Ambient air pollution and cardiovascular emergency department visits

Diesel exhaust particles induce polarization state-dependent functional and transcriptional changes in human monocyte-derived macrophages

Macrophage populations exist on a spectrum between the proinflammatory M1 and proresolution M2 states and have demonstrated the ability to reprogram between them after exposure to opposing polarization stimuli. Particulate matter (PM) has been repeatedly linked to worsening morbidity and mortality following respiratory infections and has been demonstrated to modify macrophage function and polarization. The purpose of this study was to determine whether diesel exhaust particles (DEP), a key component of airborne PM, would demonstrate polarization state-dependent effects on human monocyte-derived macrophages (hMDMs) and whether DEP would modify macrophage reprogramming. CD14+CD16- monocytes were isolated from the blood of healthy human volunteers and differentiated into macrophages with macrophage colony-stimulating factor (M-CSF). Resulting macrophages were left unpolarized or polarized into the proresolution M2 state before being exposed to DEP, M1-polarizing conditions (IFN-γ and LPS), or both and tested for phagocytic function, secretory profile, gene expression patterns, and bioenergetic properties. Contrary to previous reports, we observed a mixed M1/M2 phenotype in reprogrammed M2 cells when considering the broader range of functional readouts. In addition, we determined that DEP exposure dampens phagocytic function in all polarization states while modifying bioenergetic properties in M1 macrophages preferentially. Together, these data suggest that DEP exposure of reprogrammed M2 macrophages results in a highly inflammatory, highly energetic subpopulation of macrophages that may contribute to the poor health outcomes following PM exposure during respiratory infections.NEW & NOTEWORTHY We determined that reprogramming M2 macrophages in the presence of diesel exhaust particles (DEP) results in a highly inflammatory mixed M1/M2 phenotype. We also demonstrated that M1 macrophages are particularly vulnerable to particulate matter (PM) exposure as seen by dampened phagocytic function and modified bioenergetics. Our study suggests that PM causes reprogrammed M2 macrophages to become a highly energetic, highly secretory subpopulation of macrophages that may contribute to negative health outcomes observed in humans after PM exposure.

Ambient carbon monoxide and the risk of cardiovascular disease emergency room visits: a time-series study in Lanzhou, China

Until now, the epidemiological evidence on the association between short-term exposure to ambient carbon monoxide (CO) and cardiovascular diseases (CVDs) is relatively lacking and controversial. This study aims to examine the relationship between ambient CO and daily emergency room visits (ERVs) for total and cause-specific CVD in Lanzhou, China. A distributed lag nonlinear model was used to examine the association. For every 1 mg/m3 increase in the CO concentration, the relative risks of daily ERVs were 1.041 (95% CI: 1.017, 1.065) for total CVD, 1.065 (95% CI: 1.018, 1.114) for ischemic heart disease (IHD), 1.083 (95% CI: 1.020, 1.149) for heart rhythm disturbances (HRD), 1.062 (95% CI: 1.011, 1.115) for heart failure (HF), and 1.057 (95% CI: 1.017, 1.098) for cerebrovascular diseases (CD). For the two different gender subgroups, the short-term impact of CO on total CVD, IHD, and CD was relatively stronger for the females than for the males, while the opposite was true for HRD and HF. In the age subgroup analyses, the effect of ambient CO on total CVD and IHD appeared to be greater for the age ≥ 65 years group, while the opposite was true for HRD, HF, and CD. The associations for all disease categories were stronger in cold seasons than in warm seasons. We also observed a nearly linear correlation between CO and CVD ERVs. In conclusion, the study showed that exposure to ambient CO may increase the risks of ERVs for total and cause-specific CVD. Besides, CO-ERVs associations may vary by gender and age.

Oxidized and Unsaturated: Key Organic Aerosol Traits Associated with Cellular Reactive Oxygen Species Production in the Southeastern United States

Exposure to ambient fine particulate matter (PM2.5) is associated with millions of premature deaths annually. Oxidative stress through overproduction of reactive oxygen species (ROS) is a possible mechanism for PM2.5-induced health effects. Organic aerosol (OA) is a dominant component of PM2.5 worldwide, yet its role in PM2.5 toxicity is poorly understood due to its chemical complexity. Here, through integrated cellular ROS measurements and detailed multi-instrument chemical characterization of PM in urban southeastern United States, we show that oxygenated OA (OOA), especially more-oxidized OOA, is the main OA type associated with cellular ROS production. We further reveal that highly unsaturated species containing carbon-oxygen double bonds and aromatic rings in OOA are major contributors to cellular ROS production. These results highlight the key chemical features of ambient OA driving its toxicity. As more-oxidized OOA is ubiquitous and abundant in the atmosphere, this emphasizes the need to understand its sources and chemical processing when formulating effective strategies to mitigate PM2.5 health impacts.

Association of Fine Particulate Matter Constituents with the Predicted 10-Year Atherosclerotic Cardiovascular Disease Risk: Evidence from a Large-Scale Cross-Sectional Study

Little is known concerning the associations of fine particulate matter (PM2.5) and its constituents with atherosclerotic cardiovascular disease (ASCVD). A total of 31,162 participants enrolled from the Henan Rural Cohort were used to specify associations of PM2.5 and its constituents with ASCVD. Hybrid machine learning was utilized to estimate the 3-year average concentration of PM2.5 and its constituents (black carbon [BC], nitrate [NO3-], ammonium [NH4+], inorganic sulfate [SO42-], organic matter [OM], and soil particles [SOIL]). Constituent concentration, proportion, and residual models were utilized to examine the associations of PM2.5 constituents with 10-year ASCVD risk and to identify the most hazardous constituent. The isochronous substitution model (ISM) was employed to analyze the substitution effect between PM2.5 constituents. We found that each 1 μg/m3 increase in PM2.5, BC, NH4+, NO3-, OM, SO42-, and SOIL was associated with a 3.5%, 49.3%, 19.4%, 10.5%, 21.4%, 14%, and 28.5% higher 10-year ASCVD risk, respectively (all p < 0.05). Comparable results were observed in proportion and residual models. The ISM found that replacing BC with other constituents will generate the greatest health benefits. The results indicated that long-term exposure to PM2.5 and its constituents were associated with increased risks of ASCVD, with BC being the most attributable constituent.

Effect of Air Pollution on Heart Failure: Systematic Review and Meta-Analysis

BACKGROUND

Heart failure (HF) poses a significant global disease burden. The current evidence on the impact of air pollution on HF remains inconsistent.

OBJECTIVES

We aimed to conduct a systematic review of the literature and meta-analysis to provide a more comprehensive and multiperspective assessment of the associations between short- and long-term air pollution exposure and HF from epidemiological evidences.

METHODS

Three databases were searched up to 31 August 2022 for studies investigating the association between air pollutants (PM 2.5 , PM 10 , NO 2 , SO 2 , CO, O 3 ) and HF hospitalization, incidence, or mortality. A random effects model was used to derive the risk estimations. Subgroup analysis was conducted by geographical location, age of participants, outcome, study design, covered area, the methods of exposure assessment, and the length of exposure window. Sensitivity analysis and adjustment for publication bias were performed to test the robustness of the results.

RESULTS

Of 100 studies covering 20 countries worldwide, 81 were for short-term and 19 were for long-term exposure. Almost all air pollutants were adversely associated with the risk of HF in both short- and long-term exposure studies. For short-term exposures, we found the risk of HF increased by 1.8% [relative risk ( RR ) = 1.018 , 95% confidence interval (CI): 1.011, 1.025] and 1.6% (RR = 1.016 , 95% CI: 1.011, 1.020) per 10 - μ g / m 3 increment of PM 2.5 and PM 10 , respectively. HF was also significantly associated with NO 2 , SO 2 , and CO, but not O 3 . Positive associations were stronger when exposure was considered over the previous 2 d (lag 0-1) rather than on the day of exposure only (lag 0). For long-term exposures, there were significant associations between several air pollutants and HF with RR (95% CI) of 1.748 (1.112, 2.747) per 10 - μ g / m 3 increment in PM 2.5 , 1.212 (1.010, 1.454) per 10 - μ g / m 3 increment in PM 10 , and 1.204 (1.069, 1.356) per 10 -ppb increment in NO 2 , respectively. The adverse associations of most pollutants with HF were greater in low- and middle-income countries than in high-income countries. Sensitivity analysis demonstrated the robustness of our results.

DISCUSSION

Available evidence highlighted adverse associations between air pollution and HF regardless of short- and long-term exposure. Air pollution is still a prevalent public health issue globally and sustained policies and actions are called for to reduce the burden of HF. https://doi.org/10.1289/EHP11506.

Association Between the Incidence of Hospitalizations for Acute Cardiovascular Events, Weather, and Air Pollution

Background

The incidence of hospitalizations for cardiovascular events has been associated with specific weather conditions and air pollution. A comprehensive model including the interactions between various environmental factors remains to be developed.

Objectives

The purpose of this study was to develop a comprehensive model of the association between weather patterns and the incidence of cardiovascular events and use this model to forecast near-term spatiotemporal risk.

Methods

We present a spatiotemporal analysis of the association between atmospheric data and the incidence rate of hospital admissions related to heart failure (922,132 episodes), myocardial infarction (521,988 episodes), and ischemic stroke (263,529 episodes) in ∼24 million people in Canada between 2007 and 2017. Our hierarchical Bayesian model captured the spatiotemporal distribution of hospitalizations and identified weather and air pollution-related factors that could partially explain fluctuations in incidence.

Results

Models that included weather and air pollution variables outperformed models without those covariates for most event types. Our results suggest that environmental factors may interact in complex ways on human physiology. The impact of environmental factors was magnified with increasing age. The weather and air pollution variables included in our models were predictive of the future incidence of heart failure, myocardial infarction, and ischemic strokes.

Conclusions

The increasing importance of environmental factors on cardiovascular events with increasing age raises the need for the development of educational materials for older patients to recognize environmental conditions where exacerbations are more likely. This model could be the basis of a forecasting system used for local, short-term clinical resource planning based on the anticipated incidence of events.

Association between short-term exposure to ambient air pollution and heart failure: An updated systematic review and meta-analysis of more than 7 million participants

Introduction

Exposure to air pollution has been linked to the mortality of heart failure. In this study, we sought to update the existing systematic review and meta-analysis, published in 2013, to further assess the association between air pollution and acute decompensated heart failure, including hospitalization and heart failure mortality.

Methods

PubMed, Web of Science, EMBASE, and OVID databases were systematically searched till April 2022. We enrolled the studies regarding air pollution exposure and heart failure and extracted the original data to combine and obtain an overall risk estimate for each pollutant.

Results

We analyzed 51 studies and 7,555,442 patients. Our results indicated that heart failure hospitalization or death was associated with increases in carbon monoxide (3.46% per 1 part per million; 95% CI 1.0233-1.046, P < 0.001), sulfur dioxide (2.20% per 10 parts per billion; 95% CI 1.0106-1.0335, P < 0.001), nitrogen dioxide (2.07% per 10 parts per billion; 95% CI 1.0106-1.0335, P < 0.001), and ozone (0.95% per 10 parts per billion; 95% CI 1.0024-1.0166, P < 0.001) concentrations. Increases in particulate matter concentration were related to heart failure hospitalization or death (PM_2.5 1.29% per 10 μg/m³, 95% CI 1.0093-1.0165, P < 0.001; PM₁₀ 1.30% per 10 μg/m³, 95% CI 1.0102-1.0157, P < 0.001).

Conclusion

The increase in the concentration of all pollutants, including gases (carbon monoxide, sulfur dioxide, nitrogen dioxide, ozone) and particulate matter [(PM_2.5), (PM₁₀)], is positively correlated with hospitalization rates and mortality of heart failure.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42021256241.

Evaluating health outcome metrics and their connections to air pollution and vulnerability in Southern California's Coachella Valley

The ongoing desiccation of California's Salton Sea has led to increasing concerns about air quality and health for its surrounding communities, including the nearby Coachella Valley - a region already experiencing severe air quality and health disparities. Here we explore spatial air pollution and human health disparities in the Coachella Valley with particular attention to disparities arising across population characteristics including both socioeconomic and demographic vulnerabilities. We use two different measures of respiratory and cardiovascular health outcomes at the individual and census tract levels - one measure based on a randomly sampled telephone survey and the other measure based on emergency room visitation data - to investigate the degree to which these health outcomes are connected to air pollution and socioeconomic metrics. We further investigate biases and differences between the health outcome metrics themselves and suggest opportunities to address them in future analyses and survey efforts. We find that more vulnerable communities are associated with higher levels of fine particulates, but lower levels of ozone. While emergency visit rates show a significant positive correlation with both pollutants, no such association is found when using surveyed health outcome data. The ratio of emergency visits versus survey rates shows a positive relationship with socioeconomic and demographic vulnerability, indicating that vulnerable communities are less likely to self-report diagnoses despite higher rates of respiratory or cardiovascular hospitalization. Additionally, survey respondents tend to show less vulnerability relative to their surrounding census-based demographics. These findings suggest the need for greater attention to health issues specifically within disadvantaged communities in the Coachella Valley, building upon and working within existing community networks and local resources, to better address current and projected health needs. Our findings also highlight disparities in air pollution exposure, health outcomes, and population characteristics in the Coachella Valley, providing context for crucial pollution reduction efforts in the face of increasing environmental threats.

Is short-term and long-term exposure to black carbon associated with cardiovascular and respiratory diseases? A systematic review and meta-analysis based on evidence reliability

OBJECTIVE

Adverse health effects of fine particles (particulate matter_2.5) have been well documented by a series of studies. However, evidences on the impacts of black carbon (BC) or elemental carbon (EC) on health are limited. The objectives were (1) to explored the effects of BC and EC on cardiovascular and respiratory morbidity and mortality, and (2) to verified the reliability of the meta-analysis by drawing p value plots.

DESIGN

The systematic review and meta-analysis using adapted Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach and p value plots approach.

DATA SOURCES

PubMed, Embase and Web of Science were searched from inception to 19 July 2021.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Time series, case cross-over and cohort studies that evaluated the associations between BC/EC on cardiovascular or respiratory morbidity or mortality were included.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently selected studies, extracted data and assessed risk of bias. Outcomes were analysed via a random effects model and reported as relative risk (RR) with 95% CI. The certainty of evidences was assessed by adapted GRADE. The reliabilities of meta-analyses were analysed by p value plots.

RESULTS

Seventy studies met our inclusion criteria. (1) Short-term exposure to BC/EC was associated with 1.6% (95% CI 0.4% to 2.8%) increase in cardiovascular diseases per 1 µg/m³ in the elderly; (2) Long-term exposure to BC/EC was associated with 6.8% (95% CI 0.4% to 13.5%) increase in cardiovascular diseases and (3) The p value plot indicated that the association between BC/EC and respiratory diseases was consistent with randomness.

CONCLUSIONS

Both short-term and long-term exposures to BC/EC were related with cardiovascular diseases. However, the impact of BC/EC on respiratory diseases did not present consistent evidence and further investigations are required.

PROSPERO REGISTRATION NUMBER

CRD42020186244.

Short term exposure to ambient air pollutants and cardiovascular emergency department visits in Mexico city

Available data on the acute cardiovascular effect of ambient air pollution (AAP) in Latin America is limited considering that over 80% of its 1 billion inhabitants live in urban settlements with poor air quality. The study aim was to evaluate the association between Cardiovascular Emergency Department Visits (CEDVs) and AAP in Mexico City from 2016 to 2019 using generalized additive models with distributed lags to examine the percentage change of CEDVs and a backward approach of time-series model to calculate attributable fractions. A total of 48,891 CEDVs were recorded in a period of 1019 days. We estimated a significant percentage increase for each 10 μg/m³ of PM₁₀ at Lag0-5 (2.8%, 95%CI 0.6-5.0), PM_2.5 at Lag0-6 (3.7%, 95%CI 0.1-7.6), O₃ at Lag0-5 (1.1%, 95%CI 0.2-2.0), NO₂ at Lag0-4 (2.5%, 95%CI 0.3-4.7) and for each 1 mg/m³ of CO at Lag0 (6.6%, 95%CI 0.3-13.2). Overall, 10.3% of CEDVs in Mexico City may be related to PM¹⁰ exposure, 9.5% to PM_2.5, 10.3% to O₃, 11% to NO₂ and 5.7% to CO. AAP significantly increase cardiovascular morbidity impacting on emergency medical services.

Ambient PM Concentrations as a Precursor of Emergency Visits for Respiratory Complaints: Roles of Deep Learning and Multi-Point Real-Time Monitoring

Despite ample evidence that high levels of particulate matter (PM) are associated with increased emergency visits related to respiratory diseases, little has been understood about how prediction processes could be improved by incorporating real-time data from multipoint monitoring stations. While previous studies use traditional statistical models, this study explored the feasibility of deep learning algorithms to improve the accuracy of predicting daily emergency hospital visits by tracking their spatiotemporal association with PM concentrations. We compared the predictive accuracy of the models based on PM datasets collected between 1 December 2019 and 31 December 2021 from a single but more accurate air monitoring station in each district (Air Korea) and multiple but less accurate monitoring sites (Korea Testing & Research Institute; KTR) within Guro District in Seoul, South Korea. We used MLP (multilayer perceptron) to integrate PM data from multiple locations and then LSTM (long short-term memory) models to incorporate the intrinsic temporal PM trends into the learning process. The results reveal evidence that predictive accuracy is improved from 1.67 to 0.79 in RMSE when spatial variations of air pollutants from multi-point stations are incorporated in the algorithm as a 9-day time window. The findings suggest guidelines on how environmental and health policymakers can arrange limited resources for emergency care and design ambient air monitoring and prevention strategies.

Reduced Emergency Department Utilization During the Early Phase of the COVID-19 Pandemic: Viral Fear or Lockdown Effect?

OBJECTIVE

Since the beginning of the coronavirus disease (COVID-19) pandemic, several frontline workers have expressed their concerns about reduced emergency department (ED) utilization. We aimed to examine the changes in ED utilization during the early phase of the COVID-19 pandemic, in a country with a well-developed primary care system.

METHODS

A retrospective analysis of ED utilization was performed in 3 Dutch hospitals during a 60-day period, starting on February 15, 2020. The identical period in 2019 was used as a reference. ED visits were labeled as COVID-related (defined as COVID-19 suspected) or non-COVID-related. Admission rates were compared using chi-square tests, and the reduction in ED visits was assessed descriptively.

RESULTS

During the study period, daily ED volume was 18% lower compared to that of 2019. ED utilization further declined (-29%) during lockdown. Combined admission rates were higher in 2020 compared to those in 2019 (P < 0.001), and they were higher for COVID-19 versus non-COVID-19 ED visits (P < 0.001).

CONCLUSIONS

ED utilization was markedly reduced during the local rise of COVID-19 in a region with a well-developed primary care system and relatively low ED self-referral rates. Although it cannot directly be concluded from the findings of our study, this observation likely reflects a complex interaction between pure lockdown effects and viral fear, which warrants further research.

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

Apart from concentrations of particulate mass, PM_2.5-associated effects on health may largely depend on its chemical components. However, little is known regarding the underlying effects of specific PM_2.5 constituents. The study included nearly 1 million hospital admissions from five Chinese cities during 2015-2017. Based on the modified Community Multiscale Air Quality model, our study simulated daily concentrations of PM_2.5 and five main components. We used a time-stratified case-crossover design with conditional logistic regression models to estimate short-term effects of PM_2.5 constituents on cause-specific hospital admissions. Per interquartile range increase in exposure to PM_2.5, elemental carbon, organic carbon, nitrate, sulfate and ammonium at lag 04-day was related to an excess risk (ER%) for non-accidental admissions of 1.6% [95% confidence interval: 1.1-2.0], 1.9% [1.3-2.4], 1.0% [0.5-1.6], 1.2% [0.4-2.0], 1.2% [0.9-1.5] and 1.4% [0.9-1.9], respectively. Great heterogeneities of constituents-admission associations existed in diverse causes and constituents. This study provided multi-center high-quality evidence that hospital admissions, particularly those for ischemic heart disease (ER% ranging from 2.3 to 5.4% at lag 04-day) and pneumonia (1.9-5.1% at lag 4-day), could be triggered by short-term exposures to ambient PM_2.5 constituents. Relatively stronger constituents-admission associations were found among females for respiratory causes and the elderly for cardiovascular causes.

The Adverse Impact of the COVID-19 Pandemic on Abdominal Emergencies: A Retrospective Clinico-Pathological Analysis

The COVID-19 pandemic has caused a worldwide significant drop of admissions to the emergency department (ED). The aim of the study was to retrospectively investigate the pandemic impact on ED admissions, management, and severity of three abdominal emergencies (appendicitis, diverticulitis, and cholecystitis) during the COVID-19 pandemic using 2017–2019 data as a control. The difference in clinical and pathological disease severity was the primary outcome measure while differences in (i) ED admissions, (ii) triage urgency codes, and (iii) surgical rates were the second ones. Overall, ED admissions for the selected conditions decreased by 34.9% during the pandemic (control: 996, 2020: 648) and lower triage urgency codes were assigned for cholecystitis (control: 170/556, 2020: 66/356, p < 0.001) and appendicitis (control: 40/178, 2020: 21/157, p = 0.031). Less surgical procedures were performed in 2020 (control: 447, 2020: 309), but the surgical rate was stable (47.7% in 2020 vs. 44.8% in 2017–2019). Considering the clinical and pathological assessments, a higher percentage of severe cases was observed in the four pandemic peak months of 2020 (control: 98/192, 2020: 87/109; p < 0.001 and control: 105/192, 2020: 87/109; p < 0.001). For the first time in this study, pathological findings objectively demonstrated an increased disease severity of the analyzed conditions during the early COVID-19 pandemic.

Emergency hospital admissions for cardiovascular diseases attributed to air pollution in Tehran during 2016-2019

The burden of five main air pollutants, including CO, O3, NO2, SO2, and PM2.5, on the emergency department visits (EDVs) during January 2016-December 2019 due to all cardiovascular diseases was assessed in Tehran by using a time-series model. The pollutants data were collected from Iran Department of Environment including 10 air pollution monitoring stations for the period of our study. Cumulative relative risk and attributable number/fraction were calculated for each pollutants by a Quasi-Poisson time-series regression and distributed lag non-linear model (DLNM). The maximum lag was set to 14 days because harvesting effect is more likely happened during few days. We used percentile 25 as reference value in order to calculate cumulative relative risk and attributable fraction. About 69,000 patients with cardiovascular symptoms have been admitted into the hospital during 4 years. The cumulative relative risk during the 14 days was 1.13 (1.01, 1.26), 1.15 (1.02, 1.29), and 1.08 (1.01, 1.18) for CO, NO2, and PM2.5, respectively. The numbers attributed to all values of CO were more than others; about 3800 EDVs were significantly attributed to CO, of which over 3000 were significantly attributed to high values of the pollutant. Low values of all pollutants were, not surprisingly, responsible for low number of EDVs. PM2.5, CO, and NO2 were responsible to considerable attributable number of EDVs. Our study emphasizes the need for local authorities to establish a program to reduce the air pollution in Tehran.

Impact of national lockdown towards emergency department visits and admission rates during the COVID-19 pandemic in Thailand: A hospital-based study

OBJECTIVE

To evaluate the impact of the national lockdown because of the 2019 coronavirus (COVID-19) pandemic towards the ED visits and admission rates in Thailand.

METHODS

We retrospectively reviewed the electronic medical database of patients presenting to the ED during the national lockdown period (from 26 March to 30 June 2020). We used the same time interval in the year 2019 as the control period in our analysis. We collected baseline characteristics and outcomes of each patient in the ED. The primary outcome was the incidence rate ratio (IRR) with a 95% confidence interval (CI) of the average daily ED visits. Secondary outcomes included the IRR with 95% CI of total admissions and intensive care unit (ICU) admissions.

RESULTS

The average number of daily ED visits decreased significantly from 89.1 to 57.0 (-36.0%, IRR 0.69, 95% CI 0.67-0.70). However, the proportions of 'Resuscitation' and 'Emergency' triage level were increased (29.1% vs 19.2%, P < 0.001). Total ED admission rate and ICU admission rate were also increased (33.5% vs 28.3%, P < 0.001 and 10.2% vs 7.5%, P < 0.001, respectively). The IRR for the admission rate was 1.18 (95% CI 1.11-1.26), and the IRR for the ICU admission rate was 1.35 (95% CI 1.21-1.52).

CONCLUSION

The national lockdown in Thailand was associated with a significant reduction in average daily ED visits across traumatic and non-traumatic patients. Communication from healthcare professionals and public health officers is necessary to reinforce the importance of timely ED visits for acute health conditions.

Systemic Inflammation (C-Reactive Protein) in Older Chinese Adults Is Associated with Long-Term Exposure to Ambient Air Pollution

There is an established association between air pollution and cardiovascular disease (CVD), which is likely to be mediated by systemic inflammation. The present study evaluated links between long-term exposure to ambient air pollution and high-sensitivity C reactive protein (hs-CRP) in an older Chinese adult cohort (n = 7915) enrolled in the World Health Organization (WHO) study on global aging and adult health (SAGE) China Wave 1 in 2008–2010. Multilevel linear and logistic regression models were used to assess the associations of particulate matter (PM) and nitrogen dioxide (NO₂) on log-transformed hs-CRP levels and odds ratios of CVD risk derived from CRP levels adjusted for confounders. A satellite-based spatial statistical model was applied to estimate the average community exposure to outdoor air pollutants (PM with an aerodynamic diameter of 10 μm or less (PM₁₀), 2.5 μm or less (PM_2.5), and 1 μm or less (PM₁) and NO₂) for each participant of the study. hs-CRP levels were drawn from dried blood spots of each participant. Each 10 μg/m³ increment in PM₁₀, PM_2.5, PM₁, and NO₂ was associated with 12.8% (95% confidence interval; (CI): 9.1, 16.6), 15.7% (95% CI: 10.9, 20.8), 10.2% (95% CI: 7.3, 13.2), and 11.8% (95% CI: 7.9, 15.8) higher serum levels of hs-CRP, respectively. Our findings suggest that air pollution may be an important factor in increasing systemic inflammation in older Chinese adults.

Time-Resolved Single-Cell Assay for Measuring Intracellular Reactive Oxygen Species upon Exposure to Ambient Particulate Matter

Health risks associated with exposure to ambient particulate matter (PM) are a major concern around the world. Adverse PM health effects have been proposed to be linked to oxidative stress through the generation of reactive oxygen species (ROS). In vitro cellular assays can provide insights into components or characteristics of PM that best account for its toxicity at a cellular level. However, most current assays report cell population averages and are mostly time endpoint measurements and thus provide no temporal information. This poses limitations on our understanding of PM health effects. In this study, we developed a microfluidic assay that can measure cellular ROS responses at the single-cell level and evaluate temporal dynamic behavior of single cells. We first established a protocol that enables culturing cells in our microfluidic platform and that can provide reproducible ROS readouts. We further examined the heterogeneous ROS responses of cell populations and tracked the dynamics of individual cellular responses upon exposure to different concentrations of PM extracts. Our results show that in an alveolar macrophage cell line, cellular ROS responses are highly heterogeneous. ROS responses from different cells can vary over an order of magnitude, and large coefficients of variation at each timepoint measurement indicate a high variability. The dynamic behavior of single-cell responses is strongly dependent on PM concentrations. Our work serves as a proof-of-principle demonstration of the capability of our microfluidic technology to study time-resolved single-cell responses upon PM exposure. We envision applying this high-resolution, high-content assay to investigate a wide array of single-cell responses (beyond ROS) upon exposure to different types of PM in the future.

Atmospheric fine particulate matter and epithelial mesenchymal transition in pulmonary cells: state of the art and critical review of the in vitro studies

Exposure to fine particulate matter (PM_2.5) has been associated with several diseases including asthma, chronic obstructive pulmonary disease (COPD) and lung cancer. Mechanisms such as oxidative stress and inflammation are well-documented and are considered as the starting point of some of the pathological responses. However, a number of studies also focused on epithelial-mesenchymal transition (EMT), which is a biological process involved in fibrotic diseases and cancer progression notably via metastasis induction. Up until now, EMT was widely reported in vivo and in vitro in various cell types but investigations dealing with in vitro studies of PM_2.5 induced EMT in pulmonary cells are limited. Further, few investigations combined the necessary endpoints for validation of the EMT state in cells: such as expression of several surface, cytoskeleton or extracellular matrix biomarkers and activation of transcription markers and epigenetic factors. Studies explored various cell types, cultured under differing conditions and exposed for various durations to different doses. Such unharmonized protocols (1) might introduce bias, (2) make difficult comparison of results and (3) preclude reaching a definitive conclusion regarding the ability of airborne PM_2.5 to induce EMT in pulmonary cells. Some questions remain, in particular the specific PM_2.5 components responsible for EMT triggering. The aim of this review is to examine the available PM_2.5 induced EMT in vitro studies on pulmonary cells with special emphasis on the critical parameters considered to carry out future research in this field. This clarification appears necessary for production of reliable and comparable results.

Acute effects of short-term exposure to air pollution while being physically active, the potential for modification: A review of the literature

The science behind the combined effect of (and possible interaction between) physical activity and air pollution exposure on health endpoints is not well established, despite the fact that independent effects of physical activity and air pollution on health are well known. The objective of this review is to systematically assess the available literature pertaining to exposure to air pollution while being physically active, in order to assess statistical interaction. Articles published during 2000-2020 were identified by searching PubMed, Science Direct, and ProQuest Agricultural & Environmental Science Database for terms encompassing air pollution and exercise/physical activity. Articles were included if they examined the following four scenarios: at rest in clean air, physical activity in clean air, at rest in polluted air, and physical activity in polluted air. Risk of bias assessment was performed on all included articles. We identified 25 articles for inclusion and determined risk of bias was low to moderate. Nine articles identified evidence of statistical interaction between air pollution exposure and physical activity, while 16 identified no such interaction. However, pollutant levels, exercise intensity, and the population studied appeared to influence statistical interaction. Even in low levels of air pollution, low-intensity activities (i.e., walking), may intensify the negative impacts of air pollution, particularly among those with pre-existing conditions. However, among healthy adults, the review suggests that exercise is generally beneficial even in high air pollution environments. Particularly, the review indicates that moderate to high-intensity exercise may neutralize any short-term negative effects of air pollution.

Assessment of the Impact of PM2.5 Exposure on the Daily Mortality of Circulatory System in Shijiazhuang, China

Air pollution can increase the morbidity and mortality of cardiovascular and cerebrovascular diseases, but there are few related studies in counties and cities with serious pollution in China. China is at a critical stage of environmental pollution control. Assessing the health impact of PM2.5 (particulate matter with a diameter equal or lower than 2.5 micrometers) on the death toll from cardiovascular and cerebrovascular diseases in heavily polluted counties and cities is of great importance to the formulation of air defense policies related to PM 2.5. Generalized additive models (GAMs) were used to analyze the effects of PM2.5 exposure on the death toll of circulatory system diseases in 16 districts, counties and cities in Shijiazhuang from 2014 to 2016 after controlling the long-term trend of the time series, seasonal effects, holiday effects, air temperature, relative humidity and other factors. The average PM2.5 concentration was 121.2 ± 96.6 μg/m3; during the corresponding period, the daily mean mortality of circulatory system diseases in Shijiazhuang was 4.6 ± 4.7. With the increase of PM2.5 by 10 μg/m3, the risk of total death from circulatory system diseases with a lag of two days (lag02) increased by 3.3‰ (95% confidence interval (CI): 1.0025, 1.0041). The relative risk (RR) of the effect of PM2.5 exposure on the death toll of the circulatory system in Shijiazhuang is consistent with the spatial distribution of the PM2.5 concentration and the mortality of circulatory system diseases: the RR of the eastern plain with heavy pollution and a relatively dense population is high, while the RR of the western mountainous area with relatively light pollution and a relatively sparse population is low. For every 10-μg/m3 increase of PM2.5, the risk of the increasing death toll from circulatory system diseases in Luancheng of the eastern plain is the highest at 11.9‰ (95% CI: 1.0071, 1.0168), while the RR of Pingshan of the western mountainous area is the lowest at 2.1‰ (95% CI: 0.9981, 1.0062). Conclusions: Based on the epidemiological analysis and GAMs model, after controlling for other confounding factors, PM2.5 exposure increased the death risk of the circulatory system in Shijiazhuang, and the risk is higher in heavily polluted plain areas. It provides a scientific basis for formulating scientific air pollution prevention and control policies and provides a reference for improving the prevention awareness of sensitive groups.

Source-Apportioned PM2.5 and Cardiorespiratory Emergency Department Visits: Accounting for Source Contribution Uncertainty

BACKGROUND

Despite evidence suggesting that air pollution-related health effects differ by emissions source, epidemiologic studies on fine particulate matter (PM2.5) infrequently differentiate between particles from different sources. Those that do rarely account for the uncertainty of source apportionment methods.

METHODS

For each day in a 12-year period (1998-2010) in Atlanta, GA, we estimated daily PM2.5 source contributions from a Bayesian ensemble model that combined four source apportionment methods including chemical transport and receptor-based models. We fit Poisson generalized linear models to estimate associations between source-specific PM2.5 concentrations and cardiorespiratory emergency department visits (n = 1,598,117). We propagated uncertainty in the source contribution estimates through analyses using multiple imputation.

RESULTS

Respiratory emergency department visits were positively associated with biomass burning and secondary organic carbon. For a 1 µg/m increase in PM2.5 from biomass burning during the past 3 days, the rate of visits for all respiratory outcomes increased by 0.4% (95% CI 0.0%, 0.7%). There was less evidence for associations between PM2.5 sources and cardiovascular outcomes, with the exception of ischemic stroke, which was positively associated with most PM2.5 sources. Accounting for the uncertainty of source apportionment estimates resulted, on average, in an 18% increase in the standard error for rate ratio estimates for all respiratory and cardiovascular emergency department visits, but inflation varied across specific sources and outcomes, ranging from 2% to 39%.

CONCLUSIONS

This study provides evidence of associations between PM2.5 sources and some cardiorespiratory outcomes and quantifies the impact of accounting for variability in source apportionment approaches.

Time-series analysis of ambient PM2.5 and cardiorespiratory emergency room visits in Lima, Peru during 2010-2016

INTRODUCTION

There have been no time-series studies of air pollution in Peru. Here we evaluate the effect of ambient PM_2.5 on emergency room (ER) visits in Lima.

METHODS

We estimated daily PM_2.5 levels at a 1 km² resolution during 2010-2016 using ground measurements, satellite data, and chemical transport model simulations. Population-weighted average daily PM_2.5 levels were calculated for each district in Lima (n = 40), and assigned to patients based on residence. ER visits for respiratory and circulatory diseases were gathered from nine large public hospitals. Poisson regression was used to estimate the rate ratio for daily ER visits with change in daily PM_2.5, controlling for meteorology, time trends, and district.

RESULTS

For each interquartile range (IQR) increase in PM_2.5, respiratory disease ER visits increased 4% (95% CI: 0-5%), stroke visits 10% (3-18%), and ischemic heart disease visits (adults, 18-64 years) 11% (-1, 24%). Districts with higher poverty showed significantly stronger associations of PM_2.5 and respiratory disease ER visits than districts with lower poverty. Effects were diminished 24-42% using Lima-wide instead of district-specific PM_2.5 levels.

CONCLUSIONS

Short-term exposure to ambient PM_2.5 is associated with increases in ER visits in Lima for respiratory diseases and stroke, and among middle-aged adults, ischemic heart disease.

Developmental Origins of Health and Disease: Impact of environmental dust exposure in modulating microbiome and its association with non-communicable diseases

Non-communicable diseases (NCDs) including obesity, diabetes, and allergy are chronic, multi-factorial conditions that are affected by both genetic and environmental factors. Over the last decade, the microbiome has emerged as a possible contributor to the pathogenesis of NCDs. Microbiome profiles were altered in patients with NCDs, and shift in microbial communities was associated with improvement in these health conditions. Since the genetic component of these diseases cannot be altered, the ability to manipulate the microbiome holds great promise for design of novel therapies in the prevention and treatment of NCDs. Together, the Developmental Origins of Health and Disease concept and the microbial hypothesis propose that early life exposure to environmental stimuli will alter the development and composition of the human microbiome, resulting in health consequences. Recent studies indicated that the environment we are exposed to in early life is instrumental in shaping robust immune development, possibly through modulation of the human microbiome (skin, airway, and gut). Despite much research into human microbiome, the origin of their constituent microbiota remains unclear. Dust (also known as particulate matter) is a key determinant of poor air quality in the modern urban environment. It is ubiquitous and serves as a major source and reservoir of microbial communities that modulates the human microbiome, contributing to health and disease. There are evidence that reported significant associations between environmental dust and NCDs. In this review, we will focus on the impact of dust exposure in shaping the human microbiome and its possible contribution to the development of NCDs.

Hourly association between ambient PM2.5 and emergency ambulance dispatches in 11 cities in Japan

Numerous epidemiological studies have demonstrated that short-term exposure to ambient PM_2.5 increases mortality and morbidity. Investigating the association using hourly ambient PM_2.5 exposure may provide important insights, as current evidence is limited mostly to daily lag term. This study aimed to investigate the hourly association between ambient PM_2.5 concentrations and all-cause emergency ambulance dispatches (EAD) in 11 cities in Japan. We used a time-stratified case-crossover design and examined the hourly lags of ambient PM_2.5 up to 24 h (unconditional distributed lags and moving average lags) using a conditional Poisson regression model. A significant increase in all-cause EAD was observed at lag 0 h [relative risk (RR): 1.0037 (95% CI: 1.0000, 1.0074)] and all moving average lags. The highest RR was observed within the first 6 h (at lag 0-5 h) [RR: 1.0091 (95% CI: 1.0068, 1.0114)], with a slight ascending pattern. This was followed by a descending pattern at lags 0-11, 0-17, and 0-23 h, but significant positive RR was observed even at lag 0-23 h, when the lowest RR was observed [RR: 1.0072 (95% CI: 1.0044, 1.0100)]. Though similar pattern was observed among the elderly, a different pattern was observed among the children (gradually ascending pattern). We conclude that all-cause EAD could be triggered by ambient PM_2.5 exposure with very short lags.

Identification of ambient fine particulate matter components related to vascular dysfunction by analyzing spatiotemporal variations

Exposure to ambient fine particulate matter (PM_2.5) has been associated with vascular diseases in epidemiological studies. We have demonstrated previously that exposure to ambient PM_2.5 caused pulmonary vascular remodeling in mice and increased vascular smooth muscle cells (VSMCs) viability. Here, we further demonstrated that exposure of mice to ambient PM_2.5 increased urinary 8‑hydroxy‑2'‑deoxyguanosine (8-OHdG) and cytokines concentrations in the broncheoalveolar lavage. The objective of the present study was to identify the PM_2.5 components related to vascular dysfunction. Exposure to PM_2.5 collected from various areas and seasons in Taiwan significantly increased viability, oxidative stress, and inflammatory cytokines secretion in VSMCs. The mass concentrations of benz[a]anthracene (BaA), benzo[e]pyrene (BeP), perylene, dibenzo[a,e]pyrene, molybdenum, zinc (Zn), vanadium (V), and nickel in the PM_2.5 were significantly associated with increased viability of VSMCs. These components, except BaA and BeP, also were significantly associated with chemokine (CC motif) ligand 5 (CCL5) concentrations in the VSMCs. The effects of V and Zn on cell viability and CCL5 expression, respectively, were verified. In addition, the mass concentrations of sulfate and manganese (Mn) in PM_2.5 were significantly correlated with increased oxidative stress; this correlation was also confirmed. After extraction, the inorganic fraction of PM_2.5 increased cell viability and oxidative stress, but the organic fraction of PM_2.5 increased only cell viability, which was inhibited by an aryl hydrocarbon receptor antagonist. These data suggest that controlling the emission of Zn, V, Mn, sulfate, and PAHs may prevent the occurrence of PM_2.5-induced vascular diseases.

Systematic review and meta-analysis of case-crossover and time-series studies of short term outdoor nitrogen dioxide exposure and ischemic heart disease morbidity

BACKGROUND

Nitrogen dioxide (NO₂) is a pervasive urban pollutant originating primarily from vehicle emissions. Ischemic heart disease (IHD) is associated with a considerable public health burden worldwide, but whether NO₂ exposure is causally related to IHD morbidity remains in question. Our objective was to determine whether short term exposure to outdoor NO₂ is causally associated with IHD-related morbidity based on a synthesis of findings from case-crossover and time-series studies.

METHODS

MEDLINE, Embase, CENTRAL, Global Health and Toxline databases were searched using terms developed by a librarian. Screening, data extraction and risk of bias assessment were completed independently by two reviewers. Conflicts between reviewers were resolved through consensus and/or involvement of a third reviewer. Pooling of results across studies was conducted using random effects models, heterogeneity among included studies was assessed using Cochran's Q and I² measures, and sources of heterogeneity were evaluated using meta-regression. Sensitivity of pooled estimates to individual studies was examined using Leave One Out analysis and publication bias was evaluated using Funnel plots, Begg's and Egger's tests, and trim and fill.

RESULTS

Thirty-eight case-crossover studies and 48 time-series studies were included in our analysis. NO₂ was significantly associated with IHD morbidity (pooled odds ratio from case-crossover studies: 1.074 95% CI 1.052-1.097; pooled relative risk from time-series studies: 1.022 95% CI 1.016-1.029 per 10 ppb). Pooled estimates for case-crossover studies from Europe and North America were significantly lower than for studies conducted elsewhere. The high degree of heterogeneity among studies was only partially accounted for in meta-regression. There was evidence of publication bias, particularly for case-crossover studies. For both case-crossover and time-series studies, pooled estimates based on multi-pollutant models were smaller than those from single pollutant models, and those based on older populations were larger than those based on younger populations, but these differences were not statistically significant.

CONCLUSIONS

We concluded that there is a likely causal relationship between short term NO₂ exposure and IHD-related morbidity, but important uncertainties remain, particularly related to the contribution of co-pollutants or other concomitant exposures, and the lack of supporting evidence from toxicological and controlled human studies.

Ambient air pollution and sickle cell disease-related emergency department visits in Atlanta, GA

BACKGROUND

Sickle cell disease (SCD) is an inherited, autosomal recessive blood disorder, among the most prevalent genetic diseases, globally. While the genetic and hemolytic dynamics of SCD have been well-characterized, the etiology of SCD-related pathophysiological processes is unclear. Although limited, observational evidence suggests that environmental factors, including urban air pollution, may play a role.

OBJECTIVES

We assessed whether daily ambient air pollution concentrations are associated with corresponding emergency department (ED) visit counts for acute SCD exacerbations in Atlanta, Georgia, during a 9-year (2005-2013) period. We also examined heterogeneity in response by age and sex.

METHODS

ED visit data were from 41 hospitals in the 20-county Atlanta, GA area. Associations between daily air pollution levels for 8 urban air pollutants and counts of SCD related ED visits were estimated using Poisson generalized linear models.

RESULTS

We observed positive associations between pollutants generally indicative of traffic emissions and corresponding SCD ED visits [e.g., rate ratio of 1.022 (95% CI: 1.002, 1.043) per interquartile range increase in carbon monoxide]. Age stratified analyses indicated stronger associations with traffic pollutants among children (0-18 years), as compared to older age strata. Associations involving other pollutants, including ozone and particulate matter and for models of individuals >18 years old, were consistent a null hypothesis of no association.

DISCUSSION

This analysis represents the first North American study to examine acute risk among individuals with SCD to urban air pollution and provide evidence of urban air pollution, especially from traffic sources, as a trigger for acute exacerbations. These findings are consistent with a hypothesis that biological pathways, including several centrally associated with oxidative stress, may contribute towards enhanced susceptibility in individuals with SCD.

Age- and season-specific effects of ambient particles (PM1, PM2.5, and PM10) on daily emergency department visits among two Chinese metropolitan populations

BACKGROUND

Ambient PM_2.5 has been identified as the top leading cause of risk-attributable deaths worldwide, particularly in China. Evidence suggested that PM₁ contributed the most majority of PM_2.5 concentrations in Chinese cities. However, epidemiologic knowledge to date is of wide lack regarding PM₁-associated health effects.

METHODS

We collected daily records of all-cause emergency department visits (EDVs) and ground measurements of ambient air pollutants and meteorological factors in Guangzhou and Shenzhen, China, 2015-2016. Case-crossover design and conditional logistic regression models were used to comparatively assess the short-term effects of ambient PM₁, PM_2.5, and PM₁₀ on EDVs. Stratified analyses by gender, age and season were performed to identify vulnerable groups and periods.

RESULTS

PM₁, PM_2.5 and PM₁₀ were all significantly associated with increased EDVs in both cities. Population risks for EDVs increased by 2.2% [95% confidence interval, 1.8 to 2.6] in Guangzhou and 1.7% [1.0 to 2.4] in Shenzhen, for a 10 μg/m³ rise in PM₁ at lag 0-1 days and lag 0-4 days, respectively. Relatively lower risks were found to be associated with PM_2.5 and PM₁₀. PM-EDVs associations exhibited no gender differences, but varied across age groups. Compared with adults and the elderly, children under 14 years-of-age suffered higher PM-induced risks. Results from both cities suggested greatly significant effect modification by season, with consistently stronger PM-EDVs associations during cold months.

CONCLUSIONS

Our study added comparative evidence for increased EDVs risks associated with short-term exposures to ambient PM₁, PM_2.5 and PM₁₀. Besides, PM-associated effects were significantly stronger among children and during cold months.

Air Quality Index and air quality awareness among adults in the United States

BACKGROUND

Information about local air quality is reported across the United States using air quality alerts such as the Environmental Protection Agency's Air Quality Index. However, the role of such alerts in raising awareness of air quality is unknown. We conducted this study to evaluate associations between days with Air Quality Index ≥101, corresponding to a categorization of air quality as unhealthy for sensitive groups, unhealthy, very unhealthy, or hazardous, and air quality awareness among adults in the United States.

METHODS

Data from 12,396 respondents to the 2016-2018 ConsumerStyles surveys were linked by geographic location and survey year to daily Air Quality Index data. We evaluated associations between the number of days in the past year with Air Quality Index ≥101 and responses to survey questions about awareness of air quality alerts, perception of air quality, and changes in behavior to reduce air pollution exposure using logistic regression.

RESULTS

Awareness of air quality alerts (prevalence ratio [PR] = 1.23; 95% confidence interval [CI] = 1.15, 1.31), thinking/being informed air quality was bad (PR = 2.02; 95% CI = 1.81, 2.24), and changing behavior (PR = 2.27; 95% CI = 1.94, 2.67) were higher among respondents living in counties with ≥15 days with Air Quality Index ≥101 than those in counties with zero days in the past year with Air Quality Index ≥101. Each aspect of air quality awareness was higher among adults with than without asthma, but no differences were observed by heart disease status. Across quintiles of the number of days with Air Quality Index ≥101, air quality awareness increased among those with and without selected respiratory and cardiovascular diseases.

CONCLUSIONS

Among U.S. adults, air quality awareness increases with increasing days with alerts of unhealthy air. These findings improve our understanding of the extent to which air quality alerts prompt people to take actions to protect their health amidst poor air quality.

The association of short-term effects of air pollution and sleep disorders among elderly residents in China

Sleep disorders, oftentimes co-occurring with other mental and neurological disorders in the elderly, have been previously linked to short-term exposures to air pollution. Here we assessed such associations among 395,651 elderly Chinese in Ningbo, China where air pollution exposures are high and the proportion of elderly in the population is growing. We utilized a regional health information database in China (2008-2017) that collected information on hospital visits for sleep disorders among the elderly (age 60+). Measures of daily air pollution concentrations including nitrogen dioxide (NO₂), sulfur dioxide (SO₂), ozone (O₃), inhalable particles (PM₁₀), and ambient fine particulate matter (PM_2.5) were generated from seven environmental air quality monitoring sites in the study area. We used a generalized additive model to evaluate the associations between hospital visits for sleep disorders and short-term air pollution exposures for up to 7 days prior to a hospital visit. Short-term exposure to multiple air pollutants was associated with hospital visits for sleep disorders in an elderly population; with the strongest associations during 2-3 days prior to a clinic visits for traffic-related pollutants including air quality index (AQI), PM_2.5, PM₁₀, and NO₂ and for SO₂ and O₃ for 5 days prior to the visits. Our study based on large health care record system suggested that short-term air pollution exposures are associated with sleep disorders in the elderly. Considering the individual covariates that could not be adjusted in time-series analyses, future studies with individual level data and an ability to evaluate the severity of sleep disorders and their relation to mental and physical health in general and air pollution are needed. An aging population with increasing health problems and the frequency of high and very high air pollution events in China make our findings very health policy relevant.

The Impact of Ambient Fine Particulate Matter on Consumer Expenditures

Airborne particulate matter suspended from industrial facilities, power plants, and automobiles is detrimental to health. Growing concerns about the increasing level of airborne particulate matter have led many industrialized nations to advocate for the transformation of the energy market and investment in sustainable energy products. At the other end, consumers have made individual adjustments and attempted to reduce the exposure to the particulate matter. In this paper, we focus on the effect of ambient air pollution on consumer expenditures based on scanner panel data on consumers’ debit and credit card transactions. A series of empirical analyses found robust evidence that the increased level of particulate matter led to considerable disruption in total consumer expenditures with significant heterogeneity across categories. Our findings suggest that consumers alter their spending behaviors in an attempt to reduce the risk of exposures to particulate matter. Such an estimated effect of air pollution is qualitatively different from those of other macroeconomic factors and provides important guidance for policy interventions and practical decisions aimed at sustaining economic growth.

Short-term effects of particulate matter exposure on emergency room visits for cardiovascular disease in Lanzhou, China: a time series analysis

Cardiovascular disease (CVD) has been the leading cause of death in China. Identifying the relationship between particulate matter (PM) and CVD in China is a significant challenge. In this study, daily CVD emergency room visit, environmental monitoring, and weather data from January 1, 2017, to December 31, 2018, in Lanzhou were collected. Generalized additive models (GAMs) were constructed to estimate the short-term effects of daily PM_2.5, PM_C, and PM₁₀ concentrations on CVD emergency room visits with different lag structures after controlling for the influence of meteorological elements and gaseous pollutants. Stratified analyses were conducted according to age (≥ 65 years and < 65 years), sex (male and female), cold season (from November to April), and warm season (from May to October). The results showed that each 10 μg/m³ increase in PM_2.5 was associated with a 1.93% (95% CI 0.12-3.78%) increase in CVD emergency room visits at lag03, and no single lag model was statistically significant. The excess relative risks (ERRs) of PM₁₀ and PM_C were not statistically significant at any lag pattern. The exposure-response curves demonstrated a nonlinear upward trend for these three PM pollutants. When adjusting for other gaseous pollutants, such as NO₂, SO₂, CO, and O₃, in the two-pollutant models, the associations between PM₁₀ and PM_C and CVD emergency room visits did not change compared with the single-pollutant models. The ERRs of PM_2.5 were 1.67% (95% CI 0.03-3.34%) at lag02 after adjustment for NO₂ and 1.65% (95% CI 0.02-3.30%) at lag02 after adjustment for SO₂. The ERRs of PM_2.5 were still statistically significant at lag03 when we adjusted for any one of the gaseous pollutants. Susceptibility to PM_2.5 was increased in people aged < 65 years, in males, and in the warm season. The findings are very important for local governments to develop environmental policies and strategies to reduce ambient PM_2.5 levels.

Oxidative Potential of Particulate Matter and Generation of Reactive Oxygen Species in Epithelial Lining Fluid

Reactive oxygen species (ROS) play a central role in adverse health effects of atmospheric particulate matter (PM). Respiratory deposition can lead to the formation of ROS in the epithelial lining fluid due to redox reactions of PM components with lung antioxidants. As direct quantification of ROS is challenging, PM oxidative potential is more commonly measured using antioxidant surrogates including dithiothreitol and ascorbic acid, assuming that the decay of surrogates corresponds to ROS formation. However, this assumption has not yet been validated and the lack of ROS quantification in the respiratory tract causes major limitations in evaluating PM impacts on oxidative stress. By combining field measurements of size-segregated chemical composition, a human respiratory tract model, and kinetic modeling, we quantified production rates and concentrations of different types of ROS in different regions of the epithelial lining fluid by considering particle-size-dependent respiratory deposition. The extrathoracic region is found to have higher ROS concentrations compared to the bronchial and alveolar regions. Although H₂O₂ and O₂^- production is governed by Fe and Cu ions, OH radicals are mainly generated by organic compounds and Fenton-like reactions of metal ions. In winter when affected by biomass burning, model comparisons suggest that humic-like substances (HULIS) contribute to ROS formation substantially. We found that PM oxidative potential is a good indicator of the chemical production of H₂O₂ and O₂^- but does not represent OH generation. These results provide rationale and limitations of the use of oxidative potential as an indicator of PM toxicity in epidemiological and toxicological studies.

Joint effect of multiple air pollutants on daily emergency department visits in Chengdu, China

Existing studies have typically investigated only the association between single pollutants and health outcomes. However, in the real world, people are exposed to multiple air pollutants simultaneously. The effect of air pollutants on emergency department (ED) visits has not been previously studied in the Sichuan Basin, which is one of the most polluted areas. We collected nonaccidental, respiratory and cardiovascular daily ED visits and daily concentrations of PM_2.5, PM_c, CO, SO₂, NO₂ and O₃ in Chengdu, China, from 2014 to 2016. A weighted variable for the combination of multiple air pollutants was constructed to assess the joint adverse health effects. Each air pollutant was assigned a health-related weight, which indicated the pollutant's relative contribution to the joint effect. The effects on specific subpopulations (males and females; 15-65 years old and >65 years old) were also examined. With an increase of 10 μg/m³ of the combined multiple air pollutants, the daily ED visits for nonaccidental, respiratory and cardiovascular causes increased by 0.96% (95% CI: 0.51%-1.39%), 1.19% (95% CI: 0.53%, 1.85%) and 4.36% (95% CI: 1.06%, 7.76%) at lag 1, respectively. Males presented more pronounced effects, except for cardiovascular disease, than females. Elderly individuals were found to be more sensitive than young individuals. For nonaccidental and respiratory diseases, the contributions of particulate matter (PM) were dominant among the air pollutants, whereas cardiovascular disease was mainly affected by gaseous air pollutants. The combination of multiple air pollutants was significantly associated with ED visits in the Sichuan Basin, China. The joint effect of the combination of multiple air pollutants was highest for cardiovascular disease at lag 1. The relative contributions of individual pollutants varied by disease and subpopulation. These findings suggest that under different pollution scenarios, preventive strategies should target those with different diseases and different subpopulations.

Air pollutants and outpatient visits for cardiovascular disease in a severe haze-fog city: Shijiazhuang, China

Background

Many studies have reported the impact of air pollution on cardiovascular disease (CVD), but few of these studies were conducted in severe haze-fog areas. The present study focuses on the impact of different air pollutant concentrations on daily CVD outpatient visits in a severe haze-fog city.

Methods

Data regarding daily air pollutants and outpatient visits for CVD in 2013 were collected, and the association between six pollutants and CVD outpatient visits was explored using the least squares mean (LSmeans) and logistic regression. Adjustments were made for days of the week, months, air temperature and relative humidity.

Results

The daily CVD outpatient visits for particulate matter (PM₁₀ and PM_2.5), sulphur dioxide (SO₂), nitrogen dioxide (NO₂), carbon monoxide (CO), and ozone (O₃) in the 90th-quantile group were increased by 30.01, 29.42, 17.68, 14.98, 29.34%, and − 19.87%, respectively, compared to those in the <10th-quantile group. Odds ratios (ORs) and 95% confidence intervals (CIs) for the increase in daily CVD outpatient visits in PM₁₀ 300- and 500-μg/m³, PM_2.5 100- and 300-μg/m³ and CO 3-mg/m³ groups were 2.538 (1.070–6.020), 7.781 (1.681–36.024), 3.298 (1.559–6.976), 8.72 (1.523–49.934), and 5.808 (1.016–33.217), respectively, and their corresponding attributable risk percentages (AR%) were 60.6, 87.15, 69.68, 88.53 and 82.78%, respectively. The strongest associations for PM₁₀, PM_2.5 and CO were found only in lag 0 and lag 1. The ORs for the increase in CVD outpatient visits per increase in different units of the six pollutants were also analysed.

Conclusions

All five air pollutants except O₃ were positively associated with the increase in daily CVD outpatient visits in lag 0. The high concentrations of PM₁₀, PM_2.5 and CO heightened not only the percentage but also the risk of increased daily CVD outpatient visits. PM₁₀, PM_2.5 and CO may be the main factors of CVD outpatient visits.

Impact of air pollution control policies on cardiorespiratory emergency department visits, Atlanta, GA, 1999-2013

BACKGROUND

Air pollution control policies resulting from the 1990 Clean Air Act Amendments were aimed at reducing pollutant emissions, ambient concentrations, and ultimately adverse health outcomes.

OBJECTIVES

As part of a comprehensive air pollution accountability study, we used a counterfactual study design to estimate the impact of mobile source and electricity generation control policies on health outcomes in the Atlanta, GA, metropolitan area from 1999 to 2013.

METHODS

We identified nine sets of pollution control policies, estimated changes in emissions in the absence of these policies, and employed those changes to estimate counterfactual daily ambient pollutant concentrations at a central monitoring location. Using a multipollutant Poisson time-series model, we estimated associations between observed pollutant levels and daily counts of cardiorespiratory emergency department (ED) visits at Atlanta hospitals. These associations were then used to estimate the number of ED visits prevented due to control policies, comparing observed to counterfactual daily concentrations.

RESULTS

Pollution control policies were estimated to substantially reduce ambient concentrations of the nine pollutants examined for the period 1999-2013. We estimated that pollutant concentration reductions resulting from the control policies led to the avoidance of over 55,000 cardiorespiratory disease ED visits in the five-county metropolitan Atlanta area, with greater proportions of visits prevented in later years as effects of policies became more fully realized. During the final two years of the study period, 2012-2013, the policies were estimated to prevent 16.5% of ED visits due to asthma (95% interval estimate: 7.5%, 25.1%), 5.9% (95% interval estimate: -0.4%, 12.3%) of respiratory ED visits, and 2.3% (95% interval estimate: -1.8%, 6.2%) of cardiovascular disease ED visits.

DISCUSSION

Pollution control policies resulting from the 1990 Clean Air Act Amendments led to substantial estimated reductions in ambient pollutant concentrations and cardiorespiratory ED visits in the Atlanta area.

Association between short-term exposure to fine particulate matter and daily emergency room visits at a cardiovascular hospital in Dhaka, Bangladesh

BACKGROUND

It has been suggested that exposure to fine particulate matter (PM_2.5) adversely affects cardiovascular health. However, the effect modifications by individual characteristics and season have been less studied in developing countries where PM_2.5 levels are high.

OBJECTIVES

To estimate the risks of cardiovascular emergency room visits in relation to daily concentrations of PM_2.5 and to assess how these associations can be modified by age, sex, and nutritional status of patients and by season.

METHODS

The analytic sample was 6774 adults who visited the emergency room at a cardiovascular disease (CVD) hospital in Dhaka throughout one year (n = 364 days). A time-stratified case-crossover design with conditional Poisson regression analysis was used to estimate the relative risks (RRs) and 95% confidence intervals (CIs) of visits while adjusting for temperature. Stratification was performed by gender, age (<65 and ≥65 years), BMI (underweight, normal weight, overweight), and season (dry summer: February to April; wet summer: May to October; dry winter: November to January).

RESULTS

The mean concentration of PM_2.5 was 86.1 μg/m³. An IQR increase (103 μg/m³) in PM_2.5 at lag 3 was significantly associated with a 12% (RR: 1.12; 95% CI: 1.01-1.23) increase in CVD emergency room visits. No evidence of association was found for the other lags. Underweight and overweight patients showed evidence of increased risk at lag 2 (RR: 1.31; 95% CI: 1.02-1.67) and lag 4 (RR: 1.20; 95% CI: 1.04-1.39), respectively.

CONCLUSION

Increases in the daily concentrations of PM_2.5 may lead to more cardiovascular emergency room visits in Dhaka, Bangladesh. Response times from ambient exposure to CVD emergency visits may differ by season and the nutritional status of susceptible individuals, necessitating further research.

A multicity study of air pollution and cardiorespiratory emergency department visits: Comparing approaches for combining estimates across cities

Determining how associations between ambient air pollution and health vary by specific outcome is important for developing public health interventions. We estimated associations between twelve ambient air pollutants of both primary (e.g. nitrogen oxides) and secondary (e.g. ozone and sulfate) origin and cardiorespiratory emergency department (ED) visits for 8 specific outcomes in five U.S. cities including Atlanta, GA; Birmingham, AL; Dallas, TX; Pittsburgh, PA; St. Louis, MO. For each city, we fitted overdispersed Poisson time-series models to estimate associations between each pollutant and specific outcome. To estimate multicity and posterior city-specific associations, we developed a Bayesian multicity multi-outcome (MCM) model that pools information across cities using data from all specific outcomes. We fitted single pollutant models as well as models with multipollutant components using a two-stage chemical mixtures approach. Posterior city-specific associations from the MCM models were somewhat attenuated, with smaller standard errors, compared to associations from time-series regression models. We found positive associations of both primary and secondary pollutants with respiratory disease ED visits. There was some indication that primary pollutants, particularly nitrogen oxides, were also associated with cardiovascular disease ED visits. Bayesian models can help to synthesize findings across multiple outcomes and cities by providing posterior city-specific associations building on variation and similarities across the multiple sources of available information.

Are ambient volatile organic compounds environmental stressors for heart failure?

BACKGROUND

Numerous epidemiological studies have indicated the adverse cardiovascular effects of air pollution on heart failure (HF) risk. However, little data are available directly evaluating the association of ambient volatile organic compounds (VOCs) with HF risk. We aimed to estimate the short-term effects of ambient VOCs on HF emergency hospitalizations in Hong Kong and to evaluate whether the associations were modified by sex and age.

METHODS

We collected the daily VOCs concentrations from the Hong Kong Environmental Protection Department between April 2011 to December 2014. HF emergency hospital admission data were obtained from the Hospital Authority of Hong Kong. Generalized additive model (GAM) integrated with the distributed lag model (DLM) was used to estimate the excess risks of HF emergency hospitalizations with ambient concentrations of each VOCs groups - alkane, alkene, alkyne, benzene and substituted benzene.

RESULTS

We observed short-term effects of alkyne and benzene on an increased risk of HF emergency hospitalizations. The cumulative effect over 0-6 lag days (dlm_0-6) for an IQR increment of alkyne (1.17 ppb) was associated with 4.2% (95% CI: 1.18%-7.26%) increases of HF emergency hospitalizations, while the corresponding effect estimate over dlm_0-2 for benzene per IQR (0.43 ppb) was 2.7% (95% CI: 0.39%-5.04%). Each VOCs groups was significantly associated with HF emergency hospitalizations in men.

CONCLUSIONS

Ambient volatile organic compounds, particularly alkyne and benzene, were associated with increased risks of heart failure in the Hong Kong population.

Association of air quality with respiratory and cardiovascular morbidity rate in Delhi, India

The present study reports short-term impact of poor air quality on cardiovascular and respiratory morbidity rate in Delhi. The data on monthly count of patients visiting Out Patient Department (OPD) and hospital admission due to respiratory and cardiovascular illnesses from hospitals along with daily air quality data from air quality monitoring stations of Central Pollution Control Board (CPCB), Government of India, across Delhi were collected for the period 2008 to 2012. A semi-parametric Quasi-Poisson regression model was used to examine the association of high pollution episodes with relative risk of hospital OPD visit and hospital admission due to respiratory and cardiovascular diseases. This study has confirmed the substantial adverse health effects due to air pollution across criterion air pollutants. The study reports the short-term effects of air pollution on morbidity from a time-series study first time in India. The study findings illustrate the evidence of adverse health impact of air pollution from India to the global pool and can influence the policy makers to implement better air quality management system for Indian cities.

ABBREVIATIONS

OPD: Out Patient Department; IPD: Inpatient Department; RD: Respiratory Disease; CVD: Cardiovascular Disease; COPD: Chronic Obstructive Pulmonary Disease; CPCB: Central Pollution Control Board; NAAQMP: National Ambient Air Quality Monitoring Programme; NAAQS: National Ambient Air Quality Standards; RR; Relative Risk; IMD: Indian Meteorological Department; PM₁₀: Particulate Matter less than 10 μm in aerodynamic diameter; SO₂: Sulphur dioxide; NO₂: Nitrogen dioxide; CO: Carbon Monoxide; O₃: Ozone; DCE: Delhi College of Engineering; GTB Hospital: Guru Teg Bahadur Hospital; VPCH: Vallabhbhai Patel Chest Hospital; RMLH: Ram Manohar Lohia Hospital; SJH: Safdarjung Hospital; LNJPH: Lok Narayan Jai Prakash Hospital; GTBH: Guru Teg Bahadur Hospital; AH: Ambedkar Hospital; HRH: Hindu Rao Hospital; ESIH: ESI Hospital; SGRH: Sir Ganga Ram Hospital.

Radiative response of biomass-burning aerosols over an urban atmosphere in northern peninsular Southeast Asia

A large concentration of finer particulate matter (PM_2.5), the primary air-quality concern in northern peninsular Southeast Asia (PSEA), is believed to be closely related to large amounts of biomass burning (BB) particularly in the dry season. In order to quantitatively estimate the contributions of BB to aerosol radiative effects, we thoroughly investigated the physical, chemical, and optical properties of BB aerosols through the integration of ground-based measurements, satellite retrievals, and modelling tools during the Seven South East Asian Studies/Biomass-burning Aerosols & Stratocumulus Environment: Lifecycles & Interactions Experiment (7-SEAS/BASELInE) campaign in 2014. Clusters were made on the basis of measured BB tracers (Levoglucosan, nss-K⁺, and NO₃^-) to classify the degree of influence from BB over an urban atmosphere, viz., Chiang Mai (18.795°N, 98.957°E, 354m.s.l.), Thailand in northern PSEA. Cluster-wise contributions of BB to PM_2.5, organic carbon, and elemental carbon were found to be 54-79%, 42-79%, and 39-77%, respectively. Moreover, the cluster-wise aerosol optical index (aerosol optical depth at 500nm≈0.98-2.45), absorption (single scattering albedo ≈0.87-0.85; absorption aerosol optical depth ≈0.15-0.38 at 440nm; absorption Ångström exponent ≈1.43-1.57), and radiative impacts (atmospheric heating rate ≈1.4-3.6Kd^-1) displayed consistency with the degree of BB. PM_2.5 during Extreme BB (EBB) was ≈4 times higher than during Low BB (LBB), whereas this factor was ≈2.5 for the magnitude of radiative effects. Severe haze (visibility≈4km) due to substantial BB loadings (BB to PM_2.5≈79%) with favorable meteorology can significantly impact the local-to-regional air quality and the, daily life of local inhabitants as well as become a respiratory health threat. Additionally, such enhancements in atmospheric heating could potentially influence the regional hydrological cycle and crop productivity over Chiang Mai in northern PSEA.

Short-term effects of ambient benzene and TEX (toluene, ethylbenzene, and xylene combined) on cardiorespiratory mortality in Hong Kong

BACKGROUND

Numerous epidemiological and experimental studies have demonstrated the detrimental effects of the criteria air pollutants on population health, including particulate matters, ozone, and nitrogen dioxide. However, evidence on health effects of benzene, toluene, ethylbenzene, and xylene (BTEX in short) is insufficient.

OBJECTIVES

The present study aimed to assess the exposure-lag-response relations of ambient BTEX components with cardiorespiratory mortality in Hong Kong population.

METHODS

Daily BTEX concentrations from April 2011 to December 2014 were collected from the Hong Kong Environmental Protection Department. Cause-specific mortality records were obtained from the Census and Statistics Department of Hong Kong. Generalized additive model (GAM) integrated with a distributed lag model (DLM) was used to estimate the excess risks of cardiorespiratory mortality associated with the cumulative exposure to benzene and TEX (toluene, ethylbenzene and xylene combined) over 0-9 lag days, while adjusting for time trend, seasonality, weather conditions and calendar effects.

RESULTS

We observed the delayed and distributed lag effects of BTEX components on circulatory mortality. The cumulative exposures over 0-9 lag days for IQR increments of benzene (1.4 μg/m³) and TEX (7.9 μg/m³) were associated with 5.8% (95%CI: 1.0% to 10.8%) and 3.5% (95%CI: 1.0% to 6.1%) increases in circulatory mortality, respectively. The effect estimates of benzene and TEX were more delayed than that of PM_2.5. We didn't observe any significant association of BTEX exposure on total and respiratory deaths.

CONCLUSIONS

Short-term elevations in ambient BTEX concentrations may trigger circulatory mortality in Hong Kong population.

Air Quality Awareness Among U.S. Adults With Respiratory and Heart Disease

INTRODUCTION

Poor air quality affects respiratory and cardiovascular health. Information about health risks associated with outdoor air quality is communicated to the public using air quality alerts. This study was conducted to assess associations of existing respiratory and heart disease with three aspects of air quality awareness: awareness of air quality alerts, discussing with a health professional strategies to reduce air pollution exposure, and avoiding busy roads to reduce air pollution exposure when walking, biking, or exercising outdoors.

METHODS

During 2014-2016, a total of 12,599 U.S. adults participated in summer waves of the ConsumerStyles surveys and self-reported asthma, emphysema/chronic obstructive pulmonary disease, heart disease, and each aspect of air quality awareness. In 2017, associations between each health condition and air quality awareness were estimated using log binomial and multinomial regression.

RESULTS

Overall, 49% of respondents were aware of air quality alerts, 3% discussed with a health professional strategies to reduce air pollution exposure, and 27% always/usually avoided busy roads to reduce air pollution exposure. Asthma was associated with increased prevalence of awareness of air quality alerts (prevalence ratio=1.11, 95% CI=1.04, 1.20), discussing with a health professional (prevalence ratio=4.88, 95% CI=3.74, 6.37), and always/usually avoiding busy roads to reduce air pollution exposure (prevalence ratio=1.13, 95% CI=1.01, 1.27). Heart disease was not associated with air quality awareness.

CONCLUSIONS

Existing respiratory disease, but not heart disease, was associated with increased air quality awareness. These findings reveal important opportunities to raise awareness of air quality alerts and behavior changes aimed at reducing air pollution exposure among adults at risk of exacerbating respiratory and heart diseases.

Ambient volatile organic compounds (VOCs) in communities of the Athabasca oil sands region: Sources and screening health risk assessment

An investigation of ambient levels and sources of volatile organic compounds (VOCs) and associated public health risks was carried out at two northern Alberta oil sands communities (Fort McKay and Fort McMurray located < 25 km and >30 km from oil sands development, respectively) for the period January 2010-March 2015. Levels of total detected VOCs were comparatively similar at both communities (Fort McKay: geometric mean = 22.8 μg/m³, interquartile range, IQR = 13.8-41 μg/m³); (Fort McMurray: geometric mean = 23.3 μg/m³, IQR = 12.0-41 μg/m³). In general, methanol (24%-50%), alkanes (26%-32%) and acetaldehyde (23%-30%) were the predominant VOCs followed by acetone (20%-24%) and aromatics (∼9%). Mean and maximum ambient concentrations of selected hazardous VOCs were compared to health risk screening criteria used by United States regulatory agencies. The Positive matrix factorization (PMF) model was used to identify and apportion VOC sources at Fort McKay and Fort McMurray. Five sources were identified at Fort McKay, where four sources (oil sands fugitives, liquid/unburned fuel, ethylbenzene/xylene-rich and petroleum processing) were oil sands related emissions and contributed to 70% of total VOCs. At Fort McMurray six sources were identified, where local sources other than oil sands development were also observed. Contribution of aged air mass/regional transport including biomass burning emissions was ∼30% of total VOCs at both communities. Source-specific carcinogenic and non-carcinogenic risk values were also calculated and were below acceptable and safe levels of risk, except for aged air mass/regional transport (at both communities), and ethylbenzene/xylene-rich (only at Fort McMurray).

The January 2013 Beijing "Airpocalypse" and its Acute Effects on Emergency and Outpatient Visits at a Beijing Hospital

Severe air pollution episodes in Europe and the USA in the early- to mid-twentieth century caused large health impacts, spurring national legislation. Similarly severe episodes currently affect developing regions, as exemplified by a particularly extreme episode in January 2013 in Beijing, China. We investigated associations between this episode and medical visits at a Beijing hospital. We obtained fine particulate matter (PM_2.5) measurements from the US State Department's Embassy monitor and daily counts of all-cause, cardiovascular, and respiratory emergency visits, and outpatient visits from a nearby hospital in the Liufang Nanli community. We analyzed whether risks increased during this episode (with daily PM_2.5 ≥ 350 μg/m³) using generalized linear modeling, controlling for potential confounders. The episode brought exceptionally high PM2.5 (peak daily average, 569 μg/m³). Risk increased during the episode for all-cause (relative risk 1.29 [95% CI 1.13, 1.46]), cardiovascular (1.55 [0.90, 2.68]) and respiratory (1.33 [1.10, 1.62]) emergency medical visits, and respiratory outpatient visits (1.16 [1.00, 1.33]). Relative risks of all-cause (0.95 [0.82, 1.10]) and cardiovascular (0.83 [0.67, 1.02]) outpatient visits were not statistically significant. Results were robust to modeling choices and episode definitions. This episode was extraordinarily severe, with maximum daily PM_2.5 concentration nearly 22-fold above the World Health Organization guideline. During the episode, risk increased for all-cause, cardiovascular, and respiratory emergency medical visits, and respiratory outpatient visits, consistent with previous US-based research. However, no association was found for all-cause or cardiovascular outpatient visits. China-based studies like this one provide critical evidence in developing efforts regarding air pollution remediation in China.