Effects of ambient air pollution on pulmonary function among schoolchildren

Literature has shown adverse effects of ambient air pollution exposure on various asthma related outcomes in childhood. However, the associated evidence on pulmonary function effects is still inconsistent.We conducted a population-based study comprised of seventh-grade children in 14 Taiwanese communities. Pulmonary function tests and questionnaires were completed on 3957 subjects. We evaluated the effects of ambient air pollution exposures based on the data collected in 2005–2007 by existing air monitoring stations. Multiple linear mixed effect models were fitted to estimate the relationship between community pollutant levels and pulmonary function indices. After adjustment for individual-level confounders, pulmonary function differed only slightly between communities with different levels of air pollution. We found greater effects of ambient air pollutants on pulmonary function for boys than for girls. Among boys, traffic-related pollutants CO, NOx, NO₂, and NO were generally associated with chronic adverse effects on FVC and FEV₁, and subchronic adverse effects mainly on maximal mid-expiratory flow (MMEF) and peak expiratory flow rate. Among girls, only NOx and NO₂ showed subchronic adverse effects on MMEF. Although effect estimates of SO₂, PM₁₀, and PM_2.5 were generally negative for boys, none achieved statistical significance.Our data suggests that ambient traffic-related pollution had chronic adverse effects on pulmonary function in schoolchildren, especially for boys.     

Associations between daily mortalities from respiratory and cardiovascular diseases and air pollution in Hong Kong, China

Objective: To investigate the association between ambient concentrations of air pollutants and respiratory and cardiovascular mortalities in Hong Kong.

Methods: Retrospective ecological study. A Poisson regression of concentrations of daily air pollutants on daily mortalities for respiratory and cardiovascular diseases in Hong Kong from 1995 to the end of 1998 was performed using the air pollution and health: the European approach (APHEA) protocol. The effects of time trend, seasonal variations, temperature, and humidity were adjusted. Autocorrelation and overdispersion were corrected. Daily concentrations of nitrogen dioxide (NO₂), sulphur dioxide (SO₂), ozone (O₃), and particulate matter <10 µm in aerodynamic diameter (PM₁₀) were averaged from eight monitoring stations in Hong Kong. Relative risks (RRs) of respiratory and cardiovascular mortalities (per 10 µg/m³ increase in air pollutant concentration) were calculated.

Results: Significant associations were found between mortalities for all respiratory diseases and ischaemic heart diseases (IHD) and the concentrations of all pollutants when analysed singly. The RRs for all respiratory mortalities (for a 10 µg/m³ increase in the concentration of a pollutant) ranged from 1.008 (for PM₁₀) to 1.015 (for SO₂) and were higher for chronic obstructive pulmonary diseases (COPD) with all pollutants except SO₂, ranging from 1.017 (for PM₁₀) to 1.034 (for O₃). RRs for IHD ranged from 1.009 (for O₃) to 1.028 (for SO₂). In a multipollutant model, O₃ and SO₂ were significantly associated with all respiratory mortalities, whereas NO₂ was associated with mortality from IHD. No interactions were detected between any of the pollutants or with the winter season. A dose-response effect was evident for all air pollutants. Harvesting was not found in the short term.

Conclusions: Mortality risks were detected at current ambient concentrations of air pollutants. The associations with the particulates and some gaseous pollutants when analysed singly were consistent with many reported in temperate countries. PM₁₀ was not associated with respiratory or cardiovascular mortalities in multipollutant analyses.

     

上海市大气污染对小学生肺功能小气道指标的急性效应研究

目的 分析上海市复合型大气污染对儿童肺功能小气道指标的急性影响。方法 在上海市内环、中环和外环各选择一所小学（A、B和C）,每所学校各随机抽取3~5年级一个班级学生为研究对象（共233人）;A、B两校于2013年12月和C校于2014年12月测试肺功能3次,各校分别于次年5-6月测试第4次肺功能。同时收集同期三校就近环境空气质量监测点大气细颗粒物（PM_2.5）、可吸入颗粒物（PM₁₀）、二氧化硫（SO₂）和二氧化氮（NO₂）污染物数据和气象监测数据;采用线性混合效应模型分析大气污染对肺功能小气道指标的影响。结果 控制气象因素和个体因素后,PM_2.5、PM₁₀滞后2 d和累计滞后2 d、SO₂累计滞后2 d和NO₂检测当日浓度每增加一个四分位间距（IQR）,儿童25%肺活量最大呼吸流速（MEF_25%）、50%肺活量最大呼吸流速（MEF_50%）、75%肺活量最大呼吸流速（MEF_75%）和用力呼气中段流速（FEF_25%~75%）均有不同程度的降低（P<0.05或P<0.01）;双污染物模型分析显示SO₂和NO₂分别叠加PM_2.5和PM₁₀污染时,滞后效应值大于SO₂和NO₂单独存在时（P<0.05）。结论 上海市大气污染物短期暴露与儿童肺功能小气道指标变化呈负相关,并存在滞后效应及累计滞后效应。     

Certain biochemical changes in the trachea,lungs, and heart of squirrels exposed to three principal air pollutants

The fate of total lipids, proteins and carbohydrates in the trachea, lungs, and heart of the common ground squirrel,Funambulus pennanti, have been determined after separate exposure to three principal air pollutants, carbon monoxide (CO), sulphur dioxide (SO₂), and nitrogen dioxide (NO₂). Exposure to all of these gases produced edematous conditions; however, the moisture content of heart muscle was reduced. Carbon monoxide (CO) and NO₂ are more toxic to pulmonary lipids than SO₂. The lipid content of the heart decreased, least effects noted with SO₂ treatment. Mechanical properties of the lungs were changed by alteration of the lung lipids causing changes in the surface tension. Changes in protein content were caused by altered membrane permeability. Comparative data on the carbohydrates indicated adverse effects by the pollutants.     

Traffic related air pollution and acute hospital admission for respiratory diseases in Drammen, Norway 1995–2000

The aim of this study was to estimate the associations between seven ambient air pollutants [particulate matter (PM₁₀), nitrous dioxide (NO₂), sulfur dioxide (SO₂), ozone (O₃), benzene, formaldehyde and toluene] and acute hospital admissions for respiratory diseases in Drammen, Norway 1995–2000. Time-series analysis of counts was performed by means of generalized additive models with log link and Poisson distribution. The results showed that benzene was the pollutant having the strongest association with respiratory diseases for the total study period, the relative risk of an interquartile increase of benzene was 1.095 with 95% confidence interval: 1.031–1.163. The corresponding results were 1.049 (0.990–1.112) for formaldehyde, 1.044 (1.000–1.090) for toluene, 1.064 (1.019–1.111) for NO₂, 1.043 (1.011–1.075) for SO₂, 0.990 (0.936–1.049) for O₃ and 1.022 (0.990–1.055) for PM₁₀. Dividing the total study period into two 3-year periods, there was a substantial reduction in the exposure levels of the volatile organic compounds (benzene, formaldehyde and toluene) from the first to the second period. Separate analyses for the second time period showed weaker association between these pollutants and the health outcome. This study provides further evidence for short-term respiratory health effects of traffic related air pollution.     

Ambient air pollution the risk of stillbirth: A prospective birth cohort study in Wuhan,China

Background

Recent studies suggest that ambient air pollution exposure during pregnancy is associated with stillbirth occurrence. However, the results on the associations between ambient air pollutants and stillbirths are inconsistent and little is known about the gestational timing of sensitive periods for the effects of ambient air pollutants exposure on stillbirth.

GSTM1, GSTT1, and GSTP1 Polymorphisms and Associations between Air Pollutants and Markers of Insulin Resistance in Elderly Koreans

Background: Previous studies have suggested that diabetes mellitus (DM) is an outcome of exposure to air pollution, and metabolic detoxification genes affect air pollution–related outcomes.Objectives: We evaluated associations between air pollutants and markers of insulin resistance (IR), an underlying mechanism of type 2 DM, and effect modification by GSTM1, GSTT1, and GSTP1 genotypes among elderly participants in the Korean Elderly Environmental Panel (KEEP) study.Methods: We recruited 560 people ≥ 60 years of age and obtained blood samples from them up to three times between 2008 and 2010. For air pollution exposure, we used ambient air pollutant [i.e., particulate matter ≤ 10 µm in diameter (PM₁₀), sulfur dioxide (SO₂), ozone (O₃), and nitrogen dioxide (NO₂)] monitoring data. We measured levels of fasting glucose and insulin and derived the homeostatic model assessment (HOMA) index to assess IR. Mixed-effect models were used to estimate associations between air pollutants and IR indices on the same day or lagged up to 10 days prior, and effect modification by GSTM1, GSTT1, and GSTP1 genotypes.Results: Interquartile range increases in PM₁₀, O₃, and NO₂ were significantly associated with IR indices, depending on the lag period. Associations were stronger among participants with a history of DM and among those with GSTM1-null, GSTT1-null, and GSTP1 AG or GG genotypes.Conclusions: Our results suggest that PM₁₀, O₃, and NO₂ may increase IR in the elderly, and that GSTM1-null, GSTT1-null, and GSTP1 AG or GG genotypes may increase susceptibility to potential effects of ambient air pollutants on IR.     

Air pollution and population health: a global challenge

“Air pollution and population health” is one of the most important environmental and public health issues. Economic development, urbanization, energy consumption, transportation/motorization, and rapid population growth are major driving forces of air pollution in large cities, especially in megacities. Air pollution levels in developed countries have been decreasing dramatically in recent decades. However, in developing countries and in countries in transition, air pollution levels are still at relatively high levels, though the levels have been gradually decreasing or have remained stable during rapid economic development. In recent years, several hundred epidemiological studies have emerged showing adverse health effects associated with short-term and long-term exposure to air pollutants. Time-series studies conducted in Asian cities also showed similar health effects on mortality associated with exposure to particulate matter (PM), sulfur dioxide (SO₂), nitrogen dioxide (NO₂) and ozone (O₃) to those explored in Europe and North America. The World Health Organization (WHO) published the “WHO Air Quality Guidelines (AQGs), Global Update” in 2006. These updated AQGs provide much stricter guidelines for PM, NO₂, SO₂ and O₃. Considering that current air pollution levels are much higher than the WHO-recommended AQGs, interim targets for these four air pollutants are also recommended for member states, especially for developing countries in setting their country-specific air quality standards. In conclusion, ambient air pollution is a health hazard. It is more important in Asian developing countries within the context of pollution level and population density. Improving air quality has substantial, measurable and important public health benefits.     

Cardiovascular diseases and air pollution in Novi Sad,Serbia

Objectives

A large body of evidence has documented that air pollutants have adverse effect on human health as well as on the environment. The aim of this study was to determine whether there was an association between outdoor concentrations of sulfur dioxide (SO₂) and nitrogen dioxide (NO₂) and a daily number of hospital admissions due to cardiovascular diseases (CVD) in Novi Sad, Serbia among patients aged above 18.

Material and Methods

The investigation was carried out during over a 3-year period (from January 1, 2007 to December 31, 2009) in the area of Novi Sad. The number (N = 10 469) of daily CVD (ICD-10: I00–I99) hospital admissions was collected according to patients’ addresses. Daily mean levels of NO₂ and SO₂, measured in the ambient air of Novi Sad via a network of fixed samplers, have been used to put forward outdoor air pollution. Associations between air pollutants and hospital admissions were firstly analyzed by the use of the linear regression in a single polluted model, and then trough a single and multi-polluted adjusted generalized linear Poisson model.

Results

The single polluted model (without confounding factors) indicated that there was a linear increase in the number of hospital admissions due to CVD in relation to the linear increase in concentrations of SO₂ (p = 0.015; 95% confidence interval (95% CI): 0.144–1.329, R² = 0.005) and NO₂ (p = 0.007; 95% CI: 0.214–1.361, R² = 0.007). However, the single and multi-polluted adjusted models revealed that only NO₂ was associated with the CVD (p = 0.016, relative risk (RR) = 1.049, 95% CI: 1.009–1.091 and p = 0.022, RR = 1.047, 95% CI: 1.007–1.089, respectively).

Conclusions

This study shows a significant positive association between hospital admissions due to CVD and outdoor NO₂ concentrations in the area of Novi Sad, Serbia.     

Social disadvantage, air pollution, and asthma physician visits in Toronto, Canada

Background

Previous research demonstrates that ambient air pollution exacerbates asthma. Asthma morbidity also varies with socioeconomic position (SEP). Few studies have examined if ambient air pollution has a differential impact on income subgroups of the population. This paper investigates socioeconomic variation in ambulatory physician consultations for asthma and assesses possible effect modification of SEP on the association between physician visits and air pollution for children aged 1-17 and adults aged 18-64 in Toronto, Canada, between 1992 and 2001.

Methods

Generalized additive models and generalized linear models were used to estimate the adjusted risk of asthma physician visits associated with an interquartile range increase in sulfur dioxide (SO₂), nitrogen dioxide (NO₂), particulate matter (PM_2.5), and ozone (O₃).

Results

A socioeconomic gradient in the number of physician visits was observed among children and adults and both sexes. SO₂, NO₂, and PM_2.5 had positive associations with physician visits. The risk ratios for the low socioeconomic group were significantly greater than those for the high socioeconomic group in several of the models of SO₂ and PM_2.5.

Conclusions

These findings suggest increased ambulatory physician visits represent another component of the public health impact of urban air pollution. The burden of this impact may be borne disproportionately by those with lower SEP. Clarifying the role of SEP in altering susceptibility to the effects of air pollution is essential not only to inform revisions of ambient air quality standards, but also to design public health interventions to reduce health impacts on sensitive subgroups of the population.     

Ambient air pollution and emergency department visits among children and adults in Casablanca,Morocco

This study presents the relationships between ambient air pollutants and morbidity and emergency department visits among children and adults performed in Great Casablanca, the most populated and economic region in Morocco. This research was analyzed using conditional Poisson model for the period 2011–2013. In the period of study, the daily average concentrations of SO₂, NO₂, O₃ and PM₁₀ in Casablanca were 209.4 µg/m³, 61 µg/m³, 113.2 µg/m³ and 75.1 µg/m³, respectively. In children less than 5 years old, risk of asthma could be increased until 12% per 10 µg/m³ increase in NO₂, PM10, SO₂ and O₃. In children over 5 years and adults, an increase of 10 µg/m³ air pollutant can cause an increase until 3% and 4% in respiratory consultations and acute respiratory infection, respectively. Similarly, impact on emergency department visits due to respiratory and cardiac illness was established. Our results suggest a not negligible impact on morbidity of outdoor air pollution by NO₂, SO₂, O₃, and PM₁₀.     

Ambient air pollution and birth weight in full-term infants in Atlanta, 1994-2004

Background

An emerging body of evidence suggests that ambient levels of air pollution during pregnancy are associated with fetal growth.

Objectives

We examined relationships between birth weight and temporal variation in ambient levels of carbon monoxide, nitrogen dioxide (NO₂), sulfur dioxide (SO₂), ozone, particulate matter ≤ 10 μm in diameter (PM₁₀), ≤ 2.5 μm (PM_2.5), 2.5 to 10 μm (PM_2.5–10), and PM_2.5 chemical component measurements for 406,627 full-term births occurring between 1994 and 2004 in five central counties of metropolitan Atlanta.

Methods

We assessed relationships between birth weight and pollutant concentrations during each infant’s first month of gestation and third trimester, as well as in each month of pregnancy using distributed lag models. We also conducted capture-area analyses limited to mothers residing within 4 miles (6.4 km) of each air quality monitoring station.

Results

In the five-county analysis, ambient levels of NO₂, SO₂, PM_2.5 elemental carbon, and PM_2.5 water-soluble metals during the third trimester were significantly associated with small reductions in birth weight (−4 to −16 g per interquartile range increase in pollutant concentrations). Third-trimester estimates were generally higher in Hispanic and non-Hispanic black infants relative to non-Hispanic white infants. Distributed lag models were also suggestive of associations between air pollutant concentrations in late pregnancy and reduced birth weight. The capture-area analyses provided little support for the associations observed in the five-county analysis.

Conclusions

Results provide some support for an effect of ambient air pollution in late pregnancy on birth weight in full-term infants.     

Respiratory Disease in Relation to Outdoor Air Pollution in Kanpur,India

ABSTRACT

This paper examines the effect of outdoor air pollution on respiratory disease in Kanpur, India, based on data from 2006. Exposure to air pollution is represented by annual emissions of sulfur dioxide (SO₂), particulate matter (PM), and nitrogen oxides (NO_x) from 11 source categories, established as a geographic information system (GIS)-based emission inventory in 2 km × 2 km grid. Respiratory disease is represented by number of patients who visited specialist pulmonary hospital with symptoms of respiratory disease. The results showed that (1) the main sources of air pollution are industries, domestic fuel burning, and vehicles; (2) the emissions of PM per grid are strongly correlated to the emissions of SO₂ and NO_x; and (3) there is a strong correlation between visits to a hospital due to respiratory disease and emission strength in the area of residence. These results clearly indicate that appropriate health and environmental monitoring, actions to reduce emissions to air, and further studies that would allow assessing the development in health status are necessary.

[Supplementary materials are available for this article. Go to the publisher's online edition of Archives of Environmental & Occupational Health for material on emission of SO₂, PM, NO_x from various sources, and total number of inhabitants, total number of patients in grid squares covering the Kanpur city.]     

Ambient air pollution and risk of congenital anomalies: a systematic review and meta-analysis

Objective

We systematically reviewed epidemiologic studies on ambient air pollution and congenital anomalies and conducted meta-analyses for a number of air pollutant–anomaly combinations.

Data sources and extraction

From bibliographic searches we extracted 10 original epidemiologic studies that examined the association between congenital anomaly risk and concentrations of air pollutants. Meta-analyses were conducted if at least four studies published risk estimates for the same pollutant and anomaly group. Summary risk estimates were calculated for a) risk at high versus low exposure level in each study and b) risk per unit increase in continuous pollutant concentration.

Data synthesis

Each individual study reported statistically significantly increased risks for some combinations of air pollutants and congenital anomalies, among many combinations tested. In meta-analyses, nitrogen dioxide (NO₂) and sulfur dioxide (SO₂) exposures were related to increases in risk of coarctation of the aorta [odds ratio (OR) per 10 ppb NO₂ = 1.17; 95% confidence interval (CI), 1.00–1.36; OR per 1 ppb SO₂ = 1.07; 95% CI, 1.01–1.13] and tetralogy of Fallot (OR per 10 ppb NO₂ = 1.20; 95% CI, 1.02–1.42; OR per 1 ppb SO₂ = 1.03; 95% CI, 1.01–1.05), and PM₁₀ (particulate matter ≤ 10 μm) exposure was related to an increased risk of atrial septal defects (OR per 10 μg/m³ = 1.14; 95% CI, 1.01–1.28). Meta-analyses found no statistically significant increase in risk of other cardiac anomalies and oral clefts.

Conclusions

We found some evidence for an effect of ambient air pollutants on congenital cardiac anomaly risk. Improvements in the areas of exposure assessment, outcome harmonization, assessment of other congenital anomalies, and mechanistic knowledge are needed to advance this field.     

Acute Effects of Air Pollution on Pulmonary Function,Airway Inflammation,and Oxidative Stress in Asthmatic Children

Background

Air pollution is associated with respiratory symptoms, lung function decrements, and hospitalizations. However, there is little information about the influence of air pollution on lung injury.

Objective

In this study we investigated acute effects of air pollution on pulmonary function and airway oxidative stress and inflammation in asthmatic children.

Methods

We studied 182 children with asthma, 9–14 years of age, for 4 weeks. Daily ambient concentrations of sulfur dioxide, nitrogen dioxide, ozone, and particulate matter ≤ 2.5 μm in aerodynamic diameter (PM_2.5) were monitored from two stations. Once a week we measured spirometry and fractional exhaled nitric oxide (Fe_NO), and determined thiobarbituric acid reactive substances (TBARS) and 8-isoprostane—two oxidative stress markers—and interleukin-6 (IL-6) in breath condensate. We tested associations using mixed-effects regression models, adjusting for confounding variables.

Results

Interquartile-range increases in 3-day average SO₂ (5.4 ppb), NO₂ (6.8 ppb), and PM_2.5 (5.4 μg/m³) were associated with decreases in forced expiratory flow between 25% and 75% of forced vital capacity, with changes being −3.1% [95% confidence interval (CI), −5.8 to −0.3], −2.8% (95% CI, −4.8 to −0.8), and −3.0% (95% CI, −4.7 to −1.2), respectively. SO₂, NO₂, and PM_2.5 were associated with increases in TBARS, with changes being 36.2% (95% CI, 15.7 to 57.2), 21.8% (95% CI, 8.2 to 36.0), and 24.8% (95% CI, 10.8 to 39.4), respectively. Risk estimates appear to be larger in children not taking corticosteroids than in children taking corticosteroids. O₃ (5.3 ppb) was not associated with health end points. Fe_NO, 8-isoprostane, and IL-6 were not associated with air pollutants.

Conclusion

Air pollution may increase airway oxidative stress and decrease small airway function of asthmatic children. Inhaled corticosteroids may reduce oxidative stress and improve airway function.     

Cell type specificity of female lung cancer associated with sulfur dioxide from air pollutants in Taiwan: An ecological study

Background  

Many studies have examined the association between air pollutants (including sulfur dioxide [SO₂], carbon monoxide [CO], nitrogen dioxide [NO₂], nitric oxide [NO], ozone [O₃], and particulate matter < 10 μm [PM₁₀]) and lung cancer. However, data from previous studies on pathological cell types were limited, especially for SO₂ exposure. We aimed to explore the association between SO₂ exposure from outdoor air pollutants and female lung cancer incidence by cell type specificity.     

Ambient air pollution and congenital heart disease: a register-based study

Maternal exposure to ambient air pollution has increasingly been linked to adverse pregnancy outcomes. The evidence linking this exposure to congenital anomalies is still limited and controversial. This case–control study investigated the association between maternal exposure to ambient particulate matter with aerodynamic diameter less than 10 μm (PM₁₀), sulfur dioxide (SO₂), nitrogen dioxide, nitric oxide (NO), ozone (O₃), and carbon monoxide (CO) and the occurrence of congenital heart disease in the population of Northeast England (1993–2003). Each case and control was assigned weekly average (weeks 3–8 of pregnancy) of pollutant levels measured by the closest monitor to the mother’s residential postcode. Using exposure as both continuous and categorical variables, logistic regression models were constructed to quantify the adjusted odds ratios of exposure to air pollutants and the occurrence of each outcome group. We found exposure to CO and NO to be associated with ventricular septal defect and cardiac septa malformations. CO was also associated with congenital pulmonary valve stenosis and NO with pooled cases of congenital heart disease and tetralogy of Fallot. Findings for SO₂, O₃ and PM₁₀ were less consistent.     

Air pollution and admissions for acute lower respiratory infections in young children of Ho Chi Minh City

This study assessed the effects of exposure to air pollution on hospitalization for acute lower respiratory infection (ALRI) among children under 5 years of age in Ho Chi Minh City (HCMC) from 2003 to 2005. Case-crossover analyses with time-stratified selection of control periods were conducted using daily admissions for pneumonia and bronchiolitis and daily, citywide averages of PM₁₀, NO₂, SO₂, and O₃ (8-h maximum average) estimated from the local air quality monitoring network. Increased concentrations of NO₂ and SO₂ were associated with increased admissions in the dry season (November to April), with excess risks of 8.50% (95%CI 0.80–16.79) and 5.85% (95%CI 0.44–11.55), respectively. PM₁₀ could also be associated with increased admissions in the dry season, but high correlation between PM₁₀ and NO₂ (0.78) limits our ability to distinguish between PM₁₀ and NO₂ effects. In the rainy season (May–October), negative associations between pollutants and admissions were observed. Results of this first study of the health effects of air pollution in HCMC support the presence of an association between combustion-source pollution and increased ALRI admissions. ALRI admissions were generally positively associated with ambient levels of PM₁₀, NO₂, and SO₂ during the dry season, but not the rainy season. Negative results in the rainy season could be driven by residual confounding present from May to October. Preliminary exploratory analyses suggested that seasonal differences in the prevalence of viral causes of ALRI could be driving the observed differences in effects by season.     

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).     

Health effect of mixtures of ozone,nitrogen dioxide,and fine particulates in 85 US counties

Despite substantial improvements in ambient air quality in the past decades, ozone (O₃), nitrogen dioxide (NO₂), and fine particulate matter (PM_2.5) remain as concerns. As these pollutants exist as mixtures in ambient environments, some combinations of these pollutants may be more harmful to human health than other combinations. Identifying harmful pollutant mixtures can help develop multi-pollutant control strategies to better protect health. Current methods exhibit limitations in identifying harmful mixtures. We aim to identify harmful compositions of three-pollutant mixtures in 85 US counties during 1999–2010. We developed a new method called PANCAKE to quantify O₃-NO₂-PM_2.5 mixtures. O₃-NO₂-PM_2.5 mixtures are categorized into 27 composition types based on combinations of different O₃, NO₂, and PM_2.5 levels. We identified harmful compositions by estimating the effect of each composition of O₃-NO₂-PM_2.5 mixture compared to the reference composition on cardiovascular admissions among Medicare patients. We found that a mixture with relatively low levels of some pollutants combined with relatively high levels of other pollutants can be equally or more harmful than a mixture with high levels of all pollutants. Eight out of the 27 composition types, often with NO₂ levels >?17.3 ppb and PM_2.5 levels >?8.8 μg/m³ combined with any levels of O₃, were associated with significantly increased cardiovascular admission rates compared to the reference composition. These harmful compositions overall occurred in about 40–50% of days in winter, metropolitan areas, or the East North Central region. Mixture composition plays an important role in determining health risks and may be worth considering when developing air pollution control strategies.