Short-term effects of fine particulate matter on non-accidental and circulatory diseases mortality: A time series study among the elder in Changchun

The effects of ambient particulate matter air pollution on platelets and hemostasis

Introduction

Elevated ambient pollution exposure is potentially linked to thromboembolism. However, the mechanisms by which particulate matter (PM) interferes with the balance of hemostatic system remain unclear. This study investigates PM-mediated hemostatic changes in individuals across unique seasonal variations of ambient pollution.

Methods

This prospective study was conducted between February and July 2020 during alterations in ambient pollution in Chiang Mai, Thailand. Blood tests from 30 healthy subjects were assessed at four-week intervals, four times in total. Various coagulation tests, including prothrombin time (PT), activated partial thromboplastin time (aPTT), von Willebrand factor (vWF), platelet count, and platelet functions, were evaluated. A mixed-effects model was used to analyze the impact of high PM2.5 and PM10 on hemostatic parameters.

Results

Thirty male subjects with mean age of 38.9 ± 8.2 years, were included. High levels of PM2.5 and PM10 were significantly associated with PT shortening, with no such effect observed in aPTT. PM2.5 and PM10 values also positively correlated with vWF function, while vWF antigen levels remained unchanged. Soluble P-selectin showed a strong positive association with PM2.5 and PM10 levels. Platelet function analysis revealed no correlation with PM values.

Conclusion

Short-term exposure to elevated PM2.5 and PM10 concentrations was linked to shortened PT and enhanced vWF function in healthy individuals. Exploring the impact of these changes on clinically relevant thrombosis is crucial. Additional studies on the pathogenesis of pollution-related thrombosis are warranted for maintaining good health.

Longitudinal assessment of oxidative stress markers and their relationship with exposure to PM2.5 and its bound metals in healthy participants

OBJECTIVE

Exposure to ambient PM2.5 and its bound metals poses a risk to health and disease, via, in part, oxidative stress response. A variety of oxidative stress markers have been used as markers of response, but their relevance to environmental exposure remains to be established. We evaluated, longitudinally, a battery of oxidative stress markers and their relationship with the exposure of PM2.5 and its bound metals in a panel of healthy participants.

MATERIAL AND METHODS

Levels of residence- and personal-based ambient air PM2.5 and its bound metals, as well as of lung function parameters, were assessed in a total of 58 questionnaire-administered healthy never smoker participants (male, 39.7%). Levels of urinary oxidative stress markers, including Nε-(hexanoyl)-lysine (HEL; an early lipid peroxidation product), 4-hydroxynonenal (4-HNE), N7-methylguanine (N7-meG), and 8-hydroxy-2-deoxyguanosine (8-OHdG), plasma antioxidants [superoxide dismutase (SOD) and glutathione peroxidase (GPx), and urinary metals were measured by ELISA, LC-MS, and ICP-MS, respectively. The results of three repeated measurements at two-month intervals were analyzed using the Generalized Estimating Equation (GEE).

RESULTS

After adjusting for confounders, residence- and personal-based PM2.5 levels were positively associated with HEL (β = 0.22 and 0.18) and N7-meG (β = 0.39 and 0.13). Significant correlations were observed between personal air PM2.5-Pb and urinary Pb with HEL (β = 0.08 and 0.26). While FVC, FEV1, FEV1/FVC, MMF, and PEFR predicted% were normal, a negative interaction (pollutant*time, P < 0.05) was noted for PM2.5-V, Mn, Co, Ni, Zn, As, and Pb. Additionally, a negative interaction was found for N7-meG (β = -21.35, -18.77, -23.86) and SOD (β = -26.56, -26.18, -16.48) with FEV1, FVC, and PEFR predicted%, respectively.

CONCLUSION

These findings emphasize potential links between environmental exposure, internal dose, and health effects, thereby offering valuable markers for future research on metal exposure, oxidative stress, and health outcomes.

Automatic weighing system vs. manual weighing precision comparison in PM-loaded filter measurements under different humidity conditions

Currently, there is a lack of research directly comparing the precision of automatic weighing systems and manual weighing in the context of particulate matter (PM) filter equilibration and measurements under different humidity conditions. During experimental measurements, three different types of PM-loaded filters were weighed using manual and automatic balances. During manual weighing, every filter was weighed twice in three different relative humidity conditions. The same procedure was done using an automated weighing system. In most cases, it was found that under relative humidities in the range of 30-55% RH, the manual and automated methods can be treated as referential. Regarding device stability, very slight but overall better precision was found for 30% RH, suggesting that 40 CFR Part 50, Appendix L requirements regarding conditioning humidity (30-40% RH) seem more suitable than those presented in the PN-EN 12341:2014 standard (45-50% RH). Understanding the effects of the influence of the RH% on PM mass measurements is a matter of great importance, because water vapor condensed on a filter can affect the particulate matter concentrations. This is especially important in areas where regulatory limits are exceeded. Calculation of uncertainty in the PM mass measurements is therefore crucial for determining the actual sample mass and improving air monitoring practices. In a nutshell, the experimental results obtained clearly describe how changing RH% conditions affect the PM weighing precision during manual and automated measurements.

A longitudinal study of the influence of air pollutants on children: a robust multivariate approach

This paper aims to evaluate the statistical association between exposure to air pollution and forced expiratory volume in the first second (FEV1) in both asthmatic and non-asthmatic children and teenagers, in which the response variable FEV1 was repeatedly measured on a monthly basis, characterizing a longitudinal experiment. Due to the nature of the data, an robust linear mixed model (RLMM), combined with a robust principal component analysis (RPCA), is proposed to handle the multicollinearity among the covariates and the impact of extreme observations (high levels of air contaminants) on the estimates. The Huber and Tukey loss functions are considered to obtain robust estimators of the parameters in the linear mixed model (LMM). A finite sample size investigation is conducted under the scenario where the covariates follow linear time series models with and without additive outliers (AO). The impact of the time-correlation and the outliers on the estimates of the fixed effect parameters in the LMM is investigated. In the real data analysis, the robust model strategy evidenced that RPCA exhibits three principal component (PC), mainly related to relative humidity (Hmd), particulate matter with a diameter smaller than 10 μm (PM10) and particulate matter with a diameter smaller than 2.5 μm (PM2.5).

Benefits of Short-term Premature Mortality Reduction Attributed to PM2.5 Pollution: A Case Study in Long an Province, Vietnam

PM2.5 pollution exposure is the leading cause of disease burden globally, especially in low- and middle-income countries, including Vietnam. Therefore, economic damage in this context must be quantified. Long An province in the Southern Key Economic (SKE) region was selected as a research area. This study aimed to evaluate PM2.5-related human health effects causing early deaths attributable to respiratory, cardiovascular, and circulatory diseases in all ages and genders. Health end-points and health impact estimation, economic loss model, groups of PM2.5 concentration data, data of exposed population, data of baseline premature mortality rate, and data of health impact functions were used. Hourly PM2.5 concentration data sets were generated specifically using the coupled Weather Research and Forecasting Model (WRF)/Community Multiscale Air Quality Modelling System (CMAQ) models. Daily PM2.5 pollution levels considered mainly in the dry season (from January to April 2018) resulted in 12.9 (95% CI - 0.6; 18.7) all-cause premature deaths per 100,000 population, of which 7.8 (95% CI 1.1; 7.1), 1.5 (95% CI - 0.2; 3.1), and 3.6 (95% CI - 1.5; 8.5) were due to respiratory diseases (RDs; 60.54%), cardiovascular diseases (CVDs; 11.81%), and circulatory system diseases (CSDs; 27.65%) per 100,000 population, respectively. The total economic losses due to acute PM2.5 exposure-related premature mortality cases reached 62.0 (95% CI - 2.7; 89.6) billion VND, equivalent to 8.3 (95% CI - 0.4; 12.0) million USD. The study outcomes contributed remarkably to the generation and development of data sources for effectively managing ambient air quality in Long An.

Short-term joint effects of ambient PM2.5 and O3 on mortality in Beijing, China

Introduction

In recent years, air pollution caused by co-occurring PM2.5 and O3, named combined air pollution (CAP), has been observed in Beijing, China, although the health effects of CAP on population mortality are unclear.

Methods

We employed Poisson generalized additive models (GAMs) to evaluate the individual and joint effects of PM2.5 and O3 on mortality (nonaccidental, respiratory, and cardiovascular mortality) in Beijing, China, during the whole period (2014-2016) and the CAP period. Adverse health effects were assessed for percentage increases (%) in the three mortality categories with each 10-μg/m3 increase in PM2.5 and O3. The cumulative risk index (CRI) was adopted as a novel approach to quantify the joint effects.

Results

The results suggested that both PM2.5 and O3 exhibited the greatest individual effects on the three mortality categories with cumulative lag day 01. Increases in the nonaccidental, cardiovascular, and respiratory mortality categories were 0.32%, 0.36%, and 0.43% for PM2.5 (lag day 01) and 0.22%, 0.37%, and 0.25% for O3 (lag day 01), respectively. There were remarkably synergistic interactions between PM2.5 and O3 on the three mortality categories. The study showed that the combined effects of PM2.5 and O3 on nonaccidental, cardiovascular, and respiratory mortality were 0.34%, 0.43%, and 0.46%, respectively, during the whole period and 0.58%, 0.79%, and 0.75%, respectively, during the CAP period. Our findings suggest that combined exposure to PM2.5 and O3, particularly during CAP periods, could further exacerbate their single-pollutant health risks.

Conclusion

These findings provide essential scientific evidence for the possible creation and implementation of environmental protection strategies by policymakers.

Effect of short-term exposure to ambient air pollutants on non-accidental mortality in emergency department visits: a time-series study

Objectives

Exposure to air pollution has been linked to an increased risk of premature mortality. However, the acute effects of air pollution on the risk of non-accidental mortality have not been extensively researched in developing countries, and the findings thus far have been inconsistent. Therefore, this study aimed to examine the association between short-term exposure to six pollutants (PM_2.5, PM₁₀, SO₂, NO₂, O₃, and CO) and non-accidental mortality in Beijing, China.

Methods

Daily data on non-accidental deaths were gathered from 1 January 2017 to 31 December 2018. Air pollution data for the same period were collected from 35 fixed-site air quality monitoring stations in Beijing. Generalized additive models (GAM) based on Poisson regression were used to investigate the association between non-accidental mortality in emergency department visits and the daily average levels of air pollutants.

Results

There were 8,676 non-accidental deaths recorded during 2017-2018. After sensitivity analysis, short-term exposure to air pollutants, particularly gaseous pollutants, was linked to non-accidental mortality. Specifically, for every 10 μg/m³ increase (5 μg/m³ in SO₂, 0.5 mg/m³ in CO) of SO₂ (lag 04), NO₂ (lag 04), O₃ (lag 05), and CO (lag 04), the relative risk (RR) values were 1.054 (95% CI: 1.009, 1.100), 1.038 (95% CI: 1.013, 1.063), 1.032 (95% CI: 1.011, 1.054), and 1.034 (95% CI: 1.004, 1.066), respectively. In terms of causes of death, short-term exposure to NO₂, SO₂, and O₃ increased the risk of circulatory mortality. Further stratified analysis revealed that the stronger associations were presented in females for O₃ while in males for CO. People aged 65 and over were strongly associated with ambient air pollution.

Conclusions

Our study showed that ambient air pollutants were associated with non-accidental mortality. Our findings suggested that efforts to control gaseous pollution should be stepped up, and vulnerable groups should be the focus of health protection education.

Ambient particulate matter, a novel factor hindering life spans of HIV/AIDS patients: Evidence from a ten-year cohort study in Hubei, China

BACKGROUND

The life spans of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) patients have been extended in the era of antiretroviral therapy. However, few studies have considered the influence of the environment on the life expectancy of people living with HIV/AIDS. Several studies have investigated mortality and air pollution associations, but the evidence for associations between long-term exposure to particulate matter (PM) and mortality among HIV/AIDS patients remains extremely sparse.

METHODS

We conceived a dynamic cohort study by enrolling people with HIV/AIDS from 103 counties in Hubei province, China from 2010 to 2019, with 23,809 persons and 78,457.2 person-years of follow-up. The county-level annual concentrations of PM_2.5 and PM₁₀ were extracted from the ChinaHighAirPollutants dataset. Cox proportional hazards models with time-varying exposures were conducted to assess the associations between PM and mortality.

RESULTS

Per 1 μg/m³ increased in PM_2.5 and PM₁₀ would elevate 0.69 % (95 % CIs: 0.39, 1.00) and 0.39 % (95 % CIs: 0.18, 0.59) risk of all-cause deaths (ACD) and 1.65 % (95 % CIs: 1.14, 2.17) and 0.90 % (95 % CIs: 0.56, 1.24) of AIDS-related deaths (ARD), respectively. Significantly stronger associations of PM-ARD were found in patients aged over 60 years old, with corresponding excess risk of 2.66 % (95 % CIs: 1.76, 3.58) for PM_2.5 and 1.62 (95 % CIs: 1.01, 2.23) for PM₁₀.

CONCLUSIONS

This study added to the existing evidence that long-term exposure to ambient PM adversely affects the life spans of HIV/AIDS patients. Hence, public health departments should take proactive measures to prevent further life loss and promote survival among those living with HIV/AIDS.

Circulatory health risks from additive multi-pollutant models: short-term exposure to three common air pollutants in Canada

Numerous studies have reported adverse health effects of ambient air pollution on circulatory health outcomes mainly based on single-pollutant models. However, limited studies have focused on adjusted effect of multi-pollutant exposures on public health. This study aimed to examine short-term effects of three common air pollutants-ground-level ozone (ozone), nitrogen dioxide (NO2), and fine particulate matter (PM2.5)-through multi-pollutant models for mixed effect of adjustment. Daily data (circulatory hospitalization and mortality) and hourly data (air pollutants and temperature) were collected for 24 Canadian cities for 2001-2012. We applied generalized additive over-dispersion Poisson regression models with 1, 2, or 3 pollutants for city-specific risks, and Bayesian hierarchical models for national risks. This study found little mixed effect of adjustment through multi-pollutant models (ozone and/or NO2 and/or PM2.5) for circulatory hospitalization or mortality in Canada for 2001-2012, indicating that the 1-pollutant model did not result in considerable under- or over-estimates. It seemed weak-to-moderate correlations among air pollutants did not change the significant effect of one air pollutant after accounting for others. Inconsistent findings between other previous studies and this study indicate the need of comparable study design for multi-pollutant effect analysis.

Short-term exposure to ambient particulate matter and mortality among HIV/AIDS patients: Case-crossover evidence from all counties of Hubei province, China

BACKGROUND

Human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) has been a worrisome public health problem in the world. However, evidence for associations between short-term exposure to particulate matter (PM) and mortality among HIV/AIDS patients is scarce.

METHODS

We collected daily death records in people with HIV/AIDS from all counties (N = 103) of Hubei province, China from 2018 to 2019. The county-level daily concentrations of PM₁, PM_2.5 and PM₁₀ in the same period were extracted from ChinaHighAirPollutants dataset. A time-stratified case-crossover design with conditional logistic regression analysis was performed to assess the associations between PM and mortality.

RESULTS

Each 1 μg/m³ increased in PM₁ corresponded with 0.89 % elevated in all-cause deaths (ACD) at lag 0-4 days. The largest effects of PM₁, PM_2.5 and PM₁₀ on AIDS-related deaths (ARD) were detected at lag 0-4 days, and PM₁ [percent changes in odds ratio: 2.51 % (95 % CIs: 0.82, 4.22)] appeared greater health hazards than PM_2.5 [1.24 % (95 % CIs: 0.33, 2.15)] as well as PM₁₀ [0.65 % (95 % CIs: 0.01, 1.30)]. In subgroup analyses, the significant associations of PM₁/PM_2.5 and ACD were only found in male and the cold season. We also observed the effects of PM₁ and PM₁₀ on ARD were significantly stronger (P for interaction <0.05) in males than females. In addition, we caught sight of HIV/AIDS patients aged over 60 years old were more susceptible to ARD caused by PM than younger population.

CONCLUSIONS

Our study suggested PM₁ was positively linked with the risk of ACD and ARD. Male patients with HIV/AIDS were more significantly susceptible to PM₁, PM_2.5 and PM₁₀. PM₁/PM_2.5 appeared stronger associations with ARD in HIV/AIDS patients aged over 60 years old and in the cold season.

Effect of ambient O3 on mortality due to circulatory and respiratory diseases in a high latitude city of northeast China

In recent years, O₃ pollution had been worsening in China and became a major challenge for human health. To evaluate the O₃ effects on circulatory and respiratory mortality in Harbin, a high latitude city of northeast China, we applied a time-series study from 2014 to 2016. After collecting data and adjusting for the effects of confounders, we built the generalized additive model to assess the associations between O₃ and mortality at different lag days. The results showed that an interquartile-range (IQR) increase in O₃ concentration corresponded to excess risk (ER) of 2.00% (95%CI: - 0.25-4.30%) for circulatory mortality at lag 0 and 8.02% (95%CI: 4.18-12.01%) for respiratory mortality at lag 2 days in the single-pollutant model. Stratified analysis showed that O₃ had a greater effect on females than on males. The effect of O₃ exposure on circulatory mortality was stronger during the warm period, while the opposite trend was founded for respiratory mortality. The sensitivity analysis showed that the effects of O₃ were relatively independent and the major results were robust.

Effect modification by sex for associations of fine particulate matter (PM2.5) with cardiovascular mortality, hospitalization, and emergency room visits: systematic review and meta-analysis

Particulate matter with aerodynamic diameter no larger than 2.5 μm (PM2.5) has been linked to cardiovascular diseases (CVDs) but evidence for vulnerability by sex remains unclear. We performed systematic review and meta-analysis to synthesize the state of scientific evidence on whether cardiovascular risks from PM2.5 differ for men compared to women. The databases Pubmed, Scopus, Embase, and GreenFILE were searched for studies published Jan. 1995 to Feb. 2020. Observational studies conducting subgroup analysis by sex for impacts of short-term or long-term exposure to PM2.5 on target CVDs were included. Data were independently extracted in duplicate and pooled with random-effects meta-regression. Risk ratios (RRs) for long-term exposure and percent changes in outcomes for short-term exposure were calculated per 10 μg/m3 PM2.5 increase. Quality of evidence of risk differences by sex was rated following Grading of Recommendations Assessment, Development and Evaluation (GRADE). A total of 12,502 articles were screened, with 61 meeting inclusion criteria. An additional 32 studies were added from citation chaining. RRs of all CVD mortality for long-term PM2.5 for men and women were the same (1.14; 95% CI: 1.09, 1.22) indicating no statistically different risks. Men and women did not have statistically different risks of daily CVD mortality, hospitalizations from all CVD, ischemic heart disease, cardiac arrest, acute myocardial infarction, and heart failure from short-term PM2.5 exposure (difference in % change in risk per 10 μg/m3 PM2.5: 0.04 (95% CI, -0.42 to 0.51); -0.05 (-0.47 to 0.38); 0.17 (-0.90, 1.24); 1.42 (-1.06, 3.97); 1.33 (-0.05, 2.73); and -0.48 (-1.94, 1.01), respectively). Analysis using GRADE found low or very low quality of evidence for sex differences for PM2.5-CVD risks. In conclusion, this meta-analysis and quality of evidence assessment of current observational studies found very limited evidence of the effect modification by sex for effects of PM2.5 on CVD outcomes in adults, which can inform clinical approaches and policies.

Mutual effects of fine particulate matter, nitrogen dioxide, and fireworks on cause-specific acute cardiovascular mortality: A case-crossover study in communities affected by aircraft noise

Ambient air pollution is the leading cause of environmental mortality and morbidity worldwide. However, the individual contributions to acute mortality of traffic-related air pollutants such as nitrogen dioxide (NO₂) and fine particulate matter (PM_2.5) are still debated. We conducted a time-stratified case-crossover study for a population located around Zurich airport in Switzerland, including 24,886 adult cardiovascular deaths from the Swiss National Cohort. We estimated the risk of cause-specific cardiovascular mortality associated with daily NO₂ and PM_2.5 concentrations at home using distributed lag models up to 7 days preceding death, adjusted for daily temperature, precipitation, acute night-time aircraft noise, firework celebrations, and holidays. Cardiovascular mortality was associated with NO₂, whereas the association with PM_2.5 disappeared upon adjustment for NO₂. The strongest association was observed between NO₂ and ischemic stroke mortality (odds ratio = 1.55 per 10 μg/m³, 95% confidence intervals = 1.20-2.00). Cause-specific mortality analyses showed differences in terms of delayed effect: odds ratios were highest at 1-3 days after exposure for most outcomes but at lags of 3-5 days for heart failure. Individual vulnerabilities to NO₂ associated cardiovascular mortality also varied by cause of death, possibly highlighting the role of different behaviours and risk factors in the most susceptible groups. The risk of cardiovascular mortality was also increased on firework days and after public holidays, independent from NO₂ and PM_2.5 concentrations. This study confirms the association between ambient NO₂, as a marker for primary emissions, and acute cardiovascular mortality in a specific setting around a major airport. Future research should clarify the role of additional air pollutants including ultra-fine particles on cardiovascular diseases to inform most efficient control measures.

Relationship between Air Pollution and Hospital Admissions for Chronic Obstructive Pulmonary Disease in Changchun, China: A Season-Stratified Case-Cross Study

Background

This study aimed to explore the relationship between air pollution and hospital admissions for COPD in Changchun, a northeast city of China, in different seasons.

Methods

The data on a total of 1,733 hospitalized patients living in Changchun with acute exacerbation of COPD from September 2013 to April 2018 were collected from a comprehensive 3A hospital of Changchun. Daily average concentrations of PM2.5, PM10, SO₂, NO₂, CO, and O₃ were collected from the Department of Ecology and Environment of Jilin Province. The conditional logistic regression model was adopted to analyze the effect of air pollutant concentration on the number of hospitalized patients with COPD in different seasons.

Results

The maximum OR value for most air pollutants emitted in spring was on lag day 4, in summer and autumn on lag day 3, and in winter on lag day 2. In spring, SO₂ and NO₂ were entered into the regression equation, and the OR (95%CI) was 0.992 (0.986-0.998) and 1.009 (1.002-1.017); in autumn, PM2.5, PM10, and SO₂ were entered into the regression equation, and the OR (95%CI) was 1.005 (1.000-1.011), 0.995 (0.991-1.000), and 1.006 (1.001-1.011), respectively; and in winter, PM2.5 and PM10 were entered into the regression equation, and the OR (95%CI) was 1.008 (1.002-1.015) and 0.994 (0.988-0.999), respectively.

Conclusion

The relationship between air pollution and hospital admission for COPD in Northeast China varies with different seasons. In spring, NO₂ is likely to be the major risk factor for hospital admissions for COPD; in autumn, PM2.5 and SO₂ are the major risk factors; and in winter, PM2.5 is the major risk factor.

WITHDRAWN: Health risk assessment and countermeasure analysis of the elderly population exposed to PM2.5 microenvironment

Ahead of Print article withdrawn by publisher.

The short-term effect of PM2.5/O3 on daily mortality from 2013 to 2018 in Hefei, China

This research intends to explore the short-term impacts of PM_2.5/O₃ on daily death in Hefei from 2013 to 2018. Data on daily death of Hefei residents, meteorological factors, and air pollutants were collected from Jan 1, 2013, to Dec 31, 2018. The correlation between PM_2.5/O₃ and daily death in Hefei during the research period was studied by time series analysis. From 2013 to 2018, there were 61,683 non-accidental deaths, including 27,431 cardiovascular deaths, 5587 respiratory deaths, 20,921 malignant tumor deaths, and 1674 diabetes deaths, in Hefei. Annual mean concentrations of PM_2.5, PM₁₀, NO₂, SO₂, CO, and O₃ in Hefei were 66.18, 92.37, 39.75, 15.39, 930, and 79.08 μg m^-3, respectively. An increase of 10 μg m^-3 in PM_2.5 was related with 0.53% (95% CI 0.31-0.75%), 0.93% (95% CI 0.60-1.26%), 0.90% and (95% CI 0.23-1.57%) increase in non-accidental, cardiovascular and respiratory diseases mortality, respectively. The association between ozone and mortality was not significant. In cold seasons, PM_2.5 had a stronger effect on the deaths resulting from non-accidental, cardiovascular, and respiratory diseases. The effect of O₃ on deaths was not significantly different between the cold season and the warm season. Women and the elders (over 65 years) were at high risk of being affected by PM_2.5/O₃. Short-term exposure to PM_2.5 was positively correlated with increased deaths due to non-accidental, cardiovascular and respiratory diseases in Hefei. Females and elders were more vulnerable to PM_2.5/O₃ exposure. No significant associations were observed between ozone and deaths from non-accidental, cardiovascular, respiratory, malignant tumors, and diabetes diseases.

Health disparities attributable to air pollutant exposure in North Carolina: Influence of residential environmental and social factors

Understanding the environmental justice implications of the mortality impacts of air pollution exposure is a public health priority, as some subpopulations may face a disproportionate health burden. We examined which residential environmental and social factors may affect disparities in the air pollution-mortality relationship in North Carolina, US, using a time-stratified case-crossover design. Results indicate that air pollution poses a higher mortality risk for some persons (e.g., elderly) than others. Our findings have implications for environmental justice regarding protection of those who suffer the most from exposure to air pollution and policies to protect their health.

Particulate Matter Mortality Rates and Their Modification by Spatial Synoptic Classification

Air pollution levels are highly correlated with temperature or humidity, so we investigated the relationship between PM₁₀ and the spatial synoptic classification (SSC) scheme on daily mortality, according to age group and season. Daily death data for 2000-2014 from Seoul, Korea, were acquired, and time-series analysis was applied with respect to season and to each of seven distinct SSC types: dry moderate (DM); dry polar (DP); dry tropical (DT); moist moderate (MM); moist polar (MP); moist tropical (MT); and transition (T). Modification effects were estimated for daily, non-accidental, cardiovascular, and respiratory mortality between PM₁₀ and SSC types. The following SSC-type-specific increased mortalities were observed, by cause of death: non-accidental mortality: DT (1.86%) and MT (1.86%); cardiovascular mortality: DT (2.83%) and MM (3.00%); respiratory mortality: MT (3.78%). Based on simplified weather types, increased PM₁₀ effects in non-accidental mortality rates were observed in dry (1.54%) and moist (2.32%) conditions among those aged 40-59 years and were detected regardless of conditions in other age groups: 60-74 (1.11%), 75-84 (1.55%), and 85+ (1.75%). The effects of particulate air pollution, by SSC, suggest the applicability of SSC to the comparison and understanding of acute effects of daily mortality based on weather type.