Long-term exposure to low concentrations of air pollutants and hospitalisation for respiratory diseases: A prospective cohort study in Australia

Ambient Air Pollution and Chronic Obstructive Pulmonary Disease: The Multiethnic Cohort Study

Rationale: Globally, chronic obstructive pulmonary disease (COPD) was the third leading cause of death in 2019. Although tobacco smoking is the predominant risk factor, the role of long-term air pollution exposure in increasing the risk of COPD remains unclear. Moreover, few studies that account for smoking history and other known risk factors have been conducted in racially and ethnically minoritized and socioeconomically diverse populations. Objectives: We sought to evaluate the association of ambient air pollution with COPD in a multiethnic population in California. Methods: In the Multiethnic Cohort Study of 38,654 African-American, Japanese-American, Latino, and White California participants who were enrolled in the fee-for-service component of Medicare, we used Cox proportional hazards regression to estimate the association of time-varying ambient air pollutants-particulate matter with an aerodynamic diameter ⩽2.5 μm or ⩽10 μm, nitrogen dioxide, carbon monoxide, ozone, benzene, and ultrafine particles (UFPs)-with COPD risk (n = 10,915 cases; 8.8 yr of follow up). Subgroup analyses were conducted by race and ethnicity, sex, smoking status as recorded on the Multiethnic Cohort Study baseline questionnaire, and neighborhood socioeconomic status. Results: We observed a positive association of nitrogen oxide (per 50 ppb) with risk of COPD (hazard ratio = 1.45; 95% confidence interval = 1.35-1.55). The associations of nitrogen dioxide (per 20 ppb), particulate matter with an aerodynamic diameter ⩽2.5 μm (10 μg/m3) or ⩽10 μm (10 μg/m3), carbon monoxide (1,000 ppb), and UFPs (interquartile range = 5,241.7 particles/cm3) with risk of COPD were in similar directions, as these air pollutants are highly correlated with nitrogen oxide. These associations were found in African-American, Latino, and Japanese-American participants, but not in Whites (P heterogeneity across race and ethnicity <0.04). These associations also differed by neighborhood socioeconomic status, with effects being stronger in racially and ethnically minoritized populations and residents of low-SES neighborhoods. Conclusions: Long-term ambient air pollutant exposure is associated with COPD risk in a multiethnic, older adult (age >65 yr) population.

Long-term exposure to air pollution and greenness in association with respiratory emergency room visits and hospitalizations: The Life-GAP project

BACKGROUND

Air pollution has been linked to respiratory diseases, while the effects of greenness remain inconclusive.

OBJECTIVE

We investigated the associations between exposure to particulate matter (PM2.5 and PM10), black carbon (BC), nitrogen dioxide (NO2), ozone (O3), and greenness (normalized difference vegetation index, NDVI) with respiratory emergency room visits and hospitalizations across seven Northern European centers in the European Community Respiratory Health Survey (ECRHS) study.

METHODS

We used modified mixed-effects Poisson regression to analyze associations of exposure in 1990, 2000 and mean exposure 1990-2000 with respiratory outcomes recorded duing ECRHS phases II and III. We assessed interactions of air pollution and greenness, and of atopic status (defined by nasal allergies and hay fever status) and greenness, on these outcomes.

RESULTS

The analysis included 1675 participants, resulting in 119 emergency visits and 48 hospitalizations. Increased PM2.5 by 5 μg/m³ was associated with higher relative risk (RR) of emergency visits (1990: RR 1.16, 95% CI: 1.00-1.35; 2000: RR 1.24, 95% CI: 0.98-1.57; 1990-2000: RR 1.17, 95% CI: 0.97-1.41) and hospitalizations (1990: RR 1.42, 95% CI: 1.00-2.01; 2000: RR 2.20, 95% CI: 1.43-3.38; 1990-2000: RR 1.44, 95% CI: 1.04-2.00). Similar trends were observed for PM10, BC, and NO2, with only PM10 showing significant associations with hospitalizations across all periods. No associations were found for O3. Greenness exposure was linked to more emergency visits in 2000 but to fewer hospitalizations in 1990. Significant interactions were observed between greenness and atopic status for emergency visits, and between NDVI with O3 and BC for some time windows.

CONCLUSION

Long-term exposure to particulate matter was associated with increased emergency room visits and hospitalizations. Significant associations were observed for BC and NO2 with hospitalizations. No link was found with O3. Greenness indicated a lower risk of hospitalizations, but increased risks for emergency visits for those with atopic status.

Predictive modeling of air quality in the Tehran megacity via deep learning techniques

Air pollution is a significant challenge in metropolitan areas, where increasing amounts of air pollutants threaten public health and environmental safety. The present study aims to forecast the concentrations of various air pollutants, including CO, O3, NO2, SO2, PM10, and PM2.5, from 2013 to 2023 in the Tehran megacity, Iran, via deep learning (DL) models and evaluate their effectiveness over conventional machine learning (ML) methods. Key driving variables, including temperature, relative humidity, dew point, wind speed, and air pressure, were considered. R-squared (R2), root-mean-square error (RMSE), mean absolute error (MAE), and mean-square error (MSE) were used to assess and compare the models. This research demonstrated that DL models typically outperform ML models in forecasting air pollution. Gated recurrent units (GRUs), fully connected neural networks (FCNNs), and convolutional neural networks (CNNs) recorded R2 and MSE values of 0.5971 and 42.11 for CO, 0.7873 and 171.40 for O3, and 0.4954 and 25.17 for SO2, respectively. Consequently, the FCNN and GRU presented remarkable performance in predicting NO2 (R2 = 0.6476 and MSE = 75.16), PM10 (R2 = 0.8712 and MSE = 45.11), and PM2.5 (R2 = 0.9276 and MSE = 58.12) concentrations. In terms of operational speed, the FCNN model exhibited the most efficiency, with a minimum and maximum runtime of 13 and 28 s, respectively. The feature importance analysis suggested that CO, O3 and NO2, SO2 and PM10, and PM2.5 are most affected by temperature, humidity, PM2.5, and PM10, respectively. Thus, temperature and humidity were the primary factors affecting the variability in pollutant concentrations. The conclusions confirm that the DL models achieve significant accuracy and serve as essential instruments for managing air pollution, providing practical insights for decision-makers to adopt efficient air quality control strategies.

Long-term exposure to air pollution and lower respiratory infections in a large population-based adult cohort in Catalonia

BACKGROUND

Evidence is limited regarding the role of air pollution in acute lower respiratory infections among adults. We assessed the influence of long-term air pollution exposure on hospital admission for lower respiratory infections and whether there are vulnerable subgroups.

METHODS

We used a populational cohort in Catalonia, Spain, comprising 3,817,820 adults residing in Catalonia as of January 1, 2015. Air pollution exposure was assigned to individuaĺs residential address using locally-developed models. We characterized the concentration-response functions between long-term air pollution exposure and hospital admission for lower respiratory infections between 2015 and 2019. We assessed interaction between exposure and clinical and socio-economic factors on multiplicative and additive scales.

RESULTS

An interquartile range exposure increase was associated with an 8 % (95 % Confidence Interval: 5 %-11 %) for Nitrogen Dioxide, 10 % (95 % Confidence Interval: 8 %-13 %) for Particulate Matter with diameter equal to or smaller than 2.5 µm, 5 % (95 % Confidence Interval: 3 %-7%) for Particulate Matter with diameter equal to or smaller than 10 µm and 18 % (95 % Confidence Interval: 14 %-22%) for ozone (adjusted by Nitrogen Dioxide) increase in hospital admissions for respiratory infections. Concentration-response functions were non-linear, with steeper slopes at exposures below the median or at most extreme high values. Associations were consistently greater for individuals over 65 years or with hypertension diagnosis and males.

CONCLUSIONS

Long-term exposure to air pollution was positively associated with hospital admission for lower respiratory infections. Individuals who were older than 65 years, hypertensive or male were most vulnerable.

Long-Term Exposure to Air Pollution and Risk of Acute Lower Respiratory Infections in the Danish Nurse Cohort

Rationale: Air pollution is a major risk factor for chronic cardiorespiratory diseases, affecting the immune and respiratory systems' functionality, but epidemiological evidence in respiratory infections remains sparse. Objectives: We aimed to assess the association of long-term exposure to ambient air pollution with the risk of developing new and recurrent acute lower respiratory infections (ALRIs), characterized by persistently severe symptoms necessitating hospital contact, and identify the potential susceptible populations by socioeconomic status, smoking, physical activity status, overweight, and comorbidity with chronic lung disease. Methods: We followed 23,912 female nurses from the Danish Nurse Cohort (age >44 yr) from baseline (1993 or 1999) until 2018 for incident and recurrent ALRIs defined by hospital contact (inpatient, outpatient, and emergency room) data from the National Patient Register. Residential annual mean concentrations of fine particulate matter, nitrogen dioxide (NO2), and black carbon were modeled using the Danish Eulerian Hemispheric Model/Urban Background Model/Air Geographic Information System. We used marginal Cox models with time-varying exposures to assess the association of 3-year running mean air pollution level with incident and recurrent ALRIs and examined effect modification by age, socioeconomic status, smoking, physical activity, body mass index, and comorbidity with asthma or chronic obstructive pulmonary disease (COPD). Results: During a 21.3-year mean follow-up, 4,746 ALRIs were observed, of which 2,553 were incident. We observed strong positive associations of all three pollutants with incident ALRIs, with hazard ratios and 95% confidence intervals of 1.19 (1.08-1.31) per 2.5 μg/m3 for fine particulate matter, 1.17 (1.11-1.24) per 8.0 μg/m3 for NO2, and 1.09 (1.05-1.12) per 0.3 μg/m3 for black carbon, and slightly stronger associations with recurrent ALRIs. Associations were strongest in patients with COPD and nurses with low physical activity. Conclusions: Long-term exposure to air pollution at low levels was associated with risks of new and recurrent ALRIs, with patients with COPD and physically inactive subjects most vulnerable.

Exposure to outdoor particulate matter and risk of respiratory diseases: a systematic review and meta-analysis

According to epidemiological studies, particulate matter (PM) is an important air pollutant that poses a significant threat to human health. The relationship between particulate matter and respiratory diseases has been the subject of numerous studies, but these studies have produced inconsistent findings. The purpose of this systematic review was to examine the connection between outdoor particulate matter (PM2.5 and PM10) exposure and respiratory disorders (COPD, lung cancer, LRIs, and COVID-19). For this purpose, we conducted a literature search between 2012 and 2022 in PubMed, Web of Science, and Scopus. Out of the 58 studies that were part of the systematic review, meta-analyses were conducted on 53 of them. A random effect model was applied separately for each category of study design to assess the pooled association between exposure to PM2.5 and PM10 and respiratory diseases. Based on time-series and cohort studies, which are the priorities of the strength of evidence, a significant relationship between the risk of respiratory diseases (COPD, lung cancer, and COVID-19) was observed (COPD: pooled HR = 1.032, 95% CI: 1.004-1.061; lung cancer: pooled HR = 1.017, 95% CI: 1.015-1.020; and COVID-19: pooled RR = 1.004, 95% CI: 1.002-1.006 per 1 μg/m3 increase in PM2.5). Also, a significant relationship was observed between PM10 and respiratory diseases (COPD, LRIs, and COVID-19) based on time-series and cohort studies. Although the number of studies in this field is limited, which requires more investigations, it can be concluded that outdoor particulate matter can increase the risk of respiratory diseases.

The impact of air pollution on asthma: clinical outcomes, current epidemiology, and health disparities

INTRODUCTION

Air pollution has been shown to have a significant impact on morbidity and mortality of respiratory illnesses including asthma.

AREAS COVERED

Outdoor air pollution consists of a mixture of individual pollutants including vehicle traffic and industrial pollution. Studies have implicated an array of individual components of air pollution, with PM2.5, NO2, SO2, and ozone being the most classically described, and newer literature implicating other pollutants such as black carbon and volatile organic compounds. Epidemiological and cohort studies have described incidence and prevalence of pollution-related asthma and investigated both acute and chronic air pollution exposure as they relate to asthma outcomes. There is an increasing body of literature tying disparities in pollution exposure to clinical outcomes. In this narrative review, we assessed the published research investigating the association of pollution with asthma outcomes, focusing on the adult population and health care disparities.

EXPERT OPINION

Pollution has multiple deleterious effects on respiratory health but there is a lack of data on individualized pollution monitoring, making it difficult to establish a temporal relationship between exposure and symptoms, thereby limiting our understanding of safe exposure levels. Future research should focus on more personalized monitoring and treatment plans for mitigating exposure.

Contrasting Health Outcomes following a Severe Smoke Episode and Ambient Air Pollution in Early Life: Findings from an Australian Data Linkage Cohort Study of Hospital Utilization

BACKGROUND

Episodic spikes in air pollution due to landscape fires are increasing, and their potential for longer term health impacts is uncertain.

OBJECTIVE

Our objective is to evaluate associations between exposure in utero and in infancy to severe pollution from a mine fire, background ambient air pollution, and subsequent hospital care.

METHODS

We linked health records of births, emergency department (ED) visits, and hospitalizations of children born in the Latrobe Valley, Australia, 2012-2015, which included a severe pollution episode from a mine fire (9 February 2014 to 25 March 2014). We assigned modeled exposure estimates for fire-related and ambient particulate matter with an aerodynamic diameter of 2.5 μ m (PM 2.5 ) to residential address. We used logistic regression to estimate associations with hospital visits for any cause and groupings of infectious, allergic, and respiratory conditions. Outcomes were assessed for the first year of life in the in utero cohort and the year following the fire in the infant cohort. We estimated exposure-response for both fire-related and ambient PM 2.5 and also employed inverse probability weighting using the propensity score to compare exposed and not/minimally exposed children.

RESULTS

Prenatal exposure to fire-related PM 2.5 was associated with ED presentations for allergies/skin rash [odds ratio ( OR ) = 1.34 , 95% confidence interval (CI): 1.01, 1.76 per 240   μ g / m 3 increase]. Exposure in utero to ambient PM 2.5 was associated with overall presentations (OR = 1.18 , 95% CI: 1.05, 1.33 per 1.4   μ g / m 3 ) and visits for infections (ED: OR = 1.13 , 95% CI: 0.98, 1.29; hospitalizations: OR = 1.23 , 95% CI: 1.00, 1.52). Exposure in infancy to fire-related PM 2.5 compared to no/minimal exposure, was associated with ED presentations for respiratory (OR = 1.37 , 95% CI: 1.05, 1.80) and infectious conditions (any: OR = 1.21 , 95% CI: 0.98, 1.49; respiratory-related: OR = 1.39 , 95% CI: 1.05, 1.83). Early life exposure to ambient PM 2.5 was associated with overall ED visits (OR = 1.17 , 95% CI: 1.05, 1.30 per 1.4   μ g / m 3 increase).

DISCUSSION

Higher episodic and lower ambient concentrations of PM 2.5 in early life were associated with visits for allergic, respiratory, and infectious conditions. Our findings also indicated differences in associations at the two developmental stages. https://doi.org/10.1289/EHP12238.

Short-term effects of air pollution on hospital admissions of respiratory diseases in Hamadan, Iran, 2015 to 2021

The short-term effects of air pollution on respiratory diseases have been reported in many countries. Urban areas are most affected because of the many sources of pollution and the large number of people living there. This study aims to investigate the effect of short-term exposure to air pollutants on respiratory hospital admissions in the city of Hamadan. In this ecological study, daily hospital admission data were collected from Shahid Beheshti Hospital in Hamadan. Daily information on air pollutants (CO, SO2, NO2, O3, PM2.5 and PM10) from Hamadan Department of Environment (DoE) organization and of climate factors from Hamadan Meteorological Office were collected. A negative binomial regression model was used to examine the effect of air pollution on daily respiratory hospitalizations. The effect of exposure to pollutants was measured whit different time lags (0-7 days). Furthermore, the effect of meteorological variables was controlled. Subgroup analyses were performed by sex and age group. A total of 12,454 hospitalizations for respiratory diseases were recorded. Results showed a strong and immediate effect of CO on respiratory hospital admissions with highest association at lag 7 (relative risk (RR) = 1.38, 95% CI: 1.33, 1.42). The effects of CO and SO2 on respiratory hospitalizations are greater for men than women. Regarding the short-term effects of PM2.5, SO2 and O3, adults (aged less than 65) were more prone to hospitalization for respiratory diseases. These results show that exposure to air pollution, particularly CO, may increase hospital admissions due to respiratory illness. So reducing the concentration of these pollutants can reduce the number of hospital admissions.

Effect modification of the association between fine particulate air pollution during a wildfire event and respiratory health by area-level measures of socio-economic status, race/ethnicity, and smoking prevalence

Fine particulate air pollution (PM2.5) is decreasing in most areas of the United States, except for areas most affected by wildfires, where increasing trends in PM2.5 can be attributed to wildfire smoke. The frequency and duration of large wildfires and the length of the wildfire season have all increased in recent decades, partially due to climate change, and wildfire risk is projected to increase further in many regions including the western United States. Increasingly, empirical evidence suggests differential health effects from air pollution by class and race; however, few studies have investigated such differential health impacts from air pollution during a wildfire event. We investigated differential risk of respiratory health impacts during the 2008 northern California wildfires by a comprehensive list of socio-economic status (SES), race/ethnicity, and smoking prevalence variables. Regardless of SES level across nine measures of SES, we found significant associations between PM2.5 and asthma hospitalizations and emergency department (ED) visits during these wildfires. Differential respiratory health risk was found by SES for ED visits for chronic obstructive pulmonary disease where the highest risks were in ZIP codes with the lowest SES levels. Findings for differential effects by race/ethnicity were less consistent across health outcomes. We found that ZIP codes with higher prevalence of smokers had greater risk of ED visits for asthma and pneumonia. Our study suggests that public health efforts to decrease exposures to high levels of air pollution during wildfires should focus on lower SES communities.

Long-term Exposure to Ambient Air Pollutants and Increased Risk of Pneumonia in the UK Biobank

BACKGROUND

Short-term exposure to air pollution has been linked to pneumonia risk. However, evidence on the long-term effects of air pollution on pneumonia morbidity is scarce and inconsistent. We investigated the associations of long-term air pollutants exposure with pneumonia and explored the potential interactions with smoking.

RESEARCH QUESTION

Is long-term exposure to ambient air pollution associated with the risk of pneumonia, and does smoking modify the associations?

STUDY DESIGN AND METHODS

We analyzed data in 445,473 participants without pneumonia within 1 year before baseline from the UK Biobank. Annual average concentrations of particulate matter (particulate matter with a diameter < 2.5 μm [PM_2.5] and particulate matter with a diameter < 10 μm [PM₁₀]), nitrogen dioxide (NO₂), and nitrogen oxides (NO_x) were estimated using land-use regression models. Cox proportional hazards models were used to assess the associations between air pollutants and pneumonia incidence. Potential interactions between air pollution and smoking were examined on both additive and multiplicative scales.

RESULTS

The hazard ratios of pneumonia for each interquartile range increase in PM_2.5, PM₁₀, NO₂, and NO_x concentrations were 1.06 (95% CI, 1.04-1.08), 1.10 (95% CI, 1.08-1.12), 1.12 (95% CI, 1.10-1.15), and 1.06 (95% CI, 1.04-1.07), respectively. There were significant additive and multiplicative interactions between air pollution and smoking. Compared with never smokers with low air pollution exposure, ever smokers with high air pollution exposure had the highest pneumonia risk (PM_2.5: HR, 1.78; 95% CI, 1.67-1.90; PM₁₀: HR, 1.94; 95% CI, 1.82-2.06; NO₂: HR, 2.06; 95% CI, 1.93-2.21; NO_x: HR, 1.88; 95% CI, 1.76-2.00). The associations between air pollutants and pneumonia risk persisted in participants exposed to air pollutants concentrations meeting the European Union limits.

INTERPRETATION

Long-term exposure to air pollutants was associated with an increased risk of pneumonia, especially in smokers.

Association of walkability and fine particulate matter with chronic obstructive pulmonary disease: A cohort study in China

BACKGROUND

Walkability has been considered to be associated with metabolic and cardiovascular diseases, but the relationship between walkability and chronic obstructive pulmonary disease (COPD) remains unclear. Moreover, fine particulate matter (PM2.5), possibly positively correlated to walkability, may lead to an increased risk of COPD. The separate and joint effects of PM2.5 and walkability on risk of COPD were explored in our study.

METHODS

We used prospective data of 29,572 participants from the Yinzhou cohort in Ningbo, China. COPD cases were diagnosed based on the Yinzhou Health Information System (YHIS). Walkability was measured using walk score in relation to the built environment based on geographic information systems (GIS). Air pollution levels were assessed by fitting land use regression (LUR) models. Cox proportional hazards models were used to evaluate the relationships of PM2.5 and walkability with COPD. Furthermore, we also examined additive and multiplicative interactions between walkability and PM2.5.

RESULTS

Overall, a total of 29,572 participants were included in the final analysis and 722 COPD incident cases were identified during 134,846 person-years of follow-up. Compared with subjects with lower walkability, individuals with higher walkability had a decreased risk of COPD (HR = 0.88, 95 % CI: 0.82-0.95) for every IQR increase. By contrast, exposure to PM2.5 (every IQR increase) was associated with an elevated risk of COPD (HR = 1.21, 95 % CI: 1.06-1.37). No interaction between PM2.5 and walkability was observed.

CONCLUSIONS

Living in a highly walkable neighborhood could decrease risk of COPD, whereas high levels of PM2.5 were positively associated with COPD. In addition, the beneficial effects of walkability were not attenuated by exposure to PM2.5.

Long-term improvement of air quality associated with lung function benefits in Chinese young adults: A quasi-experiment cohort study

INTRODUCTION

Long-term exposure to air pollution is associated with lung function impairment. However, whether long-term improvements in air quality could improve lung function is unclear.

OBJECTIVES

To examine whether the reduction of long-term air pollution was associated with lung function improvement among Chinese young adults.

METHODS

We conducted a prospective quasi-experiment cohort study with 1731 college students in Shandong, China from September 2019 to September 2020, covering COVID-19 lockdown period. Data on air pollution concentrations were obtained from China Environmental Monitoring Station. Lung function indicators included forced vital capacity (FVC), forced expiratory volume in 1st second (FEV₁) and forced expiratory flow at 50 % of FVC (FEF50%). We used linear mixed-effects model to examine the associations between the change of air pollutants concentrations and the change of lung function, and additional adjustments for indoor air pollution (IAP) source. We also conducted stratified analysis by sex.

RESULTS

Compared with 2019, the mean FVC, FEV₁ and FEF50% were elevated by 414.4 ml, 321.5 ml, and 28.4 ml/s respectively in 2020. Every 5 μg/m³ decrease in annual average PM_2.5 concentrations was associated with 36.0 ml [95 % confidence interval (CI):6.0, 66.0 ml], 46.1 ml (95 % CI:16.7, 75.5 ml), and 124.2 ml/s (95 % CI:69.5, 178.9 ml/s) increment in the FVC, FEV₁, and FEF50%, respectively. Similar associations were found for PM₁₀. The estimated impact was almost unchanged after adjusting for IAP source. There was no significant effect difference between males and females.

CONCLUSION

Long-term improvement of air quality can improve lung function among young adults. Stricter policies on improving air quality are needed to protect human health.

Long-term exposure to low air pollutant concentrations and hospitalisation for respiratory diseases in older men: A prospective cohort study in Perth, Australia

Background

Acute exposure to ambient air pollution even at low concentrations has been associated with increased hospitalisation for respiratory diseases but the effects of long-term exposure are less certain. In this study, we investigated the associations between long-term exposures to PM_2.5, PM_2.5 absorbance and NO₂ and hospitalisation for asthma, chronic obstructive pulmonary disease and pneumonia in a cohort of older men living in Perth, Western Australia, a city where the levels of air pollutants are well below the world standards.

Materials and methods

The study population of 11,156 men with no prior hospitalisation for respiratory disease was drawn from the Health in Men Study (HIMS) cohort of men aged >65 years living in Perth, Western Australia between 1996-1999. PM_2.5, PM_2.5 absorbance (PM_2.5a) and NO₂ were measured across the Perth metropolitan area over three seasons in 2012. Land use regression (LUR) models were used to estimate annual concentrations of PM_2.5, PM_2.5 absorbance and NO₂ at the residential address of each participant from inception (1996) to 2015. Hospitalisation for respiratory disease between inception and 2015 was ascertained using the Western Australian Data Linkage System. The association between exposure to air pollution with hospitalisation for respiratory disease was examined using Cox regression analysis.

Results

No statistically significant associations were observed in the fully adjusted models. However, positive associations were observed with first hospitalisation for pneumonia (HR 1.08, 95% CI: 1.01–1.16) when adjusted for age, year of enrolment, smoking status, education, BMI and physical activity.

Conclusions

In this longitudinal study of older men we found no evidence of associations between increased long-term exposure to low-level air pollution with increased risk of hospitalisation for respiratory diseases in Perth, Australia. More studies on respiratory morbidity associated with exposure to low levels of air pollution are needed for more comprehensive understanding of the overall risk.

Web-Based Data to Quantify Meteorological and Geographical Effects on Heat Stroke: Case Study in China

Heat stroke is a serious heat-related health outcome that can eventually lead to death. Due to the poor accessibility of heat stroke data, the large-scale relationship between heat stroke and meteorological factors is still unclear. This work aims to clarify the potential relationship between meteorological variables and heat stroke, and quantify the meteorological threshold that affected the severity of heat stroke. We collected daily heat stroke search index (HSSI) and meteorological data for the period 2013-2020 in 333 Chinese cities to analyze the relationship between meteorological variables and HSSI using correlation analysis and Random forest (RF) model. Temperature and relative humidity (RH) accounted for 62% and 9% of the changes of HSSI, respectively. In China, cases of heat stroke may start to occur when temperature exceeds 36°C and RH exceeds 58%. This threshold was 34.5°C and 79% in the north of China, and 36°C and 48% in the south of China. Compared to RH, the threshold of temperature showed a more evident difference affected by altitude and distance from the ocean, which was 35.5°C in inland cities and 36.5°C in coastal cities; 35.5°C in high-altitude cities and 36°C in low-altitude cities. Our findings provide a possible way to analyze the interaction effect of meteorological variables on heat-related illnesses, and emphasizes the effects of geographical environment. The meteorological threshold quantified in this research can also support policymaker to establish a better meteorological warning system for public health.

Health Effects of Long-Term Exposure to Ambient PM2.5 in Asia-Pacific: a Systematic Review of Cohort Studies

Abstract

Purpose of Review

Health effects of long-term exposure to ambient PM_2.5 vary with regions, and 75% of the deaths attributable to PM_2.5 were estimated in Asia-Pacific in 2017. This systematic review aims to summarize the existing evidence from cohort studies on health effects of long-term exposure to ambient PM_2.5 in Asia-Pacific.

Recent Findings

In Asia-Pacific, 60 cohort studies were conducted in Australia, Mainland China, Hong Kong, Taiwan, and South Korea. They consistently supported associations of long-term exposure to PM_2.5 with increased all-cause/non-accidental and cardiovascular mortality as well as with incidence of cardiovascular diseases, type 2 diabetes mellitus, kidney diseases, and chronic obstructive pulmonary disease. Evidence for other health effects was limited. Inequalities were identified in PM_2.5-health associations.

Summary

To optimize air pollution control and public health prevention, further studies need to assess the health effects of long-term PM_2.5 exposure in understudied regions, the health effects of long-term PM_2.5 exposure on mortality and risk of type 2 diabetes mellitus, renal diseases, dementia and lung cancer, and inequalities in PM_2.5-health associations. Study design, especially exposure assessment methods, should be improved.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40572-022-00344-w.

Individual exposure to ambient PM2.5 and hospital admissions for COPD in 110 hospitals: a case-crossover study in Guangzhou, China

Few studies have evaluated the short-term association between hospital admissions and individual exposure to ambient particulate matter (PM_2.5). Particularly, no studies focused on hospital admissions for chronic obstructive pulmonary disease (COPD) at the individual level. We assessed the short-term effects of PM_2.5 on hospitalization admissions for COPD in Guangzhou, China, during 2014-2015, based on satellite-derived estimates of ambient PM_2.5 concentrations at a 1-km resolution near the residential address as individual-level exposure for each patient. Around 40,002 patients with COPD admitted to 110 hospitals were included in this study. A time-stratified case-crossover design with conditional logistic regression models was applied to assess the effects of PM_2.5 based on a 1-km grid data of aerosol optical depth provided by the National Aeronautics and Space Administration on hospital admissions for COPD. Further, we performed stratified analyses by individual demographic characteristics and season of hospital admission. Around 10 μg/m³ increase in individual-level PM_2.5 was associated with an increase of 1.6% (95% confidence interval [CI]: 0.6%, 2.7%) in hospitalization for COPD at a lag of 0-5 days. The impact of PM_2.5 on hospitalization for COPD was greater significantly in males and patients admitted in summer. Our study strengthened the evidence for the adverse effect of PM_2.5 based on satellite-based individual-level exposure data.

Spatially explicit analyses of environmental and health data to determine past, emerging and future threats to child health

BACKGROUND

Dire forecasts predict that an increasingly hostile environment globally will increase the threats to human health. Infants and young children are especially at risk because children are particularly vulnerable to climate-related stressors. The childhood diseases most affected, the breadth and magnitude of future health problems and the time frame over which these problems will manifest remain largely unknown.

OBJECTIVES

To review the possibility that spacially explicit analyses can be used to determine how climate change has affected children's health to date and whether these analyses can be used for future projections.

METHODS

As an example of whether these objectives can be achieved, all available Australian environmental and health databases were reviewed.

RESULTS

Environmental and health data in Australia have been collected for up to 30 years for the same spatial areas at 'Statistical Area level 1' (SA1) scale. SA1s are defined as having a population of between 200 and 800 people and collectively they cover the whole of Australia without gaps or overlap. Although the SA1 environmental and health data have been collected separately, they can be merged to allow detailed statistical analyses that can determine how climate change has affected the health of children.

CONCLUSIONS

The availability of environmental and health datasets that share the same precise spatial coordinates provides a pathway whereby past and emerging effects on child health can be measured and predicted into the future. Given that the future health and well-being of children is one of society's greatest concerns, this information is urgently needed.

Review on pollution damage costs accounting

Although the concept of damage cost accounting is already well-studied and applied, its application to pollution still lacks of an integrated accounting framework, while the spatial-temporal variability of accounting results has not been fully discussed. To fill this gap, this review frames the existing models and their limitations into static and dynamic categories, outlining the characteristics of different methods, which consider both human and non-human damages caused by pollution. Existing data sources, that could be used for accounting purposes, are detailed. Finally, this work discusses the relevance of spatial scales for the computation process, in order to obtain a more detailed information support for environmental policies for future compensatory actions. Conclusions highlights the need to develop a more comprehensive database of exposure-response relationships and to incorporate system alternatives into models to achieve a more accurate damage assessment.

Long-term exposure to ambient air pollution and road traffic noise and asthma incidence in adults: The Danish Nurse cohort

BACKGROUND

Ambient air pollution is likely a risk factor for asthma, and recent evidence suggests the possible relevance of road traffic noise.

OBJECTIVES

We examined the associations of long-term exposure to air pollution and road traffic noise with adult-asthma incidence.

METHODS

We followed 28,731 female nurses (age > 44 years) from the Danish Nurse Cohort, recruited in 1993 and 1999, for first hospital contact for asthma from 1977 until 2015. We estimated residential annual mean concentrations of particulate matter with diameter < 2.5 µm (PM_2.5) since 1990 and nitrogen dioxide (NO₂) since 1970 with the Danish DEHM/UBM/AirGIS modeling system, and road traffic noise (L_den) since 1970 with the Nord2000 model. Time-varying Cox regression models were used to associate air pollution and road traffic noise exposure with asthma incidence.

RESULTS

During 18.6 years' mean follow-up, 528 out of 23,093 participants had hospital contact for asthma. The hazard ratios (HR) and 95% confidence intervals for asthma incidence associated with 3-year moving average exposures were 1.29 (1.03, 1.61) per 6.3 µg/m³ for PM_2.5, 1.16 (1.07, 1.27) per 8.2 µg/m³ for NO₂, and 1.12 (1.00, 1.25) per 10 dB for L_den. The HR for NO₂ remained unchanged after adjustment for either PM_2.5 or L_den, while the HRs for PM_2.5 and L_den attenuated to unity after adjustment for NO₂.

CONCLUSIONS

Long-term exposure to air pollution was associated with adult-asthma incidence independently of road traffic noise, with NO₂ most relevant. Road traffic noise was not independently associated with adult-asthma incidence.

The health impacts of ambient air pollution in Australia: A systematic literature review

BACKGROUND

Ambient (outdoor) air pollution is a key risk factor for health, for which effective policy plays an important preventative role. Australian federal and related state air quality standards have historically relied on international evidence for guidance, which may not accurately reflect the Australian context. There has been, however, a large increase in Australian epidemiological studies over recent years.

AIMS

To provide an updated systematic literature review of peer-reviewed epidemiological studies that examined the health impacts of outdoor air pollution in Australia, including short- and long-term exposure.

METHODS

Following PRISMA guidelines, we conducted a systematic literature review. Broad search terms were applied to two databases (PubMed and Web of Science) and Google Scholar. Quality assessment and risk of bias were assessed using standard metrics. Included studies were summarised by tabulating key study characteristics, grouped by health outcomes.

RESULTS

In total, 72 studies were included in the review. Sixty-four studies (89%) used daily or hourly pollutant concentrations to examine short-term exposure impacts, of which 59 (92%) revealed significant associations with one or more health outcomes, including cardio-respiratory, all-cause mortality or morbidity, and birth outcomes. Eight studies (11%) used annual average pollutant concentrations to investigate long-term exposure finding significant associations with asthma, reduced lung function, atopy and cardio-respiratory mortality across five studies. The remaining three studies found no significant association with asthma, mortality and a range of self-reported diseases, respectively.

CONCLUSIONS

Ambient air pollution has substantial health impacts in Australia. The body of domestic evidence has increased markedly since national air quality standards were first set in the 1990s, which could be drawn on by policy-makers when revising the existing standards, or considering new standards. This article is protected by copyright. All rights reserved.

Long-term exposure to moderate fine particulate matter concentrations and cause-specific mortality in an ageing society

BACKGROUND

Long-term exposure to particulate matter <2.5 μm in size (PM2.5) is considered a risk factor for premature death. However, only a few studies have been conducted in areas with moderate PM2.5 concentrations. Moreover, an ageing society may be more susceptible to environmental exposure and future burden of mortality due to PM2.5.

METHODS

This study estimates hazard ratios (HRs) for all-cause and cause-specific mortality from long-term exposure to moderate PM2.5 concentrations in the elderly populations of seven cities in South Korea. We also projected nationwide elderly mortality caused by long-term exposure to PM2.5, accounting for population ageing until 2045. Mortality in 1 720 230 elderly adults aged ≥65 years in 2008 was monitored across 2009-16 and linked to modelled PM2.5 concentrations.

RESULTS

A total of 421 100 deaths occurred in 2009-16, and the mean of annual PM2.5 concentration ranged between 21.1 and 31.9 μg/m3 in most regions. The overall HR for a 10 μg/m3 increase in a 36-month PM2.5 moving average was 1.024 (95% confidence intervals: 1.009, 1.039). We estimated that 11 833 all-cause nationwide elderly deaths were attributable to PM2.5 exposure. Annual death tolls may increase to 17 948 by 2045. However, if PM2.5 is reduced to 5 μg/m3 by 2045, the tolls may show a lower increase to 3646.

CONCLUSIONS

Long-term exposure to moderately high levels of PM2.5 was associated with increased mortality risk among the elderly. Thus, PM2.5 reduction in response to the projected ageing-associated mortality in South Korea is critical.

Long-term air pollution and road traffic noise exposure and COPD: the Danish Nurse Cohort

BACKGROUND

While air pollution has been linked to the development of chronic obstructive pulmonary disease (COPD), evidence on the role of environmental noise is just emerging. We examined the associations of long-term exposure to air pollution and road traffic noise with COPD incidence.

METHODS

We defined COPD incidence for 24 538 female nurses from the Danish Nurse Cohort (age>44 years) as the first hospital contact between baseline (1993 or 1999) and 2015. We estimated residential annual mean concentrations of particulate matter with diameter<2.5 µm (PM_2.5) since 1990 and nitrogen dioxide (NO₂) since 1970 by the Danish DEHM/UBM/AirGIS modeling system, and road traffic noise (L_den) since 1970 by the Nord2000 model. Time-varying Cox regression models were applied to assess the associations of air pollution and road traffic noise with COPD incidence.

RESULTS

977 nurses developed COPD during 18.6 years' mean follow-up. We observed associations with COPD for all three exposures with hazard ratios (HRs) and 95% confidence intervals (CIs) of 1.19 (1.01, 1.41) per 6.26 µg·m^-3 for PM_2.5, 1.13 (1.05, 1.20) per 8.19 µg·m^-3 for NO₂, and 1.15 (1.06, 1.25) per 10 dB for L_den. Associations with NO₂ and L_den attenuated slightly after mutual adjustment, but were robust to adjustment for PM_2.5. Associations with PM_2.5 were attenuated to null after adjustment for either NO₂ or L_den. No potential interaction effect was observed between air pollutants and noise.

CONCLUSIONS

Long-term exposure to air pollution, especially traffic-related NO₂, and road traffic noise were independently associated with COPD.

Is a Mask That Covers the Mouth and Nose Free from Undesirable Side Effects in Everyday Use and Free of Potential Hazards?

Many countries introduced the requirement to wear masks in public spaces for containing SARS-CoV-2 making it commonplace in 2020. Up until now, there has been no comprehensive investigation as to the adverse health effects masks can cause. The aim was to find, test, evaluate and compile scientifically proven related side effects of wearing masks. For a quantitative evaluation, 44 mostly experimental studies were referenced, and for a substantive evaluation, 65 publications were found. The literature revealed relevant adverse effects of masks in numerous disciplines. In this paper, we refer to the psychological and physical deterioration as well as multiple symptoms described because of their consistent, recurrent and uniform presentation from different disciplines as a Mask-Induced Exhaustion Syndrome (MIES). We objectified evaluation evidenced changes in respiratory physiology of mask wearers with significant correlation of O2 drop and fatigue (p < 0.05), a clustered co-occurrence of respiratory impairment and O2 drop (67%), N95 mask and CO2 rise (82%), N95 mask and O2 drop (72%), N95 mask and headache (60%), respiratory impairment and temperature rise (88%), but also temperature rise and moisture (100%) under the masks. Extended mask-wearing by the general population could lead to relevant effects and consequences in many medical fields.

Smart-Mobility Services for Climate Mitigation in Urban Areas: Case Studies of Baltic Countries and Germany

The transport sector is one of the largest contributors of CO2 emissions and other greenhouse gases. In order to achieve the Paris goal of decreasing the global average temperature by 2 °C, urgent and transformative actions in urban mobility are required. As a sub-domain of the smart-city concept, smart-mobility-solutions integration at the municipal level is thought to have environmental, economic and social benefits, e.g., reducing air pollution in cities, providing new markets for alternative mobility and ensuring universal access to public transportation. Therefore, this article aims to analyze the relevance of smart mobility in creating a cleaner environment and provide strategic and practical examples of smart-mobility services in four European cities: Berlin (Germany), Kaunas (Lithuania), Riga (Latvia) and Tartu (Estonia). The paper presents a systematized literature review about the potential of smart-mobility services in reducing the negative environmental impact to urban environments in various cities. The authors highlight broad opportunities from the European Union and municipal documents for smart-mobility initiatives. The theoretical part is supplemented by socioeconomic and environmental descriptions, as well as experience, related to smart-mobility services in the four cities selected.

A novel approach for exposing and sharing clinical data: the Translator Integrated Clinical and Environmental Exposures Service

OBJECTIVE

This study aimed to develop a novel, regulatory-compliant approach for openly exposing integrated clinical and environmental exposures data: the Integrated Clinical and Environmental Exposures Service (ICEES).

MATERIALS AND METHODS

The driving clinical use case for research and development of ICEES was asthma, which is a common disease influenced by hundreds of genes and a plethora of environmental exposures, including exposures to airborne pollutants. We developed a pipeline for integrating clinical data on patients with asthma-like conditions with data on environmental exposures derived from multiple public data sources. The data were integrated at the patient and visit level and used to create de-identified, binned, "integrated feature tables," which were then placed behind an OpenAPI.

RESULTS

Our preliminary evaluation results demonstrate a relationship between exposure to high levels of particulate matter ≤2.5 µm in diameter (PM2.5) and the frequency of emergency department or inpatient visits for respiratory issues. For example, 16.73% of patients with average daily exposure to PM2.5 >9.62 µg/m3 experienced 2 or more emergency department or inpatient visits for respiratory issues in year 2010 compared with 7.93% of patients with lower exposures (n = 23 093).

DISCUSSION

The results validated our overall approach for openly exposing and sharing integrated clinical and environmental exposures data. We plan to iteratively refine and expand ICEES by including additional years of data, feature variables, and disease cohorts.

CONCLUSIONS

We believe that ICEES will serve as a regulatory-compliant model and approach for promoting open access to and sharing of integrated clinical and environmental exposures data.

Asthma and air pollution: recent insights in pathogenesis and clinical implications

PURPOSE OF REVIEW

Air pollution has adverse effects on the onset and morbidity of respiratory diseases, including asthma. In this review, we discuss recent insights into the effects of air pollution on the incidence and exacerbation of asthma. We focus on epidemiological studies that describe the association between air pollution exposure and development, mortality, persistence and exacerbations of asthma among different age groups. Moreover, we also provide an update on translational studies describing the mechanisms behind this association.

RECENT FINDINGS

Mechanisms linking air pollutants such as particulate matter, nitrogen dioxide (NO2) and ozone to the development and exacerbation of asthma include the induction of both eosinophilic and neutrophilic inflammation driven by stimulation of airway epithelium and increase of pro-inflammatory cytokine production, oxidative stress and DNA methylation changes. Although exposure during foetal development is often reported as a crucial timeframe, exposure to air pollution is detrimental in people of all ages, thus influencing asthma onset as well as increase in asthma prevalence, mortality, persistence and exacerbation.

SUMMARY

In conclusion, this review highlights the importance of reducing air pollution levels to avert the progressive increase in asthma incidence and morbidity.

Long-term exposure to low-level air pollution and incidence of chronic obstructive pulmonary disease: The ELAPSE project

BACKGROUND

Air pollution has been suggested as a risk factor for chronic obstructive pulmonary disease (COPD), but evidence is sparse and inconsistent.

OBJECTIVES

We examined the association between long-term exposure to low-level air pollution and COPD incidence.

METHODS

Within the 'Effects of Low-Level Air Pollution: A Study in Europe' (ELAPSE) study, we pooled data from three cohorts, from Denmark and Sweden, with information on COPD hospital discharge diagnoses. Hybrid land use regression models were used to estimate annual mean concentrations of particulate matter with a diameter < 2.5 µm (PM_2.5), nitrogen dioxide (NO₂), and black carbon (BC) in 2010 at participants' baseline residential addresses, which were analysed in relation to COPD incidence using Cox proportional hazards models.

RESULTS

Of 98,058 participants, 4,928 developed COPD during 16.6 years mean follow-up. The adjusted hazard ratios (HRs) and 95% confidence intervals for associations with COPD incidence were 1.17 (1.06, 1.29) per 5 µg/m³ for PM_2.5, 1.11 (1.06, 1.16) per 10 µg/m³ for NO₂, and 1.11 (1.06, 1.15) per 0.5 10^-5m^-1 for BC. Associations persisted in subset participants with PM_2.5 or NO₂ levels below current EU and US limit values and WHO guidelines, with no evidence for a threshold. HRs for NO₂ and BC remained unchanged in two-pollutant models with PM_2.5, whereas the HR for PM_2.5 was attenuated to unity with NO₂ or BC.

CONCLUSIONS

Long-term exposure to low-level air pollution is associated with the development of COPD, even below current EU and US limit values and possibly WHO guidelines. Traffic-related pollutants NO₂ and BC may be the most relevant.

Long-term exposure to low-level air pollution and incidence of asthma: the ELAPSE project

Background

Long-term exposure to ambient air pollution has been linked to childhood-onset asthma, although evidence is still insufficient. Within the multicentre project Effects of Low-Level Air Pollution: A Study in Europe (ELAPSE), we examined the associations of long-term exposures to particulate matter with a diameter <2.5 µm (PM2.5), nitrogen dioxide (NO2) and black carbon (BC) with asthma incidence in adults.

Methods

We pooled data from three cohorts in Denmark and Sweden with information on asthma hospital diagnoses. The average concentrations of air pollutants in 2010 were modelled by hybrid land-use regression models at participants’ baseline residential addresses. Associations of air pollution exposures with asthma incidence were explored with Cox proportional hazard models, adjusting for potential confounders.

Results

Of 98 326 participants, 1965 developed asthma during a mean follow-up of 16.6 years. We observed associations in fully adjusted models with hazard ratios of 1.22 (95% CI 1.04–1.43) per 5 μg·m−3 for PM2.5, 1.17 (95% CI 1.10–1.25) per 10 µg·m−3 for NO2 and 1.15 (95% CI 1.08–1.23) per 0.5×10−5 m−1 for BC. Hazard ratios were larger in cohort subsets with exposure levels below the European Union and US limit values and possibly World Health Organization guidelines for PM2.5 and NO2. NO2 and BC estimates remained unchanged in two-pollutant models with PM2.5, whereas PM2.5 estimates were attenuated to unity. The concentration–response curves showed no evidence of a threshold.

Conclusions

Long-term exposure to air pollution, especially from fossil fuel combustion sources such as motorised traffic, was associated with adult-onset asthma, even at levels below the current limit values.

Adverse birth outcomes in Victoria, Australia in association with maternal exposure to low levels of ambient air pollution

BACKGROUND

The relationship between maternal exposure to air pollution and birth outcomes is not well characterised where ambient air pollution is relatively low.

OBJECTIVES

We aimed to explore the association between maternal exposure to ambient nitrogen dioxide (NO₂) and fine particulate matter (PM_2.5) and a range of birth outcomes in Victoria, Australia. Secondary aims were to explore whether obstetric conditions, such as gestational diabetes mellitus (GDM) and hypertensive disorders of pregnancy, were effect modifiers in observed relationships.

METHODS

We included all singleton births occurring in Victoria, Australia from 1^st March 2012 to 31^st December 2015 using routinely collected government data. Outcomes included birth weight, small for gestational age (SGA), term low birth weight (tLBW), large for gestational age (LGA), and spontaneous preterm birth (sPTB). We estimated exposure to annual ambient NO₂ and PM_2.5 concentrations, assigned to maternal residence at time of birth. Confounders included maternal, meteorological and temporal variables. Multivariable linear regression and log-binomial regression were used for continuous and dichotomous outcomes, respectively.

RESULTS

There were 285,594 births during the study period. Average NO₂ exposure was 6.0 parts per billion (ppb, median 5.6; interquartile range (IQR) 3.9) and PM_2.5 was 6.9 μg/m³ (median 7.1, IQR 1.3). IQR increases in ambient NO₂ and PM_2.5 were associated with fetal growth restriction, including decrements in birth weight (NO₂ β -22.8 g; 95%CI -26.0, -19.7; PM_2.5 β -14.8 g; 95%CI -17.4, -12.2) and increased risk of SGA (NO₂ RR 1.08; 95%CI 1.06, 1.10; PM_2.5 RR 1.05; 95%CI 1.04, 1.07) and tLBW (NO₂ RR 1.06; 95%CI 1.01, 1.10; PM_2.5 RR 1.04; 95%CI 1.03, 1.08). Women with GDM and hypertensive disorders of pregnancy had greater decrements in birth weight in association with pollutant exposure.

DISCUSSION

In this exploratory study using an annual metric of exposure, maternal exposure to low-level ambient air pollution was associated with fetal growth restriction, which carries substantial public health implications.

Circular RNA 406961 interacts with ILF2 to regulate PM2.5-induced inflammatory responses in human bronchial epithelial cells via activation of STAT3/JNK pathways

Fine particulate matter (PM_2.5) has been verified to augmented the incidence of pneumonia, asthma, pulmonary fibrosis, and other pulmonary diseases. Airway inflammation is the pathological basis of the respiratory system, and understanding the molecular mechanisms responsible for airway inflammation may thus support the diagnosis and treatment of respiratory diseases. In our study, human bronchial epithelial cells (BEAS-2B) were exposed to various concentrations of PM_2.5 for 48 h. PM_2.5 entered the cells, resulting in increased production of interleukin 6 (IL-6) and interleukin 8 (IL-8) and decreased the expression of circular RNA 406961 (circ_406961). Further, PM_2.5 with a concentration of 75 μg/mL was applied to mechanism study. Functional experiments further confirmed that circ_406961 inhibited PM_2.5-induced BEAS-2B cell inflammation. RNA pull-down and mass spectrometry showed that circ_406961 interacted with interleukin enhancer-binding factor 2 (ILF2), which could regulate phosphorylation of signal transducer and activator of transcription 3 (STAT3) and mitogen-activated protein kinase 8 (MAPK8, JNK). Our studies showed that circ_406961 inhibited activation of STAT3/JNK pathways via interacting with ILF2 protein, thereby inhibiting the PM_2.5-induced inflammatory reaction.

The potential impact of bushfire smoke on brain health

Smoke from bushfires (also known as wildfires or forest fires) has blanketed large regions of Australia during the southern hemisphere summer of 2019/2020, potentially endangering residents who breathe the polluted air. While such air pollution is known to cause respiratory irritation and damage, its effect on the brain is not well described. In this review, we aim to outline the potentially damaging effects of bushfire smoke on brain health. We also describe the composition of air pollution, including ambient particulate matter (PM) and bushfire PM, before covering the general health effects of each. The investigated entry routes for ambient PM and postulated entry routes for bushfire PM are discussed, along with epidemiological and experimental evidence of the effect of both PMs in the brain. It appears that bushfire PM may be more toxic than ambient PM, and that it may enter the brain through extrapulmonary or olfactory routes to cause inflammation and oxidative stress. Ultimately, this review highlights the desperate requirement of greater research into the effects of bushfire PM on brain health.

Spatiotemporal variations and influencing factors of PM2.5 concentrations in Beijing, China

Fine particulate matter (PM_2.5) pollution has become a worldwide environmental concern because of its adverse impacts on human health. This study aimed to explore the spatiotemporal variations and influencing factors of PM_2.5 concentrations in Beijing during the 2013-2018 period, and further analyzed the impacts of environmental protection policies implemented in recent years. Notably, this study employed various statistical methods, i.e., ordinary Kriging interpolation, spatial autocorrelation analysis, time-series analysis and the Bonferroni test, to evaluate the regional and seasonal differences of PM_2.5 concentrations based on long-term monitoring data. The results illustrated that PM_2.5 concentrations decreased on a yearly basis, demonstrating that air pollution control policies have achieved initial success. Furthermore, PM_2.5 concentrations were higher in the winter and in the southern regions. Diurnal variation presented a bimodal distribution, which varied slightly with the season. Relative humidity and wind speed were the principal meteorological factors affecting the distribution of PM_2.5 concentrations, while precipitation had essentially no effect. A high positive correlation between PM_2.5 and gaseous pollutants (SO₂, NO₂, and CO) indirectly reflected the contribution of automobile exhaust and coal-fired emissions. Generally, PM_2.5 concentrations demonstrated strong spatiotemporal variations, and meteorological factors and pollutant emissions played an important role in this.

The impact of exposure to desert dust on infants' symptoms and countermeasures to reduce the effects

BACKGROUND

The association between particulate matter (PM), including desert dust, and allergic symptoms has not been well studied. We examined whether PM exacerbated nose/eye/respiratory symptoms in infants, with a focus on the desert dust element, and assessed possible countermeasures.

METHODS

We conducted a panel study of 1492 infants from October 2014 to July 2016 in 3 regions in Japan as an adjunct study of the Japan Environment and Children's Study. Infants' daily symptom scores and behaviors were acquired by web-based questionnaires sent to mothers, who answered within a day using mobile phones. Odds ratios (OR) for symptom development per increased fine PM or desert dust exposure were estimated. Regular use of medications and behaviors on the day of exposure were investigated as possible effect modifiers.

RESULTS

Infants developed nose/eye/respiratory symptoms significantly more often in accordance with fine particulate levels (adjusted OR per 10 µg/m³ increase: 1.04, 95% confidence interval [CI]: 1.01-1.07). A model including both fine particulates and desert dust showed reduced OR for fine particulates and robust OR for desert dust (adjusted OR per 0.1/km increase: 1.16, 95% CI: 1.09-1.23). An increased OR was observed both in infants who had previously wheezed and in those who had never wheezed. Receiving information on the particulate forecast, reducing time outdoors, closing windows, and regular use of leukotriene receptor antagonists were significant effect modifiers.

CONCLUSIONS

Transborder desert dust arrival increased the risk of nose/eye/respiratory symptoms development in infants. Regular use of leukotriene receptor antagonists and other countermeasures reduced the risk.

Maternal Exposure to Ambient Air Pollution and Pregnancy Complications in Victoria, Australia

The relationship between maternal exposure to ambient air pollution and pregnancy complications is not well characterized. We aimed to explore the relationship between maternal exposure to ambient nitrogen dioxide (NO₂) and fine particulate matter (PM_2.5) and hypertensive disorders of pregnancy, gestational diabetes mellitus (GDM) and placental abruption. Using administrative data, we defined a state-wide cohort of singleton pregnancies born between 1 March 2012 and 31 December 2015 in Victoria, Australia. Annual average NO₂ and PM_2.5 was assigned to maternal residence at the time of birth. 285,594 singleton pregnancies were included. An IQR increase in NO₂ (3.9 ppb) was associated with reduced likelihood of hypertensive disorders of pregnancy (RR 0.89; 95%CI 0.86, 0.91), GDM (RR 0.92; 95%CI 0.90, 0.94) and placental abruption (RR 0.81; 95%CI 0.69, 0.95). Mixed observations and smaller effect sizes were observed for IQR increases in PM_2.5 (1.3 µg/m³) and pregnancy complications; reduced likelihood of hypertensive disorders of pregnancy (RR 0.95; 95%CI 0.93, 0.97), increased likelihood of GDM (RR 1.02; 95%CI 1.00, 1.03) and no relationship for placental abruption. In this exploratory study using an annual metric of exposure, findings were largely inconsistent with a priori expectations and further research involving temporally resolved exposure estimates are required.

Acute Effects of Air Pollution on Hospital Admissions for Asthma, COPD, and Bronchiectasis in Ahvaz, Iran

Background and Aim

Although air pollution is a serious problem in Ahvaz, the association between air pollution and respiratory diseases has not been studied enough in this area. The aim of this study was to determine the relation between short-term exposure to air pollutants and the risk of hospital admissions due to asthma, COPD, and bronchiectasis in Ahvaz.

Methods

Hospital admissions data and air pollutants including O3, NO, NO2, SO2, CO, PM10, and PM2.5 were obtained from 2008 to 2018. Adjusted Quasi-Poisson regression with a distributed lag model, controlled for trend, seasonality, weather, weekdays, and holidays was used for data analysis.

Results

The results showed a significant increase in hospital admissions for asthma (RR=1.004, 95% CI: 1.002-1.007) and COPD (RR=1.003, 95% CI: 1.001-1.005) associated with PM2.5. PM10 was associated with increased hospital admissions due to bronchiectasis in both genders (Men: RR=1.003, 95% CI: 1.001-1.006) (Female: RR=1.003, 95% CI: 1.000-1.006). NO2 was also associated with an increased risk of hospital admissions for asthma (RR=1.040, 95% CI: 1.008-1.074) and COPD (RR=1.049, 95% CI: 1.010-1.090). SO2 was associated with the risk of hospital admissions of asthma (RR=1.069, 95% CI: 1.017-1.124) and bronchiectasis (RR=1.030, 95% CI: 1.005-1.056). Finally, CO was associated with COPD (RR=1.643, 95% CI: 1.233-2.191) and bronchiectasis (RR=1.542, 95% CI: 1.035-2.298) hospital admissions.

Conclusion

Short-term exposure to air pollutants significantly increases the risk of hospital admissions for asthma, COPD, and bronchiectasis in the adult and elderly population.

Immunologic and Non-Immunologic Mechanisms Leading to Airway Remodeling in Asthma

Asthma increases worldwide without any definite reason and patient numbers double every 10 years. Drugs used for asthma therapy relax the muscles and reduce inflammation, but none of them inhibited airway wall remodeling in clinical studies. Airway wall remodeling can either be induced through pro-inflammatory cytokines released by immune cells, or direct binding of IgE to smooth muscle cells, or non-immunological stimuli. Increasing evidence suggests that airway wall remodeling is initiated early in life by epigenetic events that lead to cell type specific pathologies, and modulate the interaction between epithelial and sub-epithelial cells. Animal models are only available for remodeling in allergic asthma, but none for non-allergic asthma. In human asthma, the mechanisms leading to airway wall remodeling are not well understood. In order to improve the understanding of this asthma pathology, the definition of “remodeling” needs to be better specified as it summarizes a wide range of tissue structural changes. Second, it needs to be assessed if specific remodeling patterns occur in specific asthma pheno- or endo-types. Third, the interaction of the immune cells with tissue forming cells needs to be assessed in both directions; e.g., do immune cells always stimulate tissue cells or are inflamed tissue cells calling immune cells to the rescue? This review aims to provide an overview on immunologic and non-immunologic mechanisms controlling airway wall remodeling in asthma.

A Clean Air Plan for Sydney: An Overview of the Special Issue on Air Quality in New South Wales

This paper presents a summary of the key findings of the special issue of Atmosphere on Air Quality in New South Wales and discusses the implications of the work for policy makers and individuals. This special edition presents new air quality research in Australia undertaken by (or in association with) the Clean Air and Urban Landscapes hub, which is funded by the National Environmental Science Program on behalf of the Australian Government’s Department of the Environment and Energy. Air pollution in Australian cities is generally low, with typical concentrations of key pollutants at much lower levels than experienced in comparable cities in many other parts of the world. Australian cities do experience occasional exceedances in ozone and PM2.5 (above air pollution guidelines), as well as extreme pollution events, often as a result of bushfires, dust storms, or heatwaves. Even in the absence of extreme events, natural emissions play a significant role in influencing the Australian urban environment, due to the remoteness from large regional anthropogenic emission sources. By studying air quality in Australia, we can gain a greater understanding of the underlying atmospheric chemistry and health risks in less polluted atmospheric environments, and the health benefits of continued reduction in air pollution. These conditions may be representative of future air quality scenarios for parts of the Northern Hemisphere, as legislation and cleaner technologies reduce anthropogenic air pollution in European, American, and Asian cities. However, in many instances, current legislation regarding emissions in Australia is significantly more lax than in other developed countries, making Australia vulnerable to worsening air pollution in association with future population growth. The need to avoid complacency is highlighted by recent epidemiological research, reporting associations between air pollution and adverse health outcomes even at air pollutant concentrations that are lower than Australia’s national air quality standards. Improving air quality is expected to improve health outcomes at any pollution level, with specific benefits projected for reductions in long-term exposure to average PM2.5 concentrations.

Long-term exposure to PM2.5 and ozone and hospital admissions of Medicare participants in the Southeast USA

We examined the association between average annual fine particulate matter (PM_2.5) and ozone and first hospital admissions of Medicare participants for stroke, chronic obstructive pulmonary disease (COPD), pneumonia, myocardial infarction (MI), lung cancer, and heart failure (HF). Annual average PM_2.5 and ozone levels were estimated using high-resolution spatio-temporal models. We fit a marginal structural Cox proportional hazards model, using stabilized inverse probability weights (IPWs) to account for the competing risk of death and confounding. Analyses were then repeated after restricting to exposure levels below the current U.S. standards. The results showed that PM_2.5 was significantly associated with an increased hazard of admissions for all studied outcomes; the highest observed being a 6.1% (95% CI: 5.9%-6.2%) increase in the hazard of admissions with pneumonia for each μg/m³ increase in particulate levels. Ozone was also significantly associated with an increase in the risk of first hospital admissions of all outcomes. The hazard of pneumonia increased by 3.0% (95% CI: 2.9%-3.1%) for each ppb increase in the ozone level. Our results reveal a need to regulate long-term ozone exposure, and that associations persist below current PM_2.5 standards.

Long-term exposure to PM2.5 and ozone and hospital admissions of Medicare participants in the Southeast USA

We examined the association between average annual fine particulate matter (PM_2.5) and ozone and first hospital admissions of Medicare participants for stroke, chronic obstructive pulmonary disease (COPD), pneumonia, myocardial infarction (MI), lung cancer, and heart failure (HF). Annual average PM_2.5 and ozone levels were estimated using high-resolution spatio-temporal models. We fit a marginal structural Cox proportional hazards model, using stabilized inverse probability weights (IPWs) to account for the competing risk of death and confounding. Analyses were then repeated after restricting to exposure levels below the current U.S. standards. The results showed that PM_2.5 was significantly associated with an increased hazard of admissions for all studied outcomes; the highest observed being a 6.1% (95% CI: 5.9%-6.2%) increase in the hazard of admissions with pneumonia for each μg/m³ increase in particulate levels. Ozone was also significantly associated with an increase in the risk of first hospital admissions of all outcomes. The hazard of pneumonia increased by 3.0% (95% CI: 2.9%-3.1%) for each ppb increase in the ozone level. Our results reveal a need to regulate long-term ozone exposure, and that associations persist below current PM_2.5 standards.