Comparing exposure assessment methods for traffic-related air pollution in an adverse pregnancy outcome study

Background

Previous studies reported adverse impacts of traffic-related air pollution exposure on pregnancy outcomes. Yet, little information exists on how effect estimates are impacted by the different exposure assessment methods employed in these studies.

Objectives

To compare effect estimates for traffic-related air pollution exposure and preeclampsia, preterm birth (gestational age less than 37 weeks), and very preterm birth (gestational age less than 30 weeks) based on four commonly used exposure assessment methods.

Methods

We identified 81,186 singleton births during 1997–2006 at four hospitals in Los Angeles and Orange Counties, California. Exposures were assigned to individual subjects based on residential address at delivery using the nearest ambient monitoring station data [carbon monoxide (CO), nitrogen dioxide (NO₂), nitric oxide (NO), nitrogen oxides (NO_x), ozone (O₃), and particulate matter less than 2.5 (PM_2.5) or less than 10 (PM₁₀) μm in aerodynamic diameter], both unadjusted and temporally adjusted land-use regression (LUR) model estimates (NO, NO₂, and NO_x), CALINE4 line-source air dispersion model estimates (NO_x and PM_2.5), and a simple traffic-density measure. We employed unconditional logistic regression to analyze preeclampsia in our birth cohort, while for gestational age-matched risk sets with preterm and very preterm birth we employed conditional logistic regression.

Results

We observed elevated risks for preeclampsia, preterm birth, and very preterm birth from maternal exposures to traffic air pollutants measured at ambient stations (CO, NO, NO₂, and NO_x) and modeled through CALINE4 (NO_x and PM_2.5) and LUR (NO₂ and NO_x). Increased risk of preterm birth and very preterm birth were also positively associated with PM₁₀ and PM_2.5 air pollution measured at ambient stations. For LUR-modeled NO₂ and NO_x exposures, elevated risks for all the outcomes were observed in Los Angeles only—the region for which the LUR models were initially developed. Unadjusted LUR models often produced odds ratios somewhat larger in size than temporally adjusted models. The size of effect estimates was smaller for exposures based on simpler traffic density measures than the other exposure assessment methods.

Conclusion

We generally confirmed that traffic-related air pollution was associated with adverse reproductive outcomes regardless of the exposure assessment method employed, yet the size of the estimated effect depended on how both temporal and spatial variations were incorporated into exposure assessment. The LUR model was not transferable even between two contiguous areas within the same large metropolitan area in Southern California.     

Spatio-seasonal variation in ambient air pollutants and influence of meteorological factors in Coimbatore,Southern India

Air quality is used worldwide to confirm the current status of air pollution level and associated health risks to the public. Several air pollutants reach very high concentrations in many regions across India. In this study, air pollutants were measured in an urban city of Coimbatore, Tamil Nadu, Southern India, during 2013 to 2014 based on season and location, and the influence of meteorological factors. Air pollutants (PM₁₀, PM_2.5, SO₂, NO₂, CO, and O₃) across eight locations including industrial, residential, traffic, and commercial areas were assessed. The results showed that PM₁₀, PM_2.5, and CO were the most serious pollutants and their average concentrations ranged from 65.5 to 98.6 μg/m³, 27.6 to 56.9 μg/m³, and 1.58 to 8.21 mg/m³, respectively, among various locations. Significantly higher concentration of air pollutants was recorded in industrial areas followed by traffic and commercial areas. Comparatively higher mean concentration of O₃ (2.22?±?0.75 μg/m³) and CO (7.73?±?1.86 mg/m³) was recorded during the summer season, whereas the concentration of PM₁₀ (80.3?±?24.4 μg/m³), PM_2.5 (45.1?±?17.7 μg/m³), SO₂ (7.86?±?1.55 μg/m³), and NO₂ (13?±?1.81 μg/m³) was higher in southwest monsoon. Ozone (O₃) and CO positively correlated with temperature and negatively correlated with relative humidity. The level of PM₁₀, PM_2.5, and CO concentrations exceeded the National Ambient Air Quality Standards (NAAQS) guidelines. The present study’s results emphasize the need of effective air pollution control in Coimbatore. Precautionary measures to be taken to avoid exposure of air pollutants to the public and minimize pollutants. This study further suggests an investigation on the adverse impact on human health and environment using appropriate risk analysis techniques.     

Performance of Multi-City Land Use Regression Models for Nitrogen Dioxide and Fine Particles

Background: Land use regression (LUR) models have been developed mostly to explain intraurban variations in air pollution based on often small local monitoring campaigns. Transferability of LUR models from city to city has been investigated, but little is known about the performance of models based on large numbers of monitoring sites covering a large area.Objectives: We aimed to develop European and regional LUR models and to examine their transferability to areas not used for model development.Methods: We evaluated LUR models for nitrogen dioxide (NO₂) and particulate matter (PM; PM_2.5, PM_2.5 absorbance) by combining standardized measurement data from 17 (PM) and 23 (NO₂) ESCAPE (European Study of Cohorts for Air Pollution Effects) study areas across 14 European countries for PM and NO₂. Models were evaluated with cross-validation (CV) and hold-out validation (HV). We investigated the transferability of the models by successively excluding each study area from model building.Results: The European model explained 56% of the concentration variability across all sites for NO₂, 86% for PM_2.5, and 70% for PM_2.5 absorbance. The HV R²s were only slightly lower than the model R² (NO₂, 54%; PM_2.5, 80%; PM_2.5 absorbance, 70%). The European NO₂, PM_2.5, and PM_2.5 absorbance models explained a median of 59%, 48%, and 70% of within-area variability in individual areas. The transferred models predicted a modest-to-large fraction of variability in areas that were excluded from model building (median R²: NO₂, 59%; PM_2.5, 42%; PM_2.5 absorbance, 67%).Conclusions: Using a large data set from 23 European study areas, we were able to develop LUR models for NO₂ and PM metrics that predicted measurements made at independent sites and areas reasonably well. This finding is useful for assessing exposure in health studies conducted in areas where no measurements were conducted.Citation: Wang M, Beelen R, Bellander T, Birk M, Cesaroni G, Cirach M, Cyrys J, de Hoogh K, Declercq C, Dimakopoulou K, Eeftens M, Eriksen KT, Forastiere F, Galassi C, Grivas G, Heinrich J, Hoffmann B, Ineichen A, Korek M, Lanki T, Lindley S, Modig L, Mölter A, Nafstad P, Nieuwenhuijsen MJ, Nystad W, Olsson D, Raaschou-Nielsen O, Ragettli M, Ranzi A, Stempfelet M, Sugiri D, Tsai MY, Udvardy O, Varró MJ, Vienneau D, Weinmayr G, Wolf K, Yli-Tuomi T, Hoek G, Brunekreef B. 2014. Performance of multi-city land use regression models for nitrogen dioxide and fine particles. Environ Health Perspect 122:843–849; http://dx.doi.org/10.1289/ehp.1307271     

Spatial and temporal variations in criteria air pollutants in three typical terrain regions in Shaanxi,China, during 2015

Numerous studies have investigated air pollution in severely polluted plains, but the characteristics of pollutants are not well understood in other terrain regions. In this study, air pollution characteristics were analyzed in three typical terrain regions (plateau, plain, and mountain regions) in Shaanxi, based on hourly ambient monitoring of particulate matter with diameter less than 2.5 μm (PM_2.5) and less than 10 μm (PM₁₀), CO, SO₂, NO₂, and O₃ in 2015. PM_2.5 and PM₁₀ were the dominant pollutants in three regions, and their annual concentrations exceeded the Grade II standards by 9.4–68.6 and 6.0–73.9%, respectively. PM_2.5, PM₁₀, CO, SO₂, and NO₂ concentrations had similar seasonal trends with highest values in winter and lowest values in summer, whereas O₃ concentrations exhibited the opposite trend. Guanzhong Plain had higher PM_2.5, PM₁₀, NO₂, and SO₂ concentrations but lower CO, 1-h peak O₃, and 8-h peak O₃ (8 h-O₃) compared to other regions. PM_2.5, PM₁₀, and 8 h-O₃ were the three main dominant pollutants. The nonattainment rate was highest in winter and lowest in summer or autumn. Pollution also exhibited synergy, especially in the plateau region and Guanzhong Plain. PM_2.5 was significantly correlated with PM₁₀. NO₂ and SO₂ were positively correlated with PM_2.5 and PM₁₀, while 8 h-O₃ generally had significant negative correlations with other pollutants, especially in the winter. These results provide a comprehensive understanding of pollution status in the three typical terrain regions in Shaanxi and are helpful for improving air quality.     

Spatial and seasonal variations of gaseous and particulate matter pollutants in 31 provincial capital cities,China

In order to know air pollution situation and their health, environmental, and climate effects, the air quality data with high temporal and spatial resolutions are essential. The spatial and seasonal variations of six criteria pollutants were investigated in 31 provincial capital cities between April 2014 and March 2015 using hourly mean air quality monitoring data, and the cities were classified by cluster analysis based on annual variations of air pollutants. The annual mean concentrations of PM_2.5 (particulate matter with aerodynamic diameter less than 2.5 μm) and PM₁₀ (particulate matter with aerodynamic diameter less than 10 μm) were high for all cities, which exceeded Chinese Ambient Air Quality Standards (CAAQS) Grade I standards. Only Fuzhou, Haikou, Kunming, and Lasa met Grade II standards for PM_2.5 and PM₁₀. Additionally, elevated SO₂ concentration was observed in northern cities, especially in winter. However, the seasonal variation of O₃ was opposite to other pollutants with the lowest concentrations in the winter and the highest in the summer. Winter domestic heating has significant impact on urban air quality, especially SO₂ and PM₁₀.     

An association between long-term exposure to ambient air pollution and mortality from lung cancer and respiratory diseases in Japan

Background

Evidence for a link between long-term exposure to air pollution and lung cancer is limited to Western populations. In this prospective cohort study, we examined this association in a Japanese population.

Methods

The study comprised 63 520 participants living in 6 areas in 3 Japanese prefectures who were enrolled between 1983 and 1985. Exposure to particulate matter less than 2.5 µm in aerodynamic diameter (PM_2.5), sulfur dioxide (SO₂), and nitrogen dioxide (NO₂) was assessed using data from monitoring stations located in or nearby each area. The Cox proportional hazards model was used to calculate the hazard ratios associated with the average concentrations of these air pollutants.

Results

The 10-year average concentrations of PM_2.5, SO₂, and NO₂ before recruitment (1974–1983) were 16.8 to 41.9 µg/m³, 2.4 to 19.0 ppb, and 1.2 to 33.7 ppb, respectively (inter-area range). During an average follow-up of 8.7 years, there were 6687 deaths, including 518 deaths from lung cancer. The hazard ratios for lung cancer mortality associated with a 10-unit increase in PM_2.5 (µg/m³), SO₂ (ppb), and NO₂ (ppb) were 1.24 (95% confidence interval: 1.12–1.37), 1.26 (1.07–1.48), and 1.17 (1.10–1.26), respectively, after adjustment for tobacco smoking and other confounding factors. In addition, a significant increase in risk was observed for male smokers and female never smokers. Respiratory diseases, particularly pneumonia, were also significantly associated with all the air pollutants.

Conclusions

Long-term exposure to air pollution is associated with lung cancer and respiratory diseases in Japan.Key words: air pollution, lung neoplasms, nitrogen dioxide, particulate matter, sulfur dioxide     

Air Pollution and Lung Function in Dutch Children: A Comparison of Exposure Estimates and Associations Based on Land Use Regression and Dispersion Exposure Modeling Approaches

Background

There is limited knowledge about the extent to which estimates of air pollution effects on health are affected by the choice for a specific exposure model.

Objectives

We aimed to evaluate the correlation between long-term air pollution exposure estimates using two commonly used exposure modeling techniques [dispersion and land use regression (LUR) models] and, in addition, to compare the estimates of the association between long-term exposure to air pollution and lung function in children using these exposure modeling techniques.

Methods

We used data of 1,058 participants of a Dutch birth cohort study with measured forced expiratory volume in 1 sec (FEV₁), forced vital capacity (FVC), and peak expiratory flow (PEF) measurements at 8 years of age. For each child, annual average outdoor air pollution exposure [nitrogen dioxide (NO₂), mass concentration of particulate matter with diameters ≤ 2.5 and ≤ 10 μm (PM_2.5, PM₁₀), and PM_2.5 soot] was estimated for the current addresses of the participants by a dispersion and a LUR model. Associations between exposures to air pollution and lung function parameters were estimated using linear regression analysis with confounder adjustment.

Results

Correlations between LUR- and dispersion-modeled pollution concentrations were high for NO₂, PM_2.5, and PM_2.5 soot (R = 0.86–0.90) but low for PM₁₀ (R = 0.57). Associations with lung function were similar for air pollutant exposures estimated using LUR and dispersion modeling, except for associations of PM_2.5 with FEV₁ and FVC, which were stronger but less precise for exposures based on LUR compared with dispersion model.

Conclusions

Predictions from LUR and dispersion models correlated very well for PM_2.5, NO₂, and PM_2.5 soot but not for PM₁₀. Health effect estimates did not depend on the type of model used to estimate exposure in a population of Dutch children.

Citation

Wang M, Gehring U, Hoek G, Keuken M, Jonkers S, Beelen R, Eeftens M, Postma DS, Brunekreef B. 2015. Air pollution and lung function in Dutch children: a comparison of exposure estimates and associations based on land use regression and dispersion exposure modeling approaches. Environ Health Perspect 123:847–851; http://dx.doi.org/10.1289/ehp.1408541     

Fine particulate air pollution and hospitalization for pneumonia: a case-crossover study in Shijiazhuang,China

Many epidemiological studies have shown that airborne particulate matter (PM) is a risk factor for multiple respiratory diseases and increased hospitalization rates. Fine PM (PM_2.5, diameter <2.5 μm) is considered to be a greater health hazard than coarse PM (PM₁₀, 2.5–10 μm) because it adsorbs more harmful substances and can enter deeper parts of the lungs. We investigated the correlation between hospitalization for pneumonia and PM_2.5 levels in Shijiazhuang, a city in northern China. Daily data on hospitalizations for community-acquired pneumonia and ambient air pollution levels in Shijiazhuang were obtained for 2013. A bidirectional case-crossover design was used to investigate the association between hospitalization for pneumonia and atmospheric PM_2.5, PM₁₀, SO₂, NO₂, CO, and O₃ levels. The effects of pollutant levels from lag0 (day of hospitalization) to lag5 (five days before lag0) were investigated in both single and multi-pollutant models, adjusted for daily weather variables. For the single-pollutant model, hospitalization for pneumonia correlated positively with higher PM_2.5 levels, with an increase of 1.1 % in daily admissions per 10-μg/m³ increase in the PM_2.5 level at lag0. In the multi-pollutant model, the observed effects of PM_2.5 remained significant. Stratified analysis of exposure based on sex, age, season, and comorbidities showed that the effect of PM_2.5 on hospitalization for pneumonia was stronger in males, people younger than 60 years, people without comorbidities, and on warm days. These results indicate that higher levels of PM_2.5 increase the risk of hospitalization for pneumonia in Shijiazhuang, China.     

Assessment of health-based economic costs linked to fine particulate (PM<Subscript>2.5</Subscript>) pollution: a case study of haze during January 2013 in Beijing,China

Beijing is a haze-prone city, which experienced continuous haze during January 2013. The mean fine particulate (PM_2.5) concentrations during January 2013 were 98–228 μg/m³, which were much higher than the mean concentration of 25 μg/m³ over 24 h suggested by the Air Quality Guidelines of the World Health Organization. This event provides a case study to evaluate the effects of extreme haze on health and its subsequent economic costs. We evaluated the health impacts on the Beijing population that were directly attributable to PM_2.5 pollution during the haze. Based on the principle of willingness to pay, we estimated the economic costs associated with these health impacts. This specific haze event in Beijing caused 479 acute deaths from all causes. The economic cost of the deaths attributed to PM_2.5 pollution was ~180 million USD, equivalent to 0.76 % of the gross domestic product (GDP). We also assessed discrepancies in economic costs at the district level in Beijing. Our results revealed that the ratios of economic cost to GDP varied markedly among the 16 districts of Beijing. Such data are relevant to formulating more effective countermeasures to reduce the economic burden associated with severe weather events such as haze.     

Traffic-related air toxics and term low birth weight in Los Angeles County, California

Background: Numerous studies have linked criteria air pollutants with adverse birth outcomes, but there is less information on the importance of specific emission sources, such as traffic, and air toxics.Objectives: We used three exposure data sources to examine odds of term low birth weight (LBW) in Los Angeles, California, women when exposed to high levels of traffic-related air pollutants during pregnancy.Methods: We identified term births during 1 June 2004 to 30 March 2006 to women residing within 5 miles of a South Coast Air Quality Management District (SCAQMD) Multiple Air Toxics Exposure Study (MATES III) monitoring station. Pregnancy period average exposures were estimated for air toxics, including polycyclic aromatic hydrocarbons (PAHs), source-specific particulate matter < 2.5 μm in aerodynamic diameter (PM_2.5) based on a chemical mass balance model, criteria air pollutants from government monitoring data, and land use regression (LUR) model estimates of nitric oxide (NO), nitrogen dioxide (NO₂) and nitrogen oxides (NO_x). Associations between these metrics and odds of term LBW (< 2,500 g) were examined using logistic regression.Results: Odds of term LBW increased approximately 5% per interquartile range increase in entire pregnancy exposures to several correlated traffic pollutants: LUR measures of NO, NO₂, and NO_x, elemental carbon, and PM_2.5 from diesel and gasoline combustion and paved road dust (geological PM_2.5).Conclusions: These analyses provide additional evidence of the potential impact of traffic-related air pollution on fetal growth. Particles from traffic sources should be a focus of future studies.     

Apheis: Health Impact Assessment of Long-term Exposure to PM2.5 in 23 European Cities

Introduction

Apheis aims to provide European decision makers, environmental-health professionals and the general public with up-to-date and easy-to-use information on air pollution (AP) and public health (PH). In the Apheis-3 phase we quantified the PH impact of long-term exposure to PM_2.5 (particulate matter < 2.5 μm) in terms of attributable number of deaths and the potential gain in life expectancy in 23 European cities.

Methods

We followed the World Health Organization (WHO) methodology for Health Impact Assessment (HIA) and the Apheis guidelines for data collection and analysis. We used the programme created by PSAS-9 for attributable-cases calculations and the WHO software AirQ to estimate the potential gain in life expectancy. For most cities, PM_2.5 levels were calculated from PM₁₀ measurements using a local or European conversion factor.

Results

The HIA estimated that 16,926 premature deaths from all causes, including 11,612 cardiopulmonary deaths and 1901 lung-cancer deaths, could be prevented annually if long-term exposure to PM_2.5 levels were reduced to 15 μg/m³ in each city. Equivalently, this reduction would increase life expectancy at age 30 by a range between one month and more than two years in the Apheis cities.

Conclusions

In addition to the number of attributable cases, our HIA has estimated the potential gain in life expectancy for long-term exposure to fine particles, contributing to a better quantification of the impact of AP on PH in Europe.     

Exposure to particulate air pollution and long-term incidence of frailty after myocardial infarction

PurposeFrailty, a multidimensional syndrome of increased vulnerability, is prevalent post-myocardial infarction (MI) and predicts mortality and recurrent events. We investigated whether chronic exposure to particulate matter ≤2.5 μm in diameter (PM_2.5) is associated with the development of post-MI frailty.MethodsParticipants (n = 1120) were aged 65 or less and admitted to hospital in central Israel with first MI in 1992 and 1993. Daily measures of PM_2.5 recorded at air quality monitoring stations were summarized and chronic exposure was estimated individually using the geo-coded residential location. Frailty assessment was conducted via an index based on deficit accumulation, and those defined as frail (applying a threshold of ≥0.25) at baseline were excluded. Remaining participants who survived to follow-up 10 to 13 years post-MI (n = 848) were reassessed for frailty. Logistic regression models were constructed to evaluate the role of PM_2.5 exposure in frailty risk prediction.ResultsMean exposure to PM_2.5 was 24.2 μg/m³ (range, 16.9–28.6). A total of 301 participants (35.5%) developed frailty during follow-up. Adjusting for sociodemographic and clinical variables, PM_2.5 exposure was associated with increased odds of developing frailty (odds ratio, 1.53; 95% confidence interval, 1.22–1.91, comparing the 75th vs. 25th percentiles). Addition of PM_2.5 exposure to the multivariable model resulted in an integrated discrimination improvement of 1.60% (P = .005) and a net reclassification index of 6.51% (P = .02).ConclusionsAn association was observed between exposure to PM_2.5 and incidence of frailty, providing a potential intermediary between air pollution and post-MI outcomes.     

Associations between short-term exposure to particulate matter and ultrafine particles and myocardial infarction in Augsburg,Germany

BackgroundShort-term exposure to increased particulate matter (PM) concentration has been reported to trigger myocardial infarction (MI). However, the association with ultrafine particles remains unclear.ObjectivesWe aimed to assess the effects of short-term air pollution and especially ultrafine particles on registry-based MI events and coronary deaths in the area of Augsburg, Germany.MethodsBetween 1995 and 2009, the MONICA/KORA myocardial infarction registry recorded 15,417 cases of MI and coronary deaths. Concentrations of PM < 10 μm (PM₁₀), PM < 2.5 μm (PM_2.5), particle number concentration (PNC) as indicator for ultrafine particles, and meteorological parameters were measured in the study region. Quasi-Poisson regression adjusting for time trend, temperature, season, and weekday was used to estimate immediate, delayed and cumulative effects of air pollutants on the occurrence of MI. The daily numbers of total MI, nonfatal and fatal events as well as incident and recurrent events were analysed.ResultsWe observed a 1.3% risk increase (95%-confidence interval: [−0.9%; 3.6%]) for all events and a 4.4% [−0.4%; 9.4%] risk increase for recurrent events per 24.3 μg/m³ increase in same day PM₁₀ concentrations. Nonfatal events indicated a risk increase of 3.1% [−0.1%; 6.5%] with previous day PM₁₀. No association was seen for PM_2.5 which was only available from 1999 on. PNC showed a risk increase of 6.0% [0.6%; 11.7%] for recurrent events per 5529 particles/cm³ increase in 5-day average PNC.ConclusionsOur results suggested an association between short-term PM₁₀ concentration and numbers of MI, especially for nonfatal and recurrent events. For ultrafine particles, risk increases were notably high for recurrent events. Thus, persons who already suffered a MI seemed to be more susceptible to air pollution.     

C-reactive protein (CRP) and long-term air pollution with a focus on ultrafine particles

Background

Long-term exposure to ambient air pollution contributes to the global burden of disease by particularly affecting cardiovascular (CV) causes of death. We investigated the association between particle number concentration (PNC), a marker for ultrafine particles, and other air pollutants and high sensitivity C-reactive protein (hs-CRP) as a potential link between air pollution and CV disease.

Long-term trends in ambient particulate matter,chemical composition,and associated health risk and mortality burden in Hong Kong (1995–2016)

Hong Kong is one of the special administrative regions in China and a densely populated city with poor air quality. The impact of high pollutant concentrations, especially ambient particulate matter (PM), on human health is of major concern. This study reported the temporal trends of PM masses and chemical components and assessed the PM pollution-related health risk and mortality burden in Hong Kong over a 22-year period (1995–2016). The results showed that the ambient PM increased before 2005 and then decreased gradually with overall downward trends of ??0.61 μg m^?3 year^?1 for inhalable PM (PM₁₀) and ??1.30 μg m^?3 year^?1 for fine PM (PM_2.5). No statistically significant changes were observed for secondary inorganic components (SO₄^2?, NO₃^?, and NH₄⁺), while significant decreasing trends were found for total carbon (TC) and other water-soluble irons (Na⁺, Cl^?, and K⁺). The long-term variabilities of the trace elements differed greatly with species. A health risk assessment revealed that the annual inhalational carcinogenic risk from As, Cd, Ni, Cr, and Pb was always lower than the accepted criterion of 10^?6, whereas the total noncarcinogenic risk from As, Cd, Ni, Cr, and Mn frequently exceeded the safe level of 1. Further, a health burden assessment indicated that the annual mean number of premature mortalities attributable to PM_2.5 exposure was 2918 (95% CI: 1288, 4279) cases during the period of 2001–2016. Both health risk and mortality burden presented constant reductions in recent years, confirming the health benefits of air pollution control measures and the importance of further mitigation efforts.     

Preliminary monitoring of concentration of particulate matter (PM<Subscript>2.5</Subscript>) in seven townships of Yangon City,Myanmar

Background

Airborne particulate pollution is more critical in the developing world than in the developed countries in which industrialization and urbanization are rapidly increased. Yangon, a second capital of Myanmar, is a highly congested and densely populated city. Yet, there is limited study which assesses particulate matter (PM_2.5) in Yangon currently. Few previous local studies were performed to assess particulate air pollution but most results were concerned PM₁₀ alone using fixed monitoring. Therefore, the present study aimed to assess distribution of PM_2.5 in different townships of Yangon, Myanmar. This is the first study to quantify the regional distribution of PM_2.5 in Yangon City.

Methods

The concentration of PM_2.5 was measured using Pocket PM_2.5 Sensor (Yaguchi Electric Co., Ltd., Miyagi, Japan) three times (7:00 h, 13:00 h, 19:00 h) for 15 min per day for 5 days from January 25^th to 29^th in seven townships. Detailed information of eight tracks for PM_2.5 pollution status in different areas with different conditions within Kamayut Township were also collected.

Results

The results showed that in all townships, the highest PM_2.5 concentrations in the morning followed by the evening and the lowest concentrations in the afternoon were observed. Among the seven townships, Hlaingtharyar Township had the highest concentrations (164 ± 52 μg/m³) in the morning and (100 ± 35 μg/m³) in the evening. Data from eight tracks in Kamayut Township also indicated that PM_2.5 concentrations varied between different areas and conditions of the same township at the same time.

Conclusion

Myanmar is one of the few countries that still have to establish national air quality standards. The results obtained from this study are useful for the better understanding of the nature of air pollution linked to PM_2.5. Moreover, the sensor which was used in this study can provide real-time exposure, and this could give more accurate exposure data of the population especially those subpopulations that are highly exposed than fixed station monitoring.

     

Concern over health effects of air pollution is associated to NO<Subscript>2</Subscript> in seven European cities

Subjective perception of air pollution is important and can have impacts on health in its own rights, can lead to protective behaviour, or it can be leveraged to engage citizens and stakeholders in support of cleaner air policies. The aim of the current analysis was to examine associations between level of concern over health effects of air pollution and personal and environmental factors. In seven European cities, 7622 adult participants were recruited to complete an online questionnaire on travel and physical activity behaviour, perceptions and attitudes on active mobility and the environment, and sociodemographics. Air pollution at the home address was determined using Europe-wide PM_2.5 and NO₂ land use regression models. Mixed effects logistic regression was used to model concern over air pollution (worried versus not worried; city as random effect). Fifty-eight percent of participants were worried over health effects of air pollution with large differences across cities (Antwerp 78%, Barcelona 81%, London 64%, Orebro 11%, Rome 72%, Vienna 43%, Zurich 33%). Linking mean modelled air pollution to mean level of concern per city gave a good correlation for NO₂ (r²?=?0.75), and a lower correlation for PM_2.5 (r²?=?0.49). In the regression model, sex, having children in the household, levels of physical activity, and NO₂ at the home address were significantly linked to individual concern over health effects of air pollution. We found that NO₂ but not PM_2.5 at the home address was associated with concern over health effects of air pollution.     

Regulation of fine particulate matter (PM<Subscript>2.5</Subscript>) in the Pacific Rim: perspectives from the APRU Global Health Program

While the development of evidence-based air quality standards for airborne particulate matter (PM) for Europe and North America is well-documented, the standard-setting processes in other regions are less well characterized. Many Pacific Rim economies suffer from severe and worsening air pollution. Particulate matter less than 2.5 μm in aerodynamic diameter (PM_2.5) is associated with acute and chronic health effects and is a widely used air quality indicator. This paper reports on PM regulation in selected Pacific Rim economies, focusing on PM_2.5, and provides recommendations on air quality regulation to economies without current standards Through workshops held by the Association of Pacific Rim Universities (APRU) Global Health Program, experts in air pollution from eight universities in eight Pacific Rim economies characterized current PM_2.5 standards and monitoring in their economies, and then collaboratively created recommendations. A great diversity of air pollution exposures exists in the Pacific Rim. While some economies experience low levels of exposure, others have PM levels that are among the highest in the world. The health effects of air pollution are a concern everywhere, but few economies carry out in-depth, local impact assessments and comprehensive air quality monitoring to provide evidence for guidelines and standards. The development of regulations and policies addressing PM_2.5 pollution is urgently needed in many Pacific Rim economies. The international literature provides a robust guide to local risks and should be used, in combination with country-specific population-directed air monitoring, to guide decisions on policies addressing this important global health problem.     

Systematic review and meta-analysis of epidemiological time-series studies on outdoor air pollution and health in Asia

Asia is experiencing rapid increases in industrialization, urbanization, and motor vehicle transport with correspondingly high levels of pollution. We undertook a systematic review and meta-analysis of the Asian time-series literature to assess the evidence from health effects of short-term exposure to outdoor air pollution. Eighty-two studies provided estimates suitable for quantitative meta-analysis. Summary estimates for daily mortality and hospital admissions were calculated for particulate matter with aerodynamic diameters less than 10 and 2.5???m (PM₁₀ and PM_2.5), nitrogen dioxide, sulfur dioxide, ozone, and carbon monoxide. For 10???g/m³ increases in PM₁₀, daily mean numbers of deaths increased by 0.27% (95% confidence interval: 0.12%, 0.42%), 0.86% (0.34%, 1.39%), and 0.36% (0.09%, 0.62%) for all cause, respiratory, and cardiovascular deaths, respectively. Associations in the 65+ age group tended to be larger than those for all ages combined. All other pollutants were positively associated with both mortality and hospital admissions. We found no evidence to suggest that the size and direction of PM₁₀ estimates were modified by either the average level of particles in the city or the year of publication (a proxy for more up-to-date statistical methods and the most recent pollutant concentrations and sources). There were insufficient reports for PM_2.5 to enable a quantitative meta-analysis. Our findings were generally consistent with the range of effects found in other parts of the world and suggest that global guidelines and health impacts based largely on evidence derived from the USA and Europe are likely to be reasonably reliable.     

Prospective evaluation of respiratory health benefits from reduced exposure to airborne particulate matter

We aimed to investigate if short-term exposure to reduced particulate matter (PM) air pollution would affect respiratory function in healthy adults. We followed a cohort of 42 healthy participants from a community afflicted with severe PM air pollution to a substantially less polluted area for nine days. We measured daily airborne PM [with an aerodynamic diameter of less than 2.5 μm (PM_2.5) and 10 μm (PM₁₀)] and PM_2.5 carbon component concentrations. Five repeated respiratory function measurements and fractional exhaled nitric oxide test were made for each participant. Associations between respiratory health and PM exposure were assessed using linear mixed models. Each 10 μg/m³ decrease in same-day PM_2.5 was associated with small but consistent increase in the forced expiratory volume in 1 s (FEV₁) (9.00 mL) and forced vital capacity (14.35 mL). Our observations indicate that respiratory health benefits can be achieved even after a short-term reduction of exposure to PM. Our results provide strong evidence for more rigorous air pollution controls for the health benefit of populations.