Associations between personal exposure to air pollutants and lung function tests and cardiovascular indices among children with asthma living near an industrial complex and petroleum refineries

Air quality disparities and respiratory health risks in critically polluted and relatively non-polluted areas: a prospective child health study

BACKGROUND

Air pollution, a significant global health concern, notably impacts human well-being. Children, owing to their distinctive physiology and behavior, are particularly susceptible to its adverse effects. This prospective study examines air quality variations and respiratory risks in children residing in critically polluted areas (CPA) compared to relatively non-polluted areas (NPA), utilizing a prospective design to understand the impacts of air pollution on children's respiratory health, including measures like relative risk (RR) and attributable risk (AR).

METHODS

This prospective study tracked 739 students of 5th- 7th grade residing in CPA and NPA for one year, and measured the ambient and indoor air quality levels in both these areas. Throughout the study, based on the observed respiratory symptoms new episodes of upper and lower respiratory tract illnesses were recorded for each child on a weekly basis. Incidence rate, RR and AR for both the illnesses were compared. Statistical analysis was performed with SPSS 26.0.

RESULTS

The study observes higher concentration for particulate matter and gaseous pollutants at CPA in comparison to NPA. Children living in CPA exhibited a notably greater weekly occurrence of both upper and lower respiratory tract illnesses compared to those in NPA, with RR of 1.26 (95% CI: 1.16-1.37) and 1.74 (95% CI: 1.34-2.27), respectively. The AR associated with air pollution for upper and lower respiratory tract illnesses among CPA students was found to be 20.7% and 42.7%, respectively.

CONCLUSION

This research underscores the pressing need to address air pollution in critically polluted areas and its profound effects on children's respiratory health. Public health interventions, such as reducing emissions from industries and creating green spaces, should be prioritized. Furthermore, early respiratory health screening in schools within polluted areas could aid in the timely diagnosis and management of respiratory issues in children.

Refining Children's exposure assessment to NO2, SO2, and O3: Incorporating indoor-to-outdoor concentration ratios and individual daily routine

Exposure to air pollutants like sulfur dioxide (SO2), nitrogen oxides (NOx), and ozone (O3) is associated with adverse health effects, particularly with exacerbations of asthma symptoms and new asthma cases in both children and adults. While fixed-site monitoring (FSM) stations are commonly used in air pollutant exposure studies, they may not fully capture personal exposures due to limitations such as inadequate consideration of daily routines and indoor/outdoor concentration variations. In this study, to enhance the accuracy of personal exposure calculated by using FSM data, individual's daily activity routine, encompassing both indoor and outdoor environments, were incorporated by using indoor-to-outdoor concentration ratios. Three methodologies were compared to assess the accuracy of exposure calculations: (i) direct exposure determination employing passive samplers (PS), (ii) personal exposure calculated using FSM data alone, and (iii) personal exposure calculated using FSM data refined by integrating local average individual daily activity routines and indoor-to-outdoor ratios. The results demonstrate that the refined method (iii) yields substantial improvements in estimated exposure levels, reducing the average error from 1.4% to 0.4% for NO2, from 72.1% to 12.7% for SO2, and from 323.4% to 24.9% for O3.

EAACI guidelines on environmental science for allergy and asthma: The impact of short-term exposure to outdoor air pollutants on asthma-related outcomes and recommendations for mitigation measures

The EAACI Guidelines on the impact of short-term exposure to outdoor pollutants on asthma-related outcomes provide recommendations for prevention, patient care and mitigation in a framework supporting rational decisions for healthcare professionals and patients to individualize and improve asthma management and for policymakers and regulators as an evidence-informed reference to help setting legally binding standards and goals for outdoor air quality at international, national and local levels. The Guideline was developed using the GRADE approach and evaluated outdoor pollutants referenced in the current Air Quality Guideline of the World Health Organization as single or mixed pollutants and outdoor pesticides. Short-term exposure to all pollutants evaluated increases the risk of asthma-related adverse outcomes, especially hospital admissions and emergency department visits (moderate certainty of evidence at specific lag days). There is limited evidence for the impact of traffic-related air pollution and outdoor pesticides exposure as well as for the interventions to reduce emissions. Due to the quality of evidence, conditional recommendations were formulated for all pollutants and for the interventions reducing outdoor air pollution. Asthma management counselled by the current EAACI guidelines can improve asthma-related outcomes but global measures for clean air are needed to achieve significant impact.

Sources-attributed contributions to health risks associated with PM2.5-bound polycyclic aromatic hydrocarbons during the warm and cold seasons in an urban area of Eastern Asia

Despite the well-established recognition of the health hazards posed by PM2.5-bound PAHs, a comprehensive understanding of their source-specific impact has been lacking. In this study, the health risks associated with PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) and source-specific contributions were investigated in the urban region of Taipei during both cold and warm seasons. The levels of PM2.5-bound PAHs and their potential health risks across different age groups of humans were also characterized. Diagnostic ratios and positive matrix factorization analysis were utilized to identify the sources of PM2.5-bound PAHs. Moreover, potential source contribution function (PSCF), concentration-weighted trajectory (CWT) and source regional apportionment (SRA) analyses were employed to determine the potential source regions. Results showed that the total PAHs (TPAHs) concentrations ranged from 0.08 to 2.37 ng m-3, with an average of 0.69 ± 0.53 ng m-3. Vehicular emissions emerged as the primary contributor to PM2.5-bound PAHs, constituting 39.8 % of the TPAHs concentration, followed by industrial emissions (37.6 %), biomass burning (13.8 %), and petroleum/oil volatilization (8.8 %). PSCF and CWT analyses revealed that industrial activities and shipping processes in northeast China, South China Sea, Yellow Sea, and East China Sea, contributed to the occurrence of PM2.5-bound PAHs in Taipei. SRA identified central China as the primary regional contributor of ambient TPAHs in the cold season and Taiwan in the warm season, respectively. Evaluations of incremental lifetime cancer risk demonstrated the highest risk for adults, followed by children, seniors, and adolescents. The assessments of lifetime lung cancer risk showed that vehicular and industrial emissions were the main contributors to cancer risk induced by PM2.5-bound PAHs. This research emphasizes the essential role of precisely identifying the origins of PM2.5-bound PAHs to enhance our comprehension of the related human health hazards, thus providing valuable insights into the mitigation strategies.

Adult-Onset Transcriptomic Effects of Developmental Exposure to Benzene in Zebrafish (Danio rerio): Evaluating a Volatile Organic Compound of Concern

Urban environments are afflicted by mixtures of anthropogenic volatile organic compounds (VOCs). VOC sources that drive human exposure include vehicle exhaust, industrial emissions, and oil spillage. The highly volatile VOC benzene has been linked to adverse health outcomes. However, few studies have focused on the later-in-life effects of low-level benzene exposure during the susceptible window of early development. Transcriptomic responses during embryogenesis have potential long-term consequences at levels equal to or lower than 1 ppm, therefore justifying the analysis of adult zebrafish that were exposed during early development. Previously, we identified transcriptomic alteration following controlled VOC exposures to 0.1 or 1 ppm benzene during the first five days of embryogenesis using a zebrafish model. In this study, we evaluated the adult-onset transcriptomic responses to this low-level benzene embryogenesis exposure (n = 20/treatment). We identified key genes, including col1a2 and evi5b, that were differentially expressed in adult zebrafish in both concentrations. Some DEGs overlapped at the larval and adult stages, specifically nfkbiaa, mecr, and reep1. The observed transcriptomic results suggest dose- and sex-dependent changes, with the highest impact of benzene exposure to be on cancer outcomes, endocrine system disorders, reproductive success, neurodevelopment, neurological disease, and associated pathways. Due to molecular pathways being highly conserved between zebrafish and mammals, developmentally exposed adult zebrafish transcriptomics is an important endpoint for providing insight into the long term-effects of VOCs on human health and disease.

Personal PM2.5-bound PAH exposure and lung function in healthy office workers: A pilot study in Beijing and Baoding, China

The effect of short-term exposure to polycyclic aromatic hydrocarbons (PAHs) on the respiratory system among healthy residents is unclear. Beijing and Baoding are typical polluted cities in China, and there is little research on PAH exposure and its health effects at the individual level. Fourteen healthy female office workers were recruited in urban Beijing and Baoding, China, in 2019. The personal exposure to fine particulate matter (PM_2.5)-bound PAHs and lung function were seasonally monitored. The relationships between PAH exposure and lung function were determined by a generalized mixed linear model. Subjects were exposed to high levels of PAH, in which the benzo[a]pyrene (BaP) level (1.26 ng/m³) was over than Chinese national indoor standard (1 ng/m³). All PAHs concentration was higher in winter than that in summer and autumn. Only benz[a]anthracene (BaA) and chrysene (Chr) exposure showed weak relations with decreased lung function, i.e., a 0.58% and 0.73% decrease in peak expiratory flow at lag 2 day, respectively (p < 0.05). PAHs may not be suitable exposure indicators for short-term change in lung function. Our findings highlight the importance of reducing PAH pollution for public respiratory health protection in heavy-polluted cities of China. This pilot study also provides experience on personal PAH assessment such as estimation of the number of repeated measurements required, which is helpful to determine the relationship between PAH exposure and health effect.

Breathing zone pollutant levels are associated with asthma exacerbations in high-risk children

Background

Indoor and outdoor air pollution levels are associated with poor asthma outcomes in children. However, few studies have evaluated whether breathing zone pollutant levels associate with asthma outcomes.

Objective

Determine breathing zone exposure levels of NO 2 , O 3 , total PM 10 and PM 10 constituents among children with exacerbation-prone asthma, and examine correspondence with in-home and community measurements and associations with outcomes.

Methods

We assessed children's personal breathing zone exposures using wearable monitors. Personal exposures were compared to in-home and community measurements and tested for association with lung function, asthma control, and asthma exacerbations.

Results

81 children completed 219 monitoring sessions. Correlations between personal and community levels of PM 10 , NO 2 , and O 3 were poor, whereas personal PM 10 and NO 2 levels correlated with in-home measurements. However, in-home monitoring underdetected brown carbon (Personal:79%, Home:36.8%) and ETS (Personal:83.7%, Home:4.1%) personal exposures, and detected black carbon in participants without these personal exposures (Personal: 26.5%, Home: 96%). Personal exposures were not associated with lung function or asthma control. Children experiencing an asthma exacerbation within 60 days of personal exposure monitoring had 1.98, 2.21 and 2.04 times higher brown carbon (p<0.001), ETS (p=0.007), and endotoxin (p=0.012), respectively. These outcomes were not associated with community or in-home exposure levels.

Conclusions

Monitoring pollutant levels in the breathing zone is essential to understand how exposures influence asthma outcomes, as agreement between personal and in-home monitors is limited. Inhaled exposure to PM 10 constituents modifies asthma exacerbation risk, suggesting efforts to limit these exposures among high-risk children may decrease their asthma burden.

CLINICAL IMPLICATIONS

In-home and community monitoring of environmental pollutants may underestimate personal exposures. Levels of inhaled exposure to PM 10 constituents appear to strongly influence asthma exacerbation risk. Therefore, efforts should be made to mitigate these exposures.

CAPSULE SUMMARY

Leveraging wearable, breathing-zone monitors, we show exposures to inhaled pollutants are poorly proxied by in-home and community monitors, among children with exacerbation-prone asthma. Inhaled exposure to multiple PM 10 constituents is associated with asthma exacerbation risk.

Assessing volatile organic compounds exposure and chronic obstructive pulmonary diseases in US adults

Background

Volatile organic compounds (VOCs) are a large group of chemicals widely used in People's Daily life. There is increasing evidence of the cumulative toxicity of VOCs. However, the association between VOCs and the risk of COPD has not been reported.

Objective

We comprehensively evaluated the association between VOCs and COPD.

Methods

Our study included a total of 1,477 subjects from the National Health and Nutrition Examination Survey, including VOCs, COPD, and other variables in the average US population. Multiple regression models and smooth-curve fitting (penalty splines) were constructed to examine potential associations, and stratified analyses were used to identify high-risk groups.

Results

We found a positive association between blood benzene and blood o-xylene concentrations and COPD risk and identified a concentration relationship between the two. That is, when the blood benzene and O-xylene concentrations reached 0.28 ng/mL and 0.08 ng/mL, respectively, the risk of COPD was the highest. In addition, we found that gender, age, and MET influence the relationship, especially in women, young people, and people with low MET.

Significance

This study revealed that blood benzene and blood o-xylene were independently and positively correlated with COPD risk, suggesting that long-term exposure to benzene and O-xylene may cause pulmonary diseases, and providing a new standard of related blood VOCs concentration for the prevention of COPD.

Biodiesel exhaust particle airway toxicity and the role of polycyclic aromatic hydrocarbons

Renewable alternatives to fossil diesel (FD) including fatty acid methyl ester (FAME) biodiesel have become more prevalent. However, toxicity of exhaust material from their combustion, relative to the fuels they are displacing has not been fully characterised. This study was carried out to examine particle toxicity within the lung epithelium and the role for polycyclic aromatic hydrocarbons (PAHs). Exhaust particles from a 20% (v/v) blend of FAME biodiesel had little impact on primary airway epithelial toxicity compared to FD derived particles but did result in an altered profile of PAHs, including an increase in particle bound carcinogenic B[a]P. Higher blends of biodiesel had significantly increased levels of more carcinogenic PAHs, which was associated with a higher level of stress response gene expression including CYP1A1, NQO1 and IL1B. Removal of semi-volatile material from particulates abolished effects on airway cells. Particle size difference and toxic metals were discounted as causative for biological effects. Finally, combustion of a single component fuel (Methyl decanoate) containing the methyl ester molecular structure found in FAME mixtures, also produced more carcinogenic PAHs at the higher fuel blend levels. These results indicate the use of FAME biodiesel at higher blends may be associated with an increased particle associated carcinogenic and toxicity risk.

Impacts of household PM2.5 pollution on blood pressure of rural residents: Implication for clean energy transition

High blood pressure associated with PM_2.5 exposure is of great concern, especially for rural residents exposed to high PM_2.5 levels. However, the impact of short-term exposure to high PM_2.5 on blood pressure (BP) has not been well elucidated. Thus, this study aims to focus on the association between short-term PM_2.5 exposure with BP of rural residents and its variation between summer and winter. Our results showed that the summertime PM_2.5 exposure concentration was 49.3 ± 20.6 μg/m³, among which, mosquito coil users had 1.5-folds higher PM_2.5 exposure than non-mosquito coil users (63.6 ± 21.7 vs 43.0 ± 16.7 μg/m³, p < 0.05). The mean systolic and diastolic BP (SBP and DBP, respectively) of rural participants were 122 ± 18.2 and 76.2 ± 11.2 mmHg in summer, respectively. The PM_2.5 exposure, SBP, and DBP in summer were 70.7 μg/m³, 9.0 mmHg, and 2.8 mmHg lower than that in winter, respectively. Furthermore, the correlation between PM_2.5 exposure and SBP was stronger in winter than that in summer, possibly due to higher PM_2.5 exposure levels in winter. The transition of household energy from solid fuels in winter to clean fuels in summer would be benefit to the decline of PM_2.5 exposure as well as BP. Results from this study suggested that the reduction of PM_2.5 exposure would have positive effect on human health.

Maternal exposure to urinary polycyclic aromatic hydrocarbons (PAH) in pregnancy and childhood asthma in a pooled multi-cohort study

BACKGROUND

Prenatal exposure to polycyclic aromatic hydrocarbons (PAH) may increase risk of pediatric asthma, but existing human studies are limited.

OBJECTIVES

We estimated associations between gestational PAHs and pediatric asthma in a diverse US sample and evaluated effect modification by child sex, maternal asthma, and prenatal vitamin D status.

METHODS

We pooled two prospective pregnancy cohorts in the ECHO PATHWAYS Consortium, CANDLE and TIDES, for an analytic sample of N = 1296 mother-child dyads. Mono-hydroxylated PAH metabolites (OH-PAHs) were measured in mid-pregnancy urine. Mothers completed the International Study on Allergies and Asthma in Childhood survey at child age 4-6 years. Poisson regression with robust standard errors was used to estimate relative risk of current wheeze, current asthma, ever asthma, and strict asthma associated with each metabolite, adjusted for potential confounders. We used interaction models to assess effect modification. We explored associations between OH-PAH mixtures and outcomes using logistic weighted quantile sum regression augmented by a permutation test to control Type 1 errors.

RESULTS

The sociodemographically diverse sample spanned five cities. Mean (SD) child age at assessment was 4.4 (0.4) years. While there was little evidence that either individual OH-PAHs or mixtures were associated with outcomes, we observed effect modification by child sex for most pairs of OH-PAHs and outcomes, with adverse associations specific to females. For example, a 2-fold increase in 2-hydroxy-phenanthrene was associated with current asthma in females but not males (RRfemale = 1.29 [95 % CI: 1.09, 1.52], RRmale = 0.95 [95 % CI: 0.79, 1.13]; pinteraction = 0.004). There was no consistent evidence of modification by vitamin D status or maternal asthma.

DISCUSSION

This analysis, the largest cohort study of gestational PAH exposure and childhood asthma to date, suggests adverse associations for females only. These preliminary findings are consistent with hypothesized endocrine disruption properties of PAHs, which may lead to sexually dimorphic effects.

Effects of Benzene: Hematological and Hypersensitivity Manifestations in Resident Living in Oil Refinery Areas

Literature is teeming with publications on industrial pollution. Over the decades, the main industrial pollutants and their effects on human health have been widely framed. Among the various compounds involved, benzene plays a leading role in the onset of specific diseases. Two systems are mainly affected by the adverse health effects of benzene exposure, both acute and chronic: the respiratory and hematopoietic systems. The most suitable population targets for a proper damage assessment on these systems are oil refinery workers and residents near refining plants. Our work fits into this area of interest with the aim of reviewing the most relevant cases published in the literature related to the impairment of the aforementioned systems following benzene exposure. We perform an initial debate between the two clinical branches that see a high epidemiological expression in this slice of the population examined: residents near petroleum refinery areas worldwide. In addition, the discussion expands on highlighting the main immunological implications of benzene exposure, finding a common pathophysiological denominator in inflammation, oxidative stress, and DNA damage, thus helping to set the basis for an increasingly detailed characterization aimed at identifying common molecular patterns between the two clinical fields discussed.

Associations of urinary polycyclic aromatic hydrocarbon metabolites and blood pressure with the mediating role of cytokines: A panel study among children

Little was known regarding the relations of polycyclic aromatic hydrocarbon (PAH) mixture with children's blood pressure (BP) and its potential mechanism. We conducted a panel study with up to 3 visits across 3 seasons in 2017-2018 among 103 children aged 4-13 years. Urinary PAH metabolites (OH-PAHs) were measured by gas chromatograph-tandem triple quadrupole mass spectrometer, and serum cytokines were detected by Bio-Rad 48-Plex Screening Panel. We employed linear mixed-effects models to assess the relations of each urinary OH-PAH with BP, least absolute shrinkage and selection operator (LASSO), and weighted quantile sum (WQS) regression to evaluate associations of OH-PAHs mixture with BP, and mediation analyses for the role of serum cytokines. We found the consistently positive associations of 1-hydroxynaphthalene and 9-hydroxyphenanthrene (9-OHPh) with systolic BP (SBP), 4-OHPh, and 9-OHPh with diastolic BP (DBP) and mean arterial pressure (MAP) in a dose-responsive manner. For instance, each 1-fold increment of 9-OHPh was related with increase of 0.92% (95% confidence interval (CI): 0.25%, 1.60%) in SBP, 1.32% (95%CI: 0.25%, 2.39%) in DBP, and 1.15% (95%CI: 0.40%, 1.88%) in MAP. Meanwhile, based on LASSO and WQS regression, OH-PAHs mixture was linked with increased DBP and MAP, to which 9-OHPh and 4-OHPh were the major contributors. Such relationships were modified by passive smoking status and 3-4 times stronger in passive smokers than non-passive smokers. A 1-fold increase in 9-OHPh was associated with an elevation of 3.51% in SBP among passive smokers while that of 0.55% in SBP among non-passive smokers. Furthermore, 4-OHPh and 9-OHPh were related to multiple cytokines elevation, of which platelet-derived growth factor (PDGF) mediated 9.99% and 12.57% in 4-OHPh-related DBP and MAP elevation, respectively. Accordingly, urinary OH-PAHs dominated by 9-OHPh and 4-OHPh were dose-responsively associated with elevated BP whereby a mechanism partly involving PDGF among children.

Sulfur dioxide-enhanced asthma susceptibility is involved with inhibition of bitter taste transduction in mouse lung

Sulfur dioxide (SO₂) may induce asthma-like symptoms or worsen existing asthma, but the underlying mechanism is still unclear. In this study, the relationship between SO₂ exposure, asthma development, and bitter taste transduction was analyzed using ovalbumin (OVA)-induced and SO₂-aggravated asthma models. The results showed that twenty-seven and twelve bitter taste receptors (Tas2rs) were detectable in mouse trachea and lung, respectively, and that all of them were nearly down-regulated in OVA-induced BALB/c and C57BL/6 asthmatic mice. SO₂ exposure alone did not trigger a distinct asthma-like phenotype, but the combination of SO₂ and OVA allergen caused more severe asthma symptoms in mice including enhanced inflammatory cells infiltration, thickened airway walls, increased mucus secretion, and elevated expression of proinflammatory and Th2 cytokines (TNF-α, IL-4, IL-5, IL-13). Furthermore, SO₂ enhanced the transcriptional repression of Tas2rs in OVA-induced asthmatic mice. These results indicated that the occurrence of mice asthma was correlated with the inhibition of bitter taste transduction, and more severe airway inflammation and injury were accompanied with an enhanced inhibition of bitter taste transduction. Our findings suggest that SO₂ inhalation may amplify Th2 inflammatory responses in the lung of asthmatic mice by inhibiting bitter taste transduction, and thereby exacerbate asthma symptoms.

Comparing human exposure to fine particulate matter in low and high-income countries: A systematic review of studies measuring personal PM2.5 exposure

BACKGROUND

Due to the adverse health effects of air pollution, researchers have advocated for personal exposure measurements whereby individuals carry portable monitors in order to better characterise and understand the sources of people's pollution exposure.

OBJECTIVES

The aim of this systematic review is to assess the differences in the magnitude and sources of personal PM2.5 exposures experienced between countries at contrasting levels of income.

METHODS

This review summarised studies that measured participants personal exposure by carrying a PM2.5 monitor throughout their typical day. Personal PM2.5 exposures were summarised to indicate the distribution of exposures measured within each country income category (based on low (LIC), lower-middle (LMIC), upper-middle (UMIC), and high (HIC) income countries) and between different groups (i.e. gender, age, urban or rural residents).

RESULTS

From the 2259 search results, there were 140 studies that met our criteria. Overall, personal PM2.5 exposures in HICs were lower compared to other countries, with UMICs exposures being slightly lower than exposures measured in LMICs or LICs. 34% of measured groups in HICs reported below the ambient World Health Organisation 24-h PM2.5 guideline of 15 μg/m3, compared to only 1% of UMICs and 0% of LMICs and LICs. There was no difference between rural and urban participant exposures in HICs, but there were noticeably higher exposures recorded in rural areas compared to urban areas in non-HICs, due to significant household sources of PM2.5 in rural locations. In HICs, studies reported that secondhand smoke, ambient pollution infiltrating indoors, and traffic emissions were the dominant contributors to personal exposures. While, in non-HICs, household cooking and heating with biomass and coal were reported as the most important sources.

CONCLUSION

This review revealed a growing literature of personal PM2.5 exposure studies, which highlighted a large variability in exposures recorded and severe inequalities in geographical and social population subgroups.

Impact of acute temperature and air pollution exposures on adult lung function: A panel study of asthmatics

Background

Individuals with respiratory conditions, such as asthma, are particularly susceptible to adverse health effects associated with higher levels of ambient air pollution and temperature. This study evaluates whether hourly levels of fine particulate matter (PM_2.5) and dry bulb globe temperature (DBGT) are associated with the lung function of adult participants with asthma.

Methods and findings

Global positioning system (GPS) location, respiratory function (measured as forced expiratory volume at 1 second (FEV₁)), and self-reports of asthma medication usage and symptoms were collected as part of the Exposure, Location, and Lung Function (ELF) study. Hourly ambient PM_2.5 and DBGT exposures were estimated by integrating air quality and temperature public records with time-activity patterns using GPS coordinates for each participant (n = 35). The relationships between acute PM_2.5, DBGT, rescue bronchodilator use, and lung function collected in one week periods and over two seasons (summer/winter) were analyzed by multivariate regression, using different exposure time frames.

In separate models, increasing levels in PM_2.5, but not DBGT, were associated with rescue bronchodilator use. Conversely DBGT, but not PM_2.5, had a significant association with FEV₁. When DBGT and PM_2.5 exposures were placed in the same model, the strongest association between cumulative PM_2.5 exposures and the use of rescue bronchodilator was identified at the 0–24 hours (OR = 1.030; 95% CI = 1.012–1.049; p-value = 0.001) and 0–48 hours (OR = 1.030; 95% CI = 1.013–1.057; p-value = 0.001) prior to lung function measure. Conversely, DBGT exposure at 0 hours (β = 3.257; SE = 0.879; p-value>0.001) and 0–6 hours (β = 2.885; SE = 0.903; p-value = 0.001) hours before a reading were associated with FEV₁. No significant interactions between DBGT and PM_2.5 were observed for rescue bronchodilator use or FEV₁.

Conclusions

Short-term increases in PM_2.5 were associated with increased rescue bronchodilator use, while DBGT was associated with higher lung function (i.e. FEV₁). Further studies are needed to continue to elucidate the mechanisms of acute exposure to PM_2.5 and DBGT on lung function in asthmatics.

Air pollution and metabolic disorders: Dynamic versus static measures of exposure among Hispanics/Latinos and non-Hispanics

INTRODUCTION

Exposure to air pollution disproportionately affects racial/ethnic minorities that could contribute to health inequalities including metabolic disorders. However, most existing studies used a static assessment of air pollution exposure (mostly using the residential address) and do not account for activity space when modelling exposure to air pollution. The aim of this study is to understand how exposure to air pollution impacts metabolic disorders biomarkers, how this effect differs according to ethnicity, and for the first time compare these findings with two methods of exposure assessment: dynamic and static measures.

METHODS

Among the Community of Mine study, a cross-sectional study conducted in San Diego County, insulin resistance, diabetes, hypertension, obesity, dyslipidemia, and metabolic syndrome (MetS) were assessed. Exposure to air pollution (PM_2.5, NO₂, traffic) was calculated using static measures around the home, and dynamic measures of mobility derived from Global Positioning Systems (GPS) traces using kernel density estimators to account for exposure variability across space and time. Associations of air pollution with metabolic disorders were quantified using generalized estimating equation models to account for the clustered nature of the data.

RESULTS

Among 552 participants (mean age 58.7 years, 42% Hispanic/Latino), Hispanics/Latinos had a higher exposure to PM_2.5 compared to non-Hispanics using static measures. In contrast, Hispanics/Latinos had less exposure to PM_2.5 using dynamic measures. For all participants, higher dynamic exposure to PM_2.5 and NO₂ was associated with increased insulin resistance and cholesterol levels, and increased risk of obesity, dyslipidemia and MetS (RR 1.17, 95% CI: 1.07-1.28; RR 1.21, 95% CI: 1.12-1.30, respectively). The association between dynamic PM_2.5 exposure and MetS differed by Hispanic/Latino ethnicity.

CONCLUSION

These results highlight the importance of considering people's daily mobility in assessing the impact of air pollution on health.

Effects of Polycyclic Aromatic Hydrocarbons on Lung Function in Children with Asthma: A Mediation Analysis

Studies investigating the association between urinary Polycyclic Aromatic Hydrocarbons (PAHs) and asthma in children provided inhomogeneous results. We aimed to use Mediation Analysis to discover whether a link between urinary PAHs and lung function exists and if it might be ascribed to a direct or a symptom-mediated (indirect) effect in children with asthma. This single-center prospective study was conducted in Palermo, Italy, between March and July 2017 and involved 50 children with persistent mild-moderate asthma, aged 6–11 years. At each time visit (day 0, 30, 60, and 90), physical examination, spirometry, and urine collection for detection of urinary cotinine and PAHs were performed. A symptom score was computed. The sum of individually calculated molar mass of nine PAH metabolites (ΣPAH), naphthalene metabolites (ΣPAHn) and phenanthrene metabolites (ΣPAHp) were calculated. Three children withdrew from the study due to technical problems (n = 1) and adverse events (n = 2). PAHs indirect effects on FEV1 (ΣPAH: −0.011, p = 0.04; ΣPAHn: −0.011, p = 0.04; ΣPAHp: −0.012, p < 0.001) and FVC (ΣPAH: −0.012, p = 0.02; ΣPAHn: −0.0126, p = 0.02; ΣPAHp: −0.013, p < 0.001) were statistically significant. In conclusion, PAHs exposures have significant indirect (symptom-mediated) effects on lung function, emphasizing the role of PAHs-induced respiratory morbidity in decreasing lung function in children with asthma.

Urinary phthalate metabolites mixture, serum cytokines and renal function in children: A panel study

Epidemiological evidence regarded the relations of phthalates with children's renal function and its underlying mechanism were largely unknown. We conducted a panel study using 287 paired urine-blood samples by repeated measurements of 103 children (4-13 years) across 3 seasons to explore effects of urinary phthalate metabolites on estimated glomerular filtration rate (eGFR) and the potential role of multiple cytokines. We found that mono-ethyl phthalate (MEP), monobutyl phthalate (MBP), mono-benzyl phthalate (MBzP) and mono-n-octyl phthalate (MOP) were significantly associated with eGFR reduction. Compared with the lowest quartile, MBP, MBzP and MEP in the third and fourth quartiles exhibited a graded decrease in eGFR. Meanwhile, weighted quantile sum regression analyses showed an inverse association of metabolites mixture with eGFR, to which MEP, MBzP, MOP were the major contributors. MEP also remained robust in multiple-phthalate model. Age and weight status might modify such relationships with significant interactions. Furthermore, eGFR related phthalate metabolites were associated with increased multiple cytokines, and CCL27, CXCL1 might be potential mediators between MEP and eGFR with mild mediated proportions. Accordingly, urinary phthalate metabolites were related to eGFR reduction in dose-response manner and multiple cytokines elevation, of which CCL27 and CXCL1 might partly mediate phthalate-associated decreased renal function among children.

Personal PM2.5-bound PAH exposure, oxidative stress and lung function: The associations and mediation effects in healthy young adults

Decreased lung function is an early hazard of respiratory damage from fine particulate matter (PM_2.5) exposure. Limited studies have explored the association between PM_2.5-bound polycyclic aromatic hydrocarbons (PAHs) and lung function, but studies at the personal level in healthy young adults are scarce. Here, we assessed personal PM_2.5 and PM_2.5-bound PAH levels in a panel of 45 healthy young adults by a time-weighted model. The aims were to investigate the relationship between personal exposure and lung function by a linear mixed effect model, and to explore the mediating effects of oxidative stress in this association. The results showed that personal exposure to PM_2.5 and PAHs had the greatest negative effect on forced expiratory volume in 1 s (FEV₁), peak expiratory flow rate (PEF) and forced expiratory flow between 25% and 75% vital capacity (FEF_25-75) at lag 3 days. An IQR increase in personal PM_2.5 exposure was associated with a change of 0.35% (95% CI: 0.27%, 0.42%) in FEV₁, 0.39% (95% CI: 0.29%, 0.47%) in PEF and 0.36% (95% CI: 0.27%, 0.45%) in FEF_25-75. An IQR increase in personal PAH exposure was associated with a decrease of 0.63% (95% CI: 0.55%, 0.69%) in FEV₁, 0.69% (95% CI: 0.61%, 0.75%) in PEF and 0.66% (95% CI: 0.57%, 0.72%) in FEF_25-75. Additionally, exposure to PM_2.5 and PAHs resulted in the strongest positive effects on urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-iso-prostaglandin-F_2α (8-iso-PGF_2α). Of these, 8-OHdG mediated 10.33%, 8.87% and 9.45% of the associations of personal PM_2.5 exposure with FEV₁, PEF and FEF_25-75, respectively. Our results revealed that personal exposure to PM_2.5 and PAHs was associated with lung function decline in healthy young adults, and urinary 8-OHdG mediated the association between personal PM_2.5 and lung function.

Household determinants of biocontaminant exposures in Canadian homes

Exposure to biocontaminants, such as dust mites, animal dander, bacteria, and mold, is associated with a range of health effects. This study identified household characteristics associated with indoor biocontaminant loadings in four Canadian cities. Floor dust was collected in 290 Canadian homes in Edmonton, Halifax, Montreal, and Windsor. The dust samples were analyzed for house dust mite allergens (Der f 1 and Der p 1), cat allergen (Fel d 1), cockroach allergen (Bla g 1), beta-(1,3)-D-glucan, and endotoxin. Household information was obtained through questionnaires and home inspections. We performed univariate and multivariate analyses to identify household determinants of biocontaminant loadings and mold odor presence. We observed large regional variations for all biocontaminants, except for cockroach allergen. The ranges of the contaminants measured in loadings and concentrations were similar to that of previous Canadian studies. Household characteristics including presence of carpeting, low floor cleaning frequency, older home age, presence of pets, and indoor relative humidity above 45% were positively associated with the presence of multiple indoor biocontaminants. High floor cleaning frequency and use of dehumidifiers were negatively associated with the presence of multiple indoor biocontaminants. Mold odor was positively associated with older home age, past water damage, and visible mold growth.

Respiratory function declines in children with asthma associated with chemical species of fine particulate matter (PM2.5) in Nagasaki, Japan

BACKGROUND

The differential effects of PM_2.5 fractions on children's lung function remain inconclusive. This study aimed to examine whether lung function in asthmatic children was associated with increased PM_2.5 fractions in urban areas in Nagasaki prefecture, Japan, where the air pollution level is relatively low but influenced by transboundary air pollution.

METHODS

We conducted a multiyear panel study of 73 asthmatic children (boys, 60.3%; mean age, 8.2 years) spanning spring 2014-2016 in two cities. We collected self-measured peak expiratory flow (PEF) twice a day and daily time-series data for PM_2.5 total mass and its chemical species. We fitted a linear mixed effects model to examine short-term associations between PEF and PM_2.5, adjusting for individual and time-varying confounders. A generalized linear mixed effects model was also used to estimate the association for worsening asthma defined by severe PEF decline. Back-trajectory and cluster analyses were used to investigate the long-range transboundary PM_2.5 in the study areas.

RESULTS

We found that morning PEFs were adversely associated with higher levels of sulfate (- 1.61 L/min; 95% CI: - 3.07, - 0.15) in Nagasaki city and organic carbon (OC) (- 1.02 L/min; 95% CI: - 1.94, - 0.09) in Isahaya city, per interquartile range (IQR) increase at lag1. In addition, we observed consistent findings for worsening asthma, with higher odds of severe PEF decline in the morning for sulfate (odds ratio (OR) = 2.31; 95% CI: 1.12, 4.77) and ammonium (OR = 1.73; 95% CI: 1.06, 2.84) in Nagasaki city and OC (OR = 1.51; 95% CI: 1.06, 2.15) in Isahaya city, per IQR increase at lag1. The significant chemical species were higher on days that could be largely attributed to the path of Northeast China origin (for sulfate and ammonium) or both the same path and local sources (for OC) than by other clusters.

CONCLUSIONS

This study provides evidence of the differential effects of PM_2.5 fractions on lung function among asthmatic children in urban areas, where the Japanese national standards of air quality have been nearly met. Continuous efforts to promote mitigation actions and public awareness of hazardous transboundary air pollution are needed to protect susceptible children with asthma.

"I am an air quality scientist"- Using citizen science to characterise school children's exposure to air pollution

Children are particularly vulnerable to the harmful effects of air pollution. To tackle this issue and implement effective strategies to reduce child exposure, it is important to understand how children are exposed to this risk. This study followed a citizen science approach to air pollution monitoring, aiming to characterise school children's exposure to air pollution and to analyse how a citizen science approach to data collection could contribute to and enhance the research process. 258 children across five London primary schools attended air pollution education sessions and measured air pollution for a week using backpacks with built-in air quality sensors. Children received a summary of the results, advice and information on how to reduce exposure to air pollution. Data on the impact of the approach on the school community were collected using surveys and focus groups with children and their parents and interviews with the teachers involved. The unique data set obtained permitted us to map different routes and modes of transport used by the children and quantify different exposure levels. We identified that, on average, children were exposed to higher levels of air pollution when travelling to and from school, particularly during the morning journey where air pollution levels were on average 52% higher than exposures at school. Children who walked to and from school through busy main roads were exposed to 33% higher levels of air pollution than those who travelled through back streets. The findings from this study showed that using a citizen science approach to data collection, where children are actively involved in the research process, not only facilitated the gathering of a large data set by encouraging participation and stimulating adherence with the study protocol, but also increased children's awareness of air pollution, encouraging them to adopt positive behaviour changes to reduce their exposure.

Association of personal fine particulate matter and its respiratory tract depositions with blood pressure in children: From two panel studies

Evidence is limited regarding the acute effects of personal fine particulate matter (PM_2.5) exposure and its respiratory tract depositions on the alteration of children's blood pressure (BP). We conducted 2 longitudinal panel studies in 2 cities to evaluate the relations of 72-h real-time personal PM_2.5 exposure and its depositions in 3 respiratory tract regions over different lag times with BP and the risk of prehypertension and hypertension among 286 children aged 4-12 years. We found the strongest effects of PM_2.5 exposure on increased BP and risk of prehypertension and hypertension at lag 2 day, in dose-response manner, even when PM_2.5 below Chinese Ambient Air Quality Standard (CAAQS) Grade II. Moreover, compared to PM_2.5, tracheobronchial and alveolar depositions displayed more evident effects on BP outcomes. Interestingly, all above relationships were stronger among children in Guangzhou with lower PM_2.5 and its deposited doses than those in Weinan. Additionally, boys and those with daily extra-school activity ≥ 1 h were more susceptible to PM_2.5-induced BP effects with significant interactions. Our results highlighted that short-term PM_2.5 exposure and its respiratory tract depositions were dose-responsive related to higher BP, prevalence of prehypertension and hypertension among children, even when PM_2.5 below CAAQS II.

Effect of Seasonal Variation on the Relationship of Indoor Air Particulate Matter with Measures of Obesity and Blood Pressure in Children

BACKGROUND

Particulate matter (PM) air pollution is an important environmental health risk factor. Although some studies have shown PM to be associated with obesity and hypertension, very few studies have assessed the association of indoor PM specifically with obesity and blood pressure measures in children with respect to seasonal variation.

OBJECTIVES

The present study investigated the relationship of PM with obesity and blood pressure variables in children across the winter and summer seasons.

METHODS

A comparative descriptive approach was adopted and school children from 10-14 years of age from selected rural and urban localities of the Eastern Cape Province of South Africa were assessed in winter and summer. Anthropometric measurements were taken, including height, weight, waist circumference, body mass index (BMI), and total fat mass (TFM), while blood pressure variables including systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) were measured. Indoor air PM concentrations were measured in the classrooms in the presence of children.

RESULTS

The prevalence of obesity and hypertension in children were 13.4% and 5.1% in winter and 12.9% and 1.0% in summer, respectively. High blood pressure was more prevalent in children in rural areas, while the prevalence of obesity in children was higher in urban areas. Particulate matter was significantly (p<0.05) higher in rural areas compared to urban areas. Obese children in summer had a greater than 3-fold association (AOR: 3.681, p=0.005) with 4th interquartile range (IQR) of PM5 and a greater than 3- and 4-fold association (AOR: 3.08; 4.407; p<0.05) with 2nd and 4th IQR of PM10, respectively, than their overweight, normal weight or underweight counterparts. High blood pressure was not associated (p< 0.05) with PM.

CONCLUSIONS

High concentrations of indoor PM were positively associated with obesity in children in summer, particularly among rural children. This association could be accounted for by location and seasonal differences.

PARTICIPANT CONSENT

Obtained.

ETHICS APPROVAL

Ethics approval was obtained from the Health Sciences Ethics Committee of Walter Sisulu University, South Africa (Ref No: CHI011SCHU01).

COMPETING INTERESTS

The authors declare no competing financial interests.

Short-Term Effects of Particle Size and Constituents on Blood Pressure in Healthy Young Adults in Guangzhou, China

Background Although several studies have focused on the associations between particle size and constituents and blood pressure, results have been inconsistent. Methods and Results We conducted a panel study, between December 2017 and January 2018, in 88 healthy university students in Guangzhou, China. Weekly systolic blood pressure and diastolic blood pressure were measured for each participant for 5 consecutive weeks, resulting in a total of 440 visits. Mass concentrations of particles with an aerodynamic diameter of ≤2.5 µm (PM2.5), ≤1.0 µm (PM1.0), ≤0.5 µm (PM0.5), ≤0.2 µm (PM0.2), and number concentrations of airborne particulates of diameter ≤0.1 μm were measured. Linear mixed-effect models were used to estimate the associations between blood pressure and particles and PM2.5 constituents 0 to 48 hours before blood pressure measurement. PM of all the fractions in the 0.2- to 2.5-μm range were positively associated with systolic blood pressure in the first 24 hours, with the percent changes of effect estimates ranging from 3.5% to 8.8% for an interquartile range increment of PM. PM0.2 was also positively associated with diastolic blood pressure, with an increase of 5.9% (95% CI, 1.0%-11.0%) for an interquartile range increment (5.8 μg/m3) at lag 0 to 24 hours. For PM2.5 constituents, we found positive associations between chloride and diastolic blood pressure (1.7% [95% CI, 0.1%-3.3%]), and negative associations between vanadium and diastolic blood pressure (-1.6% [95% CI, -3.0% to -0.1%]). Conclusions Both particle size and constituent exposure are significantly associated with blood pressure in the first 24 hours following exposure in healthy Chinese adults.

Assessing Approaches of Human Inhalation Exposure to Polycyclic Aromatic Hydrocarbons: A Review

Polycyclic aromatic hydrocarbons (PAHs) are a class of important organic pollutants widely emitted from anthropogenic activities, with a general distribution in the gas and particulate phases. Some PAHs are carcinogenic, teratogenic, and mutagenic. Inhalation exposure to PAHs is correlated with adverse health outcomes in the respiratory and cardiovascular systems. Thus, it is significant to determine the exposure level of the general population. This study summarizes the evaluation methods for PAH exposure, focusing on different exposure parameters. External exposure can be determined via the collection of the environmental pollution concentration through active samplers or passive samplers during environmental monitoring or personal sampling. Time-activity patterns give critical exposure information that captures the exposure period, origin, and behaviors. Modeling is a labor-less approach for human exposure estimation, and microenvironmental exposure requires specific research. It is important to select appropriate methods to quantify the exposure level to provide accurate data to establish the exposure–risk relationship and make scientific suggestions for the protection of public health.

Personal Exposure to PM2.5 Oxidative Potential in Association with Pulmonary Pathophysiologic Outcomes in Children with Asthma

Fine particulate matter (PM_2.5) with a higher oxidative potential has been thought to be more detrimental to pulmonary health. We aim to investigate the associations between personal exposure to PM_2.5 oxidative potential and pulmonary outcomes in asthmatic children. We measured each of the 43 asthmatic children 4 times for airway mechanics, lung function, airway inflammation, and asthma symptom scores. Coupling measured indoor and outdoor concentrations of PM_2.5 mass, constituents, and oxidative potential with individual time-activity data, we calculated 24 h average personal exposures 0-3 days prior to a health outcome measurement. We found that increases in daily personal exposure to PM_2.5 oxidative potential were significantly associated with increased small, large, and total airway resistance, increased airway impedance, decreased lung function, and worsened scores of individual asthma symptoms and the total symptom score. Among the PM_2.5 constituents, organic matters largely of indoor origin contributed the greatest to PM_2.5 oxidative potential. Given that the variability in PM_2.5 oxidative potential was a stronger driver than PM_2.5 mass for the variability in the respiratory health outcomes, it is suggested to reduce PM_2.5 oxidative potential, particularly by reducing the organic matter constituent of indoor PM_2.5, as a targeted source control strategy in asthma management.

Personal PM2.5 exposure and lung function: Potential mediating role of systematic inflammation and oxidative damage in urban adults from the general population

BACKGROUND

Short-term effects of fine particulate matter (PM_2.5) exposure on lung function have been reported. However, few studies have assessed PM_2.5 exposure on the personal level, and the mechanism underlying the effects of PM_2.5 exposure on lung function remains less clear.

OBJECTIVES

To evaluate the association between personal PM_2.5 exposure and lung function alteration in general population and to explore the roles of systematic inflammation and oxidative damage in this association.

METHODS

A total of 7685 lung function tests were completed among 4697 urban adults in Wuhan, China. Plasma C-reactive protein (CRP), urinary 8-iso-prostaglandin-F_2α (8-iso-PGF_2α) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels were measured. Personal PM_2.5 exposure levels were estimated using an estimation model from the actual measurements of individual PM_2.5 levels in 191 participants. Mixed linear models were used to evaluate the association between personal PM_2.5 exposure and lung function. Mediation analyses were conducted to investigate the roles of CRP, 8-iso-PGF_2α and 8-OHdG in above associations.

RESULTS

After adjusting for confounders, each 10 μg/m³ increase in the previous-day personal PM_2.5 exposure was associated with 2.94 mL, 2.02 mL and 16.14 mL/s decreases in forced vital capacity (FVC), forced expiration volume in 1 s (FEV₁) and peak expiratory flow, respectively. The associations were more obvious among never smokers compared with current smokers. Cumulative 7-day exposure to PM_2.5 led to the strongest adverse effects on lung function. Among never smokers with high PM_2.5 exposure levels, a positive relationship was observed between personal PM_2.5 level and urinary 8-iso-PGF_2α, and 8-iso-PGF_2α meditated 4.69% and 12.30% of the association between the 7-day moving PM_2.5 concentration and FVC and FEV₁, respectively. We did not observe a significant positive association between PM_2.5 exposure and plasma CRP or urinary 8-OHdG.

CONCLUSION

Short-term personal exposure to PM_2.5 is associated with reduced pulmonary ventilation function. Urinary 8-iso-PGF_2α partly mediates these associations.

Potential role of polycyclic aromatic hydrocarbons in air pollution-induced non-malignant respiratory diseases

Epidemiological studies have found strong associations between air pollution and respiratory effects including development and/or exacerbation of asthma and chronic obstructive pulmonary disease (COPD) as well as increased occurrence of respiratory infections and lung cancer. It has become increasingly clear that also polycyclic aromatic hydrocarbons (PAHs) may affect processes linked to non-malignant diseases in the airways. The aim of the present paper was to review epidemiological studies on associations between gas phase and particle-bound PAHs in ambient air and non-malignant respiratory diseases or closely related physiological processes, to assess whether PAH-exposure may explain some of the effects associated with air pollution. Based on experimental in vivo and in vitro studies, we also explore possible mechanisms for how different PAHs may contribute to such events. Epidemiological studies show strongest evidence for an association between PAHs and asthma development and respiratory function in children. This is supported by studies on prenatal and postnatal exposure. Exposure to PAHs in adults seems to be linked to respiratory functions, exacerbation of asthma and increased morbidity/mortality of obstructive lung diseases. However, available studies are few and weak. Notably, the PAHs measured in plasma/urine also represent other exposure routes than inhalation. Furthermore, the role of PAHs measured in air is difficult to disentangle from that of other air pollution components originating from combustion processes. Experimental studies show that PAHs may trigger various processes linked to non-malignant respiratory diseases. Physiological- and pathological responses include redox imbalance, oxidative stress, inflammation both from the innate and adaptive immune systems, smooth muscle constriction, epithelial- and endothelial dysfunction and dysregulated lung development. Such biological responses may at the molecular level be initiated by PAH-binding to the aryl hydrocarbon receptor (AhR), but possibly also through interactions with beta-adrenergic receptors. In addition, reactive PAH metabolites or reactive oxygen species (ROS) may interfere directly with ion transporters and enzymes involved in signal transduction. Overall, the reviewed literature shows that respiratory effects of PAH-exposure in ambient air may extend beyond lung cancer. The relative importance of the specific PAHs ability to induce disease may differ between the biological endpoint in question.

Short-term effects of real-time personal PM2.5 exposure on ambulatory blood pressure: A panel study in young adults

BACKGROUND

Short-term exposure to PM_2.5 has been shown to be associated with changes in blood pressure. However, most of the evidence is based on PM_2.5 measurements from fixed stations and resting blood pressure measured at a regular time.

OBJECTIVES

To evaluate the short-term daily and hourly effects of real-time personal PM_2.5 exposure on ambulatory blood pressure, and to compare the effects with those of PM_2.5 exposure from fixed stations.

METHODS

Between April 2017 and December 2017, 37 young adults were recruited in a panel study from a central urban area and a suburban area, to measure personal hourly PM_2.5 and ambulatory systolic blood pressure (SBP) as well as diastolic blood pressure (DBP) for three consecutive days. Hourly PM_2.5 concentrations were also obtained from the nearest monitoring station operated by Guangdong Environmental Monitoring Center. Generalized additive mixed model was employed to evaluate the effects of PM_2.5 on ambulatory blood pressure.

RESULTS

During the study period, the mean concentration of personal PM_2.5 exposure was 60.30 ± 52.14 μg/m³, while the value of PM_2.5 from fixed stations was 36.77 ± 21.52 μg/m³. Both personal PM_2.5 exposure and exposure from fixed stations averaged over the previous 1 to 3 days decreased blood pressure. During daytime, a 10 μg/m³ increase in 1-day moving average of personal PM_2.5 was associated with a 0.54 mmHg (95% CI: -1.03, -0.05) and 0.22 mmHg (95% CI: -0.59, 0.15) decrease in SBP and DBP, respectively. When using PM_2.5 exposures from fixed stations, the decrease in SBP and DBP were 0.95 mmHg (95% CI: -1.82, -0.07) and 0.74 mmHg (95% CI: -1.46, -0.03). Stratified analysis showed stronger effects in the central urban area and among males.

CONCLUSIONS

Both personal PM_2.5 exposure and exposure from fixed stations averaged over the previous 1 to 3 days decreased blood pressure. Stronger effects were found in a central urban area and among males.

Effects of personal nitrogen dioxide exposure on airway inflammation and lung function

BACKGROUND

Few epidemiological studies have evaluated the respiratory effects of personal exposure to nitrogen dioxide (NO₂), a major traffic-related air pollutant. The biological pathway for these effects remains unknown.

OBJECTIVES

To evaluate the short-term effects of personal NO₂ exposure on lung function, fractional exhaled nitric oxide (FeNO) and DNA methylation of genes involved.

METHODS

We conducted a longitudinal panel study among 40 college students with four repeated measurements in Shanghai from May to October in 2016. We measured DNA methylation of the key encoding genes of inducible nitric oxide synthase (NOS2A) and arginase (ARG2). We applied linear mixed-effect models to assess the effects of NO₂ on respiratory outcomes.

RESULTS

Personal exposure to NO₂ was 27.39 ± 23.20 ppb on average. In response to a 10-ppb increase in NO₂ exposure, NOS2A methylation (%5 mC) decreased 0.19 at lag 0 d, ARG2 methylation (%5 mC) increased 0.21 and FeNO levels increased 2.82% at lag 1 d; and at lag 2 d the percentage of forced vital capacity, forced expiratory volume in 1 s and peak expiratory flow in predicted values decreased 0.12, 0.37 and 0.67, respectively. The model performance was better compared with those estimated using fixed-site measurements. These effects were robust to the adjustment for co-pollutants and weather conditions.

CONCLUSIONS

Our study suggests that short-term personal exposure to NO₂ is associated with NOS2A hypomethylation, ARG2 hypermethylation, respiratory inflammation and lung function impairment. The use of personal measurements may better predict the respiratory effects of NO₂.

Effect modifiers of lung function and daily air pollutant variability in a panel of schoolchildren

BACKGROUND

Acute pollutant-related lung function changes among children varies across pollutants and lag periods. We examined whether short-term air pollutant fluctuations were related to daily lung function among a panel of children and whether these effects are modified by airway hyperresponsiveness, location and asthma severity.

METHODS

Students from randomly selected grade 4 classrooms at seven primary schools in Durban, participated, together with asthmatic children from grades 3-6 (n=423). The schools were from high pollutant exposed communities (south) and compared with schools from communities with lower levels of pollution (north), with similar socioeconomic profiles. Interviews, spirometry and methacholine challenge testing were conducted. Bihourly lung function measurements were performed over a 3-week period in four phases. During all schooldays, students blew into their personal digital monitors every 1.5-2 hours. Nitrogen dioxide (NO₂), nitrogen oxide (NO), sulphur dioxide and particulate matter (<10 μm diameter) (PM₁₀) were measured at each school. Generalised estimating equations assessed lag effects, using single-pollutant (single or distributed lags) models.

RESULTS

FEV₁ declines ranged from 13 to 18 mL per unit increase in IQR for NO and 14-23 mL for NO₂. Among the 5-day average models, a 20 mL and 30 mL greater drop in FEV₁ per IQR for NO₂ and NO, respectively, among those with airway hyperresponsiveness compared with those without. Effects were seen among those with normal airways.

CONCLUSIONS

This first panel study in sub-Saharan Africa, showed significant declines in lung function, in response to NO and NO₂ with effects modified by airway hyperresponsiveness or persistent asthma.

The impact of air exchange rate on ambient air pollution exposure and inequalities across all residential parcels in Massachusetts

Individual housing characteristics can modify outdoor ambient air pollution infiltration through air exchange rate (AER). Time and labor-intensive methods needed to measure AER has hindered characterization of AER distributions across large geographic areas. Using publicly-available data and regression models associating AER with housing characteristics, we estimated AER for all Massachusetts residential parcels. We conducted an exposure disparities analysis, considering ambient PM_2.5 concentrations and residential AERs. Median AERs (h^-1) with closed windows for winter and summer were 0.74 (IQR: 0.47-1.09) and 0.36 (IQR: 0.23-0.57), respectively, with lower AERs for single family homes. Across residential parcels, variability of indoor PM_2.5 concentrations of ambient origin was twice that of ambient PM_2.5 concentrations. Housing parcels above the 90th percentile of both AER and ambient PM_2.5 (i.e., the leakiest homes in areas of highest ambient PM_2.5)-vs. below the 10 percentile-were located in neighborhoods with higher proportions of Hispanics (20.0% vs. 2.0%), households with an annual income of less than $20,000 (26.0% vs. 7.5%), and individuals with less than a high school degree (23.2% vs. 5.8%). Our approach can be applied in epidemiological studies to estimate exposure modifiers or to characterize exposure disparities that are not solely based on ambient concentrations.

Respiratory symptoms, asthma and levels of fractional exhaled nitric oxide in schoolchildren in the industrial areas of Estonia

OBJECTIVES

Exposure to air pollutants in the ambient environment has been associated with various respiratory symptoms, and with increased asthma diagnosis, in both children and adults. Most research to date has focussed on core pollutants, such as PM₁₀, PM_2.5, SO₂ and NO₂, and less attention has been given to the effects of industry-specific contamination. The current study aimed to examine the associations between respiratory symptoms, asthma, increased levels of fractional exhaled nitric oxide (FeNO) (as a marker of eosinophilic airway inflammation) and ambient levels of industrial pollutants (such as benzene, phenol, formaldehyde and non-methane hydrocarbons) for schoolchildren living near oil shale industries in Ida-Viru County, Estonia.

METHODS

A total of 1326 schoolchildren from Ida-Viru, Lääne-Viru and Tartu Counties participated in a cross-sectional study, consisting of questionnaires on respiratory symptoms and asthma, as well as clinical examinations to measure FeNO. Dispersion modelling was used to characterize individual-level exposure to industrial air pollutants at each subject's home address. Associations between exposure and respiratory health were investigated using logistic regression analysis, and differences in results between regions were analysed using the Chi-squared test.

RESULTS

The prevalence of respiratory symptoms (p < 0.05) in children living near (i.e. within 5 km) of an oil shale industry site in Ida-Viru County was 2-4 times higher than in children living in the reference area of Tartu County. Children exposed to 1 μg/m³ higher levels of benzene and formaldehyde had a higher odds ratio (OR) of having rhinitis without a cold (OR 1.03, 95% confidence interval (CI) 1.01-1.06), of ever having had attacks of asthma (OR 1.05, 95% CI 1.01-1.10) and of having a dry cough a few days per year (OR 1.05, 95% CI 1.01-1.10). Children exposed to 1 μg/m³ higher levels of benzene, formaldehyde, phenol and non-methane hydrocarbons had a higher odds ratio of having high FeNO levels (≥30 ppb): OR and 95% CI of 1.05, 1.01-1.09; 1.22, 1.06-1.41; 1.01, 1.00-1.01; and 1.75, 1.75-2.62, respectively.

Interactions between polycyclic aromatic hydrocarbons and epoxide hydrolase 1 play roles in asthma

Asthma, as one of the most common chronic diseases in children and adults, is a consequence of complex gene-environment interactions. Polycyclic aromatic hydrocarbons (PAHs), as a group of widespread environmental organic pollutants, are involved in the development, triggering and pathologic changes of asthma. Various previous studies reported the critical roles of PAHs in immune changes, oxidative stress and environment-gene interactions of asthma. EPHX1 (the gene of epoxide hydrolase 1, an enzyme mediating human PAH metabolism) had a possible association with asthma by influencing PAH metabolism. This review summarized that (1) the roles of PAHs in asthma-work as risk factors; (2) the possible mechanisms involved in PAH-related asthma-through immunologic and oxidative stress changes; (3) the interactions between PAHs and EPHX1 involved in asthma-enzymatic activity of epoxide hydrolase 1, which affected by EPHX1 genotypes/SNPs/diplotypes, could influence human PAH metabolism and people's vulnerability to PAH exposure. This review provided a better understanding of the above interactions and underlying mechanisms for asthma which help to raise public's concern on PAH control and develop strategies for individual asthma primary prevention.

A population-based birth cohort study of the association between childhood-onset asthma and exposure to industrial air pollutant emissions

BACKGROUND

Studies of the association between air pollution and asthma onset have mostly focused on urban and traffic-related air pollution. We investigated the associations between exposure to industrial emissions and childhood-onset asthma in a population-based birth cohort in Quebec, Canada, 2002-2011.

METHODS

The cohort was built from administrative health databases. We developed separately for PM_2.5 and SO₂ different metrics representing children's time-varying residential exposure to industrial emissions: 1) yearly number of tons of air pollutant emitted by industries located within 2.5 km of the residence; 2) distance to the nearest "major emitter" (≥100 tons) of either PM_2.5 and SO₂ within 7.5 km of the residence, and; 3) tons of air pollutant emitted by the nearest "major emitter" within 7.5 km, weighted by the inverse of the distance and the percentage of time that the residence was downwind. To handle the large number of zeros (i.e., children unexposed) we decomposed the exposure variable into two covariates simultaneously included in the regression model: a binary indicator of exposure and a continuous exposure variable centered at the mean value among exposed children. We performed Cox models using age as the time axis, adjusted for gender, material and social deprivation and calendar year. We indirectly adjusted for unmeasured secondhand smoke.

RESULTS

The cohort included 722,667 children and 66,559 incident cases of asthma. Across the different exposure metrics, mean percentage changes in the risk of asthma onset in children exposed to the mean relative to those unexposed ranged from 4.5% (95% CI: 2.8, 6.3%) to 10.6% (95% CI: 6.2, 15.2%) for PM_2.5 and, from 1.1% (95% CI: -0.1, 3.3%) to 8.9% (95% CI: 7.1, 11.1%) for SO₂. Indirect adjustment for secondhand smoke did not substantially affect the associations. In children exposed, the risk of asthma onset increased with the magnitude of the exposure for all metrics, except the distance to the nearest major emitter of SO₂.

CONCLUSIONS

In this population-based birth cohort, residential exposure to industrial air pollutant emissions was associated with childhood-onset asthma. Additional studies with improved models for estimating exposure to industrial point-sources are needed to further support the observed associations.

Association of PAHs and BTEX exposure with lung function and respiratory symptoms among a nonoccupational population near the coal chemical industry in Northern China

Emissions (particularly aromatic compounds) from coal industries and biomass fuels combustion lead to high health risks for neighboring residents. To investigate the association of polycyclic aromatic hydrocarbons (PAHs) and benzene, toluene, ethylbenzene and 1,2-dimethylbenzene (BTEX) exposure with lung function and respiratory symptoms among adults and children near the coal-chemical industry in Northern China, adults and children from a county dotted with coal chemical industry were chosen as subjects for investigation (investigated area, IR). The control group consisted of adults and children from an agricultural county (control area, CR). The environmental and urinary PAH and BTEX levels of adults and children were determined by isotope dilution liquid chromatography coupled with tandem mass spectrometry. The Mann-Whitney U test and multivariate linear regression models were used to analyze the relationship between pollutant exposure and the respiratory system. The results showed that in an ambient environment, levels of PAHs and BTEX in the IR were significantly higher than those in the CR. Particularly, the concentration profiles for air samples were IR > CR and indoor > outdoor. Both for adults and children, the geometric (GM) concentrations of urinary PAHs and BTEX from the IR were significantly higher than those measured in the CR. Additionally, the urinary PAH exposure level profiles of smokers were higher than those of nonsmokers, indicating that indoor air and smoking were both important nonoccupational exposure sources. The decline of the forced expiratory in the first second (FEV₁, %) and the forced expiratory middle flow rate (FEF_25%) in children were associated with increasing urinary PAH metabolite levels (p < 0.05). The increase in urinary 1-OHN, 3-OHPhe, 4-OHPhe and 1-OHP levels could be linked to a decrease in FEV1 (r = -0.179, p < 0.05) and FEF_25% with the coefficient of -0.166, -0.201 and -0.175 (p < 0.05), respectively. Medical examinations and lung function tests indicated that residents in the IR had higher occurrences of chest inflammation or declining lung function than residents in the CR. Moreover, exposure to PAHs and BTEX could decrease child lung function, though decreased lung function was not observed in adults. Both urinary monitoring and lung function data showed that children were more sensitive to PAH and BTEX exposure than adults.

Short-term effects of ambient benzene and TEX (toluene, ethylbenzene, and xylene combined) on cardiorespiratory mortality in Hong Kong

BACKGROUND

Numerous epidemiological and experimental studies have demonstrated the detrimental effects of the criteria air pollutants on population health, including particulate matters, ozone, and nitrogen dioxide. However, evidence on health effects of benzene, toluene, ethylbenzene, and xylene (BTEX in short) is insufficient.

OBJECTIVES

The present study aimed to assess the exposure-lag-response relations of ambient BTEX components with cardiorespiratory mortality in Hong Kong population.

METHODS

Daily BTEX concentrations from April 2011 to December 2014 were collected from the Hong Kong Environmental Protection Department. Cause-specific mortality records were obtained from the Census and Statistics Department of Hong Kong. Generalized additive model (GAM) integrated with a distributed lag model (DLM) was used to estimate the excess risks of cardiorespiratory mortality associated with the cumulative exposure to benzene and TEX (toluene, ethylbenzene and xylene combined) over 0-9 lag days, while adjusting for time trend, seasonality, weather conditions and calendar effects.

RESULTS

We observed the delayed and distributed lag effects of BTEX components on circulatory mortality. The cumulative exposures over 0-9 lag days for IQR increments of benzene (1.4 μg/m³) and TEX (7.9 μg/m³) were associated with 5.8% (95%CI: 1.0% to 10.8%) and 3.5% (95%CI: 1.0% to 6.1%) increases in circulatory mortality, respectively. The effect estimates of benzene and TEX were more delayed than that of PM_2.5. We didn't observe any significant association of BTEX exposure on total and respiratory deaths.

CONCLUSIONS

Short-term elevations in ambient BTEX concentrations may trigger circulatory mortality in Hong Kong population.

The mediating role of risk perception in the association between industry-related air pollution and health

Background

Heavy industry emits many potentially hazardous pollutants into the air which can affect health. Awareness about the potential health impacts of air pollution from industry can influence people’s risk perception. This in turn can affect (self-reported) symptoms. Our aims were to investigate the associations of air pollution from heavy industry with health symptoms and to evaluate whether these associations are mediated by people’s risk perception about local industry.

Methods

A cross-sectional questionnaire study was conducted among children (2–18 years) and adults (19 years and above) living in the direct vicinity of an area with heavy industry. A dispersion model was used to characterize individual-level exposures to air pollution emitted from the industry in the area. Associations between PM_2.5 and NO_X with presence of chronic diseases (adults) and respiratory symptoms (adults and children) were investigated by logistic regression analysis. Risk perception was indirectly measured by worries about local industry (0–10 scale). Mediation analyses were performed to investigate the role of mediation by these worries.

Results

The response was 54% (2,627/4,877). In adults exposure to modelled PM_2.5 from industry (per μg/m³) was related with reported high blood pressure (OR 1.56, 95% CI 1.13–2.15) and exposure to modelled NO_X (per μg/m³) was inversely related with cardiovascular diseases (OR 0.91, 95% CI 0.84–0.98). In children higher PM_2.5 and NO_X concentrations (per μg/m³) were related with wheezing (OR 2.00, 95% CI 1.24–3.24 and OR 1.13, 95% CI 1.06–1.21 respectively) and dry cough (OR 2.33, 95% CI 1.55–3.52 and OR 1.16, 95% CI 1.10–1.22 respectively). Parental worry about local industry was an important mediator in exposure–health relations in children (indirect effect between 19–28%).

Conclusion

Exposure from industry was associated with self-reported reported high blood pressure among adults and respiratory symptoms among their children. Risk perception was found to mediate these associations for children.

Effects of Environmental Air Pollution on Pulmonary Function Level of Residents in Korean Industrial Complexes

This study aims to identify environmental air pollution adversely affecting pulmonary function among a community-based general population living in Korean industrial complexes. A total of 1963 residents participated in a pulmonary function test (PFT). The sample population consisted of an exposed group (n = 1487) living within a radius of 5 km of industrial complexes and a control group (n = 476) living over a radius of 10 km from the industrial complexes in Gwangyang and Yeosu cities. PFT results were calculated for each resident of the study population. On-site questionnaire surveys with face-to-face interviews were also conducted to collect more detailed information on personal lifestyles, medical history, exposure to air pollution, and respiratory disease and related symptoms. A total of 486 measured samples were collected by eight automated air-monitoring stations installed in four counties of Gwangyang and four counties of Yeosu in South Korea from January 2006 to February 2007. Mean levels of SO₂ (0.012 ppm), CO (0.648 ppm), NO₂ (0.02 ppm), O₃ (0.034 ppm), and PM₁₀ (43.07 μg/m³), collected within a radius of 5 km, were significantly higher than those collected over a radius of 10 km from Gwangyang and Yeosu industrial complexes. Prevalence odds ratio (OR) of abnormal pulmonary function in the exposed group of residents (<5 km) was elevated at 1.24 (95% CI 0.71–1.96), but not statistically significant (p > 0.05). In multiple linear regression analysis, forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC) levels significantly declined as SO₂, CO, and O₃ levels increased when adjusting for age, sex, body mass index (BMI), alcohol, smoking, secondhand smoke, and respiratory disease and related symptoms (n = 1963) (p < 0.05). These results suggest that exposure to air pollution affects pulmonary function levels of residents living in Korean industrial complexes.

Effects of personal air pollution exposure on asthma symptoms, lung function and airway inflammation

BACKGROUND

There is evidence that air pollution increases the risk of asthma hospitalizations and healthcare utilization, but the effects on day-to-day asthma control are not fully understood.

OBJECTIVE

We undertook a prospective single-centre panel study to test the hypothesis that personal air pollution exposure is associated with asthma symptoms, lung function and airway inflammation.

METHODS

Thirty-two patients with a clinical diagnosis of asthma were provided with a personal air pollution monitor (Cairclip NO₂ /O₃ ) which was kept on or around their person throughout the 12-week follow-up period. Ambient levels of NO₂ and particulate matter were modelled based upon satellite imaging data. Directly measured ozone, NO₂ and particulate matter levels were obtained from a monitoring station in central Leicester. Participants made daily electronic records of asthma symptoms, peak expiratory flow and exhaled nitric oxide. Spirometry and asthma symptom questionnaires were completed at fortnightly study visits. Data were analysed using linear mixed effects models and cross-correlation.

RESULTS

Cairclip exposure data were of good quality with clear evidence of diurnal variability and a missing data rate of approximately 20%. We were unable to detect consistent relationships between personal air pollution exposure and clinical outcomes in the group as a whole. In an exploratory subgroup analysis, total oxidant exposure was associated with increased daytime symptoms in women but not men.

CONCLUSIONS AND CLINICAL RELEVANCE

We did not find compelling evidence that air pollution exposure impacts on day-to-day clinical control in an unselected asthma population, but further studies are required in larger populations with higher exposure levels. Women may be more susceptible than men to the effects of air pollution, an observation which requires confirmation in future studies.

Estimated individual inhaled dose of fine particles and indicators of lung function: A pilot study among Chinese young adults

Fine particle (PM_2.5)-related lung damage has been reported in most studies regarding environmental or personal PM_2.5 concentrations. To assess effects of personal PM_2.5 exposures on lung function, we recruited 20 postgraduate students and estimated the individual doses of inhaled PM_2.5 based on their microenvironmetal PM_2.5 concentrations, time-activity patterns and refereed inhalation rates. During the period of seven consecutive days in each of the four seasons, we repeatedly measured the daily lung function parameters and airway inflammation makers such as fractional exhaled nitric oxide (FeNO) as well as systemic inflammation markers including interleukin-1β on the final day. The high individual dose (median (IQR)) of inhaled PM_2.5 was 957 (948) μg/day. We observed a maximum FeNO increase (9.1% (95%CI: 2.2-15.5)) at lag 0 day, a maximum decrease of maximum voluntary ventilation (11.8% (95% CI: 4.6-19.0)) at lag 5 day and a maximum interleukin-1β increase (103% (95% CI: 47-159)) at lag 2 day for an interquartile range increase in the individual dose of inhaled PM_2.5 during the four seasons. Short-term exposure to PM_2.5 assessed by the individual dose of inhaled PM_2.5 was associated with higher airway and systemic inflammation and reduced lung function. Further studies are needed to understand better underlying mechanisms of lung damage following acute exposure to PM_2.5.

The effect of industry-related air pollution on lung function and respiratory symptoms in school children

BACKGROUND

Heavy industry emits many potentially hazardous pollutants into the air which can affect health. However, the effects of air pollution from heavy industry on lung function and respiratory symptoms have been investigated scarcely. Our aim was to investigate the associations of long-term air pollution from heavy industry with lung function and respiratory symptoms in school children.

METHODS

A cross-sectional lung function study was conducted among school children (7-13 years) in the vicinity of an area with heavy industry. Lung function measurements were conducted during school hours. Parents of the children were asked to complete a questionnaire about the health of their children. A dispersion model was used to characterize the additional individual-level exposures to air pollutants from the industry in the area. Associations between PM_2.5 and NO_X exposure with lung function and presence of respiratory symptoms were investigated by linear and/or logistic regression analysis.

RESULTS

Participation in the lung function measurements and questionnaires was 84% (665/787) and 77% (603/787), respectively. The range of the elevated PM_2.5 and NO_X five years average concentrations (2008-2012) due to heavy industry were 0.04-1.59 μg/m³ and 0.74-11.33 μg/m³ respectively. After adjustment for confounders higher exposure to PM_2.5 and NO_X (per interquartile range of 0.56 and 7.43 μg/m³ respectively) was associated with lower percent predicted peak expiratory flow (PEF) (B -2.80%, 95%CI -5.05% to - 0.55% and B -3.67%, 95%CI -6.93% to - 0.42% respectively). Higher exposure to NO_X (per interquartile range of 7.43 μg/m³) was also associated with lower percent forced vital capacity (FVC) and percent predicted forced expiration volume in 1 s (FEV1) (B -2.30, 95% CI -4.55 to - 0.05 and B -2.73, 95%CI -5.21 to - 0.25 respectively). No significant associations were found between the additional exposure to PM_2.5 or NO_X and respiratory symptoms except for PM_2.5 and dry cough (OR 1.40, 95%CI 1.00 to 1.94).

CONCLUSION

Exposure to PM_2.5 and NO_X from industry was associated with decreased lung function. Exposure to PM_2.5 was also associated with parents' reports of dry cough among their children.

Sulfur dioxide exposure enhances Th2 inflammatory responses via activating STAT6 pathway in asthmatic mice

Sulfur dioxide (SO₂) is one of potential risk factors for induction and/or exacerbation of asthma, but the underlying mechanisms are not well understood. In this study, we investigate the role of SO₂ in asthma using a classical asthmatic model with allergic airway inflammation by treating C57BL/6 mice with ovalbumin (OVA) and/or 10 mg/m³ SO₂. Our results showed that SO₂ exposure alone induced slight pathological changes but did not significantly increase inflammatory cell counts, pro-inflammatory cytokine expression, and mucus production in the airway of mice, whereas SO₂ exposure in OVA-induced asthmatic mice caused marked pulmonary pathological changes and significantly increased the counts of eosinophil-rich leukocytes compared with OVA alone asthmatic mice. The expression of MUC5AC, TNF-α, Th2 cytokines (IL-4, IL-5, and IL-13) and STAT6 was further up-regulated in OVA plus SO₂ treated mice compared with OVA alone treated mice. In addition, exposure to SO₂ alone markedly elevated STAT6 mRNA levels and hydrogen peroxide (H₂O₂) content in the lung. These findings suggest that SO₂ amplifies Th2 inflammatory responses in OVA-induced asthmatic mice by activating STAT6, which can further induce Th2 cytokine expression. Induction of STAT6 expression might be an important mechanism underlying the increased risk for asthma after environmental exposure.

Assessment of indoor air quality exposures and impacts on respiratory outcomes in River Rouge and Dearborn, Michigan

Ambient air pollution is a public health issue which could potentially exacerbate pre-existing respiratory conditions and contribute to increases in asthma incidence. This study aims to address gaps in understanding how IAQ is impacted by outdoor air quality, which was done by sampling for indoor gaseous and particulate pollutants in residence and facilities near the sources of pollution. The study areas were selected due to non-attainment status with air quality standards, as well as demographic and socioeconomic status of those residing in these areas. Samples are obtained from five locations around the study areas. The sampling procedure involves active sampling methodologies for particulate matter (PM) and gases. Average volatile organic compounds (VOC) levels of 2.71 ppm were measured at a location, while the average particulate matter (PM) concentrations in three study locations were; 15,979 pt/cc, 9533 pt/cc, 5267 pt/cc respectively, which exceeded clean background environment level of 500-2000 pt/cc. All locations had average CO concentrations above 0.3 ppm, which is potentially associated with elevated asthma symptoms. Results demonstrated that facilities in the study area have increased levels of indoor air pollutants that potentially increase asthma and respiratory issues. The study concludes that particulate and gaseous pollutant levels in the study areas are a concerning human health issue. The study outcomes have significant implications for air quality exposure modeling and potential exposure mitigation strategies, which are expected to facilitate the implementation of public policies for improved human health conditions.

The influence of polycyclic aromatic hydrocarbons on lung function in a representative sample of the Canadian population

We investigated the associations between exposure to polycyclic aromatic hydrocarbons (PAHs) and selected respiratory physiologic measures in cycles 2 and 3 of the Canadian Health Measures Survey, a nationally representative population sample. Using generalized linear mixed models, we tested the association between selected PAH metabolites and 1-second forced expiratory volume (FEV₁), forced vital capacity (FVC), and the ratio between the two (FEV₁/FVC) in 3531 people from 6 to 79 years of age. An interquartile change in urinary PAH metabolite was associated with significant decrements in FEV₁ and FVC for eight PAHs, 2-hydroxynapthalene, 1-, and 2-hydroxyphenanthrene, 2-, 3-, and 9-hydroxyfluorene and 3- and 4-hydroxyphenanthrene. Exposure to PAH may negatively affect lung function in the Canadian population.

Transgenerational inheritance of neurobehavioral and physiological deficits from developmental exposure to benzo[a]pyrene in zebrafish

Benzo[a]pyrene (B[a]P) is a well-known genotoxic polycylic aromatic compound whose toxicity is dependent on signaling via the aryl hydrocarbon receptor (AHR). It is unclear to what extent detrimental effects of B[a]P exposures might impact future generations and whether transgenerational effects might be AHR-dependent. This study examined the effects of developmental B[a]P exposure on 3 generations of zebrafish. Zebrafish embryos were exposed from 6 to 120h post fertilization (hpf) to 5 and 10μM B[a]P and raised in chemical-free water until adulthood (F0). Two generations were raised from F0 fish to evaluate transgenerational inheritance. Morphological, physiological and neurobehavioral parameters were measured at two life stages. Juveniles of the F0 and F2 exhibited hyper locomotor activity, decreased heartbeat and mitochondrial function. B[a]P exposure during development resulted in decreased global DNA methylation levels and generally reduced expression of DNA methyltransferases in wild type zebrafish, with the latter effect largely reversed in an AHR2-null background. Adults from the F0 B[a]P exposed lineage displayed social anxiety-like behavior. Adults in the F2 transgeneration manifested gender-specific increased body mass index (BMI), increased oxygen consumption and hyper-avoidance behavior. Exposure to benzo[a]pyrene during development resulted in transgenerational inheritance of neurobehavioral and physiological deficiencies. Indirect evidence suggested the potential for an AHR2-dependent epigenetic route.

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

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