Traffic-related particulate matter and acute respiratory symptoms among New York City area adolescents

Effects of a choral program combining wind instrument performance and breathing training on respiratory function, stress, and quality of life in adolescents: A randomized controlled trial

BACKGROUND

Choral activities are correlated with various health and wellbeing parameters. However, an intervention combining a music program using wind instruments and choral activities has not yet been investigated. Thus, this study aimed to assess the effects of a 12-week intervention combining a wind instrument performance program and a choral program on stress factors, quality of life, and respiratory function in adolescents located in a metropolitan city with exposure to air pollution.

METHOD

This randomized controlled trial consisted of 50 adolescents, and the subjects were randomly assigned to a combination wind instrument and choral training group, a choral training group, and a control group. Following a 12-week intervention program, respiratory function, stress factors, and quality of life were compared between the three groups.

RESULTS

Regarding respiratory function, with the exception of maximal inspiratory pressure, all measured variables exhibited an interaction to indicate a variation in the pattern of change(p<0.05). Furthermore, regarding stress factors and quality of life, all measured variables exhibited an interaction to indicate a variation in the pattern of change(p<0.05). As a result of the post-hoc analysis, significant differences were found in all variables in experimental group 1 compared to other groups (p<0.05).

CONCLUSION

The results showed that the 12-week intervention combining a wind instrument performance program and a choral program had positive effects in improving the respiratory function, stress factors, and quality of life in adolescents. This study findings are expected to support future studies aimed at promoting overall health including respiratory function and psychological factors through various music-based programs.

Assessment of seasonal variability of PM, BC and UFP levels at a highway toll stations and their associated health risks

As a part of their occupation, workers at toll stations are exposed to traffic emissions during the working shift, which sometimes stretches to 12 h. To assess the exposure and subsequent health risk of these workers, a study was performed on a highway toll station in India. PM1, PM2.5, PM10, BC and UFP concentration were determined inside a toll collectors' cabin and outside in a free-flowing traffic section (125 m from the toll cabin). The concentrations varied in the following range: PM1 (40.69-226.13 μg m-3), PM2.5 (49.71-247.36 μg m-3), PM10 (83.15-458.14 μg m-3) and BC (2.1-87.5 μg m-3) and UFP: 101-53705 pt cm-3. The mean concentration inside the cabin was 1.34 (PM1), 1.35 (PM2.5), 1.16 (PM10) and 2.91 (BC) times the concentration outside for the summer season. The corresponding levels in the winter season were 1.14 (PM1), 1.11 (PM2.5), 1.11 (PM10), 2.50 (BC) and 1.82 (UFP). In addition to the exhaust emission, the non-exhaust emissions such as resuspension of crustal particles, fly ash and bioaerosols were identified. Using the Multiple Path Particle Dosimetry model for two groups - adults (18-21 years) and adults (21+ years), it was estimated that the pulmonary deposition of in-cabin workers were 50% (PM2.5) -75% (PM1) higher than the workers outside the cabin. Particle mass deposition was found to be higher for adults (21+ years) than adults (18-21 years) for both the seasons. The study quantitatively assessed the health risk faced by the workers in terms of exposure concentration and deposition in respiratory tract. More such studies at different traffic mix and climate can provide better estimates of health risk of toll workers that can be used to devise appropriate strategies for control of it.

Associations between air pollutants and acute exacerbation of drug-resistant tuberculosis: evidence from a prospective cohort study

BACKGROUND

Short-term exposure to air pollution may trigger symptoms of drug-resistant tuberculosis (DR-TB) through stimulating lung tissue, damaging tracheobronchial mucosa, the key anti-mycobacterium T cell immune function, and production and release of inflammatory cytokines.

OBJECTIVE

To investigate the association between acute exacerbations of DR-TB and short-term residential exposure to air pollutants (PM10, PM2.5, SO2, NO2, CO and O3) based on a large prospective cohort in Anhui Province, China.

METHOD

Patients were derived from a prospective cohort study of DR-TB in Anhui Province. All DR-TB patients underwent drug-susceptibility testing and prefecture-level reference laboratories confirmed their microbiologies. The case-crossover design was performed to evaluate the association between the risk of acute exacerbations of DR-TB and short-term residential exposure to air pollution.

RESULTS

Short-term NO2 exposure was significantly related to an elevated risk of first-time outpatient visit due to acute exacerbations of DR-TB(relative risk:1.159, 95% confidence interval:1.011 ~ 1.329). Stratification analyses revealed that the relationship between the risk of acute exacerbations and NO2 exposure was stronger in the elderly (age ≥ 65) DR-TB patients, and in individuals with a history of TB treatment.

CONCLUSIONS

NO2 Exposure was significantly associated with an elevated risk of acute exacerbation of DR-TB in Anhui Province, China.

Characteristics and health risks of parent, alkylated, and oxygenated PAHs and their contributions to reactive oxygen species from PM2.5 vehicular emissions in the longest tunnel in downtown Xi'an, China

A vehicular emission study was conducted in the longest inner-city tunnel in Xi'an, northwestern China in four time periods (I: 07:30-10:30, II: 11:00-14:00, III: 16:30-19:30, and IV: 20:00-23:00 LST). A sum of 40 PAHs, including parent (p-PAHs), alkylated (a-PAHs), and oxygenated (o-PAHs) in fine particulate matter (PM_2.5) were quantified. The relationships between the PAHs and the formation of reactive oxygen species (ROS) were also studied. The average total quantified PAHs concentration was 236.3 ± 48.3 ng m^-3. The p-PAHs were found to be the most dominated group, accounting for an average of 88.1% of the total quantified PAHs, followed by a-PAHs (6.1%) and o-PAHs (5.8%). On the base of the number of aromatic rings, the groups of ≤5 rings (92.5 ± 1.2%) had higher fractions than the high ones (≥6 rings, 7.5 ± 1.2%) for pPAHs. Diurnal variations of PAHs subgroups exhibited the highest levels in Period III, consistent with the largest traffic counts in evening rush hours. However, less reduction of few PAHs in the night period demonstrates that the emissions of compressed natural gas (CNG) and methanol-fueled vehicles cannot be ignored while their contribution increased. High ROS activity levels were observed in the traffic-dominated samples, implying the potential oxidative damages to humans. Additionally, diurnal variation of the ROS activity was consistent with the total quantified PAHs and toxic equivalency of benzo[a]pyrene. Good correlations (R > 0.6, p < 0.05) were seen between individual groups of PAHs (especially for 3-5 rings p-PAHs, 4 rings a-PAHs, and 2-3 rings o-PAHs) and ROS activity, supporting that the vehicular emitted PAHs possibly initiate oxidative stress. The multiple linear regression analysis further illustrated that chrysene contributed the highest (25.0%) to ROS activity. In addition to highlighting the potential hazards to the PAHs from the vehicular emission, their roles to mitigate the health effects by formations of ROS were firstly reported in northwestern China.

Effect of time-activity patterns and microenvironments on the personal exposure of undergraduate students to black carbon

In this study, the personal exposure to and potential dose of black carbon (BC) of undergraduate students (22-27 years old, nonsmokers) were determined. BC was continuously measured by a portable device (microAeth^® AE51) for four consecutive days in Istanbul between April and May 2019. The time-activity diaries filled out by each volunteer were assessed to define the activities and microenvironments (home, school, transportation and entertainment) that contributed to daily BC exposure. The overall mean concentration of BC was 2.0 μg/m³, and the mean concentrations on weekdays and weekends were 3.0 μg/m³ and 1.1 μg/m³, respectively. Transportation made the highest contribution to mean BC exposure (42%) and dose (45.8%) on weekdays, while the contributions of home-based activities to BC exposure (66.1%) and dose (63.2%) were higher on weekends. Students had the most intense exposure to (2.8% and 4.6%) and dose (3.1% and 5.8%) of BC in transportation both on weekdays and on weekends, respectively. Between transportation modes, the mean BC concentration was the highest for minibuses (14.8 μg/m³), while walking made the largest contribution to BC exposure (16.8%) on weekdays. Students spent 12.8% of their weekdays at school, and the contributions of the school environment to BC exposure and dose were 8.5% and 7%, respectively. Exposure to BC increased during cooking and eating activities in microenvironments such as the kitchen, cafe and dining hall.

The impact of traffic-related air pollution on lung function status and respiratory symptoms among children in Klang Valley, Malaysia

Increasing the range of vehicles on traffic roads in the urban area has led to traffic-related air pollution (TRAP) and is currently becoming the main concern for health, especially among children. The study aimed to determine associations between TRAP and respiratory health, also to identify the main factors that influenced them. A cross-sectional comparative study was carried out among children in high and low traffic areas. Air quality monitoring was conducted in six primary schools. A set of standardized questionnaires was distributed to obtain respondents' exposure history and respiratory health symptoms, while spirometry test was carried out to determine the lung function status. There were associations between TRAP and abnormality of FEV₁% among children. NO₂ was the main predictor that influenced both chest tightness and abnormality of FEV₁%. Children exposed to a high level of traffic-related air pollution have an increased risk of respiratory symptoms and abnormality of lung function.

Defining pediatric asthma: phenotypes to endotypes and beyond

Asthma is the most common chronic pediatric lung disease that has traditionally been defined as a syndrome of airway inflammation characterized by clinical symptoms of cough and wheeze. Highlighting the complex and heterogeneous nature of asthma, this review summarizes recent advances in asthma classification that are based on pathobiology, and thereby directly addresses limitations of existent definitions of asthma. By reviewing and contrasting clinical and mechanistic features of adult and childhood asthma, the review summarizes key biomarkers that distinguish childhood asthma subtypes. While atopy and its severity are important features of childhood asthma, there is evidence to support the existence of a childhood asthma endotype distinct from the atopic endotype. Although biomarkers of non-atopic asthma are an area of future research, we summarize a clinical approach that includes existing measures of airway-specific and systemic measures of atopy, co-existing morbidities, and disease severity and control, in the definition of childhood asthma, to empower health care providers to better characterize asthma disease burden in children. Identification of biomarkers of non-atopic asthma and the contribution of genetics and epigenetics to pediatric asthma burden remains a research need, which can potentially allow delivery of precision medicine to pediatric asthma. IMPACT: This review highlights asthma as a complex and heterogeneous disease and discusses recent advances in the understanding of the pathobiology of asthma to demonstrate the need for a more nuanced definitions of asthma. We review current knowledge of asthma phenotypes and endotypes and put forth an approach to endotyping asthma that may be useful for defining asthma for clinical care as well as for future research studies in the realm of personalized medicine for asthma.

Traffic Density-Related Black Carbon Distribution: Impact of Wind in a Basin Town

Black carbon is one of the riskiest particle matter pollutants that is harmful to human health. Although it has been increasingly investigated, factors that depend on black carbon distribution and concentration are still insufficiently researched. Variables, such as traffic density, wind speeds, and ground levels can lead to substantial variations of black carbon concentrations and potential exposure, which is even riskier for people living in less-airy sites. Therefore, this paper “fills the gaps” by studying black carbon distribution variations, concentrations, and oscillations, with special emphasis on traffic density and road segments, at multiple locations, in a small city located in a basin, with frequent temperature inversions and infrequent low wind speeds. As wind speed has a significant impact on black carbon concentration trends, it is critical to present how low wind speeds influence black carbon dispersion in a basin city, and how black carbon is dependent on traffic density. Our results revealed that when the wind reached speeds of 1 ms⁻¹, black carbon concentrations actually increased. In lengthy wind periods, when wind speeds reached 2 or 3 ms⁻¹, black carbon concentrations decreased during rush hour and in the time of severe winter biomass burning. By observing the results, it could be concluded that black carbon persists longer in higher altitudes than near ground level. Black carbon concentration oscillations were also seen as more pronounced on main roads with higher traffic density. The more the traffic decreases and becomes steady, the more black carbon concentrations oscillate.

Assessment of Home-Based and Mobility-Based Exposure to Black Carbon in an Urban Environment: A Pilot Study

The combustion of fossil fuels is a significant source of particulate-bound black carbon (BC) in urban environments. The personal exposure (PE) of urban dwellers to BC and subsequent health impacts remain poorly understood due to a lack of observational data. In this study, we assessed and quantified the levels of PE to BC under two exposure scenarios (home-based and mobility-based exposure) in the city of Trivandrum in India. In the home-based scenario, the PE to BC was assessed in a naturally ventilated building over 24 h each day during the study period while in the mobility-based scenario, the PE to BC was monitored across diverse microenvironments (MEs) during the day using the same study protocol for consistency. Elevated BC concentrations were observed during the transport by motorcycle (26.23 ± 2.33 µg/m³) and car (17.49 ± 2.37 µg/m³). The BC concentrations observed in the MEs decreased in the following order: 16.58 ± 1.38 µg/m³ (temple), 13.78 ± 2.07 µg/m³ (restaurant), 11.44 ± 1.37 µg/m³ (bus stop), and 8.27 ± 1.88 µg/m³ (home); the standard deviations represent the temporal and spatial variations of BC concentrations. Overall, a relatively larger inhaled dose of BC in the range of 148.98–163.87 µg/day was observed for the mobility-based scenario compared to the home-based one (118.10–137.03 µg/day). This work highlights the importance of reducing PE to fossil fuel-related particulate emissions in cities for which BC is a good indicator. The study outcome could be used to formulate effective strategies to improve the urban air quality as well as public health.

Air quality around schools: Part I - A comprehensive literature review across high-income countries

Children are particularly vulnerable to the detrimental health impacts of poor air quality. In the UK, recent initiatives at local council level have focussed on mitigating children's air pollution exposure at school. However, an overview of the available evidence on concentration and exposure in school environments - and a summary of key knowledge gaps - has so far been lacking. To address this, we conducted a review bringing together recent academic and grey literature, relating to air quality in outdoor school environments - including playgrounds, drop-off zones, and the school commute - across high-income countries. We aimed to critically assess, synthesise, and categorise the available literature, to produce recommendations on future research and mitigating actions. Our searches initially identified 883 articles of interest, which were filtered down in screening and appraisal to a final total of 100 for inclusion. Many of the included studies focussed on nitrogen dioxide (NO₂), and particulate matter (PM) in both the coarse and fine fractions, around schools across a range of countries. Some studies also observed ozone (O₃) and volatile organic compounds (VOCs) outside schools. Our review identified evidence that children can encounter pollution peaks on the school journey, at school gates, and in school playgrounds; that nearby traffic is a key determinant of concentrations outside schools; and that factors relating to planning and urban design - such as the type of playground paving, and amount of surrounding green space - can influence school site concentrations. The review also outlines evidence gaps that can be targeted in future research. These include the need for more personal monitoring studies that distinguish between the exposure that takes place indoors and outdoors at school, and a need for a greater number of studies that conduct before-after evaluation of local interventions designed to mitigate children's exposure, such as green barriers and road closures. Finally, our review also proposes some tangible recommendations for policymakers and local leaders. The creation of clean air zones around schools; greening of school grounds; careful selection of new school sites; promotion of active travel to and from school; avoidance of major roads on the school commute; and scheduling of outdoor learning and play away from peak traffic hours, are all advocated by the evidence collated in this review.

Particulate Matter 10 (PM10) Is Associated with Epistaxis in Children and Adults

The impact of atmospheric concentration of particulate matter ≤10 μm in diameter (PM₁₀) continues to attract research attention. This study aimed to evaluate the effects of meteorological factors, including PM₁₀ concentration, on epistaxis presentation in children and adults. We reviewed the data from 1557 days and 2273 cases of epistaxis between January 2015 and December 2019. Eligible patients were stratified by age into the children (age ≤17 years) and adult groups. The main outcome was the incidence and cumulative number of epistaxis presentations in hospital per day and month. Meteorological factors and PM₁₀ concentration data were obtained from the Korea Meteorological Administration. Several meteorological factors were associated with epistaxis presentation in hospital; however, these associations differed between children and adults. Only PM₁₀ concentration was consistently associated with daily epistaxis presentation in hospital among both children and adults. Additionally, PM₁₀ concentration was associated with the daily cumulative number of epistaxis presentations in hospital in children and adults. Furthermore, the monthly mean PM₁₀ concentration was significantly associated with the total number of epistaxis presentations in the corresponding month. PM₁₀ concentration should be regarded as an important environmental factor that may affect epistaxis in both children and adults.

In-vitro human lung cell injuries induced by urban PM2.5 during a severe air pollution episode: Variations associated with particle components

Environmental air pollutants pose significant threats to public health, especially the toxicity and diseases caused by the atmospheric fine particulate matters (PM_2.5). Since the health risks vary with both the concentrations and compositions of PM_2.5 which are determined by aerosol sources, how are their toxic effects relevant to the pollution level becomes an important issue, such as the haze episodes covering clean and polluted days. With the transition from non-pollution to pollution stage, daily PM_2.5 samples were collected from both the urban and industrial areas of Nanjing city, eastern China, covering a typical haze event in autumn-winter. Their unpropitious effects on human lung epithelial cells (A549) were compared by in vitro toxicity assays and chemical component analysis. Both air levels and cytotoxic effects of PM_2.5 varied with the transition of haze event. Although the concentration of PM_2.5 in air is of course the highest in pollution stage driven by local stable meteorological condition, unit mass of them posed higher toxicity (lower cell viability and higher IL-6) but induced lower cell oxidative (evidences of ROS and NQO1 mRNA expression) and inflammatory cytokine TNF-α responses than those particles during non-pollution stage. These patterns were explained by the metals and water-soluble components decreased with the haze development. Non-soluble particulate carbonaceous aerosol compositions might play a significant role in inducing cytotoxicity. Moreover, the regional pattern of episode pollution weakened the spatial variation within a city scale. Since the haze development intensified both the quantity and toxicity of PM_2.5 in air, the health risks of overall aerosol exposure were synthetically amplified during haze weather, so the increased air particles with higher toxic components from fuel combustion sources should be key targets of pollution control.

An exploratory evaluation of the potential pulmonary, neurological and other health effects of chronic exposure to emissions from municipal solid waste fires at a large dumpsite in Olusosun, Lagos, Nigeria

Open municipal solid waste (MSW) combustion is a major emission source of particulate air pollution, polycyclic aromatic hydrocarbons, and more exotic hazardous organic pollutants including polychlorinated biphenyls and brominated flame retardants. However, the adverse impact of MSW combustion emission on health among the general population is unknown. Therefore, a cross-sectional study was conducted to explore the associations between potential exposure to MSW combustion-related air pollution and symptoms of adverse health effects among residents of a community adjacent to a large open landfill in Lagos, Nigeria. Using ordinal logistic regression and controlling for age, sex, and smoking, it was observed that residence for ≥ 11 years had increased odds (p < 0.05) of daily occurrence of tingling/numbness/whiteness of fingers (2.614), headaches (2.725), memory problems (2.869), tremor/cramps (2.748), and confusion (3.033) among other symptoms. These results indicate adverse health impacts of chronic exposure to MSW combustion emission.

Cytotoxicity of PM2.5 vehicular emissions in the Shing Mun Tunnel, Hong Kong

Associations between human exposures to vehicular emissions (VE) and cardiopulmonary diseases have been found, with a dearth of information on particle cytotoxicity. This study exposes human lung alveolar epithelial (A549) cells to PM_2.5 (particulate matter with aerodynamic diameter <2.5 μm) samples collected in a tunnel and investigates the oxidative and inflammatory responses. The cytotoxicity factor (CF) is used to normalize the VE cytotoxicity. The emission factors (EFs) were 27.2 ± 12.0 mg vehicle^-1 km^-1 for PM_2.5 and 4.93 ± 1.67 μg vehicle^-1 km^-1 for measured polycyclic aromatic hydrocarbons (PAHs). Higher EFs were found for high (4-6 rings) than low (2-3 rings) molecular-weight particulate PAHs. PM_2.5 VE caused oxidative stress and inflammation of human lung cells. Organic carbon (OC), element carbon (EC), and several PAHs were significantly (p < 0.05) correlated with bioreactivity. Higher CFs were found when diesel vehicle counts were highest during the morning rush hour, implying that diesel-fueled VE were major contributors to cytotoxic effects. This study provides a broader understanding of the toxicity in an engine-exhaust dominated environment.

Association Between Metabolic and Hormonal Derangements and Professional Exposure to Urban Pollution in a High Intensity Traffic Area

Rationale: Studies suggest a relation between exposure to air particulate matter (PM)_2.5 pollution and greater cardiovascular morbidity, as well as increased risk for obesity and diabetes. We aimed to identify association(s) between nutritional and metabolic status and exposure to environmental pollution in a cohort of policemen exposed to high levels of air pollution. Methods: We considered adult municipal policemen, working in an urban area at high-traffic density with documented high levels of air PM_2.5 (exposed group) compared to non-exposed policemen. Clinical characteristics, including the presence/absence of metabolic syndrome, were recorded, and serum biomarkers, including adiponectin, leptin, and ghrelin, were assessed. Results: One hundred ninety-nine participants were enrolled, 100 in the exposed group and 99 in the non-exposed group. Metabolic syndrome was documented in 32% of exposed group and in 52.5% of non-exposed group (P = 0.008). In the exposed group, we found a positive correlation between body mass index and serum leptin as well as in the non-exposed group (P < 0.0001). Within the exposed group, subjects with metabolic syndrome showed lower serum adiponectin (P < 0.0001) and higher leptin (P = 0.002) levels with respect to those without metabolic syndrome, whereas in the non-exposed group, subjects with metabolic syndrome showed only higher leptin levels when compared to those without metabolic syndrome (P = 0.01). Among the participants with metabolic syndrome, we found lower adiponectin levels in those of the exposed group with respect to the non-exposed ones (P = 0.007). When comparing the exposed and non-exposed groups, after stratifying participants for Homeostatic Model Assessment for Insulin Resistance >2.5, we found lower adiponectin levels in those of the exposed group with respect to the non-exposed ones (P = 0.038). Conclusions: Exposure to air PM pollution was associated with lower levels of adiponectin in adult males with metabolic syndrome.

Indoor measurements of air pollutants in residential houses in urban and suburban areas: Indoor versus ambient concentrations

Indoor exposure to air pollutants was assessed through 99 visits to 51 homes located in downtown high-rise buildings and detached houses in suburban and rural areas. The ambient concentrations of ultrafine particles (UFP), black carbon (BC), particulate matter smaller than 2.5 μm in diameter (PM2.5), and trace elements were concurrently measured at a central monitoring site in downtown Toronto. Median hourly indoor concentrations for all measurements were 4700 particles/cm³ for UFP, 270 ng/m³ for BC, and 4 μg/m³ for PM2.5, which were lower than ambient outdoor levels by a factor of 2-3. Much higher variability was observed for indoor UFP and BC across the homes compared to ambient levels, mostly due to the influence of indoor cooking emissions. Traffic emissions appeared to have a strong influence on the indoor background (i.e., outdoor-originated) concentrations of BC, UFP, and some trace elements. Specifically, 85% and 34% of the indoor concentrations of BC and UFP were predominantly from outdoor sources, respectively. Moreover, a positive correlation was observed between indoor concentrations of BC and UFP and total road length within a 300 m buffer zone. There was no significant decrease in indoor air pollution with increasing floor level among high-rise residences. In addition to the influence of outdoor sources on indoor air quality, indoor sources contributed to elevated concentrations of K, Ca, Cr, and Cu. A factor analysis was performed on trace elements, UFP, and BC in homes to further resolve possible sources. Local traffic emissions, soil dust, biomass burning, and regional coal combustion were identified as outdoor-originated sources, while cooking emissions was a dominant indoor source. This study highlights how outdoor sources can contribute to chronic exposure in indoor environments and how indoor activities can be associated with acute exposure to temporally varying indoor-originated air pollutants.

Characteristics of PM2.5 and Black Carbon Exposure Among Subway Workers

This study aimed to assess the characteristics of exposure to both PM_2.5 and black carbon (BC) among subway workers. A total of 61 subway workers, including 26, 23, and 12 subway station managers, maintenance engineers, and train drivers, respectively, were investigated in 2018. Real-time measurements of airborne PM_2.5 and BC were simultaneously conducted around the breathing zones of workers. Maintenance engineers had the highest average levels of exposure to both PM_2.5 and BC (PM_2.5, 76 µg/m³; BC, 9.3 µg/m³), followed by train drivers (63.2 µg/m³, 5.9 µg/m³) and subway station managers (39.7 µg/m³, 2.2 µg/m³). In terms of the relationship between mass concentrations of PM_2.5 and BC, train drivers demonstrated the strongest correlation (R = 0.72), indicating that the proportion of BC contained in PM_2.5 is relatively steady. The average proportion of BC in PM_2.5 among maintenance engineers (13.0%) was higher than that among train drivers (9.4%) and subway station managers (6.4%). Univariate and mixed effect multiple analyses demonstrated the type of task and worksite to be significant factors affecting exposure levels in maintenance engineers and subway station managers. The use of diesel engine motorcars in tunnel maintenance was found to be a key contributor to PM_2.5 and BC exposure levels among subway workers.

Stronger association between particulate air pollution and pulmonary function among healthy students in fall than in spring

Previous studies have reported the short-term effects of particulate air pollution on health. However, most of those studies were relatively short in duration, with only a few, in healthy adolescents. We investigated the short-term effects of particulate air pollution on pulmonary function in healthy adolescents over a long period. A panel study was repeatedly conducted twice a year for about one month each, in spring and fall from 2014 to 2016, in an isolated island in the Seto Inland Sea, Japan. Daily measurements of peak expiratory flow (PEF) and forced expiratory volume in 1 s (FEV₁) were performed in a total of 48 healthy college students aged 15-19 years. The ambient concentrations of particulate matter with diameter ≤2.5 μm (PM_2.5) and between 2.5 and 10 μm (PM_10-2.5), and black carbon (BC) were continuously measured. A mixed-effects model was used to investigate the relationships between air pollutants and pulmonary function. In the overall analyses of the six study periods, decreases in the PEF and FEV₁ were significantly associated with increases in the PM_2.5 and BC concentrations. The greatest decrease was found in FEV₁ (-1.97% [95% confidence interval (CI): -2.90, -1.04]), which was associated with an interquartile range (IQR) increase in the 0-72-h average concentrations of PM_2.5 (14.1 μg/m³). Neither PEF nor FEV₁ were associated with PM_10-2.5 concentrations. In the analyses by season, both the PEF and FEV₁ values decreased significantly in relation to increases in the PM_2.5, PM_10-2.5 and BC concentrations in the fall. However, in spring, both PEF and FEV₁ showed weak associations with each of the pollutants. In conclusion, relatively low increases in the ambient particulate matter levels were associated with reduced pulmonary function among healthy adolescents. This association was stronger in fall than in spring.

Evaluation of the Impact of Black Carbon on the Worsening of Allergic Respiratory Diseases in the Region of Western Serbia: A Time-Stratified Case-Crossover Study

Background and Objectives: Many epidemiological studies have shown a positive association between black carbon (BC) and the exacerbation of allergic rhinitis and allergic asthma. However, none of the studies in Serbia examined this relationship yet. The aim of this study was to examine the associations between BC and emergency department (ED) visits for allergic rhinitis and allergic asthma in the Užice region of Serbia. Materials and Methods: A time-stratified case-crossover design was applied to 523 ED visits for allergic rhinitis and asthma exacerbation that occurred in the Užice region of Serbia between 2012–2014. Data regarding ED visits were routinely collected in the Health Center of Užice. The daily average concentrations of BC were measured by automatic ambient air quality monitoring stations. Odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were estimated using conditional logistic regression adjusted for the potential confounding influence of weather variables (temperature, humidity, and air pressure). Results: Statistically significant associations were observed between ED visits for allergic rhinitis and 2-day lagged exposure to BC (OR = 3.20; CI = 1.00–10.18; p = 0.049) and allergic asthma and 3-day lagged exposure to BC (OR = 3.23; CI = 1.05–9.95; p = 0.041). Conclusion: Exposure to BC in the Užice region increases the risk of ED visits for allergic rhinitis and asthma, particularly during the heating season.

Modeled and perceived RF-EMF, noise and air pollution and symptoms in a population cohort. Is perception key in predicting symptoms?

BACKGROUND

Psychosocial research has shown that perceived exposure can influence symptom reporting, regardless of actual exposure. The impact of this phenomenon on the interpretation of results from epidemiological research on environmental determinants of symptoms is unclear.

OBJECTIVE

Our aim was to compare associations between modeled exposures, the perceived level of these exposures and reported symptoms (non-specific symptoms, sleep disturbances, and respiratory symptoms) for three different environmental exposures (radiofrequency electromagnetic fields (RF-EMF), noise, and air pollution). These environmental exposures vary in the degree to which they can be sensorially observed.

METHODS

Participant characteristics, perceived exposures, and self-reported health were assessed with a baseline (n = 14,829, 2011/2012) and follow-up (n = 7905, 2015) questionnaire in the Dutch population-based Occupational and Environmental Health Cohort (AMIGO). Environmental exposures were estimated at the home address using spatial models. Cross-sectional and longitudinal regression models were used to examine the associations between modeled and perceived exposures, and reported symptoms.

RESULTS

The extent to which exposure sources could be observed by participants likely influenced correlations between modeled and perceived exposure as correlations were moderate for air pollution (r_Sp = 0.34) and noise (r_Sp = 0.40), but less so for RF-EMF (r_Sp = 0.11). Perceived exposures were consistently associated with increased symptom scores (respiratory, sleep, non-specific). Modeled exposures, except RF-EMF, were associated with increased symptom scores, but these associations disappeared or strongly diminished when accounted for perceived exposure in the analyses.

DISCUSSION

Perceived exposure has an important role in symptom reporting. When environmental determinants of symptoms are studied without acknowledging the potential role of both modeled and perceived exposures, there is a risk of bias in health risk assessment. However, the etiological role of exposure perceptions in relation to symptom reporting requires further research.

Effect of PM2.5 on invasion and proliferation of HeLa cells and the expression of inflammatory cytokines IL-1 and IL-6

Effects of different levels of PM2.5 on invasion and proliferation of HeLa cells and the expression levels of inflammatory cytokines IL-1 and IL-6 under 10 µg/ml PM2.5 were investigated. Different groups of HeLa cells were treated with PM2.5 at 0, 10, 25, 50, 100 and 200 µg/ml for 36 h, respectively. Cell proliferation was detected by MTT assay. Transwell assay was performed to detect the invasion of HeLa cells. Enzyme-linked immunosorbent assay (ELISA), RT-qPCR and western blotting were used to detect the expression levels of inflammatory cytokines IL-1 and IL-6 in PM2.5-stimulated HeLa cells. It was observed that proliferation of cells treated with PM2.5 at a concentration of 10 µg/ml was basically the same as that of untreated cells, while high concentration of PM2.5 inhibited the proliferation of HeLa cells in a dose-dependent manner in the range from 25 to 200 µg/ml (P<0.05). Transwell invasion assay showed that the number of migrating HeLa cells stimulated by 10 µg/ml PM2.5 was significantly greater than that of NC group cells (P<0.05). Western blotting showed that IL-1 and IL-6 protein expression levels in HeLa cells after stimulation with 10 µg/ml PM2.5 were significantly higher than that in NC group (P<0.05). RT-qPCR results also showed that IL-1 mRNA and IL-6 mRNA expression levels in HeLa cells stimulated by 10 µg/ml PM2.5 were significantly higher than those in the NC group (P<0.05). Additionally, ELISA results showed that IL-1 and IL-6 levels in HeLa cells stimulated by 10 µg/ml PM2.5 were significantly higher than those in NC group (P<0.05). We conclude that high concentrations of PM2.5 can inhibit the proliferation of HeLa cells to a certain extent. Stimulation with 10 µg/ml PM2.5 increases the invasion ability of HeLa cells and promotes the expression of inflammatory cytokines IL-1 and IL-6.

The association of ambient PM2.5 with school absence and symptoms in schoolchildren: a panel study

BACKGROUND

Children are a susceptible population to exposure of ambient fine particulate air pollution (PM_2.5), and the associated symptoms are sensitive prevalent indicators of morbidity. However, few studies to date investigate the association between PM_2.5 exposure and school absence and symptoms.

METHODS

In a panel study including 20,291 observations in 615 schoolchildren 8-13 years of age, we asked the participants to record their school absence and symptoms on every school day from 17 November to 31 December 2014 in Jinan, China. We used the generalized linear mixed effects models to examine the adverse effects of ambient PM_2.5 on school absence and symptoms, adjusting for covariates including meteorological and individual factors.

RESULTS

The 3-day moving average of PM_2.5 was significantly associated with school absence (1.37; 95% CI: 1.07-1.74) and increases in symptoms of the throat (1.03; 95% CI: 1.00-1.05), nose (1.03; 95% CI: 1.01-1.06), and skin (1.09; 95% CI: 1.06-1.12). High PM_2.5 exposure also increased the risks of individual symptoms, especially for cough (1.02; 95% CI: 1.00-1.04), sneezing (1.03; 95% CI: 1.00-1.07), and stuffy nose (1.09; 95% CI: 1.02-1.17).

CONCLUSION

High PM_2.5 exposure is a risk factor for the health of schoolchildren. Allocation of medical resources for children should take into account the ambient PM_2.5 concentrations and be proportioned accordingly.

RISK EFFECTS OF NEAR-ROADWAY POLLUTANTS AND ASTHMA STATUS ON BRONCHITIC SYMPTOMS IN CHILDREN

Supplemental Digital Content is available in the text.

Background:

Bronchitic symptoms in children pose a significant clinical and public health burden. Exposures to criteria air pollutants affect bronchitic symptoms, especially in children with asthma. Less is known about near-roadway exposures.

Methods:

Bronchitic symptoms (bronchitis, chronic cough, or phlegm) in the past 12 months were assessed annually with 8 to 9 years of follow-up on 6757 children from the southern California Children’s Health Study. Residential exposure to freeway and non-freeway near-roadway air pollution was estimated using a line-source dispersion model. Mixed-effects logistic regression models were used to relate near-roadway air pollutant exposures to bronchitic symptoms among children with and without asthma.

Results:

Among children with asthma, a 2 SD increase in non-freeway exposures (odds ratio [OR]: 1.44; 95% confidence interval [CI]: 1.17, 1.78) and freeway exposures (OR: 1.31; 95% CI: 1.06, 1.60) were significantly associated with increased risk of bronchitic symptoms. Among children without asthma, only non-freeway exposures had a significant association (OR: 1.14; 95% CI: 1.00, 1.29). Associations were strongest among children living in communities with lower regional particulate matter.

Conclusions:

Near-roadway air pollution was associated with bronchitic symptoms, especially among children with asthma and those living in communities with lower regional particulate matter. Better characterization of traffic pollutants from non-freeway roads is needed since many children live in close proximity to this source.

Acute respiratory symptoms associated with short term fluctuations in ambient pollutants among schoolchildren in Durban, South Africa

Ambient air pollution has been associated with adverse respiratory outcomes, especially among children with asthma. This study reports on associations between daily ambient air pollutant concentrations and the respiratory symptoms of schoolchildren living in Durban, South Africa. This city is Africa's busiest port and a key hub for imported crude oil and exported refined petroleum and petrochemical products, and it experiences a mixture of air pollutants that reflects emissions from industry, traffic and biomass burning. Children in four communities in the highly industrialized southern portion of the city were compared to children of similar socio-economic profiles living in the north of the city. One school was selected in each community. A total of 423 children were recruited. Symptom logs were completed every 1.5-2 h over 3-week period in each of four seasons. Ambient concentrations of NO₂, NO, SO₂, CO, O_3, PM_2.5 and PM₁₀ were measured throughout the study. Generalized estimating equation (GEE) models were used to estimate odds ratios (ORs) and assess lag effects (1-5 days) using single pollutant (single lags or distributed lags) models. Concentrations of SO₂ and NO_x were markedly higher in the south, while PM₁₀ did not vary. Significant increase in the odds ratios of cough were identified for the various lags analyzed. The OR of symptoms was further increased among those living in the south compared to the north. In conclusion, in this analysis of over 70,000 observations, we provide further evidence that exposure to PM₁₀, SO₂, NO₂ and NO is associated with significantly increased occurrence of respiratory symptoms among children. This was evident for cough, shortness of breath, and chest tightness, across the four pollutants and for different lags of exposure. This is the first study describing these changes in sub-Saharan Africa.

PM2.5 components and outpatient visits for asthma: A time-stratified case-crossover study in a suburban area

The effects of fine particles (PM_2.5) on asthma have been widely confirmed by epidemiological research studies. However, a limited number of studies have investigated the relationship between exposure to different PM_2.5 components and asthma. We characterized the PM_2.5 components in a suburban site of central Taiwan and conducted a time-stratified case-crossover study to elaborate the effects of daily concentration of each PM_2.5 component on asthma outpatient visits. We retrieved asthma outpatient claims for individuals less than 20 years old with a residential address in the Shalu district, Taiwan, from the National Health Insurance Research Database during 2000-2010. Multiple linear regression models were used to back extrapolate the historic concentration of individual components of PM_2.5 from 2000 through to 2010, including black carbon (BC) and eight ions, namely, sulfate, nitrate (NO₃^-), ammonium, chloride, potassium (K⁺), magnesium, calcium, sodium. The odds ratio (OR) with a 95% confidence interval (CI) of individual PM_2.5 components on asthma was estimated by conditional logistic regression. A total of 887 asthma outpatient visits with individuals who have an average age of 7.96±3.88 years were selected. After adjusting for confounders, we found an interquartile range (IQR) increase in BC level, an IQR increase in NO₃^- level, and an IQR increase in K⁺ level that were all associated with the increased risk of asthma outpatient visits from the current day (OR = 1.18, 95% CI: 1.05-1.34; OR = 1.11, 95% CI: 1.01-1.21; and OR = 1.16, 95% CI: 1.04-1.30, respectively). The effects of these components on asthma were stronger in the cold season than in the warm season. However, we did not find any lagging effects. The results suggest that exposure to NO₃^-, BC, and K⁺ derived from industry-related combustion or motor vehicles emission sources may increase the risk of asthma outpatient visits, particularly during the cold season.

Low-dose combined exposure of nanoparticles and heavy metal compared with PM2.5 in human myocardial AC16 cells

The co-exposure toxicity mechanism of ultrafine particles and pollutants on human cardiovascular system are still unclear. In this study, the combined effects of silica nanoparticles (SiNPs) and/or carbon black nanoparticles (CBNPs) with Pb(AC)₂ compared with particulate matter (PM)_2.5 were investigated in human myocardial cells (AC16). Our study detected three different combinations of SiNPs and Pb(AC)₂, CBNPs and Pb(AC)₂, and SiNPs and CBNPs compared with PM_2.5 at low-dose exposure. Using PM_2.5 as positive control, our results suggested that the combination of SiNPs and Pb(AC)₂/CBNPs could increase the production of reactive oxygen species (ROS), lactate dehydrogenase leakage (LDH), and malondialdehyde (MDA) and decrease the activities of superoxide dismutase (SOD) and glutathione (GSH); induce inflammation by the upregulation of protein CRP and TNF-α, and apoptosis by the upregulation of protein caspase-3, caspase-9, and Bax while the downregulation of protein Bcl-2; and trigger G2/M phase arrest by the upregulation of protein Chk2 and downregulation of protein Cdc2 and cyclin B1. In addition, the combination of CBNPs and Pb(AC)₂ induced a significant increase in MDA and reduced the activities of ROS, LDH, SOD, and GSH, with G1/S phase arrest via upregulation of Chk1 and downregulation of CDK6 and cyclin D1. Our data suggested that the additive interaction and synergistic interaction are the major interaction in co-exposure system, and PM_2.5 could trigger more severe oxidative stress, G2/M arrest, and apoptosis than either co-exposure or single exposure.

Biomarker Sensitivity to Vehicle Exhaust in Experimentally Exposed European Starlings

The effects of vehicle-related emissions on health has been a long-standing question in human health sciences; however, the toxicology of chronic exposure to environmentally relevant concentrations of these complex mixtures has not been characterized in wild birds. Adult European starlings (Sturnus vulgaris) were exposed to vehicle emissions, with combined benzene, toluene, ethylbenzene, and xylenes (BTEX) concentrations totaling 13.3 μg/m³ over 20 days of exposure for 5 h per day. Exposed birds had significantly lower cell-mediated immunity (measured using phytohaemagglutinin skin test, p < 0.0001), thyroxine (T4, p = 0.042), and glutathione (GSH, p = 0.034) concentrations than control birds. There was no difference in body condition, antibody response to vaccination, triiodothyronine (T3), hepatic biotransformation (7-ethoxyresorufin-O-deethylase activity), or oxidative stress (thiobarbituric acid-reactive substances and ratios of reduced to oxidized GSH) or organ masses between exposed and control birds. This study supports findings of previous studies examining wild birds exposed to these air contaminants and raises concern that environmentally relevant concentrations of common urban volatile pollutants may have measurable effects on health.

Acute effects of air pollutants on pulmonary function among students: a panel study in an isolated island

Background

Many epidemiological studies on the health effects of air pollutants have been carried out in regions with major sources such as factories and automobiles. However, the health effects of air pollutants in regions without major sources remain unclear. This study investigated the acute effects of ambient air pollution on pulmonary function among healthy students in an isolated island without major artificial sources of air pollutants.

Methods

A panel study was conducted of 43 healthy subjects who attended a school in an isolated island in the Seto Inland Sea, Japan. We measured the forced expiratory volume in 1 s (FEV₁) and peak expiratory flow (PEF) every morning for about 1 month in May 2014. Ambient concentrations of particulate matter ≤ 2.5 μm in diameter (PM_2.5), particulate matter between 2.5 and 10 μm in diameter (PM_10-2.5), black carbon (BC), ozone (O₃), and nitrogen dioxide (NO₂) were measured. The associations between the concentrations of air pollutants and pulmonary function were analyzed using mixed-effects models.

Results

A decrease in FEV₁ was significantly associated with BC concentrations (−27.28 mL [95%confidence interval (CI):−54.10,−0.46] for an interquartile range (IQR) increase of 0.23 μg/m³). The decrease in PEF was significantly associated with indoor O₃ concentrations (−8.03 L/min [95% CI:−13.02,−3.03] for an IQR increase of 11 ppb). Among subjects with a history of allergy, an increase in PM_2.5 concentrations was significantly associated with low FEV₁. In subjects with a history of asthma, an inverse association between the indoor O₃ concentration and pulmonary function was observed.

Conclusions

Our results demonstrate that increases in BC and O₃ concentrations have acute effects on the pulmonary function among students in an isolated island without major artificial sources of air pollutants.

Electronic supplementary material

The online version of this article (doi:10.1186/s12199-017-0646-3) contains supplementary material, which is available to authorized users.

Air pollution, PM2.5 composition, source factors, and respiratory symptoms in asthmatic and nonasthmatic children in Santiago, Chile

The objective of this study was to determine the association of respiratory symptoms and medication use and exposure to various air pollutants, PM_2.5 components, and source factors in a panel of asthmatic and nonasthmatic children in Santiago, Chile. To this end, 174 children (90 asthmatics and 84 nonasthmatics) were followed throughout the winter months of 2010 and 2011. During the study period, children filled out daily diaries to record respiratory symptoms and medication use. Air pollution data were obtained from government central site measurements and a PM_2.5 characterization campaign. PM_2.5 source factors were obtained using positive matrix factorization (PMF). Associations of symptoms and exposure to pollutants and source-factor daily scores were modeled separately for asthmatic and nonasthmatic children using mixed logistic regression models with random intercepts, controlling for weather, day of the week, year, and viral outbreaks. Overall, high concentrations of air pollutants and PM_2.5 components were observed. Six source factors were identified by PMF (motor vehicles, marine aerosol, copper smelter, secondary sulfates, wood burning, and soil dust). Overall, single pollutant models showed significant and strong associations between 7-day exposures for several criteria pollutants (PM_2.5, NO₂, O₃), PM_2.5 components (OC, K, S, Se, V), and source factors (secondary sulfate) and coughing, wheezing and three other respiratory symptoms in both in asthmatic and nonasthmatic children. No associations were found for use of rescue inhalers in asthmatics. Two-pollutant models showed that several associations remained significant after including PM_2.5, and other criteria pollutants, in the models, particularly components and source factors associated with industrial sources. In conclusion, exposure to air pollutants, especially PM_2.5, NO₂, and O₃, were found to exacerbate respiratory symptoms in both asthmatic and nonasthmatic children. Some of the results suggest that PM_2.5 components associated with a secondary sulfate source may have a greater impact on some symptoms than PM_2.5. In general, the results of this study show important associations at concentrations close or below current air quality standards.

Occupation exposed to road-traffic emissions and respiratory health among Congolese transit workers, particularly bus conductors, in Kinshasa: a cross-sectional study

Objectives

Road-traffic emissions (RTE) induce adverse health effects, notably respiratory symptoms and respiratory diseases, as a result of pollutants deposited into the respiratory tract. The aim of this study was to evaluate the association between occupation groups of Congolese transit workers exposed to RTE, particularly bus conductors and respiratory health, in Kinshasa.

Methods

A cross-sectional study was conducted from 2015 April 20^th to May 14^th, whose participants were bus conductors (n = 110), bus drivers (n = 107), taxi-motorcyclists (n = 102) and high school teachers (control group; n = 106). Subjects had completed the American Thoracic Society respiratory symptom questionnaire. Lung function test was performed by spirometry. Air pollutants levels of PM_2.5, NO₂ and SO₂ were measured between 7:30 and 8:30 and 16:30–17:30 using a portable gas monitor.

Multivariate analysis was performed to evaluate the association between occupation exposed to RTE and impaired pulmonary function, after adjustment by plausible confounders.

Results

The prevalence of mixed syndrome was 21.9% for bus conductors, 10.9% for bus drivers, 15.4% for taxi-motorcyclists and 7.1% for high school teachers with (p < 0.05). The risk of developing a mixed syndrome was seven times higher among bus conductors [OR = 7.64; 95% CI: 1.83–31.67; p < 0.05] than other groups. Additionally, the prevalence of respiratory syndromes increased with the duration of exposure.

Conclusions

Occupation exposed to RTE is associated with impaired pulmonary function and the prevalence of respiratory symptoms among transit workers, especially bus conductors. Furthermore, this association increases with the duration of exposure suggesting the necessity to regulate these categories of occupations and to apply preventives measures.

Comparison of lung damage in mice exposed to black carbon particles and 1,4-naphthoquinone coated black carbon particles

Black carbon (BC) is a key component of atmospheric particles and has a significant effect on human health. BC can provide reactive sites and surfaces thus absorb quinones which were primarily generated from fossil fuel combustion and/or atmospheric photochemical conversions of PAHs. Oxidation could change the characteristics of BC and increase its toxicity. The comparison of lung damage in mice exposed to BC and 1,4-NQ-coated BC (1,4NQ-BC) particles is investigated in this study. Mice which were intratracheally instilled with particles have a higher expression of IL-1β, IL-6 and IL-33 in bronchoalveolar lavage fluid (BALF). Also, the IL-6, IL-33 mRNA expression in the lung tissue of mice instilled with 1,4NQ-BC were higher than that of mice instilled with BC. The pathology results showed that the lung tissue of mice instilled with 1,4NQ-BC particles have much more inflammatory cells infiltration than that of mice treated with BC. It is believed that the MAPK and PI3K-AKT pathway might be involved in the 1,4NQ-BC particles caused lung damage. Results indicated that 1,4NQ-BC particles in the atmosphere may cause more damage to health.

Comparison of lung damage in mice exposed to black carbon particles and ozone-oxidized black carbon particles

Black carbon (BC) is a key component of atmospheric particles and has a significant effect on human health. Oxidation could change the characteristics of BC and increase its toxicity. The comparison of lung damage in mice exposed to BC and ozone-oxidized BC (oBC) particles is investigated in this study. Mice which were intratracheally instilled with particles have a higher expression of IL-1β, IL-6 and IL-33 in bronchoalveolar lavage fluid (BALF). Also, the IL-6, IL-33 mRNA expression in the lung tissue of mice instilled with oBC was higher than that of mice instilled with BC. The expression of CD3 in the lung tissue of mice intratracheally instilled with oBC was higher than the mice distilled with BC. The pathology results showed that the lung tissue of mice instilled with oBC particles have much more inflammatory cells infiltration than that of mice treated with BC. It is believed that the PI3K-AKT pathway might be involved in the oBC particles caused lung damage. Results indicated that oBC particles in the atmosphere may cause more damage to health.

Short-term exposure to high ambient air pollution increases airway inflammation and respiratory symptoms in chronic obstructive pulmonary disease patients in Beijing, China

BACKGROUND

Few studies have investigated the short-term respiratory effects of ambient air pollution in chronic obstructive pulmonary disease (COPD) patients in the context of high pollution levels in Asian cities.

METHODS

A panel of 23 stable COPD patients was repeatedly measured for biomarkers of airway inflammation including exhaled nitric oxide (FeNO) and exhaled hydrogen sulfide (FeH2S) (215 measurements) and recorded for daily respiratory symptoms (794person-days) in two study periods in Beijing, China in January-September 2014. Daily ambient air pollution data were obtained from nearby central air-monitoring stations. Mixed-effects models were used to estimate the associations between exposures and health measurements with adjustment for potential confounders including temperature and relative humidity.

RESULTS

Increasing levels of air pollutants were associated with significant increases in both FeNO and FeH2S. Interquartile range (IQR) increases in PM2.5 (76.5μg/m(3), 5-day), PM10 (75.0μg/m(3), 5-day) and SO2 (45.7μg/m(3), 6-day) were associated with maximum increases in FeNO of 13.6% (95% CI: 4.8%, 23.2%), 9.2% (95% CI: 2.1%, 16.8%) and 34.2% (95% CI: 17.3%, 53.4%), respectively; and the same IQR increases in PM2.5 (6-day), PM10 (6-day) and SO2 (7-day) were associated with maximum increases in FeH2S of 11.4% (95% CI: 4.6%, 18.6%), 7.8% (95% CI: 2.3%, 13.7%) and 18.1% (95% CI: 5.5%, 32.2%), respectively. Increasing levels of air pollutants were also associated with increased odds ratios of sore throat, cough, sputum, wheeze and dyspnea.

CONCLUSIONS

FeH2S may serve as a novel biomarker to detect adverse respiratory effects of air pollution. Our results provide potential important public health implications that ambient air pollution may pose risk to respiratory health in the context of high pollution levels in densely-populated cities in the developing world.

Linking mobile source-PAHs and biological effects in traffic police officers and drivers in Rawalpindi (Pakistan)

The aim of this study was to evaluate the effect of traffic related polycyclic aromatic hydrocarbons (PAHs) on blood parameters of subjects, including traffic police officers (TP), drivers (DR) and control subjects (CN) with presumably different levels of exposure. We quantified the urinary 1-hydroxypyrene (1-OHPyr), α-naphthol and β-naphthol (α- and β-naph) as biomarkers of exposure to PAHs in relation with biomarkers of effect (Hb, MCV, PCV, PLT, RBCs), biomarkers of inflammation/infection (CRP, WBCs), oxidative stress (SOD) and oxidative DNA damage i.e. 8-hydroxy-2-deoxyguanosine (8-OHdG). Results showed that mean 1-OHPyr, α-naph and β-naph concentrations were significantly higher in TPs (0.98, 1.55, and 1.9µmolmol-Cr(-1), respectively, p<0.05) than CNs (0.7, 0.6; 0.67µmolmol-Cr(-1), respectively, P<0.05). Furthermore, WBC and CRP were found in higher concentrations in TPs than CNs (7.04×10(3)µL(-1) and 0.95mgL(-1) vs. 5.1×10(3)µL(-1) and 0.54mgL(-1), respectively). The urinary 8-OHdG level, a biomarker of oxidative DNA damage, was higher in TPs than both CN and DR subjects (48ngmg-Cr(-1), 24ngmg-Cr(-1) and 33ngmg-Cr(-1), respectively). Self-reported health assessment indicates that, on the basis of daily time spent in the middle of heavy traffic, TPs and DRs more frequently suffered from adverse head and respiratory symptoms. The PCA analysis evidenced the impact of traffic pollution on exposure biomarkers and DNA damage. The study suggests that traffic pollution may be associated with important health risk, in particular on the respiratory system, not only for workers exposed to traffic exhausts but also for general public. Finally, vehicular air pollution in the city of Rawalpindi should be a high-priority concern for the Pakistan Government that needs to be addressed.

TRP channels and traffic-related environmental pollution-induced pulmonary disease

Environmental pollutant exposures are major risk factors for adverse health outcomes, with increased morbidity and mortality in humans. Diesel exhaust (DE) is one of the major harmful components of traffic-related air pollution. Exposure to DE affects several physiological systems, including the airways, and pulmonary diseases are increased in highly populated urban areas. Hence, there are urgent needs to (1) create newer and lesser polluting fuels, (2) improve exhaust aftertreatments and reduce emissions, and (3) understand mechanisms of actions for toxic effects of both conventional and cleaner diesel fuels on the lungs. These steps could aid the development of diagnostics and interventions to prevent the negative impact of traffic-related air pollution on the pulmonary system. Exhaust from conventional, and to a lesser extent, clean fuels, contains particulate matter (PM) and more than 400 additional chemical constituents. The major toxic constituents are nitrogen oxides (NOx) and polycyclic aromatic hydrocarbons (PAHs). PM and PAHs could potentially act via transient receptor potential (TRP) channels. In this review, we will first discuss the associations between DE from conventional as well as clean fuel technologies and acute and chronic airway inflammation. We will then review possible activation and/or potentiation of TRP vanilloid type 1 (TRPV1) and ankyrin 1 (TRPA1) channels by PM and PAHs. Finally, we will discuss and summarize recent findings on the mechanisms whereby TRPs could control the link between DE and airway inflammation, which is a primary determinant leading to pulmonary disease.

Combined exposure to nano-silica and lead induced potentiation of oxidative stress and DNA damage in human lung epithelial cells

Growing evidence has confirmed that exposure to ambient particulate matters (PM) is associated with increased morbidity and mortality of cardiovascular and pulmonary diseases. Ambient PM is a complex mixture of particles and air pollutants. Harmful effects of PM are specifically associated with ultrafine particles (UFPs) that can adsorb high concentrations of toxic air pollutants and are easily inhaled into the lungs. However, combined effects of UFPs and air pollutants on human health remain unclear. In the present study, we elucidated the combined toxicity of silica nanoparticles (nano-SiO2), a typical UFP, and lead acetate (Pb), a typical air pollutant. Lung adenocarcinoma A549 cells were exposed to nano-SiO2 and Pb alone or their combination, and their combined toxicity was investigated by focusing on cellular oxidative stress and DNA damage. Factorial analyses were performed to determine the potential interactions between nano-SiO2 and Pb. Our results showed that exposure of A549 cells to a modest cytotoxic concentration of Pb alone induced oxidative stress, as evidenced by elevated reactive oxygen species generation and lipid peroxidation, and reduced glutathione content and superoxide dismutase and glutathione peroxidase activities. In addition, exposure of A549 cells to Pb alone induced DNA damage, as evaluated by alkaline comet assay. Exposure of A549 cells to non-cytotoxic concentration of nano-SiO2 did not induce cellular oxidative stress and DNA damage. However, exposure to the combination of nano-SiO2 and Pb potentiated oxidative stress and DNA damage in A549 cells. Factorial analyses indicated that the potentiation of combined toxicity of nano-SiO2 and Pb was induced by additive or synergistic interactions.

Effects of High-Intensity Swimming on Lung Inflammation and Oxidative Stress in a Murine Model of DEP-Induced Injury

Studies have reported that exposure to diesel exhaust particles (DEPs) induces lung inflammation and increases oxidative stress, and both effects are susceptible to changes via regular aerobic exercise in rehabilitation programs. However, the effects of exercise on lungs exposed to DEP after the cessation of exercise are not clear. Therefore, the aim of this study was to evaluate the effects of high-intensity swimming on lung inflammation and oxidative stress in mice exposed to DEP concomitantly and after exercise cessation. Male Swiss mice were divided into 4 groups: Control (n = 12), Swimming (30 min/day) (n = 8), DEP (3 mg/mL—10 μL/mouse) (n = 9) and DEP+Swimming (n = 8). The high-intensity swimming was characterized by an increase in blood lactate levels greater than 1 mmoL/L between 10th and 30th minutes of exercise. Twenty-four hours after the final exposure to DEP, the anesthetized mice were euthanized, and we counted the number of total and differential inflammatory cells in the bronchoalveolar fluid (BALF), measured the lung homogenate levels of IL-1β, TNF-α, IL-6, INF-ϫ, IL-10, and IL-1ra using ELISA, and measured the levels of glutathione, non-protein thiols (GSH-t and NPSH) and the antioxidant enzymes catalase and glutathione peroxidase (GPx) in the lung. Swimming sessions decreased the number of total cells (p<0.001), neutrophils and lymphocytes (p<0.001; p<0.05) in the BALF, as well as lung levels of IL-1β (p = 0.002), TNF-α (p = 0.003), IL-6 (p = 0.0001) and IFN-ϫ (p = 0.0001). However, the levels of IL-10 (p = 0.01) and IL-1ra (p = 0.0002) increased in the swimming groups compared with the control groups, as did the CAT lung levels (p = 0.0001). Simultaneously, swimming resulted in an increase in the GSH-t and NPSH lung levels in the DEP group (p = 0.0001 and p<0.002). We concluded that in this experimental model, the high-intensity swimming sessions decreased the lung inflammation and oxidative stress status during DEP-induced lung inflammation in mice.

Weather elements, chemical air pollutants and airborne pollen influencing asthma emergency room visits in Szeged, Hungary: performance of two objective weather classifications

Weather classification approaches may be useful tools in modelling the occurrence of respiratory diseases. The aim of the study is to compare the performance of an objectively defined weather classification and the Spatial Synoptic Classification (SSC) in classifying emergency department (ED) visits for acute asthma depending from weather, air pollutants, and airborne pollen variables for Szeged, Hungary, for the 9-year period 1999-2007. The research is performed for three different pollen-related periods of the year and the annual data set. According to age and gender, nine patient categories, eight meteorological variables, seven chemical air pollutants, and two pollen categories were used. In general, partly dry and cold air and partly warm and humid air aggravate substantially the symptoms of asthmatics. Our major findings are consistent with this establishment. Namely, for the objectively defined weather types favourable conditions for asthma ER visits occur when an anticyclonic ridge weather situation happens with near extreme temperature and humidity parameters. Accordingly, the SSC weather types facilitate aggravating asthmatic conditions if warm or cool weather occur with high humidity in both cases. Favourable conditions for asthma attacks are confirmed in the extreme seasons when atmospheric stability contributes to enrichment of air pollutants. The total efficiency of the two classification approaches is similar in spite of the fact that the methodology for derivation of the individual types within the two classification approaches is completely different.

Biomarker as a research tool in linking exposure to air particles and respiratory health

Some of the environmental toxicants from air pollution include particulate matter (PM₁₀), fine particulate matter (PM_2.5), and ultrafine particles (UFP). Both short- and long-term exposure could result in various degrees of respiratory health outcomes among exposed persons, which rely on the individuals' health status. Methods. In this paper, we highlight a review of the studies that have used biomarkers to understand the association between air particles exposure and the development of respiratory problems resulting from the damage in the respiratory system. Data from previous epidemiological studies relevant to the application of biomarkers in respiratory system damage reported from exposure to air particles are also summarized. Results. Based on these analyses, the findings agree with the hypothesis that biomarkers are relevant in linking harmful air particles concentrations to increased respiratory health effects. Biomarkers are used in epidemiological studies to provide an understanding of the mechanisms that follow airborne particles exposure in the airway. However, application of biomarkers in epidemiological studies of health effects caused by air particles in both environmental and occupational health is inchoate. Conclusion. Biomarkers unravel the complexity of the connection between exposure to air particles and respiratory health.

Airway oxidative stress and inflammation markers in exhaled breath from children are linked with exposure to black carbon

BACKGROUND

The current study aimed at assessing the associations between black carbon (BC) exposure and markers for airway inflammation and oxidative stress in primary school children in a Western European urban area.

METHODS

In 130 children aged 6-12 years old, the fraction of exhaled nitric oxide (FeNO), exhaled breath condensate (EBC) pH, 8-isoprostane and interleukin (IL)-1β were measured in two seasons. BC concentrations on the sampling day (2-h average, 8:00-10:00 AM) and on the day before (24-h average) were assessed using measurements at a central monitoring site. Land use regression (LUR) models were applied to estimate weekly average BC exposure integrated for the time spent at home and at school, and seasonal average BC exposure at the home address. Associations between exposure and biomarkers were tested using linear mixed effect regression models. Next to single exposure models, models combining different BC exposure metrics were used.

RESULTS

In single exposure models, an interquartile range (IQR) increase in 2-h BC (3.10 μg/m(3)) was linked with a 5.9% (95% CI: 0.1 to 12.0%) increase in 8-isoprostane. FeNO increased by 16.7% (95% CI: 2.2 to 33.2%) per IQR increase in 24-h average BC (4.50 μg/m(3)) and by 12.1% (95% CI: 2.5 to 22.8%) per IQR increase in weekly BC (1.73 μg/m(3)). IL-1β was associated with weekly and seasonal (IQR=1.70 μg/m(3)) BC with respective changes of 38.4% (95% CI: 9.0 to 75.4%) and 61.8% (95% CI: 3.5 to 153.9%) per IQR increase in BC. An IQR increase in weekly BC was linked with a lowering in EBC pH of 0.05 (95% CI: -0.10 to -0.01). All associations were observed independent of sex, age, allergy status, parental education level and meteorological conditions on the sampling day. Most of the associations remained when different BC exposure metrics were combined in multiple exposure models, after additional correction for sampling period or after exclusion of children with airway allergies. In additional analyses, FeNO was linked with 24-h PM10 levels, but the effect size was smaller than for BC. 8-Isoprostane was not linked with either 2-h or 24-h concentrations of PM2.5 or PM10.

CONCLUSION

BC exposure on the morning of sampling was associated with airway oxidative stress while 24-h and weekly exposures were linked with airway inflammation.

Domestic airborne black carbon levels and 8-isoprostane in exhaled breath condensate among children in New York City

BACKGROUND

Exposure to airborne black carbon (BC) has been associated with asthma development, respiratory symptoms and decrements in lung function. However, the mechanism through which BC may lead to respiratory symptoms has not been completely elucidated. Oxidative stress has been suggested as a potential mechanism through which BC might lead to adverse health outcomes. Exhaled breath condensate (EBC) allows for the non-invasive collection of airway lining fluid containing biomarkers of oxidative stress like 8-isoprostane, a stable by-product of lipid peroxidation. Therefore, we sought to characterize the association between domestic airborne BC concentrations and 8-isoprostane in EBC.

MATERIALS AND METHODS

Seven- and eight-year-old children participated in an asthma case-control study in New York City. During home visits, air samples and EBC were collected. Seven day averages of domestic levels of particulate matter <2.5μm (PM2.5), BC and environmental tobacco smoke (ETS) were measured. Urea and 8-isoprostane were measured by liquid chromatography tandem mass spectrometry (LC/MS/MS) in EBC.

RESULTS

In univariate models, PM2.5 and BC, but not ETS, were significantly associated with increases in 8-isoprostane in the EBC (β=0.006 and β=0.106 respectively, p<0.05 for both). These associations remained statistically significant for both PM2.5 and BC after adjustment for covariates. In a co-pollutant model including PM2.5, BC and ETS, only BC remained a statistically significant predictor of 8-isoprostane (p<0.05).

CONCLUSIONS

Our findings suggest the BC fraction of PM might contain exposure relevant to increased oxidative stress in the airways.

Toxicological and epidemiological studies of cardiovascular effects of ambient air fine particulate matter (PM2.5) and its chemical components: coherence and public health implications

Recent investigations on PM2.5 constituents' effects in community residents have substantially enhanced our knowledge on the impacts of specific components, especially the HEI-sponsored National Particle Toxicity Component (NPACT) studies at NYU and UW-LRRI that addressed the impact of long-term PM2.5 exposure on cardiovascular disease (CVD) effects. NYU's mouse inhalation studies at five sites showed substantial variations in aortic plaque progression by geographic region that was coherent with the regional variation in annual IHD mortality in the ACS-II cohort, with both the human and mouse responses being primarily attributable to the coal combustion source category. The UW regressions of associations of CVD events and mortality in the WHI cohort, and of CIMT and CAC progression in the MESA cohort, indicated that [Formula: see text] had stronger associations with CVD-related human responses than OC, EC, or Si. The LRRI's mice had CVD-related biomarker responses to [Formula: see text]. NYU also identified components most closely associated with daily hospital admissions (OC, EC, Cu from traffic and Ni and V from residual oil). For daily mortality, they were from coal combustion ([Formula: see text], Se, and As). While the recent NPACT research on PM2.5 components that affect CVD has clearly filled some major knowledge gaps, and helped to define remaining uncertainties, much more knowledge is needed on the effects in other organ systems if we are to identify and characterize the most effective and efficient means for reducing the still considerable adverse health impacts of ambient air PM. More comprehensive speciation data are needed for better definition of human responses.

Environmental pollution: a tangible risk for NAFLD pathogenesis

The liver is crucial for human life, and the health of this organ often mirrors the health of the individual. The liver can be the target of several diseases, the most prevalent of which, as a consequence of development and changes in human lifestyles, is the nonalcoholic fatty liver disease (NAFLD). NAFLD is a multifactorial disease that embraces many histo-pathologic conditions and is highly linked to metabolic derangements. Technological progress and industrialization have also had the consequence of releasing pollutants in the environment, for instance pesticides or solvents, as well as by-products of discharge, such as the particulate matter. In the last decade, a growing body of evidence has emerged, shedding light on the potential impact of environmental pollutants on liver health and, in particular, on NAFLD occurrence. These contaminants have a great steatogenic potential and need to be considered as tangible NAFLD risk factors. There is an urgent need for a deeper comprehension of their molecular mechanisms of action, as well as for new lines of intervention to reduce their worldwide diffusion. This review wishes to sensitize the community to the effects of several environmental pollutants on liver health.

Chemical constituents of fine particulate air pollution and pulmonary function in healthy adults: the Healthy Volunteer Natural Relocation study

The study examined the associations of 32 chemical constituents of particulate matter with an aerodynamic diameter ≤2.5 μm (PM₂.₅) with pulmonary function in a panel of 21 college students. Study subjects relocated from a suburban area to an urban area with changing ambient air pollution levels and contents in Beijing, China, and provided daily morning/evening peak expiratory flow (PEF) and forced expiratory volume in 1s (FEV₂₁) measurements over 6 months in three study periods. There were significant reductions in evening PEF and morning/evening FEV₂₁ associated with various air pollutants and PM₂.₅ constituents. Four PM₂.₅ constituents (copper, cadmium, arsenic and stannum) were found to be most consistently associated with the reductions in these pulmonary function measures. These findings provide clues for the respiratory effects of specific particulate chemical constituents in the context of urban air pollution.

Effects of exposure to nanoparticle-rich diesel exhaust on 8-OHdG synthesis in the mouse asthmatic lung

It has been demonstrated that exposure to diesel exhaust (DE) is associated with the induction and exacerbation of respiratory disorders; however, the impacts of DE containing mainly nanoparticles have been less studied. We have previously demonstrated that inhalation exposure to nanoparticle-rich DE (NR-DE) exacerbated allergic pulmonary inflammation, in the context of enhanced local expression of proinflammatory molecules. However, the underlying mechanisms have not been fully elucidated. 8-Hydroxydeoxyguanosine (8-OHdG) is a marker of oxidative damage, particularly in DNA. This study examined the effects of NR-DE on 8-OHdG synthesis in the lung in the presence or absence of an allergen. Institute for Cancer Research (ICR) mice were exposed by inhalation to four different gas compositions (control air, low-concentration DE, high-concentration DE and high-concentration DE without particulate matter) for 8 weeks, in the presence or absence of repetitive intratracheal administration of ovalbumin (OVA). Thereafter, we assessed the levels of 8-OHdG synthesis and expression in the lungs by means of enzyme immunoassay (EIA) and immunohistochemistry. The EIA revealed that the level of 8-OHdG was significantly higher in the high-concentration NR-DE-exposed and allergen-sensitized/stimulated group compared with that in the control air-exposed and allergen-treated group. The immunohistochemistry results demonstrated that the level of immunoreactive 8-OHdG was higher in the NR-DE-exposed and allergen-treated lungs compared with that in the corresponding control air-exposed lungs. The results suggested that NR-DE exposure enhanced 8-OHdG formation in asthmatic lungs. This, at least in part, is involved in the NR-DE-mediated exacerbation of the allergic pathophysiology that was identified in our previous study.

Oxidative DNA damage and inflammatory responses in cultured human cells and in humans exposed to traffic-related particles

Particulate pollution is a major public health concern because epidemiological studies have demonstrated that exposure to particles is associated with respiratory diseases and lung cancer. Diesel exhaust particles (DEP), which is classified as a human carcinogen (IARC, 2012), are considered a major contributor to traffic-related particulate matter (PM) in urban areas. DEP consists of various compounds, including PAHs and metals which are the principal components that contribute to the toxicity of PM. The present study aimed to investigate effects of PM on induction of oxidative DNA damage and inflammation by using lymphocytes in vitro and in human exposed to PM in the environment. Human lymphoblasts (RPMI 1788) were treated with DEP (SRM 2975) at various concentrations (25-100 μg/ml) to compare the extent of responses with alveolar epithelial cells (A549). ROS generation was determined in each cell cycle phase of DEP-treated cells in order to investigate the influence of the cell cycle stage on induction of oxidative stress. The oxidative DNA damage was determined by measurement of 8-hydroxy-deoxyguanosine (8-OHdG) whereas the inflammatory responses were determined by mRNA expression of interleukin-6 and -8 (IL-6 and IL-8), Clara cell protein (CC16), and lung surfactant protein-A (SP-A). The results showed that RPMI 1788 and A549 cells had a similar pattern of dose-dependent responses to DEP in terms of particle uptake, ROS generation with highest level found in G2/M phase, 8-OHdG formation, and induction of IL-6 and IL-8 expression. The human study was conducted in 51 healthy subjects residing in traffic-congested areas. The effects of exposure to PM2.5 and particle-bound PAHs and toxic metals on the levels of 8-OHdG in lymphocyte DNA, IL-8 expression in lymphocytes, and serum CC16 were evaluated. 8-OHdG levels correlated with the exposure levels of PM2.5 (P<0.01) and PAHs (P<0.05), but this was not the case with IL-8. Serum CC16 showed significantly negative correlations with B[a]P equivalent (P<0.05) levels, but positive correlation with Pb (P<0.05). In conclusion, a similar pattern of the dose-dependent responses to DEP in the lymphoblasts and lung cells suggests that circulating lymphocytes could be used as a surrogate for assessing PM-induced oxidative DNA damage and inflammatory responses in the lung. Human exposure to PM leads to oxidative DNA damage whereas PM-induced inflammation was not conclusive and should be further investigated.