Long-term Effects Of PM2 Research Articles

Effects of long-term PM2.5 exposure on dementia: A Burden of Proof study

Effects of long-term PM2.5 exposure on dementia: A Burden of Proof study

Does diet quality moderate the long-term effects of discrete but extreme PM2.5 exposure on respiratory symptoms? A study of the Hazelwood coalmine fire

In 2014, a fire at an open cut coalmine in regional Victoria, Australia burned for 6 weeks. Residents of the nearby town of Morwell were exposed to smoke, which included high levels of fine particulate matter (PM2.5). We investigated whether the long-term effects of PM2.5 on respiratory health were moderated by diet quality. A cross-sectional analysis was conducted of data collected 8.5 years after the mine fire from 282 residents of Morwell and 166 residents from the nearby unexposed town of Sale. Primary outcomes were respiratory symptoms. Exposure was coalmine fire-related PM2.5 and diet quality was assessed as Australian Recommended Food Score (ARFS) derived using the Australian Eating Survey (AES). The moderating effect of diet quality on respiratory outcomes associated with PM2.5 was assessed using logistic regression models, adjusting for potential confounders. Diet quality was poor in this sample, with 60% in the lowest category of overall diet quality. Overall diet quality and fruit and vegetable quality significantly attenuated the association between PM2.5 and prevalence of chronic cough and phlegm. Sauce/condiment intake was associated with a greater effect of PM2.5 on COPD prevalence. No other moderating effects were significant. The moderating effects of overall diet quality and vegetable and fruit intake aligned with a priori hypotheses, suggesting potential protective benefits. While more evidence is needed to confirm these findings, improving diets, especially fruit and vegetable intake, may provide some protection against the effects of smoke exposure from fire events.

An ecological study of PM2.5 and black carbon and acute hemorrhagic stroke: a long term effect study

Both PM2.5 and black carbon particle are associated with acute ischemic stroke. There is limited data on the correlation of long term effects of PM2.5 and black carbon on acute hemorrhagic stroke with a large sample size. This was an ecological study. Numbers of acute hemorrhagic stroke who were admitted and reimbursed from the national database of Thailand were collected. Data of PM2.5 and black carbon were collected. Poisson regression analysis adjusted by physical factors and regions was used to evaluate the association between PM2.5 and black carbon on acute hemorrhagic stroke. There were 82,389 patients diagnosed as acute hemorrhagic stroke throughout Thailand. The median of PM2.5 of all provinces was 29.19 microgram m−3, while black carbon had the median of 1.17 microgram m−3. PM 2.5 was significantly associated with numbers of acute hemorrhagic stroke with an adjusted coefficient of 0.019 (p < 0.001), while black carbon was also had significant adjusted coefficient of 0.199 (p < 0.001). Both PM2.5 and black carbon particle were associated with acute hemorrhagic stroke in a long term fashion by an ecological study of the national database.

Long-term effects of PM2.5 constituents on metabolic syndrome and mediation effects of serum uric acid

Exposure to particulate matter with aerodynamic diameter ≤2.5 μm (PM2.5) was associated with the risk for metabolic syndrome (MetS) in the general population, but the contributions of individual PM2.5 constituents to this association and the potential pathway between PM2.5 constituents and MetS risk are not well elaborated. This study aimed to investigate associations between PM2.5 constituents and MetS in general populations, relative importance of PM2.5 constituents to and mediation effects of serum uric acid (SUA) on those associations. The 48,148 participants from a provincially representative cohort established in southwest China were included. The 3-year average concentrations of PM2.5 and its constituents (nitrate [NO3−], sulfate [SO42−], ammonium [NH4+], organic matter [OM], and black carbon [BC]) were estimated using a series of machine-learning models. Multivariate logistic regression and weighted quantile sum regression were used to estimate effects of independent PM2.5 constituents on MetS and their contributions to the joint effect. Mediation analysis examined the potential mediation effects of SUA on the associations between PM2.5 constituents and MetS. Each interquartile range (IQR) increase in the concentration of PM2.5 constituents was all positively associated with the increased MetS odds, including SO42− (OR = 1.15 [1.11, 1.19]]), NO3− (OR = 1.12 [1.08, 1.16]), NH4+ (OR = 1.13 [1.09, 1.17]), OM (OR = 1.09 [1.06, 1.13]), and BC (OR = 1.09 [1.06, 1.13]). Their joint associations on MetS were mainly attributed to SO42− (weight=46.1%) and NH4+ (44.0%). The associations of PM2.5 constituents with abnormal MetS components were mainly attributed to NH4+ for elevated BP (51.6%) and reduced HDL-C (97.0%), SO42− for elevated FG (68.9%), NO3- for elevated TG (51.0%), and OM for elevated WC (63.0%). Percentages mediated by SUA for the associations of PM2.5, SO42−, NO3−, and BC with MetS were 13.6%, 13.1%, 10.6%, and 11.1%, respectively. Long-term exposure to PM2.5 constituents, mainly NH4+ and SO42−, was positively associated with MetS odds, partially mediated by SUA.

Associations of long-term fine particulate matter exposure with all-cause and cause-specific mortality: results from the ChinaHEART project

The chronic effects of fine particulate matter (PM2.5) at high concentrations remains uncertain. We aimed to examine the relationship of long-term PM2.5 exposure with all-cause and the top three causes of death (cardiovascular disease [CVD], cancer, and respiratory disease), and to analyze their concentration-response functions over a wide range of concentrations. We enrolled community residents aged 35-75 years from 2014 to 2017 from all 31 provinces of the Chinese Mainland, and followed them up until 2021. We used a long-term estimation dataset for both PM2.5 and O3 concentrations with a high spatiotemporal resolution to assess the individual exposure, and used Cox proportional hazards models to estimate the associations between PM2.5 and mortalities. We included 1,910,923 participants, whose mean age was 55.6±9.8 years and 59.4% were female. A 10μg/m3 increment in PM2.5 exposure was associated with increased risk for all-cause death (hazard ratio 1.02 [95% confidence interval 1.012-1.028]), CVD death (1.024 [1.011-1.037]), cancer death (1.037 [1.023-1.052]), and respiratory disease death (1.083 [1.049-1.117]), respectively. Long-term PM2.5 exposure nonlinearly related with all-cause, CVD, and cancer mortalities, while linearly related with respiratory disease mortality. The overall effects of long-term PM2.5 exposure on mortality in the high concentration settings are weaker than previous reports from settings of PM2.5 concentrations < 35μg/m³. The distinct concentration-response relationships of CVD, cancer, and respiratory disease mortalities could facilitate targeted public health efforts to prevent death caused by air pollution. The Chinese Academy of Medical Sciences Innovation Fund for Medical Science, the National High Level Hospital Clinical Research Funding, the Ministry of Finance of China and National Health Commission of China, the 111 Project from the Ministry of Education of China.

An Estimation of Daily PM2.5 Concentration in Thailand Using Satellite Data at 1-Kilometer Resolution

This study addresses the limited coverage of regulatory monitoring for particulate matter 2.5 microns or less in diameter (PM2.5) in Thailand due to the lack of ground station data by developing a model to estimate daily PM2.5 concentrations in small regions of Thailand using satellite data at a 1-km resolution. The study employs multiple linear regression and three machine learning models and finds that the random forest model performs the best for PM2.5 estimation over the period of 2011–2020. The model incorporates several factors such as Aerosol Optical Depth (AOD), Land Surface Temperature (LST), Normalized Difference Vegetation Index (NDVI), Elevation (EV), Week of the year (WOY), and year and applies them to the entire region of Thailand without relying on monitoring station data. Model performance is evaluated using the coefficient of determination (R2) and root mean square error (RMSE), and the results indicate high accuracy for training (R2: 0.95, RMSE: 5.58 μg/m3), validation (R2: 0.78, RMSE: 11.18 μg/m3), and testing (R2: 0.71, RMSE: 8.79 μg/m3) data. These PM2.5 data can be used to analyze the short- and long-term effects of PM2.5 on population health and inform government policy decisions and effective mitigation strategies.

Investigations of PM2.5 Long-term Exposure and Subclinical Atherosclerosis in Women: An Overview

Background/Aim Evidence demonstrates that coronary artery calcification (CAC) is a biological marker for cardiovascular disease (CVD) risk prediction. Acute cardiovascular effects of temporary and chronic environmental particle exposures sensitive to ≤2.5 micrometers in diameter (here termed “PM2.5”) have been well-studied. However, there is less information on the long-term effects of PM2.5 exposures on the earlier pre-clinical stage of CVD, especially in women (in whom it is also established experience frequent cardiovascular late- and under-diagnoses). This phase of pre-diagnosis pathological activity is classified as subclinical atherosclerosis (SCA) unless and until a patient meets established clinical diagnostic criteria. In this systematic review, we summarize reported associations of long-term PM2.5 and SCA exposure, with investigators placing an emphasis on gender differences in any documented associations. Methods We conducted a comprehensive literature review for articles published from 2007 to 2022 that reported associations of long-term PM2.5 and SCA and evaluated each study with areas of particular focus including study designs, populations at risk, and exposure measures. Results Investigations representing four cohorts yielded equivocal findings related to long-term PM2.5 exposure and CAC. Three cohorts reported positive associations between long-term PM2.5 and CAC development/progression. Two studies supported a strongly positive associations among women or postmenopausal women for PM2.5 on CAC. Studies, however, evaluating PM2.5 exposure associations with carotid intima-media thickness (another biomarker of SCA), reflect increases in both men and women with ↑ PM2.5 levels but reporting no gender differences in PM2.5 exposure and this measure of SCA. Conclusion Our study identifies important gaps in current knowledge synthesis including different methods of PM2.5 estimation and linkage, a lack of consensus of what constitutes long-term air pollution, and the selection of important covariates and intermediate variables. Our aim is to outline best practices going forward in the investigation of PM2.5 long-term exposure and SCA in women

Effects of long-term PM2.5 exposure on metabolic syndrome among adults and elderly in Guangdong, China

BackgroundWe aimed to explore the association between long-term exposure to particulate matter ≤ 2.5 µm (PM2.5) and metabolic syndrome (MetS) and its components including fasting blood glucose (FBG), blood pressure, triglyceride (TG), high-density lipoprotein cholesterol (HDL-c) and waist circumference among adults and elderly in south China.MethodsWe surveyed 6628 participants in the chronic disease and risk factors surveillance conducted in 14 districts of Guangdong province in 2015. MetS was defined based on the recommendation by the Joint Interim Societies’ criteria. We used the spatiotemporal land-use regression (LUR) model to estimate the two-year average exposure of ambient air pollutants (PM2.5, PM10, SO2, NO2, and O3) at individual levels. We recorded other covariates by using a structured questionnaire. Generalized linear mixed model was used for analysis.ResultsA 10-μg/m3 increase in the two-year mean PM2.5 exposure was associated with a higher risk of developing MetS [odd ratio (OR): 1.17, 95% confidence interval (CI): 1.01, 1.35], increased risk of fasting blood glucose level.(OR: 1.18, 95% CI: 1.02, 1.36), and hypertriglyceridemia (OR: 1.36, 95% CI: 1.18, 1.58) in the adjusted/unadjusted models (all P < 0.05). We found significant interaction between PM2.5 and the region, exercise on the high TG levels, and an interaction with the region, age, exercise and grain consumption on FBG (Pinteraction < 0.05).ConclusionsLong-term exposure to PM2.5 was associated with MetS, dyslipidemia and FBG impairment. Efforts should be made for environment improvement to reduce the burden of MetS-associated non-communicable disease.

Inverse association between ambient particulate matter and semen quality in Central China: Evidence from a prospective cohort study of 15,112 participants

Emerging evidence indicates that ambient particulate matter (PM) is harmful to male fertility, but the associations between ambient PM exposure and semen quality were inconsistent. This study aimed to quantitatively evaluate the association between ambient PM exposure and semen quality based on a large prospective cohort. Using data from the prospective assisted reproduction cohort in Anhui province, China, we included 15,112 males with 28,267 semen tests, whose partner has undergone assisted reproductive technology from September 1, 2015 to September, 22 2020. Individual ambient PM, gaseous air pollutants, and temperature exposures of the participants during 0–90, 0–9, 10–14, and 70–90 days before semen quality tests were evaluated using inverse distance weighting interpolation. Linear mixed-effects models were conducted to evaluate the relationship between PM2.5 and PM10 exposures and standardized semen quality parameters. Models were adjusted for age, body mass index, smoking, drinking, education attainment, occupation type, sampling month, temperature and the principal component of gaseous air pollutants. PM2.5 and PM10 were inversely associated with sperm concentration, total sperm count, total motility, progressive motility, total motile sperm count, and progressively motile sperm count during 0–90, 0–9, and 70–90 days period (all p < 0.05), but not 10–14 days period. The regression coefficients of PM2.5 exposure on semen quality parameters during 0–90 days period were larger than 0–9 and 70–90 days periods, and the effects of PM2.5 on semen quality parameters were stronger than PM10. Our results showed that ambient PM2.5 and PM10 exposures were associated with semen quality, during 70–90 days and 0–9 days before sampling, and the entire spermatogenesis process. The effects of PM2.5 on semen quality parameters were stronger than PM10, and the long-term effects of PM2.5 and PM10, throughout spermatogenesis, were stronger than the short-term effects.

Long-term effects of PM2.5 components on blood pressure and hypertension in Chinese children and adolescents.

Growing evidence has linked fine particulate matter (PM2.5) exposure to elevated blood pressure, but the effects of PM2.5 components are unclear, particularly in children and adolescents. Based on a cross-sectional investigation in China, we analyzed the associations between long-term exposure to PM2.5 and its major components with elevated blood pressure in children and adolescents. A representative sample (N=37,610) of children and adolescents with age 7-18years was collected in seven Chinese provinces. Exposures to PM2.5 and five of its major components, including black carbon (BC), organic matter (OM), inorganic nitrate (NO3-), sulfate (SO42-), and soil particles (SOIL), were estimated using satellite-based spatiotemporal models. The associations between long-term exposures to PM2.5 and its components and diastolic blood pressure (DBP), systolic blood pressure (SBP), and hypertension were investigated using mixed-effects logistic and linear regression models. Within the populations, 11.5 % were classified as hypertension. After adjusting for a variety of covariates, per interquartile range (IQR) increment in PM2.5 mass and BC levels were significantly associated with a higher hypertension prevalence with odds ratios (ORs) of 1.56 (95% confidence interval (CI): 1.08, 2.25) for PM2.5 and 1.19 (95% CI: 1.04, 1.35) for BC. Long-term exposures to PM2.5 and BC have also been associated with elevated SBP and DBP. Additionally, OM and NO3- were significantly associated with increased SBP, while SOIL was significantly associated with increased DBP. In the subgroup analysis, the associations between long-term exposures to BC and blood pressure vary significantly by urbanicity of residential area and diet habits. Our study suggests that long-term exposure to PM2.5 mass and specific PM2.5 components, especially for BC, are significantly associated with elevated blood pressure and a higher hypertension prevalence in Chinese children and adolescents.

Long-term effects of PM2.5 components on incident dementia in the northeastern United States

Growing evidence has linked long-term fine particulate matter (PM2.5) exposure to neurological disorders. Less is known about the individual effects of PM2.5 components. A population-based cohort study investigated the association between long-term (1-year average) exposure to PM2.5 components and dementia incidence among the elderly population (age, ≥65 years) in the United States. We used data from the Medicare Chronic Conditions Warehouse and a high-resolution PM2.5 components dataset of the northeastern United States (2000–2017). We identified dementia diagnoses from patients’ hospital and medical insurance records and carried out Cox proportional hazards regression to investigate their association with PM2.5 components. Among ∼2 million participants, 15.1% developed dementia. From the single-pollutant models, hazard ratios per interquartile range increase were 1.10 (95% confidence interval [CI]: 1.09–1.11) for black carbon, 1.08 (95% CI: 1.07, 1.10) for inorganic nitrate, 1.03 (95% CI: 1.02, 1.04) for organic matter, 1.13 (95% CI: 1.11, 1.15) for sulfate, 1.07 (95% CI: 1.06, 1.07) for soil particles, and 1.04 (95% CI: 1.03, 1.05) for sea salt. Increase in exposure to black carbon and sulfate per interquartile range had the strongest associations with dementia incidence. Penalized spline models indicated that dementia incidence increased linearly with elevated black carbon concentrations, whereas the incidence of dementia was only elevated significantly following sulfate concentrations above ∼2 μg/m3. Our study suggests that long-term exposure to PM2.5 components is significantly associated with increased dementia incidence and that different components have different neurotoxicity. Reduction of PM2.5 emissions, especially for main sources of black carbon and sulfate, may reduce the burden of dementia in the aging United States population.

A National-Scale 1-km Resolution PM2.5 Estimation Model over Japan Using MAIAC AOD and a Two-Stage Random Forest Model

Satellite-based models for estimating concentrations of particulate matter with an aerodynamic diameter less than 2.5 μm (PM2.5) have seldom been developed in islands with complex topography over the monsoon area, where the transport of PM2.5 is influenced by both the synoptic-scale winds and local-scale circulations compared with the continental regions. We validated Multi-Angle Implementation of Atmospheric Correction (MAIAC) aerosol optical depth (AOD) with ground observations in Japan and developed a 1-km-resolution national-scale model between 2011 and 2016 to estimate daily PM2.5 concentrations. A two-stage random forest model integrating MAIAC AOD with meteorological variables and land use data was applied to develop the model. The first-stage random forest model was used to impute the missing AOD values. The second-stage random forest model was then utilised to estimate ground PM2.5 concentrations. Ten-fold cross-validation was performed to evaluate the model performance. There was good consistency between MAIAC AOD and ground truth in Japan (correlation coefficient = 0.82 and 74.62% of data falling within the expected error). For model training, the model showed a training coefficient of determination (R2) of 0.98 and a root mean square error (RMSE) of 1.22 μg/m3. For the 10-fold cross-validation, the cross-validation R2 and RMSE of the model were 0.86 and 3.02 μg/m3, respectively. A subsite validation was used to validate the model at the grids overlapping with the AERONET sites, and the model performance was excellent at these sites with a validation R2 (RMSE) of 0.94 (1.78 μg/m3). Additionally, the model performance increased as increased AOD coverage. The top-ten important predictors for estimating ground PM2.5 concentrations were day of the year, temperature, AOD, relative humidity, 10-m-height zonal wind, 10-m-height meridional wind, boundary layer height, precipitation, surface pressure, and population density. MAIAC AOD showed high retrieval accuracy in Japan. The performance of the satellite-based model was excellent, which showed that PM2.5 estimates derived from the model were reliable and accurate. These estimates can be used to assess both the short-term and long-term effects of PM2.5 on health outcomes in epidemiological studies.

Association between ambient particulate matter exposure and platelet counts in adults: a retrospective cohort study.

Associations between ambient particulate matter exposure and platelet counts are inconsistent in previous studies, and study on the effect of long-term exposure especially in Asian populations is limited. We explored the associations between long-term PM2.5 (particulate matter < 2.5 μm) exposure and platelet counts using a prospective cohort study in Northeast China. We used a logistic regression model to analyze the effects of different PM2.5 increments and platelet count elevation. Mixed linear models were used to analyze the association between PM2.5 concentration and platelet counts. Interaction and sub-group analyses were also conducted. Results showed that every 1 μg/m3 increment of PM2.5 exposure was associated with 0.29% (95%CI: 0.25-0.32%) increase in platelet counts and 10% (95%CI: 8-12%) higher risk of platelet elevation. Effects of long-term PM2.5 exposure on platelet elevation were stronger in male participants, of Han ethnicity, and without diabetes. Long-term PM2.5 exposure would increase platelet counts in adults in Northeast area of China, which might add more evidence to the potential biological mechanisms responsible for the effect of air pollution exposure on cardiovascular disease.

Causal effects of air pollution on mortality in Massachusetts

Background: Epidemiologic studies of air pollution and mortality have primarily investigated long- and short-term exposures separately, have used multiplicative models, and have been associational studies.Methods: We analyzed 1.5 million Medicare beneficiaries living in Massachusetts with 3.9 billion person-days of follow-up during 2000-2012. We implemented a generalized propensity score adjustment approach, which accounted for joint confounding by the concurrent exposures, individual- and area-level covariates, meteorological covariates, seasonal variations, and long-term time trend, to evaluate causal effects of long- (one-year moving average) and short-term (two-day moving average) exposures to PM2.5, O3, and NO2 on all-cause mortality. By modeling the binary outcome of death with linear probability model, we estimated the potential number of deaths that would occur per unit increase in each air pollutant exposure.Results: We found that long- and short-term PM2.5, O3, and NO2 were all associated with an increased risk of mortality. Specifically, per 10 million person-days, each 1 µg·m-3 increase in long- and short-term PM2.5 were associated with 35.4 (95% confidence interval [CI], 33.4-37.6) and 3.04 (95% CI, 2.17-3.94) excess deaths, respectively; each 1 ppb increase in long- and short-term O3 were associated with 2.35 (95% CI, 1.08-3.61) and 2.41 (95% CI, 1.81-2.91) excess deaths, respectively; and each 1 ppb increase in long- and short-term NO2 were associated with 3.24 (95% CI, 2.75-3.77) and 5.60 (95% CI, 5.24-5.98) excess deaths, respectively. Importantly, risk differences associated with long-term effects of PM2.5 and O3 increased substantially when the exposure levels went below the increasingly stringent thresholds, including those well below the current National Ambient Air Quality Standards (NAAQS).Conclusions: The findings suggest that air pollution exposures were causally associated with mortality, even at levels below NAAQS. The estimates on additive probability scale provide clearer insights into the relative magnitude of air pollution effects.

Long-term effects of PM2·5 on neurological disorders in the American Medicare population: a longitudinal cohort study

SummaryBackgroundAccumulating evidence links fine particulate matter (PM2·5) to premature mortality, cardiovascular disease, and respiratory disease. However, less is known about the influence of PM2·5 on neurological disorders. We aimed to investigate the effect of long-term PM2·5 exposure on development of Parkinson’s disease or Alzheimer’s disease and related dementias.MethodsWe did a longitudinal cohort study in which we constructed a population-based nationwide open cohort including all fee-for-service Medicare beneficiaries (aged ≥65 years) in the contiguous United States (2000–16) with no exclusions. We assigned PM2·5 postal code (ie, ZIP code) concentrations based on mean annual predictions from a high-resolution model. To accommodate our very large dataset, we applied Cox-equivalent Poisson models with parallel computing to estimate hazard ratios (HRs) for first hospital admission for Parkinson’s disease or Alzheimer’s disease and related dementias, adjusting for potential confounders in the health models.FindingsBetween Jan 1, 2000, and Dec 31, 2016, of 63 038 019 individuals who were aged 65 years or older during the study period, we identified 1·0 million cases of Parkinson’s disease and 3·4 million cases of Alzheimer’s disease and related dementias based on primary and secondary diagnosis billing codes. For each 5 μg/m3 increase in annual PM2·5 concentrations, the HR was 1·13 (95% CI 1·12–1·14) for first hospital admission for Parkinson’s disease and 1·13 (1·12–1·14) for first hospital admission for Alzheimer’s disease and related dementias. For both outcomes, there was strong evidence of linearity at PM2·5 concentrations less than 16 μg/m3 (95th percentile of the PM2·5 distribution), followed by a plateaued association with increasingly larger confidence bands.InterpretationWe provide evidence that exposure to annual mean PM2·5 in the USA is significantly associated with an increased hazard of first hospital admission with Parkinson’s disease and Alzheimer’s disease and related dementias. For the ageing American population, improving air quality to reduce PM2·5 concentrations to less than current national standards could yield substantial health benefits by reducing the burden of neurological disorders.

Short-term and long-term effects of PM2.5 on acute nasopharyngitis in 10 communities of Guangdong, China

ObjectivesWe aimed to assess the effects of short-term and long-term exposure to ambient fine particle matter (PM2.5) on acute nasopharyngitis. MethodsA total of 9468 participants aged 18 years and above were recruited from 10 communities in four cities of Guangdong, China during the baseline survey in 2014, and they were followed-up from January 2015 to December 2016. Air pollution exposure was assessed based on the daily concentrations (short-term) and annual concentrations (long-term) of the nearby air monitoring station and the survey date. A mixed-effect logistic model and Cox proportional hazards model were used to quantify the short-term and long-term associations after adjustment for potential confounding factors. ResultsSignificantly positive associations were found between both short-term and long-term exposures of PM2.5 and acute nasopharyngitis. The adjusted odds ratio was 1.15 (95% CI: 1.07, 1.23) for each 10 μg/m3 increase in daily PM2.5 at lag2 day (short-term effects), and the hazard risk was 1.18 (95% CI: 1.10, 1.25) for each 10 μg/m3 increase in annual PM2.5 (long-term effects). Stronger associations between short-term PM2.5 exposure and acute nasopharyngitis were observed among men (OR = 1.10; 95% CI: 1.04, 1.17) and participants aged above 65 years (OR = 1.13; 95% CI: 1.04, 1.23) in the stratified analyses. No significant association was found in women (OR = 1.00; 95% CI: 0.92, 1.10) or young participants ≤65 years (OR = 0.96; 95% CI: 0.88, 1.04). However, for the long-term exposure, the hazard risk was higher for participants younger than 65 years (OR = 1.22; 95% CI: 1.12, 1.32) than the older group (OR = 1.11; 95% CI: 1.00, 1.24). ConclusionThis study indicates that both short-term and long-term exposures to higher concentrations of PM2.5 could increase the risk of acute nasopharyngitis.

Change in the number of PM2.5-attributed deaths in China from 2000 to 2010: Comparison between estimations from census-based epidemiology and pre-established exposure-response functions

Long-term exposure to ambient fine particulate matter (PM2.5) has been identified as a major contributor to disease burden in many countries, including China. The effects of long-term PM2.5 exposure have been evaluated by risk assessment studies, which are based on an exposure-response function (ERF) derived from a specific epidemiological study or multiple studies. To explore whether generalization from the pre-established ERFs (including the integrated exposure-response [IER] model and the global exposure mortality model [GEMM]) introduces biases into risk assessment of a specific local population, we conducted the first census-based epidemiological study of PM2.5, aimed at the entire population of mainland China. Using a difference-in-difference analysis at the county level, we associated mortality changes from 2000 to 2010 to corresponding PM2.5 changes, with adjustments made for multiple socioeconomic factors. Based on the epidemiological linkage between PM2.5 and total mortality, we calculated the change in PM2.5-attributed deaths and compared this value with the results derived from the pre-established models (IER and GEMM). According to the epidemiological model, a 10-μg/m3 increment in PM2.5 was associated with a 4.3% (95% confidence interval [CI]: 1.9%–6.7%) increment in total mortality, and the change in PM2.5-attributed deaths from 2000 to 2010 was estimated as 561,000 (95% CI: 539,000–581,000). The census-based estimation was in better agreement with the GEMM results (545,000–612,000) than was the IER result (354,000 [95% CI: 286,000–421,000]). In sensitivity analyses of the epidemiological model, the association between PM2.5 exposure and mortality was stronger among younger adults, consistent with the pre-established models. Due to the potential limitations of our findings, we cannot conclusively state that GEMM is more reliable than IER in China. Future studies are warranted to confirm or refute our findings.

Long-Term Effects of PM2.5 on Total Mortality in Seoul, Korea

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 have been reported in Korea, where higher levels of exposure are experienced. Objectives: We estimated the association between long-term exposure to PM2.5 with total mortality in a cohort of Korean. Methods: We conducted a prospective cohort study of 4,171,410 residents 30-year-old or older from 25 areas in Seoul in 2008 and followed-up the cohort until 2015. Average PM2.5 levels for the 12 or 24 months prior to death were estimated for each cohort location using a Krigging. A Cox proportional hazards regression model was used to estimate hazard ratios (HR) for total mortality after controlling for age, sex, income, year of event, population, area-level socioeconomic indices, and prevalence of chronic obstructive pulmonary disease.Results: The mean level of 12- and 24-month average of PM2.5 exposure was 22.9 &amp;#956;g/m3 (S.D. 1.6) and 23.8 &amp;#956;g/m3 (S.D. 1.3). Of Seoul residents, 228,329 of death occurred (5.47%). Mortality HRs (95% CI) per 1-&amp;#956;g/m3 increase in PM2.5 were 1.046 (95% CI, 1.043, 1.048) and 1.056 (95% CI, 1.051, 1.059) for 12- and 24-month exposures, respectively.Conclusions: Long-term exposure to PM2.5 was associated with total mortality in Seoul, Korea.

An LPW Estimate of the Effects of Annual Exposure to PM2.5 and Ozone on Hospital Admission Rates of Medicare Participants in the Southeast U.S.A.

Introduction: Air pollution is associated with hospital admissions, but few studies have examined the long-term effects of PM2.5 and ozone, or at low concentrations. Existing studies do not use cau...

Mortality and morbidity for cardiopulmonary diseases attributed to PM2.5 exposure in the metropolis of Rome, Italy

The aim of the study was to evaluate the health effects associated with the exposure to ground-level of particulate matters with aerodynamic diameter ≤ 2.5 μm (PM2.5) on citizens in Rome (Italy) in 2015 and 2016. Based on the new version of the World Health Organization's AirQ+ model, we have estimated the short- and long-term effects of PM2.5 on hospital admissions due to cardiovascular (HA-CVD) and respiratory diseases (HA-RD) as well as on mortality for ischemic heart disease (M-IHD) and chronic obstructive pulmonary disease (M-COPD). In this study, city-specific relative risk values and baseline incidence rates were used to calculate the association between PM2.5 and daily counts of emergency hospitalizations and mortality. The annual mean PM2.5 concentrations were 18 μg m−3 and 14 μg m−3 in 2015 and 2016, respectively. In Rome, the citizens are mostly exposed to daily mean PM2.5 concentrations of 10–20 μg m−3 during the study period. In 2015–2016, 0.4–0.6% for HA-CVD, 1.1–1.5% for HA-RD, 16.5–18.1% for M-IHD and 8.5–9.2% for M-COPD are attributed to PM2.5. In 2015–2016, 134–186 HA-CVD, 126–175 HA-RD, 947–1037 M-IHD and 244–279 M-COPD, caused by PM2.5 exposure, could be “avoided” if PM2.5 concentrations would not exceed 10 μg m−3, i.e. the threshold recommended by the World Health Organization. Thus, a consistent air quality management and sustainable city planning are needed, urgently, to mitigate the adverse effects of PM2.5 exposure in Rome.