Long-term Particulate Matter Exposure Research Articles

How long-term PM exposure may affect all-site cancer mortality: Evidence from a large cohort in southern China

BackgroundEvidence of a potential causal link between long-term exposure to particulate matter (PM) and all-site cancer mortality from large population cohorts remained limited and suffered from residual confounding issues with traditional statistical methods. AimsWe aimed to examine the potential causal relationship between long-term PM exposure and all-site cancer mortality in South China using causal inference methods. MethodsWe used a cohort in southern China that recruited 580,757 participants from 2009 through 2015 and tracked until 2020. Annual averages of PM1, PM2.5, and PM10 concentrations were generated with validated spatiotemporal models. We employed a causal inference approach, the Marginal Structural Cox model, based on observational data to evaluate the association between long-term exposure to PM and all-site cancer mortality. ResultsWith an increase of 1 µg/m³ in PM1, PM2.5, and PM10, the hazard ratios (HRs) and 95% confidence interval (CI) for all-site cancer were 1.033 (95% CI: 1.025–1.041), 1.032 (95% CI: 1.027–1.038), and 1.020 (95% CI: 1.016–1.025), respectively. The HRs (95% CI) for digestive system and respiratory system cancer mortality associated with each 1 µg/m³ increase in PM1 were 1.022 (1.009–1.035) and 1.053 (1.038–1.068), respectively. In addition, inactive participants, who never smoked, or who lived in areas of low surrounding greenness were more susceptible to the effects of PM exposure, the HRs (95% CI) for all-site cancer mortality were 1.042 (1.031–1.053), 1.041 (1.032–1.050), and 1.0473 (1.025–1.070) for every 1 µg/m³ increase in PM1, respectively. The effect of PM1 tended to be more pronounced in the low-exposure group than in the general population, and multiple sensitivity analyses confirmed the robustness of the results. ConclusionThis study provided evidence that long-term exposure to PM may elevate the risk of all-site cancer mortality, emphasizing the potential health benefits of improving air quality for cancer prevention.

Unveiling causal connections: Long-term particulate matter exposure and type 2 diabetes mellitus mortality in Southern China

Evidence of the potential causal links between long-term exposure to particulate matters (PM, i.e., PM1, PM2.5, and PM1–2.5) and T2DM mortality based on large cohorts is limited. In contrast, the existing evidence usually suffers from inherent bias with the traditional association assessment.A prospective cohort of 580,757 participants in the southern region of China were recruited during 2009 and 2015 and followed up through December 2020. PM exposure at each residential address was estimated by linking to the well-established high-resolution simulation dataset. Hazard ratios (HRs) were calculated using time-varying marginal structural Cox models, an established causal inference approach, after adjusting for potential confounders.During follow-up, a total of 717 subjects died from T2DM. For every 1 μg/m3 increase in PM2.5, the adjusted HRs and 95% confidence interval (CI) for T2DM mortality was 1.036 (1.019–1.053). Similarly, for every 1 μg/m3 increase in PM1 and PM1–2.5, the adjusted HRs and 95% CIs were 1.032 (1.003–1.062) and 1.085 (1.054–1.116), respectively. Additionally, we observed a generally more pronounced impact among individuals with lower levels of education or lower residential greenness which as measured by the Normalized Difference Vegetation Index (NDVI). We identified substantial interactions between NDVI and PM1 (P-interaction = 0.003), NDVI and PM2.5 (P-interaction = 0.019), as well as education levels and PM1 (P-interaction = 0.049).The study emphasizes the need to consider environmental and socio-economic factors in strategies to reduce T2DM mortality. We found that PM1, PM2.5, and PM1–2.5 heighten the peril of T2DM mortality, with education and green space exposure roles in modifying it.

Long-Term Particulate Matter Exposure and Mortality in Hospitalized Patients with COVID-19 in South Korea.

Rationale: Particulate matter (PM) exposure exacerbates health outcomes by causing lung damage. Objectives: To investigate whether prior exposure to particulate matter ⩽10 μm and ⩽2.5 μm in aerodynamic diameter (PM10 and PM2.5) was associated with clinical outcomes among patients with coronavirus disease (COVID-19). Methods: Data from the nationwide registration database of the National Health Insurance and Korea Disease Control and Prevention Agency in South Korea were used. The study included adult patients who were admitted to monitoring centers or hospitals between October 8, 2020 and December 31, 2021, after COVID-19 confirmation. AirKOREA database, which compiles air pollutant data from 642 stations in 162 cities and counties across South Korea, was used to extract data on PM levels. Average values of monthly exposure to PM10 and PM2.5 from the year previous to hospital admission because of COVID-19 to the date of confirmation of COVID-19 were calculated and used to define PM exposures of patients with COVID-19. Results: In total, 322,289 patients with COVID-19 were included, and 4,633 (1.4%) died during hospitalization. After adjusting for covariates, a 1-μg/m3 increase in PM10 and PM2.5 exposure was associated with 4% (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.03-1.05; P < 0.001) and 6% (OR, 1.06; 95% CI, 1.04-1.07; P < 0.001) increase in the risk of in-hospital mortality, respectively. In addition, a 1-μg/m3 increase in PM10 and PM2.5 was associated with 5% (OR, 1.05; 95% CI, 1.04-1.07; P < 0.001) and 8% (OR, 1.08; 95% CI, 1.06-1.10; P < 0.001) increase in the risks of requiring intensive care unit (ICU) admission and mechanical ventilation, respectively. Conclusions: PM10 and PM2.5 exposure was associated with increased in-hospital mortality and the need for ICU admission and mechanical ventilation among patients with COVID-19 in South Korea.

Effects of particulate matter exposure on the expression of the SARS-CoV-2 ACE2 receptor in ocular surface tissues and cells.

Particulate matter (PM) has been reported to be one of the risk factor for COVID-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, although the ocular surface is deeply affected by both PM exposure and SARS-COV-2 infection, no studies have investigated the effects of PM exposure on the ocular route of SARS-COV-2 infection. To this end, we explored the effects of PM on the expression of SARS-COV-2-associated receptors and proteins in ocular surface. Herein, short- and long-term PM-exposed rat models were established by topically administering PM for 3 and 10days, respectively. Immortalized human corneal epithelial cells (HCECs) and human conjunctival epithelial cells (HCjECs) were exposed to PM. ACE2, TMPRSS2, CD147, and ADAM17 expression levels were measured by western blot analysis. Our results show that short-term PM exposure had little effect on the expressions of ACE2, TMPRSS2, and CD147 in ocular surface tissues. However, long-term PM exposure decreased the ACE2 expression in conjunctival tissues and increased the CD147 expression in corneal or conjunctival tissues. PM exposure reduced the ACE2 expression by increasing the ADAM17 expression and ACE2 shedding level in HCECs and HCjECs. Our findings suggest that long-term PM exposure down-regulate the expression of the SARS-CoV-2 receptor ACE2 in conjunctival tissues through ADAM17-dependent ACE2 shedding. However, long-term PM exposure up-regulates the expression of another SARS-CoV-2 receptor CD147 in ocular surface tissues, accompanied by ocular surface damage and cytotoxicity. This study provides a new insight into uncovering potential risk factors for infection with SARS-CoV-2 via the ocular route.

Particulate Matter in Human Elderly: Higher Susceptibility to Cognitive Decline and Age-Related Diseases.

This review highlights the significant impact of air quality, specifically particulate matter (PM), on cognitive decline and age-related diseases in the elderly. Despite established links to other pathologies, such as respiratory and cardiovascular illnesses, there is a pressing need for increased attention to the association between air pollution and cognitive aging, given the rising prevalence of neurocognitive disorders. PM sources are from diverse origins, including industrial activities and combustion engines, categorized into PM10, PM2.5, and ultrafine PM (UFPM), and emphasized health risks from both outdoor and indoor exposure. Long-term PM exposure, notably PM2.5, has correlated with declines in cognitive function, with a specific vulnerability observed in women. Recently, extracellular vesicles (EVs) have been explored due to the interplay between them, PM exposure, and human aging, highlighting the crucial role of EVs, especially exosomes, in mediating the complex relationship between PM exposure and chronic diseases, particularly neurological disorders. To sum up, we have compiled the pieces of evidence that show the potential contribution of PM exposure to cognitive aging and the role of EVs in mediating PM-induced cognitive impairment, which presents a promising avenue for future research and development of therapeutic strategies. Finally, this review emphasizes the need for policy changes and increased public awareness to mitigate air pollution, especially among vulnerable populations such as the elderly.

Exposure to particulate matter may affect semen quality via trace metals: Evidence from a retrospective cohort study on fertile males

Particulate matter (PM) exposure may be associated with male semen quality. Besides, PM exposure induces up and down levels of trace metals in tissues or organs. The levels of trace metals in semen are critical for adverse male semen quality. This study aims to evaluate the concentrations of seminal-level trace metals in fertile men and assess its associations with PM exposure and to explore the mediation role of trace metals in seminal plasma plays in the relationship between PM exposure and semen quality. Total 1225 fertile men who participated in a cohort study from 2014 to 2016 were finally recruited. Multivariate linear regression was applied to explore associations between each two of PM exposure, trace metals and semen parameters. 1-year PM2.5 and PM10 exposure levels were positively associated with arsenic (As), mercury (Hg), lanthanum (La), praseodymium (Pr), neodymium (Nd) but negatively associated with vanadium (V), magnesium (Mg), strontium (Sr), barium (Ba) in semen. It was also found that most of the elements were associated with total sperm number, followed by sperm concentration. Redundancy analysis (RDA) also determined several strong positive correlations or negative correlations between 1-year PM exposure and trace metals. Mediation analysis found that trace metals had a potentially compensatory or synergetic indirect effect on the total effect of the association between 1-year PM exposure and semen quality. The retrospective cohort study provides long-term PM exposure that may cause abnormal semen quality by affecting seminal plasma element levels.

Long-term particulate matter exposure and the risk of neurological hospitalization: Evidence from causal inference of a large longitudinal cohort in South China

With limited evidence on the neurological impact of particulate matter (PM) exposure in China, particularly for PM1 which is smaller but more toxic, we conducted a large Chinese cohort study using causal inference approaches to comprehensively clarify such impact. A total of 36,271 participants in southern China were recruited in 2015 and followed up through 2020. We obtained the neurological hospitalizations records by linking the cohort data to the electronic reports from 418 medical institutions across the study area. By using high-resolution PM concentrations from satellite-based spatiotemporal models and the cohort data, we performed marginal structural Cox models under causal assumptions to assess the potential causal links between time-varying PM exposure and neurological hospitalizations. Our findings indicated that increasing PM1, PM2.5, and PM10 concentrations by 1 μg/m³ were associated with higher overall neurological hospitalization risks, with hazard ratios (HRs) of 1.10 (95% confidence interval (CI) 1.04–1.16), 1.09 (95% CI 1.04–1.14), and 1.03 (95% CI 1.00–1.06), respectively. PM1 appeared to have a stronger effect on neurological hospitalization, with a 1% and 7% higher impact compared to PM2.5 and PM10, respectively. Additionally, each 1-μg/m3 increase in the annual PM1 concentration was associated with an elevated risk of hospitalizations for ischemic stroke (HR: 1.15; 95% CI, 1.06–1.26), which tended to be larger than the estimates for PM2.5 (HR: 1.13, 95% CI, 1.04–1.23) and PM10 (HR: 1.05, 95% CI, 1.00–1.09). Furthermore, never-married or female individuals tended be at a greater risk compared with their counterparts. Our study provides important insights into the health impact of particles, particularly smaller particles, on neurological hospitalization risk and highlights the need for clean-air policies that specifically target these particles.

Comparison of short-term effects of particulate matter with different particle sizes on first-ever stroke: A national case-crossover study in China

ObjectivesTo compare the effects of short-term exposure to particulate matter (PM) with different particle sizes on first-ever stroke risk in the middle-aged and elderly Chinese population. MethodsHealth information was collected from the China National Stroke Screening Survey (CNSSS) from March 1, 2013, to April 10, 2015. Ambient exposures to PM1, PM2.5, and PM10 were obtained from ChinaHighAirPollutants (CHAP) Grid data. Case-crossover design was used to estimate the increase of first-ever stroke risk per 10 μg/m3 increase in ambient exposures to different size particles. We used distributed lag linear model (DLM) to estimate the hysteresis effects of particle exposures. In addition, in order to assess the effect modification of long-term exposure, we did a stratified analysis using median exposure as the dividing line. ResultsWe included 1326 first-ever stroke events from 242 communities in the present study. We found that effects on first-ever stroke risk increased with the decrease in particle size. The percent increases of first-ever stroke risk increased by 6.6% (95% CI: 1.4, 12.0), 3.3% (95% CI: 0.5, 6.1), and 0.6% (95% CI: -1.2, 2.6) per 10 g/m3 increases in PM1, PM2.5, and PM10 exposures in lag 0–2 days, respectively. Furthermore, the cumulative effect of PM on first-ever stroke reached its peak at distinct time points under different layers of long-term PM exposure. In areas with low PM exposure, the cumulative effects of the three kinds of particles on stroke reached their peak in lag1 day, while the cumulative effect peaked in lag3 day in areas with high PM exposure. ConclusionsThis study found that smaller particles had a stronger short-term effect on first-ever stroke. We also found that people in areas with long-term exposures to lower levels were more sensitive to short-term exposures. These results have public health significance for stroke prevention and air pollution reduction.

Association between long-term exposure to ambient particulate matter and pulmonary function among men and women in typical areas of South and North China.

Studies comparing the effects of different sizes and concentrations of ambient particulate matter (PM) on pulmonary function in different regions and sexes remain sparse. To investigate the associations of different sizes and levels of long-term ambient PM exposure with pulmonary function among people of different sexes in typical areas of South and North China. In 2021, a total of 1,592 participants aged 20-73 years were recruited to participate in the pulmonary function test from the baseline survey of the Diverse Life-Course Cohort (DLCC) in typical areas of Guangdong Province and Hebei Province. The three-year (2018-2020) average ambient PM concentrations were assessed from the ChinaHighPM1 dataset, ChinaHighPM2.5 dataset and ChinaHighPM10 dataset. Mean differences in pulmonary function were used in multilevel models for different regions and sexes. We discovered significant associations of ambient PM exposure with reduced forced vital capacity (FVC) and increased forced expiratory volume in 1 s/forced vital capacity ratio (FEV1/FVC) among men and lower levels of FEV1 and FVC among women, such that a 5-μg/m3 concentration increase in PM1, PM2.5, and PM10 was associated with decreases in FVC of 122.1 ml (95% confidence interval (CI): 30.8, 213.4), 54.6 ml (95% CI: 15.8, 93.3) and 42.9 ml (95% CI: 12.7, 73.1) and increases in FEV1/FVC of 2.2% (95% CI: 0.6, 3.9), 1.1% (95% CI: 0.4, 1.9) and 0.9% (95% CI: 0.3, 1.5) among men and decreases in FEV1 of 51.1 ml (95% CI: 9.7, 92.4), 21.6 ml (95% CI: 4.3, 38.9) and 16.7 ml (95% CI: 3.3, 30.1) and in FVC of 77.8 ml (95% CI: 10.0, 145.6), 38.7 ml (95% CI: 9.0, 68.5) and 31.1 ml (95% CI: 8.1, 54.1) among women in Hebei Province. There was no association between ambient PM and pulmonary function in Guangdong Province. Long-term exposure to different sizes and concentrations of ambient PM were associated with FEV1 and FVC among men and women differently. The impact of ambient PM on FVC should be of greater concerned.

Association of long-term particulate matter exposure with all-cause mortality among patients with ovarian cancer: A prospective cohort

BackgroundEvidence of the association between particles with a diameter of 2.5 μm or less (PM2.5) in long term and ovarian cancer (OC) mortality is limited. MethodsThis prospective cohort study analyzed data collected between 2015 and 2020 from 610 newly diagnosed OC patients, aged 18–79 years. The residential average PM2.5 concentrations 10 years before the date of OC diagnosis were assessed by random forest models at a 1 km × 1 km resolution. Cox proportional hazard models fully adjusted for the covariates (including age at diagnosis, education, physical activity, kitchen ventilation, FIGO stage, and comorbidities) and distributed lag non-linear models were used to estimate the hazard ratios (HRs) and 95 % confidence intervals (CIs) of PM2.5 and all-cause mortality of OC. ResultsDuring a median follow-up of 37.6 months (interquartile: 24.8–50.5 months), 118 (19.34 %) deaths were confirmed among 610 OC patients. One-year PM2.5 exposure levels before OC diagnosis was significantly associated with an increase in all-cause mortality among OC patients (single-pollutant model: HR = 1.22, 95 % CI: 1.02–1.46; multi-pollutant models: HR = 1.38, 95 % CI: 1.10–1.72). Furthermore, during 1 to 10 years prior to diagnosis, the lag-specific effect of long-term PM2.5 exposure on the all-cause mortality of OC had a risk increase for lag 1–6 years, and the exposure-response relationship was linear. Of note, significant interactions between several immunological indicators as well as solid fuel use for cooking and ambient PM2.5 concentrations were observed. ConclusionHigher ambient PM2.5 concentrations were associated with an increased risk of all-cause mortality among OC patients, and there was a lag effect in long-term PM2.5 exposure.

Associations between source-apportioned PM2.5 and 30-day readmissions in heart failure patients

BackgroundAir pollution exposure is a significant risk factor for morbidity and mortality, especially for those with pre-existing chronic disease. Previous studies highlighted the risks that long-term particulate matter exposure has for readmissions. However, few studies have evaluated source and component specific associations particularly among vulnerable patient populations. ObjectivesUse electronic health records from 5556 heart failure (HF) patients diagnosed between July 5, 2004 and December 31, 2010 that were part of the EPA CARES resource in conjunction with modeled source-specific fine particulate matter (PM2.5) to estimate the association between exposure to source and component apportioned PM2.5 at the time of HF diagnosis and 30-day readmissions. MethodsWe used zero-inflated mixed effects Poisson models with a random intercept for zip code to model associations while adjusting for age at diagnosis, year of diagnosis, race, sex, smoking status, and neighborhood socioeconomic status. We undertook several sensitivity analyses to explore the impact of geocoding precision and other factors on associations and expressed associations per interquartile range increase in exposures. ResultsWe observed associations between 30-day readmissions and an interquartile range increase in gasoline- (16.9% increase; 95% confidence interval = 4.8%, 30.4%) and diesel-derived PM2.5 (9.9% increase; 95% confidence interval = 1.7%, 18.7%), and the secondary organic carbon component of PM2.5 (SOC; 20.4% increase; 95% confidence interval = 8.3%, 33.9%). Associations were stable in sensitivity analyses, and most consistently observed among Black study participants, those in lower income areas, and those diagnosed with HF at an earlier age. Concentration-response curves indicated a linear association for diesel and SOC. While there was some non-linearity in the gasoline concentration-response curve, only the linear component was associated with 30-day readmissions. DiscussionThere appear to be source specific associations between PM2.5 and 30-day readmissions particularly for traffic-related sources, potentially indicating unique toxicity of some sources for readmission risks that should be further explored.

Personal air pollution exposure and metals in the nasal epithelial lining fluid of COPD patients

Sampling of the nasal epithelial lining fluid is a potential method to assess exposure to air pollution within the respiratory tract among high risk populations. We investigated associations of short- and long-term particulate matter exposure (PM) and pollution-related metals in the nasal fluid of people with chronic obstructive pulmonary disease (COPD). This study included 20 participants with moderate-to-severe COPD from a larger study who measured long-term personal exposure to PM2.5 using portable air monitors and short-term PM2.5 and black carbon (BC) using in-home samplers for the seven days preceding nasal fluid collection. Nasal fluid was sampled from both nares by nasosorption, and inductively coupled plasma mass spectrometry was used to determine the concentration of metals with major airborne sources. Correlations of selected elements (Fe, Ba, Ni, Pb, V, Zn, Cu) were determined within the nasal fluid. Associations between personal long-term PM2.5 and seven day home PM2.5 and BC exposure and nasal fluid metal concentrations were determined by linear regression. Within nasal fluid samples, concentrations of vanadium and nickel (r = 0.8) and lead and zinc (r = 0.7) were correlated. Seven day and long-term PM2.5 exposure were both associated with higher levels of copper, lead, and vanadium in the nasal fluid. BC exposure was associated with higher levels of nickel in the nasal fluid. Levels of certain metals in the nasal fluid may serve as biomarkers of air pollution exposure in the upper respiratory tract.

Potential causal links between long-term ambient particulate matter exposure and cerebrovascular mortality: Insights from a large cohort in southern China

Cohort studies conducted in North America and Europe have linked cerebrovascular mortality to long-term exposure to particulate matter (PM). However, limited evidence from large cohorts in high-exposure areas and the traditional approach of association assessment may cause residual confounding issues. In this study, we aimed to investigate the causal links between cerebrovascular mortality and long-term exposure to PM2.5, PM10, and PM2.5-10 in an ongoing cohort study with 580,757 participants in southern China. Using satellite-based estimates of PM concentration at a 1-km2 spatial resolution, we assigned exposure levels to each participant and used the marginal structural Cox model to assess the association between PM exposure and cerebrovascular mortality while accounting for time-varying covariates. We also explored the potential modification effects of sociodemographic and behavioral factors on the PM-health associations. Adjusted hazard ratios (HR) for overall cerebrovascular mortality were 1.041 (95% confidence interval (CI): 1.034–1.049) and 1.032 (95% CI: 1.026–1.038) for each 1 μg/m3 increase in PM2.5, and PM10, respectively. Similar trends were observed in the mortality risk from stroke and ischemic stroke, with HRs ranging from 1.040 to 1.069 and 1.025 to 1.052, respectively, across 2 p.m. exposures. The impact of PM exposure was generally more apparent among women, participants with primary school diplomas and below, and the subgroup under low-exposure. Multiple sensitivity analyses confirmed the robustness of the results. In conclusion, this sizable prospective cohort study hypothesizes causal links between long-term PM exposure and cerebrovascular mortality, particularly among vulnerable participants, supporting the rationale for reducing PM concentration in China to reduce cerebrovascular mortality.

Long-term particulate matter exposure is associated with the development of nonallergic rhinitis: A case-control study.

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Estimating causal links of long-term exposure to particulate matters with all-cause mortality in South China

BackgroundThe association between long-term particulate matter (PM) exposure and all-cause mortality has been well-documented. However, evidence is still limited from high-exposed cohorts, especially for PM1 which is smaller while more toxic than other commonly investigated particles. We aimed to examine the potential casual links of long-term PMs exposure with all-cause mortality in high-exposed areas. MethodsA total of 580,757 participants in southern China were enrolled during 2009–2015 and followed up to 2020. The annual average concentration of PM1, PM2.5, and PM10 at 1 km2 spatial resolution was assessed for each residential address through validated spatiotemporal models. We used marginal structural Cox models to estimate the PM-mortality associations which were further stratified by sociodemographic, lifestyle factors and general exposure levels. Results37,578 deaths were totally identified during averagely 8.0 years of follow-up. Increased exposure to all 3 PM size fractions were significantly associated with increased risk of all-cause mortality, with hazard ratios (HRs) of 1.042 (95 % confidence interval (CI): 1.037–1.046), 1.031 (95 % CI: 1.028–1.033), and 1.029 (95 % CI: 1.027–1.031) per 1 μg/m3 increase in PM1, PM2.5, and PM10 concentrations, respectively. We observed greater effect estimates among the elderly (age ≥ 65 years), unmarried participants, and those with low education attainment. Additionally, the effect of PM1, PM2.5, and PM10 tend to be higher in the low-exposure group than in the general population. ConclusionsWe provided comprehensive evidence for the potential causal links betweenlong-term PM exposureand all-cause mortality, and suggested stronger links for PM1compared to large particles and among certain vulnerable subgroups.

Long-term exposure to particulate matter and COPD mortality: Insights from causal inference methods based on a large population cohort in southern China

BackgroundEvidence of the association between long-term exposure to particulate matter (PM) and chronic obstructive pulmonary disease (COPD) mortality from large population-based cohort study is limited and often suffers from residual confounding issues with traditional statistical methods. We hereby assessed the casual relationship between long-term PM (PM2.5, PM10 and PM10–2.5) exposure and COPD mortality in a large cohort of Chinese adults using state-of-the-art causal inference approaches. MethodsA total of 580,757 participants in southern China were enrolled in a prospective cohort study from 2009 to 2015 and followed up until December 2020. Exposures to PM at each residential address were obtained from the Long-term Gap-free High-resolution Air Pollutant Concentration dataset. Marginal structural Cox models were used to investigate the association between COPD mortality and annual average exposure levels of PM exposure. ResultsDuring an average follow-up of 8.0 years, 2250 COPD-related deaths occurred. Under a set of causal inference assumptions, the hazard ratio (HR) for COPD mortality was estimated to be 1.046 (95 % confidence interval: 1.034–1057), 1.037 (1.028–1.047), and 1.032 (1.006–1.058) for each 1-μg/m3 increase in annual average concentrations of PM2.5, PM10, and PM10–2.5 respectively. Additionally, the detrimental effects appeared to be more pronounced among the elderly (age ≥ 65) and inactive participants. The effect estimates of PM2.5, PM10, and PM10–2.5 tend to be greater among participants who were generally exposed to PM10 concentrations below 70 μg/m3 than that among the general population. ConclusionOur results support causal links between long-term PM exposure and COPD mortality, highlighting the urgency for more effective strategies to reduce PM exposure, with particular attention on protecting potentially vulnerable groups.

Resveratrol reversed ambient particulate matter exposure-perturbed oscillations of hepatic glucose metabolism by regulating SIRT1 in mice.

Much evidence has shown that ambient particulate matter (PM) exposure is associated with abnormal glucose metabolism, but the underlying mechanism has not yet been fully characterized. Circadian disruption has adverse effects on glucose metabolism. In this study, we investigated the effects of long-term ambient PM exposure on the hepatic circadian clock and the expression rhythm of genes associated with hepatic glucose metabolism in mice. C57BL/6 mice were exposed to filtered air (FA), ambient PM, or ambient PM plus resveratrol (RES). After 15weeks (12h per day, 7days per week) of exposure, glucose homeostasis, the rhythmic expression of clock genes, and genes associated with hepatic glucose metabolism were determined. Our results found that PM exposure induced glucose metabolism disorder and perturbed the rhythmic mRNA expression of core clock genes and their target genes involved in hepatic glucose metabolism. Mechanistic investigations demonstrated that ambient PM exposure markedly altered the expression patterns of BMAL1, clock, and SIRT1 in vivo. Simultaneously, we demonstrated that RES (an activator of SIRT1) changed the expression pattern of SIRT1, thereby reversing the rhythm misalignment of BMAL1 and clock and hepatic glucose metabolism disorder induced by ambient PM exposure. In addition, PM2.5 exposure perturbed the rhythmic protein expression of BMAL1, clock, and SIRT1 in L-02 cells. Simultaneously, we demonstrated that RES restored the SIRT1 circadian rhythm, which reversed the rhythm misalignment of BMAL1 and clock in L-02 cells induced by PM2.5 exposure. Taken together, our results suggested that long-term ambient PM exposure perturbed the hepatic core circadian clock rhythm and caused glucose metabolism disorder, which could be reversed by RES supplementation. Our study offers a potential application of RES for combating circadian misalignment-related metabolic diseases.

Particulate Matter Concentration and Microbial Load in Heavy Traffic Areas of District Lahore, Pakistan

A major threat to the environment and public health is air pollution. Previous research has looked at the harmful health impacts of both short- and long-term particulate matter exposure. In addition, PM (particulate matter) of fine or coarse size (PM 2.5 and PM 10) was linearly related with mortality, with PM 2.5 being associated with long-term mortality and PM10 being connected with short-term mortality. Traffic congestion is one of the foremost problems. Objective: To characterize gram positive and gram negative airborne bacteria from air samples of heavy traffic areas. Methods: These were assessed using direct as well as indirect sampling technique. A total of 40 samples 10 from each traffic areas (i.e., Bhatti Gate, Bohr wala chowk, Chauburji and Railway Station) were collected. These were collected with the help of Mini Vol portable air sampler. Filter papers containing particulate matter 2.5 and 10 were placed on prepared petri dishes. The petri dishes were then kept in an incubator for 24 hours at 37 °C, the appearances of colonies were characterized and proceeded for morphological and biochemical identification. Results: The results showed the presence of different bacteria including Bacillus spp., Micrococcus spp. Streptococcus and Staphylococcus aureus, Pseudomonas aeroginosa. Conclusion: It was found that air was heavily polluted with PM 10 and micrococcus aureus.

Long-term exposure to particulate air pollution and incidence of Parkinson's disease: A nationwide population-based cohort study in South Korea

There has been increasing interest in the neurological impact of particulate matter (PM). However, its association with the incidence of Parkinson's disease (PD) remains unclear. We selected 313,355 participants satisfying inclusion criteria from the National Health Insurance Service-National Sample Cohort based on the nationwide population of South Korea, and followed them up from January 2007 through December 2015. Individual-level long-term PM exposure was assessed as the five time-varying average concentrations estimated for the previous 1, 2, 3, 4 and 5 years on each year (until censored or event occurred) at the district-level residential addresses of participants using a previously validated prediction model. Incident PD was defined as the first diagnosis accompanied by anti-PD medication prescription from 2007 through 2015. Time-varying Cox proportional hazards models were employed to estimate the hazard ratio (HR) of incident PD for long-term PM exposure, adjusting for individual- and area-level covariates. During the 8 years (2,745,389 person-years) of follow-up for a total of 313,355 participants (mean [range] age, 48.9 [19–87] years; 169,571 males [54.1%]), 2621 participants (0.8%) developed PD. The HR of incident PD per interquartile range (3.3 μg/m3) increase in fine PM (PM2.5) for the previous 1 year was 1.08 (95% confidence interval: 1.01–1.19). In subgroup-specific analyses, HRs for PM2.5 were significant among older participants, males, participants living in metropolitan cities, ibuprofen users, and participants with comorbidities (HR: 1.10–1.20). Long-term exposure to PM2.5 might play a role in PD development.

Long-term particulate matter exposure and bone mineral density in the Women’s Health Initiative

BACKGROUND AND AIM: Ambient particulate matter air pollution 10 μm (PM10) concentrations have been associated with several outcomes, but few studies have examined their association with bone mineral density (BMD). Previous studies have suggested an effect of air pollution on bone health, but none has evaluated its impact in postmenopausal women. METHODS: We studied the longitudinal PM10-BMD association among 5,080 postmenopausal women in the Women’s Health Initiative Clinical Trials (WHI-CT). We used log-normal, ordinary kriging to estimate daily mean PM10 concentrations (μg/m3) at geocoded participant addresses. We averaged the means over 1-, 3-, and 5-year periods before triennial, dual energy X-ray absorptiometry (DXA) exams. We estimated total hip, lumbar spine, and total body BMD (in g/cm2) and their corresponding T-scores. We estimated the association of PM10 with BMD and T-scores using multivariable linear mixed models while controlling for correlation of repeated measures among participants and adjusting for age at DXA, race/ethnicity, income, body mass index (kg/m2), smoking status, coffee consumption, physical activity, CT randomization arm, US region of residence, and DXA equipment serial number. Multiple imputation was done for missing data. RESULTS:At baseline, women were aged 50-79 years, 78% were White, 40% were college graduates, and 71% earned $40,000/year. PM10 concentrations at baseline were cross-sectionally associated with both hip, lumbar spine, and whole-body BMD and T-scores (p 0.05). Longitudinally, lumbar spine BMD decreased 0.052 (95% confidence interval [95%CI]: 0.067, 0.037) g/cm2/year per 10% (2.21 ug/m3) increase in 5-year mean PM10 concentration. Lumbar spine T-scores also decreased with increasing duration of the 3- and 5-year mean PM10 concentrations: -0.362 Standard Deviations (SD) (-0.490, -0.235) and -0.512 SD (-0.649, -0.375), respectively. No association was seen with changes in hip or total body BMD. CONCLUSIONS:This is the first study suggesting an inverse association of ambient PM10 with BMD among postmenopausal women. KEYWORDS: Air pollution, long-term, PM10, bone mineral density, t-score, osteoporosis.