Relationships between mild PM10 and ozone urban air levels and spontaneous abortion: clues for primary prevention

The effects of environmental pollution on spontaneous abortion (SAB) are still unclear. Records of SAB were collected from five cities (514,996 residents) and correlated with PM10, NO₂ and ozone levels. Median pollutant concentrations were below legal limits. Monthly SABs positively correlated with PM10 and ozone levels but not with NO₂ levels. The mean monthly SAB rate increase was estimated equal to 19.7 and 33.6 % per 10 μg/m³ increase in PM10 or ozone concentration, respectively. Higher values of PM10 and SABs were evident in cities with- than in those without pollutant industries, with a number of SABs twofolds higher in the former group. In conclusion, SAB occurrence is affected by PM10 (particularly if industrial areas are present) and ozone concentrations, also at levels below the legal limits. Thus, SAB might be considered, at least in part, a preventable condition.     

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.     

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.     

Oxidative potential of PM10 and PM2.5 collected at high air pollution site related to chemical composition: Krakow case study

Measurements of the oxidative potential (OP) of airborne particulate matter may be applied for the assessment of the health-based exposure by integrating various biologically relevant properties of particles. This study aimed at the determination of oxidative activity of two size fractions of particulate using the ascorbic acid (AA) and reduced glutathione (GSH) assay. Samples of PM were collected in Krakow, one of the most polluted cities in Poland, in the city centre. Samples were collected during wintertime, when heating sources used in residential areas have significant influence on the concentrations of particulate matter in the air. PM10 and PM2.5 concentrations varied from 8.9 to 92.5 μg m^?3. Samples were chemically analysed for elemental carbon, organic carbon, ions and metals. PM2.5 was found as a more oxidative active fraction, where OP_AA and OP_GSH depletions were up to 81.7 and 132.0 μg m^?3, respectively. The average values of OP_AA of PM10 and PM2.5 were similar and equalled 40.8 and 37.2 μg m^?3, respectively. The average value of OP_GSH of PM2.5 equalled 56.7 μg m^?3 and was 3.5 times higher than OP_GSH of PM10. The loss of AA amount in PM10 and PM2.5 and the depletion of GSH in PM2.5 were best described by the pseudo second-order kinetics model. The kinetics of the GSH depletion reaction in PM10 was best described by the pseudo first-order kinetics model. The strong correlations between carbonaceous and metallic constituents of PM and oxidative potential suggest their relevance in participation in oxidative activity of particulate matter.     

Effects of air pollution on asthma hospitalization rates in different age groups in metropolitan cities of Korea

Many studies have shown associations between air pollution and asthma admissions in Korea, but have not reported whether these effects differ by age classification. The purpose of this study was to determine whether air pollution effects on asthmatic hospital admissions are different by three age groups (years): children (less than 15), adults (15–64; reference group), and the elderly (over 65). Daily time-series data from seven metropolitan cities in South Korea were analyzed in two stages. In the first stage, relative asthma morbidity rates associated with air pollution were estimated for each city and age group, using semiparametric log-linear regression. In the second stage, estimates from all seven cities were combined by age group using Bayesian hierarchical modeling. The effects of exposure to particulate matter <10 μm in aerodynamic diameter (PM₁₀), carbon monoxide (CO), and nitrogen dioxide (NO₂) varied significantly by age groups. Using adults as the referent, the relative rate (RR) of asthma admissions with 10 μg/m³ increase of PM10 is 1.5 % (95 % CI 0.1–2.8 %) lower for children and 1.3 % (95 % CI 0.7–1.9 %) higher for the elderly; RR with 1 ppm increase of CO is 1.9 % (95 % CI 0.3–3.8 %) lower for children; RR with 1 ppb increase of NO₂ (1 ppb) is 0.5 % (95 % CI 0.3–0.7 %) higher for the elderly. No significant age group difference in relative rate was found for ozone or sulfur dioxide.     

Particulate pollution in Ulaanbaatar, Mongolia

The World Health Organization (WHO) listed the air pollution in Ulaanbaatar (Mongolia) among the top 5 cities with the worst air quality in the world. Air quality in the winter season reaches highs of 750 μg/m³ for daily average fine particulates (PM) due to increased coal combustion and lower mixing heights (<200 m), coupled with the city’s geography surrounded by mountains, which further restricts the vertical and horizontal dispersion of the pollutants. The annual average concentrations in 2010–2011 ranged 136?±?114 μg/m³ (the WHO guideline for fine PM is 10 μg/m³). The single largest source of particulate pollution in Ulaanbaatar is coal and biomass combustion in households and heat-only boilers, followed by power plants. In this paper, we present sector-specific emissions for 2010 accounting for 62,000 tons of fine PM, 55,000 tons of sulfur dioxide, and 89,000 tons of nitrogen oxide emissions. The inventory is spatially disaggregated at 0.01° resolution on a GIS platform for use in a chemical transport model (ATMoS). The modeled concentrations for the urban area ranged 153?±?70 μg/m³, when overlaid on gridded population, resulted in estimated 1,000–1,500 premature deaths per year due to outdoor air pollution. This study also highlights the linkages between indoor and outdoor air pollution. In these harsh temperate conditions, with 50 % of the emissions originating from Ger households, they are as big a health risk for indoor air quality as they are for outdoor air quality. Any intervention improving combustion efficiency or providing clean fuel for these stoves will have a combined benefit for indoor air quality, outdoor air quality, and climate policy. The analysis shows that aggressive pollution control measures are imperative to protect the population in Ulaanbaatar from excess exposure levels, and implementation of control measures like the introduction of heat efficient stoves, clean coal for heating boilers, and urban transport planning will result in significant health benefits, which surpass any costs of institutional, technical, and economic interventions.     

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.     

An assessment of air pollution and its attributable mortality in Ulaanbaatar, Mongolia

Epidemiologic studies have consistently reported associations between outdoor fine particulate matter (PM_2.5) air pollution and adverse health effects. Although Asia bears the majority of the public health burden from air pollution, few epidemiologic studies have been conducted outside of North America and Europe due in part to challenges in population exposure assessment. We assessed the feasibility of two current exposure assessment techniques, land use regression (LUR) modeling and mobile monitoring, and estimated the mortality attributable to air pollution in Ulaanbaatar, Mongolia. We developed LUR models for predicting wintertime spatial patterns of NO₂ and SO₂ based on 2-week passive Ogawa measurements at 37 locations and freely available geographic predictors. The models explained 74% and 78% of the variance in NO₂ and SO₂, respectively. Land cover characteristics derived from satellite images were useful predictors of both pollutants. Mobile PM_2.5 monitoring with an integrating nephelometer also showed promise, capturing substantial spatial variation in PM_2.5 concentrations. The spatial patterns in SO₂ and PM, seasonal and diurnal patterns in PM_2.5, and high wintertime PM_2.5/PM₁₀ ratios were consistent with a major impact from coal and wood combustion in the city’s low-income traditional housing (ger) areas. The annual average concentration of PM_2.5 measured at a centrally located government monitoring site was 75 μg/m³ or more than seven times the World Health Organization’s PM_2.5 air quality guideline, driven by a wintertime average concentration of 148 μg/m³. PM_2.5 concentrations measured in a traditional housing area were higher, with a wintertime mean PM_2.5 concentration of 250 μg/m³. We conservatively estimated that 29% (95% CI, 12–43%) of cardiopulmonary deaths and 40% (95% CI, 17–56%) of lung cancer deaths in the city are attributable to outdoor air pollution. These deaths correspond to nearly 10% of the city’s total mortality, with estimates ranging to more than 13% of mortality under less conservative model assumptions. LUR models and mobile monitoring can be successfully implemented in developing country cities, thus cost-effectively improving exposure assessment for epidemiology and risk assessment. Air pollution represents a major threat to public health in Ulaanbaatar, Mongolia, and reducing home heating emissions in traditional housing areas should be the primary focus of air pollution control efforts.     

Carbonaceous species and physicochemical characteristics of PM<Subscript>10</Subscript> in coal mine fire area—a case study

When exposed to air, coal catches fire due to self-oxidation. Coal mine fire is one of the major sources of particulate matter (PM) emissions in coal mining areas. Coal mine is widespread in India with Jharia Coalfield having a number of coal seams and coal dumps under fire. The understanding of magnitude and character of particulate matter emitted from coal mine fire areas is important in order to understand its health impacts, about which not many studies have been carried out. The paper presents findings of a study aimed to characterize physical and chemical properties of airborne respirable particle (PM₁₀) in the fire-affected area at Jharia Coalfield, India. The study was carried out for a period of 8 months from October 2011 to June 2012. The mean concentrations of PM₁₀ were 338.0, 369.0, and 357.0 μg m^?3 during summer, winter, and post-monsoon, respectively. Scanning electron microscopy (SEM) showed the presence of rounded, spherical, and oval formed particulate in ambient air that is characteristics of combustion sources. Dominance of irregular-shaped particulate in all samples indicated road dust as the source. Abundance of fine PM (<4 mm) indicated burning process to be the source. For the “qualitative analysis,” techniques like Fourier transform infrared (FTIR) spectroscopy, gas chromatography–mass spectrometry (GC-MS), and inductively coupled plasma optical emission spectrometry (ICP-OES) were used. Chemical analysis shows the presence of elements like Fe, Al, Cu, Si, Na, Cr, Mn, Zn, Cd, Ni, K, and Pb. Anionic concentrations of SO₄ ^2?, NO₃ ^?,Cl^?, F^?, and PO₄ ^2? were analyzed using ion chromatography. Carbonaceous aerosol analysis results indicated that concentrations of carbonaceous species were 19.51 μg m^?3 for organic carbon (OC) and 238.0 μg m^?3 for elemental carbon (EC) in PM₁₀ samples.     

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.     

Long-term exposure to air pollution and the incidence of asthma: meta-analysis of cohort studies

We quantified the association between long-term exposure to air pollution and the incidence of asthma by conducting a systematic review and meta-analysis of cohort studies. Incidence was defined as the incidence of diagnosed asthma or of new wheeze symptom between two assessments or, in birth cohorts followed up to 10 years of age, a lifetime prevalence estimate of asthma or wheeze symptom. We identified 17 cohorts (eight birth cohorts and nine child/adult cohorts) with a total of 99 population-based risk estimates. The studies were heterogeneous in their design and methods of measurement. Follow-up ranged from 3 to 23 years. Most studies were based on within-community exposure contrasts dominated by traffic pollution. Twelve of the cohorts reported at least one positive statistically significant association between air pollution and a measure of incidence. Of the total of 99 estimates, only a minority (29) were positive and statistically significant. Estimates for meta-analysis were chosen a priori using a protocol. For the 13 studies with estimates for nitrogen dioxide (NO₂), the random effects odds ratio was 1.07 (95% CI 1.02 to 1.13) per 10 μg/m³. For five studies with estimates for particulate matter with aerodynamic diameter <2.5 μm (PM_2.5), the random effects estimate was 1.16 (95% CI 0.98 to 1.37) per 10 μg/m³. These estimates were reduced in size and statistical significance by adjustment for publication bias but remained positive. The results are consistent with an effect of outdoor air pollution on asthma incidence. Future meta-analyses would benefit from greater standardisation of cohort methods.     

Source emissions and health impacts of urban air pollution in Hyderabad,India

The source apportionment study in Hyderabad listed transportation, industries, and waste burning as critical sources of particulate matter (PM) pollution in the city. In this paper, we present sector-specific emissions for 2010–2011 for the Greater Hyderabad Municipal Corporation region, accounting for 42,600 t of PM₁₀ (PM size <10 μm), 24,500 t of PM_2.5 (PM size <2.5 μm), 11,000 t of sulfur dioxide, 127,000 t of nitrogen oxides, 431,000 t of carbon monoxide, 113,400 t of non-methane volatile organic compounds, and 25.2 million tons of carbon dioxide emissions. The inventory is spatially disaggregated at 0.01° resolution on a GIS platform, for use in a chemical transport model (ATMoS). The modeled concentrations for the urban area are 105.2?±?28.6 μg/m³ for PM₁₀ and 72.6?±?18.0 μg/m³ for PM_2.5, when overlaid on gridded population, resulted in estimated 3,700 premature deaths and 280,000 asthma attacks for 2010–2011. The analysis shows that aggressive pollution control measures are imperative to control pollution in Hyderabad and reduce excess exposure levels on the roads and in the residential areas. The planning and implementation of measures like advancing the public transportation systems, integrating the road and metro-rail services, promotion of walking and cycling, introduction of cleaner brick production technologies, encouraging efficient technologies for the old and the new industries, and better waste management systems to control garbage burning need to take priority, as these measures are expected to result in health benefits, which surpass any of the institutional, technical, and economic costs.     

An analysis on the impact of large-scale transports of dust pollution on air quality in East Asia as observed in central Korea in 2014

The large-scale transport of dust air pollution in the East Asian region has been being monitored using satellites and ground-based measurements in central Korea for the last 20 years. Severe haze in eastern China as well as dust storms in Mongolia and northern China occurred and moved toward central Korea during the first 5 months of 2014. In addition, severe prolonged haze in eastern China occurred on a large scale in February 2014. The daily mass concentrations originating from haze and dust storms at a background observation site in central Korea exceeded the air quality standard of PM10 (100 μg m^?3 day^?1) and PM2.5 (50 μg m^?3 day^?1). Dust loadings caused by dust air pollution from Mongolia and China are clearly worsening the air quality in the background area in central Korea. Anthropogenic dust pollution from severe haze loads dust particulates finer than 2.5 μm. On the other hand, a natural dustfall case originating from a dust storm usually loads coarse dust particulates in the atmosphere. The impact of dust storms on air quality varies depending on the passing route in East Asia.     

A novel approach for characterizing neighborhood-level trends in particulate matter using concentration and size fraction distributions: a case study in Charleston,SC

In this study, we aim to illustrate how novel technologies and methodologies can be used to enhance neighborhood level studies of ambient particulate matter (PM). This is achieved by characterizing temporal and spatial features of PM levels and by assessing patterns in particle size composition using simultaneous measures across multiple size fraction ranges in Charleston, SC, USA. The study is conducted in three stages: (1) we monitor real-time PM concentrations for the following: PM ≤ 15 μm, PM ≤ 10 μm, PM ≤ 4 μm, PM ≤ 2.5 μm, and PM ≤ 1 μm at five locations during February–July, 2016; (2) we apply a generalized additive model (GAM) to assess temporal and spatial trends in PM_2.5 after controlling for meteorology, instrument, and temporal confounders; and (3) we employ a self-organizing map (SOM) to identify hourly profiles that characterize the types of size fraction distribution compositions measured at our sites. Monitoring results found that average PM_2.5 levels during our ‘snapshot’ monitoring were 6–8 μg/m³ at our sites, with 95th percentiles ranging from 9 to 13 μg/m³. GAM results identified that temporal peaks for PM_2.5 occurred during the early morning hours (6–8 am) across all sites and that the marginal means for four of our inland sites were significantly different (higher) than a waterfront site. SOM results identified six hourly profiles, ranging from hours when all size fractions were relatively low, to hours dominated by single size fractions (e.g., PM₁), and to hours when multiple size fractions were relatively high (e.g., PM_15–10 and PM₁₀-PM_2.5). Frequency and duration distributions show variability in the occurrence and persistence of each hourly type. Collectively, our findings reveal the complexity of PM behavior across a relatively small geographic region and illustrate the potential usefulness of using size fraction composition to better understand air quality. However, it is important to note that this study only presents a snapshot of air quality and that longer monitoring periods are recommended for more definitive characterizations.     

Trends and patterns of air quality in Santa Cruz de Tenerife (Canary Islands) in the period 2011–2015

Air quality trends and patterns in the coastal city of Santa Cruz de Tenerife (Canary Islands, Spain) for the period 2011–2015 were analyzed. The orographic and meteorological characteristics, the proximity to the African continent, and the influence of the Azores anticyclone in combination with the anthropogenic (oil refinery, road/maritime traffic) and natural emissions create specific dispersion conditions. SO₂, NO₂, PM₁₀, PM_2.5, and O₃ pollutants were assessed. The refinery was the primary source of SO₂; EU hourly and daily average limit values were exceeded during 2011 and alert thresholds were reached in 2011 and 2012. WHO daily mean guideline was occasionally exceeded. Annual averages in the three stations that registered the highest concentrations in 2011 and 2012 were between 9.3 and 20.4 μg/m³. The spatial analysis of SO₂ concentrations with respect to prevailing winds corroborates a clear influence of the refinery to the SO₂ levels. In 2014 and 2015, the refinery did not operate and the concentrations fell abruptly to background levels of 2.5–7.1 μg/m³ far below from WHO AQG. NO₂ EU limit values, as well as WHO AQG for the period 2011–2015, were not exceeded. The progressive dieselization of the vehicle fleet caused an increment on NO₂ annual mean concentrations (from 2011 to 2015) measured at two stations close to busy roads 25 to 31 μg/m³ (+21%) and 27 to 35 μg/m³ (+29%). NO _x daily and weekly cycles (working days and weekends) were characterized. An anti-correlation was found between NO _x and O₃, showing that O₃ is titrated by locally emitted NO. Higher O₃ concentrations were reported because less NO _x emitted during the weekends showing a clear weekend effect. Saharan dust intrusions have a significant impact on PM levels. After subtracting natural sources contribution, none of the stations reached the EU maximum 35 yearly exceedances of daily means despite seldom exceedances at some stations. None of the stations exceeded the annual mean EU limit values; however, many stations exceeded the annual mean WHO AQG. Observed PM₁₀ annual average concentrations in all the stations fluctuated between 10.1 and 35.3 μg/m³, where background concentrations were 6.5–24.4 μg/m³ and natural contributions: 4.2–9.1 μg/m³. No PM₁₀ temporal trends were identified during the period except for an effect of washout due to the rain: concentrations were lower in 2013 and 2014 (the most rainy years of the period). None of the stations reached the PM_2.5 annual mean EU 2015 limit value. However, almost all the stations registered daily mean WHO AQG exceedances. During 2015, PM_2.5 concentrations were higher than the previous years (2015, 8.8–12.3 μg/m³; 2011–2014, 3.7–9.6 μg/m³). O₃ complied with EU target values; stricter WHO AQG were sometimes exceeded in all the stations for the whole time period.     

Source apportionment studies in six Indian cities—drawing broad inferences for urban PM<Subscript>10</Subscript> reductions

PM₁₀ is a critical air pollutant in urban areas of India. Out of 176 cities, 140 exceeded annual PM₁₀ standard of 60 μg m^?3 in 2010. A detailed PM₁₀ source apportionment study was conducted in six Indian cities during 2007–2010, providing insight to urban PM₁₀ issues. Data on emission inventory along with carbon, secondary inorganic aerosol (SIA) and crustal components of ambient PM₁₀ were analyzed to get broad actions for urban PM₁₀ reduction. Road dust and vehicles emerged as two major sources accounting for ~30 to 70 % and ~15 to 20 % of PM₁₀ emissions, respectively. Maximum concentration of EC, SIA, and crustal components varied between 10.3–38.0, 15.5–30.2, and 17.5–40.6 μg m^?3, respectively. Kerbside locations showed higher EC levels. Background SO₄ ^2? and NO₃ ^? levels were ~70–80 % of city average. Controlling dust from road segments with high traffic volume, emissions from heavy duty vehicles, and efficient public transport emerged as key actions. Reducing SO₂ and NO_x emissions from industries in nonattainment cities will reduce SIA. The six-city project represents a large range of activity, geophysical, and meteorological profiles, and as such would represent source mix of many Indian cities and towns. It would, therefore, be reasonable to apply broad inferences from the study to other Indian cities and towns.     

Health benefits of a reduction of PM10 and NO2 exposure after implementing a clean air plan in the Agglomeration Lausanne-Morges

Exposure to urban air pollution has been associated with adverse effects on cardio-vascular and respiratory health, both short and long term. Consequently, governments have applied policies to reduce air pollution. Quantitative health impact assessments of hypothetic changes in air pollution have been conducted at national and global level, but assessments of observed air pollution changes associated with specific clean air policies at a local or regional scale remain scarce. This study estimates health impacts attributable to a decrease in PM₁₀ and NO₂ exposure in the Agglomeration of Lausanne-Morges (ALM), Switzerland, between 2005 and 2015, corresponding to the implementation period of a supra-municipal plan of measures to reduce air pollution in different sectors such as transport, energy, and industry (called Plan OPair 05). The health impact assessment compares health effects attributed to air pollution exposure levels in 2015 (reference case) with those in 2005 (counterfactual scenario), using 2015 as baseline for all other input data.In the ALM, the modeled PM₁₀ exposure reduction of 3.3 μg/m³ from 2005 to 2015 prevents 26 premature deaths (equivalent to around 290 years of life lost), 215 hospitalization days due to cardio-vascular and respiratory diseases as well as approximately 47,000 restricted activity days annually. Monetized health impacts of the reduction of PM₁₀ exposure are valued at approximately CHF 36 million annually. Immaterial costs, mainly related to the economic valuation of years of life lost, dominate the monetized health impacts (90% of total value), while savings at the workplace (net loss in production and reoccupation costs) amount to about CHF 1.9 million, and savings in health care costs to about CHF 0.5 million. The assessment is sensitive to the value assigned to immaterial costs and to uncertainties in the relative risk estimates, whereas variations in the baseline year (i.e. using 2005 data instead of 2015 data) affect results to a much lower degree. The alternative calculation based on NO₂ exposure, which dropped by 5.6 μg/m³, suggests the prevention of 51 premature deaths (equivalent to around 550 years of life lost) overall impacts valued at CHF 49 million. All in all, the reduction in mortality due to the air quality improvements accounts for (depending on the considered pollutant) about 1% to 2% of total all-cause annual mortality in the ALM population or 4–8 times larger than the annual traffic fatalities in the ALM.     

Distributed lag associations between respiratory illnesses and mortality with suspended particle concentration in Tula, a highly polluted industrial region in Central Mexico

Purpose

We aimed to evaluate the association between changes in airborne particulate matter concentration (PM) with changes in cases of mortality, acute respiratory infections (ARI) and asthma over 2004–2008 in an industrialized and polluted region in central Mexico.

Methods

A generalized linear model with a Poisson distribution and a negative binomial analysis was used to evaluate the influence of PM and temperature on all-cause mortality (All-cause-M), cause-specific mortality (Cause-specific-M), ARI and asthma, using cubic spline functions and distributed lags of PM. Estimated changes in relative risk were calculated for an exposure corresponding to each increase of 10 μg/m³ in PM level.

Results

Associations between PM and mortality and morbidity were statistically most consistent for total suspended particulate (TSP) than for particulate matter <10 μM aerodynamic diameter (PM₁₀). The greatest effects in mortality were observed with a 3-week lag, and effects were greater for Cause-specific-M. We also found a displacement effect up to 4-week lag for Cause-specific-M and TSP. The greatest effects in morbidity were observed at 0-week lag, yet they were statistically marginal and were greater for asthma. We found a displacement effect at 4–5–6-week lag for asthma and TSP. All associations of mortality and morbidity, expressed as change in relative risk, were greater with PM₁₀; however, all of them were statistically marginal.

Conclusions

Increased respiratory morbidity and mortality is associated with weekly changes of PM air pollution in the region. A reduction in air pollutants from industrial sources would benefit life quality and health of the exposed population.     

Indoor air quality in urban and rural kindergartens: short-term studies in Silesia,Poland

More than 80% of people living in urban areas who monitor air pollution are exposed to air quality levels that exceed limits defined by the World Health Organization (WHO). Although all regions of the world are affected, populations in low-income cities are the most impacted. According to average annual levels of fine particulate matter (PM2.5, ambient particles with aerodynamic diameter of 2.5 μm or less) presented in the urban air quality database issued by WHO in 2016, as many as 33 Polish cities are among the 50 most polluted cities in the European Union (EU), with Silesian cities topping the list. The aim of this study was to characterize the indoor air quality in Silesian kindergartens based on the concentrations of gaseous compounds (SO₂, NO₂), PM2.5, and the sum of 15 PM2.5-bound polycyclic aromatic hydrocarbons (PAHs), including PM2.5-bound benzo(a)pyrene (BaP), as well as the mutagenic activity of PM2.5 organic extracts in Salmonella assay (strains: TA98, YG1024). The assessment of the indoor air quality was performed taking into consideration the pollution of the atmospheric air (outdoor). I/O ratios (indoor/outdoor concentration) for each investigated parameter were also calculated. Twenty-four-hour samples of PM2.5, SO₂, and NO₂ were collected during spring in two sites in southern Poland (Silesia), representing urban and rural areas. Indoor samples were taken in naturally ventilated kindergartens. At the same time, in the vicinity of the kindergarten buildings, the collection of outdoor samples of PM2.5, SO₂, and NO₂ was carried out. The content of BaP and the sum of 15 studied PAHs was determined in each 24-h sample of PM2.5 (indoor and outdoor). In the urban site, statistically lower concentrations of SO₂ and NO₂ were detected indoors compared to outdoors, whereas in the rural site, such a relationship was observed only for NO₂. No statistically significant differences in the concentrations of PM2.5, PM2.5-bound BaP, and Σ15 PAHs in kindergartens (indoor) versus atmospheric (outdoor) air in the two studied areas were identified. Mutagenic effect of indoor PM2.5 samples was twice as low as in outdoor samples. The I/O ratios indicated that all studied air pollutants in the urban kindergarten originated from the ambient air. In the rural site concentrations of SO₂, PM2.5 and BaP in the kindergarten were influenced by internal sources (gas and coal stoves).     

Sources of trace metals in PM<Subscript>10</Subscript> from a petrochemical industrial complex in Northern Mexico

Concentrations, sources, and relative contributions of Cd, Cr, Cu, Fe, Mn, Pb, Ni, Ti, V, and Zn observed in PM₁₀ in the petrochemical industrial zone of Altamira in Northern Mexico are reported for the first time. Results show that oil refining, alloys, fertilizer, mining, metallurgical processes, and steel production industries are important contributions to PM₁₀ and metal concentrations. PM₁₀ concentrations ranged from 21 to 92 μg m^?3 and exceeded the revised 24-h average Mexican standard NOM-025-SSA1-2014 of 75 μg m^?3 12 % of the study period. The highest metal concentrations were Fe (1.64 μg m^?3), Mn (0.57 μg m^?3), and Ti (0.29 μg m^?3) and were associated with two dominant wind directions. Ti and Fe were associated with NNW winds (natural sources), and Mn and Fe were associated with SSW winds (ferromanganese industry). An average V/Ni ratio of 8.5 was found in this study with highest ratios associated to two dominant wind directions, NNW-NW and SE-SSE, suggesting origins from a fuel oil thermoelectric power plant and a refinery fuel oil, respectively. Pb was associated with industrial activity and never exceeded the Mexican standard of 1.5 μg m^?3 in 24 h. Zn and Cd were correlated with a dominant easterly wind, suggesting the presence of vehicle exhaust pollutants. The study of the size and shape of PM₁₀ particles by scanning electronic microscopy and energy-dispersive spectroscopy (SEM-EDS) allowed us to confirm the presence of trace metals associated to natural soils and clays, combustion, and industrial processes. The results presented here constitute the first efforts to evaluate toxic metals in a heavily industrialized area in Mexico and can be used to develop air quality management programs.