction, and potential life expectancy benefits (PLEB) of RD and COPD by reducing the daily concentration of PM_2.5 and PM₁₀ to attain the Chinese and World Health Organization (WHO) air quality standard targets were estimated during 2015-2019. The stratified analyses by gender were also conducted. A total of 18279 RD and 7767 COPD deaths were included in this study. Per 10 μg/m³ increments in PM_2.5 and PM₁₀ at lag1 were significantly associated with 0.83(95%CI: 0.11, 1.55) years and 0.57(95%CI: 0.06, 1.08) years increasing in YLL of total RD and 0.48 (95%CI: 0.07, 0.90) years and 0.30 (95%CI: 0.01, 0.60) years increasing in YLL of total COPD. If the daily PM_2.5 and PM₁₀ concentrations decreased to attain the Chinese and WHO air quality standard targets, 0.06-0.39 years PLEB due to total RD and 0.08-0.53 years PLEB due to COPD could be gained. And more PLEB on RD could be gained by decreasing the daily PM concentrations to attain the WHO air quality standard targets than that of attaining the Chinese air quality standard targets. These evidence-based findings emphasize the importance of the Chinese PM-related guideline updating and may have implications for PM-related policy-making.

The threshold and spatial effects of PM2.5 pollution on resident health: evidence from China

Health capital investment is an integral aspect of human capital investment, and it is vitally important to improve residents' health by encouraging them to maintain insurance. This paper estimates the potential impact of particulate pollution (PM2.5) on health insurance buyers at the city level. Using PM2.5 as a representative air pollution indicator, we construct a threshold panel model and a spatial econometric model based on 2000-2019 panel data from 256 Chinese cities and the health production function to examine the impact mechanism through which PM2.5 pollution causes changes in the number of health insurance buyers. The results indicate that higher PM2.5 pollution significantly increases health insurance buyers in China. Considering the threshold effect, per capita GDP has a nonlinear relationship with an increasing marginal effect on the higher number of health insurance buyers. Due to spatial spillover effects, PM2.5 pollution has an additional impact on the number of health insurance buyers, indicating that a lack of awareness of the spatial correlation will result in underestimating the impact of PM2.5 pollution on residents' health. The robustness of adjacency and geographic distance matrices demonstrates that the regression results are robust and reliable. The findings of this study provide a practical reference for health insurers' development and policymakers' pollution control efforts.