Acute effects on pulmonary function in young healthy adults exposed to traffic-related air pollution in semi-closed transport hub in Beijing

Traffic-related air pollution, chronic stress, and changes in exhaled nitric oxide and lung function among a panel of children with asthma living in an underresourced community

We examined associations between short-term exposure to traffic-related air pollutants (TRAP) and airway inflammation and lung function in children with asthma, and whether these associations are modified by chronic psychological stress. Residents of underresourced port-adjacent communities in New Jersey were concerned about the cumulative impacts of exposure to TRAP, particularly diesel-engine truck emissions, and stress on exacerbation of asthma among children. Children with asthma aged 9-14 (n = 35) were recruited from non-smoking households. We measured each participant's (1) continuous personal exposure to black carbon (BC, a surrogate of TRAP) at 1-min intervals, (2) 24-h integrated personal exposure to nitrogen dioxide (NO2), (3) daily fractional exhaled nitric oxide (FeNO), and (4) lung function for up to 30 consecutive days. Personal BC was recorded by micro-aethalometers. We measured daily FeNO using the NIOX MINO, forced expiratory volume in one second (FEV1), and forced vital capacity (FVC) using Easy One Frontline spirometers. Chronic stress was measured with the UCLA Life Stress Interview for Children. The association was examined using linear mixed-effect models. In the fully adjusted model, an interquartile range (IQR) increase in BC at lag 0-6 h before the FeNO measurement was associated with 8 % (95 % CI: 3 % - 12 %) increase in FeNO, whereas an IQR increase in BC at lag 7-12 h and lag 0-24 h were associated with 6 % (95 % CI: 2 % - 11 %) and 7 % (2 % - 12 %) FeNO increases, respectively. There were no significant lung function changes per IQR increase in BC. No interactions were observed between chronic stress and BC on FeNO. Chronic stress was negatively associated with individual average FeNO levels. Our findings suggest that higher levels of BC exposure within the prior 24 h increased airway inflammation levels in children with asthma, with the strongest effect observed within the first 6 h.

Personal PM2.5 Elemental Components, Decline of Lung Function, and the Role of DNA Methylation on Inflammation-Related Genes in Older Adults: Results and Implications of the BAPE Study

Epidemiological evidence of the effects of PM_2.5 elements on lung function and DNA methylation is limited. We conducted a longitudinal panel study of 76 healthy older adults aged 60-69 years in Jinan, China, from September 2018 to January 2019. We periodically measured individual 72 h PM_2.5 and element concentrations, lung function, and DNA methylation levels of eight inflammation-related genes. We used linear mixed-effect models to investigate the effects of exposure to personal PM_2.5 elements on the lung function and DNA methylation. Mediation analysis was used to investigate the underlying effect mechanism. Negative changes in the ratio of forced expiratory volume in 1 s to forced vital capacity, ranging from -1.23% [95% confidence interval (CI): -2.11%, -0.35%] to -0.77% (95% CI: -1.49%, -0.04%), were significantly associated with interquartile range (IQR) increases in personal PM_2.5 at different lag periods (7-12, 13-24, 25-48, 0-24, 0-48, and 0-72 h). Arsenic (As), nickel, rubidium (Rb), selenium, and vanadium were significantly associated with at least three lung function parameters, and IQR increases in these elements led to 0.12-5.66% reductions in these parameters. PM_2.5 elements were significantly associated with DNA methylation levels. DNA methylation mediated 7.28-13.02% of the As- and Rb-related reduced lung function. The findings indicate that exposure to elements in personal PM_2.5 contributes to reduced lung function through DNA methylation.

Short-term effects of the toxic component of traffic-related air pollution (TRAP) on lung function in healthy adults using a powered air purifying respirator (PAPR)

Short-term exposure to traffic-related air pollution (TRAP) are associated with reduced lung function. However, TRAP is a mixture of various gaseous pollutants and particulate matter (PM), and therefore it is unknown that which components of TRAP are responsible for the respiratory toxicity. Using a powered air-purifying respirator (PAPR), we conducted a randomized, double-blind, crossover trial in which 40 adults were exposed to TRAP for 2 h at the sidewalk of a busy road. During the exposure, the participants wore the PAPR fitted with a PM filter, a PM and volatile organic compounds (VOCs) filter, or a sham filter (no filtration, Sham mode). The participants were blinded to the type of filter in their PAPR, and experienced three exposures, once for each intervention mode in random order. We measured two lung function measures (forced expiratory volume in 1 s [FEV1] and forced vital capacity [FVC]) and an airway inflammation marker (fraction of exhaled nitric oxide [FE_NO]) before and immediately after each exposure, and further measured them at different time periods after exposure. We applied linear mixed effect models to estimate the effects of the interventions on the changes of lung function from baseline values after controlling for other covariates. Compared to baseline, exposing to TRAP decreased FEV1 and FVC, and increased FEV1/FVC and FE_NO in all three intervention modes. The mixed models showed that with the sham mode as reference, lung function and airway inflammation post exposure were significantly improved by filtering both PM and VOCs, but marginally affected by filtering only PM. In conclusion, the VOCs component of TRAP is responsible for the reduction in lung function caused by short-term exposure to TRAP. However, the result needs to be interpreted cautiously before further verified by laboratory experiment using purely isolated component(s) of TRAP.

Exposure to urban greenspace and pathways to respiratory health: An exploratory systematic review

BACKGROUND/OBJECTIVE

Urban greenspace may have a beneficial or adverse effect on respiratory health. Our objective was to perform an exploratory systematic review to synthesise the evidence and identify the potential causal pathways relating urban greenspace and respiratory health.

METHODS

We followed PRISMA guidelines on systematic reviews and searched five databases for eligible studies during 2000-2021. We incorporated a broad range of urban greenspace and respiratory health search terms, including both observational and experimental studies. Screening, data extraction, and risk of bias, assessed using the Navigation Guide criteria, were performed independently by two authors. We performed a narrative synthesis and discuss suggested pathways to respiratory health.

RESULTS

We identified 108 eligible papers (n = 104 observational, n = 4 experimental). The most common greenspace indicators were the overall greenery or vegetation (also known as greenness), green land use/land cover of physical area classes (e.g., parks, forests), and tree canopy cover. A wide range of respiratory health indicators were studied, with asthma prevalence being the most common. Two thirds (n = 195) of the associations in these studies were positive (i.e., beneficial) with health, with 31% (n = 91) statistically significant; only 9% (n = 25) of reported associations were negative (i.e., adverse) with health and statistically significant. The most consistent positive evidence was apparent for respiratory mortality. There were n = 35 (32%) 'probably low' and n = 73 (68%) 'probably high' overall ratings of bias. Hypothesised causal pathways for health benefits included lower air pollution, more physically active populations, and exposure to microbial diversity; suggested mechanisms with poorer health included exposure to pollen and other aeroallergens.

CONCLUSION

Many studies showed positive association between urban greenspace and respiratory health, especially lower respiratory mortality; this is suggestive, but not conclusive, of causal effects. Results underscore the importance of contextual factors, greenspace metric employed, and the potential bias of subtle selection factors, which should be explored further.

Fine Particulate Matter and Lung Function among Burning-Exposed Deepwater Horizon Oil Spill Workers

BACKGROUND

During the 2010 Deepwater Horizon (DWH) disaster, controlled burning was conducted to remove oil from the water. Workers near combustion sites were potentially exposed to increased fine particulate matter [with aerodynamic diameter ≤2.5μm (PM2.5)] levels. Exposure to PM2.5 has been linked to decreased lung function, but to our knowledge, no study has examined exposure encountered in an oil spill cleanup.

OBJECTIVE

We investigated the association between estimated PM2.5 only from burning/flaring of oil/gas and lung function measured 1-3 y after the DWH disaster.

METHODS

We included workers who participated in response and cleanup activities on the water during the DWH disaster and had lung function measured at a subsequent home visit (n=2,316). PM2.5 concentrations were estimated using a Gaussian plume dispersion model and linked to work histories via a job-exposure matrix. We evaluated forced expiratory volume in 1 s (FEV1; milliliters), forced vital capacity (FVC; milliliters), and their ratio (FEV1/FVC; %) in relation to average and cumulative daily maximum exposures using multivariable linear regressions.

RESULTS

We observed significant exposure-response trends associating higher cumulative daily maximum PM2.5 exposure with lower FEV1 (p-trend=0.04) and FEV1/FVC (p-trend=0.01). In comparison with the referent group (workers not involved in or near the burning), those with higher cumulative exposures had lower FEV1 [-166.8mL, 95% confidence interval (CI): -337.3, 3.7] and FEV1/FVC (-1.7, 95% CI: -3.6, 0.2). We also saw nonsignificant reductions in FVC (high vs. referent: -120.9, 95% CI: -319.4, 77.6; p-trend=0.36). Similar associations were seen for average daily maximum PM2.5 exposure. Inverse associations were also observed in analyses stratified by smoking and time from exposure to spirometry and when we restricted to workers without prespill lung disease.

CONCLUSIONS

Among oil spill workers, exposure to PM2.5 specifically from controlled burning of oil/gas was associated with significantly lower FEV1 and FEV1/FVC when compared with workers not involved in burning. https://doi.org/10.1289/EHP8930.

Studies of the effectiveness of transport sector interventions in low- and middle-income countries: An evidence and gap map

BACKGROUND

There are great disparities in the quantity and quality of infrastructure. European countries such as Denmark, Germany, Switzerland, and the UK have close to 200 km of road per 100 km², and the Netherlands over 300 km per 100 km². By contrast, Kenya and Indonesia have <30, Laos and Morocco <20, Tanzania and Bolivia <10, and Mauritania only 1 km per 100 km². As these figures show, there is a significant backlog of transport infrastructure investment in both rural and urban areas, especially in sub-Saharan Africa. This situation is often exacerbated by weak governance and an inadequate regulatory framework with poor enforcement which lead to high costs and defective construction.The wellbeing of many poor people is constrained by lack of transport, which is called "transport poverty". Lucas et al. suggest that up to 90% of the world's population are transport poor when defined as meeting at least one of the following criteria: (1) lack of available suitable transport, (2) lack of transport to necessary destinations, (3) cost of necessary transport puts household below the income poverty line, (4) excessive travel time, or (5) unsafe or unhealthy travel conditions.

OBJECTIVES

The aim of this evidence and gap map (EGM) is to identify, map, and describe existing evidence from studies reporting the quantitative effects of transport sector interventions related to all means of transport (roads, rail, trams and monorail, ports, shipping, and inland waterways, and air transport).

METHODS

The intervention framework of this EGM reframes Berg et al's three categories (infrastructure, prices, and regulations) broadly as infrastructure, incentives, and institutions as subcategories for each intervention category which are each mode of transport (road, rail trams and monorail, ports, shipping, and inlands waterways, and air transport). This EGM identifies the area where intervention studies have been conducted as well as the current gaps in the evidence base.This EGM includes ongoing and completed impact evaluations and systematic reviews (SRs) of the effectiveness of transport sector interventions. This is a map of effectiveness studies (impact evaluations). The impact evaluations include experimental designs, nonexperimental designs, and regression designs. We have not included the before versus after studies and qualitative studies in this map. The search strategies included both academic and grey literature search on organisational websites, bibliographic searches and hand search of journals.An EGM is a table or matrix which provides a visual presentation of the evidence in a particular sector or a subsector. The map is presented as a matrix in which rows are intervention categories (e.g., roads) and subcategories (e.g., infrastructure) and the column outcome domains (e.g., environment) and subcategories as (e.g., air quality). Each cell contains studies of the corresponding intervention for the relevant outcome, with links to the available studies. Included studies were coded according to the intervention and outcomes assessed and additional filters as region, population, and study design. Critical appraisal of included SR was done using A Measurement Tool to Assess Systematic Reviews (AMSTAR -2) rating scale.

SELECTION CRITERIA

The search included both academic and grey literature available online. We included impact evaluations and SRs that assessed the effectiveness of transport sector interventions in low- and middle-income countries.

RESULTS

This EGM on the transport sector includes 466 studies from low- and middle-income countries, of which 34 are SRs and 432 impact evaluations. There are many studies of the effects of roads intervention in all three subcategories-infrastructure, incentives, and institutions, with the most studies in the infrastructure subcategories. There are no or fewer studies on the interventions category ports, shipping, and waterways and for civil aviation (Air Transport).In the outcomes, the evidence is most concentrated on transport infrastructure, services, and use, with the greatest concentration of evidence on transport time and cost (193 studies) and transport modality (160 studies). There is also a concentration of evidence on economic development and health and education outcomes. There are 139 studies on economic development, 90 studies on household income and poverty, and 101 studies on health outcomes.The major gaps in evidence are from all sectors except roads in the intervention. And there is a lack of evidence on outcome categories such as cultural heritage and cultural diversity and very little evidence on displacement (three studies), noise pollution (four studies), and transport equity (2). There is a moderate amount of evidence on infrastructure quantity (32 studies), location, land use and prices (49 studies), market access (29 studies), access to education facilities (23 studies), air quality (50 studies), and cost analysis including ex post CBA (21 studies).The evidence is mostly from East Asia and the Pacific Region (223 studies (40%), then the evidence is from the sub-Saharan Africa (108 studies), South Asia (96 studies), Latin America & Caribbean (79 studies). The least evidence is from Middle East & North Africa (30 studies) and Europe & Central Asia (20 studies). The most used study design is other regression design in all regions, with largest number from East Asia and Pacific (274). There is total 33 completed SRs identified and one ongoing, around 85% of the SR are rated low confidence, and 12% rated as medium confidence. Only one review was rated as high confidence. This EGM contains the available evidence in English.

CONCLUSION

This map shows the available evidence and gaps on the effectiveness of transport sector intervention in low- and middle-income countries. The evidence is highly concentrated on the outcome of transport infrastructure (especially roads), service, and use (351 studies). It is also concentrated in a specific region-East Asia and Pacific (223 studies)-and more urban populations (261 studies). Sectors with great development potential, such as waterways, are under-examined reflecting also under-investment.The available evidence can guide the policymakers, and government-related to transport sector intervention and its effects on many outcomes across sectors. There is a need to conduct experimental studies and quality SRs in this area. Environment, gender equity, culture, and education in low- and middle-income countries are under-researched areas in the transport sector.

Environmental and Occupational Short-Term Exposure to Airborne Particles and FEV1 and FVC in Healthy Adults: A Systematic Review and Meta-Analysis

Background: No study has compared the respiratory effects of environmental and occupational particulate exposure in healthy adults. Methods: We estimated, by a systematic review and meta-analysis, the associations between short term exposures to fine particles (PM_2.5 and PM₄) and certain parameters of lung function (FEV₁ and FVC) in healthy adults. Results: In total, 33 and 14 studies were included in the qualitative synthesis and meta-analyses, respectively. In environmental studies, a 10 µg/m³ increase in PM_2.5 was associated with an FEV₁ reduction of 7.63 mL (95% CI: −10.62 to −4.63 mL). In occupational studies, an increase of 10 µg/m³ in PM₄ was associated with an FEV₁ reduction of 0.87 mL (95% CI: −1.36 to −0.37 mL). Similar results were observed with FVC. Conclusions: Both occupational and environmental short-term exposures to fine particles are associated with reductions in FEV₁ and FVC in healthy adults.

Effects of air purification of indoor PM2.5 on the cardiorespiratory biomarkers in young healthy adults

Ambient fine particulate matter (PM_2.5 ), as one of the predominant air pollutants, has achieved effective control in recent years in China. Whether the use of indoor air purifiers is still necessary needs further exploration. A randomized crossover trial was conducted in 54 healthy students in Beijing, China. Participants were randomized assigned to the use of real or sham high-efficiency particulate air filter (HEPA) for a week and changed the status after a washout period. Health measurements of cardiorespiratory biomarkers were performed at the end of each period. Linear mixed-effects models were used to evaluate the association between PM_2.5 exposure and cardiorespiratory biomarkers. Compared with sham air purification, average diastolic blood pressure (DBP), fractional exhaled nitric oxide (FeNO), and 8-isoprostane (8-isoPGF2α) levels decreased significantly in the real purification. The effects of indoor air purification on lung function indicators including forced expiratory volume in one second (FEV₁ ), peak expiratory flow (PEF), and forced expiratory flow between the 25th and 75th percentile of forced vital capacity (FEF_25%-75% ) were also significant. Our findings showed a protective effect of indoor HEPA air purifiers on cardiorespiratory health of young healthy adults reflected by the decreased blood pressure, respiratory inflammation, and systematic oxidative stress and improved lung function.

Extremely high concentrations of zinc in birch tree leaves collected in Chelyabinsk, Russia

Zinc is an essential trace element and a vital microelement for human health. Zinc can be toxic when exposures exceed physiological needs. Toxic effects in humans are most evident from inhalation exposure to high concentrations of Zn compounds. Urban air pollution can be especially dangerous due to the Zn content in airborne dust. Tree leaves can absorb significant levels of zinc. In this study, leaf deposition of Zn was investigated in Chelyabinsk, Russia. Russian zinc production plant and metallurgical plant are located in Chelyabinsk. Extremely high concentrations of Zn (316-4000 mg kg^-1) were found in the leaves of birch trees. It is well known that traffic also is Zn source in an urban environment. Trees, growing at the different distances from zinc production and metallurgical plants and road to identify the contribution of each source (road or industry), were studied. Through SEM analysis, the prevalence of small particulates (PM10 and less), containing Zn, illustrated leaf Zn deposition from the air by passing root accumulation. It was shown that emission of zinc production plant and the metallurgical plant is the main source of leaf Zn deposition in Chelyabinsk.

Source specific PM2.5 associated with heart rate variability in the elderly with coronary heart disease: A community-based panel study

There is increasingly concern that PM_2.5 constituents play a significant role in PM_2.5-related cardiovascular outcomes. However, little is known about the associations between specific constituents of PM_2.5 and risk for cardiovascular health. To evaluate the exposure to specific chemicals of PM_2.5 from various sources and their cardiac effects, a longitudinal investigation was conducted with four repeated measurements of elderly participants' HRV and PM_2.5 species in urban Beijing. Multiple chemicals in PM_2.5 (metals, ions and PAHs) were characterized for PM_2.5 source apportionment and personalized exposure assessment. Five sources were finally identified with specific chemicals as the indicators: oil combustion (1.1%, V & PAHs), secondary particle (11.3%, SO₄^2- & NO₃^-), vehicle emission (1.2%, Pd), construction dust (28.7%, Mg & Ca), and coal combustion (57.7%, Se & As). As observed, each IQR increase in exposure to oil combustion (V), vehicle emission (Pd), and coal combustion (Se) significantly decreased rMSSD by 13.1% (95% CI: -25.3%, -1.0%), 27.4% (95% CI: -42.9%, -7.6%) and 24.7% (95% CI: -39.2%, -6.9%), respectively, while those of PM_2.5 mass with decreases of rMSSD by 11.1% (95% CI: -19.6%, -1.9%) at lag 0. Elevated exposures to specific sources/constituents of PM_2.5 disrupt cardiac autonomic function in elderly and have more adverse effects than PM_2.5 mass. In the stratified analysis, medication and gender modify the associations of specific chemicals from variable sources with HRV. The findings of this study provide evidence on the roles of influential constituents of ambient air PM_2.5 and their sources in terms of their adverse cardiovascular health effects.

Road dust trace elements contamination, sources, dispersed composition, and human health risk in Chelyabinsk, Russia

There are many sources of urban road dust, such as soil dispersal, emissions of industrial enterprises and thermal power plants, road traffic-related processes. Chelyabinsk was selected as a typical Russian industrial city. This work was the first pollution study of road dust in Chelyabinsk. We examined 125 road dust samples were on the content toxic trace elements (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Sr, and Zn). The concentrations of trace elements in road dust were determined using ICP-MS. Results showed that the metal concentrations in dust were higher than the background value of local soil. The distribution curves of dust were asymmetric, had have two peaks, and showed significant unimodal distribution. The higher share of particles was in the range from 30 … 40 to 250 … 300 μm. The thoracic fraction volume (%) and concentrations of trace elements were higher near metallurgical plants. Cadmium, Сu, Mn, Ni, Sr, Pb and Zn were originated from industry and transport; electrometallurgical plant was source of Cr; Al, Co, and Fe derived from local soils and pavement erosion; As, Hg and Sb were the tracers of coal-fired power stations emission. Ingestion was a major exposure way of toxic elements in the dust. The results suggested that there was no significant potential health risk to both children and adults from exposure to any elements in road dust. The cancer risk for adults and children from exposure to As, Cd, Cr, and Pb was found to be at the acceptable or tolerable level. The study deals with the contamination of potentially toxic trace elements (As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sb, Sr and Zn) in road dust collected from Chelyabinsk urban area.

Long-term effect of personal PM2.5 exposure on lung function: A panel study in China

Exposure to fine particulate matter (PM_2.5) have been associated with adverse respiratory outcomes, but long-term effect of personal exposure on lung function remains largely unknown. We conducted a panel study of 158 adult residents with 394 measurements of personal PM_2.5 concentration and lung function within six years to investigate the long-term association. Linear mixed models were used to identify the associations between lung function changes in relation to different levels of persistent personal PM_2.5 exposure in three or six years. We further attempted to validate resident areas (city) and smoking status as potential predictors of the long-term PM_2.5 exposure levels (persistently high/ persistently low) by generating ROC curves. Compared with subjects who had persistently low exposure level, those with persistently high levels of personal PM_2.5 exposure had an additional 3.63 % decline in FEV₁/FVC in three years (-3.63 [-7.25, -0.02]), while 7.15 % decline in six years (-7.15 [-14.27, -0.03]). BMI can modify the association. The AUCs were 0.68 (95 %CI: 0.54, 0.82), 0.75 (0.64, 0.86), and 0.82 (0.71, 0.93) for models including smoking status, resident areas, and smoking status combining resident areas respectively. These findings provide new evidence for the long-term effect of personal PM_2.5 exposure on lung function decline.

Effect of outdoor particulate air pollution on FEV1 in healthy adults: a systematic review and meta-analysis

The effect of acute and long-term exposures to outdoor particulate air pollution on lung function in healthy adults is not well established. The objective of this study was to conduct a systematic literature review and meta-analysis of studies that assessed the relationship of outdoor particulate air pollution and lung function in healthy adults. Studies that contained data on outdoor air particulate matter levels (PM₁₀ or PM_2.5) and forced expiratory volume in 1 s (FEV₁) in healthy adults were eligible for inclusion. Effect estimates, in relation to long-term and acute exposures, were quantified separately using random effects models. A total of 27 effect estimates from 23 studies were included in this review. Acute exposures were typically assessed with PM_2.5, while long-term exposures were predominantly represented by PM₁₀ A 10 µg/m3 increase in short-term PM_2.5 exposure (days) was associated with a -7.02 mL (95% CI -11.75 to -2.29) change in FEV₁ A 10 µg/m³ difference in long-term PM₁₀ exposure was associated with a -8.72 mL (95% CI -15.39 to -2.07) annual change in FEV₁ and an absolute difference in FEV₁ of -71.36 mL (95% CI -134.47 to -8.24). This study provides evidence that acute and long-term exposure to outdoor particulate air pollution are associated with decreased FEV₁ in healthy adults. Residual confounding from other risk factors, such as smoking, may explain some of the effect for long-term exposures. More studies are required to determine the relationship of long-term exposure to PM_2.5 and short-term exposure to PM₁₀, which may have different biologic mechanisms.

Effects of Indoor and Ambient Black Carbon and [Formula: see text] on Pulmonary Function among Individuals with COPD

BACKGROUND

Particulate matter (PM) air pollution has been associated with decreased pulmonary function, but the exposure–response relationship in chronic obstructive pulmonary disease (COPD) patients is uncertain, and most studies have only focused on exposures to ambient pollution.

OBJECTIVES

We aimed to assess associations between pulmonary function and indoor and ambient PM [Formula: see text] ([Formula: see text]) and black carbon (BC).

METHODS

Between November 2012 and December 2014, 125 patients with COPD (mean age, 73.4 y) who were not currently smoking and without known indoor BC sources were recruited. Indoor BC and [Formula: see text] were measured in each home for a week in each season, up to four times a year, followed by in-person spirometry pre- and post-bronchodilator. Ambient exposures were available from a central site monitor. Multivariable adjusted mixed effects regression models were used to assess associations scaled per interquartile range (IQR) of exposure.

RESULTS

There were 367 study visits; the median (IQR) indoor BC and [Formula: see text] were 0.19 (0.22) [Formula: see text] and 6.67 (5.80) [Formula: see text], respectively. Increasing indoor exposures to BC were associated with decreases in pre-bronchodilator forced expiratory volume in 1 s [Formula: see text] and forced vital capacity (FVC), and [Formula: see text]. For example, in multivariable adjusted models, each IQR increase in indoor BC from the weekly integrated filter was associated with a [Formula: see text] [95% confidence interval (CI): [Formula: see text], [Formula: see text]] decrease in pre-bronchodilator [Formula: see text]. Increases in indoor [Formula: see text] were associated with decreases in [Formula: see text] and FVC of smaller magnitude than those for indoor BC; however, the results were less precise. Ambient BC was not associated with pre-bronchodilator pulmonary function, ambient [Formula: see text] was only associated with decreases in FVC and increases in [Formula: see text], and neither indoor nor ambient BC or [Formula: see text] were associated with post-bronchodilator pulmonary function.

CONCLUSIONS

Low-level exposures to indoor BC and [Formula: see text], but not ambient exposures, were consistently associated with decreases in pre-bronchodilator pulmonary function. There was no association between exposures and post-bronchodilator pulmonary function. https://doi.org/10.1289/EHP3668.

Cardiovascular benefits of reducing personal exposure to traffic-related noise and particulate air pollution: A randomized crossover study in the Beijing subway system

To assess the cardiovascular benefits of protecting against particulate air pollution and noise, we conducted a randomized crossover study with 40 young healthy college students from March to May 2017 in the underground subway, Beijing. Participants each received 4 treatments (no intervention phase [NIP], respirator intervention phase [RIP], headphone intervention phase [HIP], respirator plus headphone intervention phase [RHIP]) in a randomized order during 4 different study periods with 2-week washout intervals. We measured personal exposure to particulate matter (PM), noise and electrocardiogram (ECG) parameters (heart rate variability (HRV), heart rate (HR) and ST segment changes), ambulatory blood pressure (BP) continuously for 4 hours to investigate the cardiovascular effects. Compared with NIP, most of the HRV parameters increased, especially high frequency (HF) [21.1% (95% CI: 15.7%, 26.9%), 18.2% (95% CI: 12.8%, 23.9%), and 35.5% (95% CI: 29.3%, 42.0%) in RIP, HIP, and RHIP, respectively], whereas ST segment elevation and HR decreased for all 3 modes of interventions. However, no significant differences were observed in BP among the 4 treatments. In summary, short-term wearing of a respirator and/or headphone may be an effective way to minimize cardiovascular risk induced by air pollution in the subway by improving autonomic nervous function.

Characterization of PM2.5 exposure concentration in transport microenvironments using portable monitors

Recently, portable monitors have been increasingly used to quantify air pollutant concentrations at high spatiotemporal resolution. A sampling campaign was conducted to measure the fine particulate matter (PM_2.5) and carbon monoxide (CO) exposure concentrations in transport microenvironments (TMEs) in Hong Kong in January and June 2015 using TSI DustTrak and Q-Trak portable monitors. The objectives were to: (1) calibrate DustTrak and Q-Trak; (2) evaluate variability between seasons and microenvironments; (3) estimate indoor/outdoor relationships; and (4) determine minimum sample size. Calibration equations, obtained through side-by-side measurement against stationary reference methods in winter and summer, were applied to correct the measured PM_2.5 data set. In general, PM_2.5 concentrations in all TMEs were significantly higher in winter than in summer. The mean PM_2.5 concentration in winter was lower for underground sections of the Mass Transit Railway (MTR) metro system (31 μg/m³) than for other TMEs, whereas in summer TMEs had mean PM_2.5 concentrations in the range of 10-15 μg/m³, with above-ground MTR train as an exception, at 23 μg/m³. PM_2.5 concentrations measured in TMEs were strongly correlated with nearby air quality monitoring stations (AQMSs) measurements in winter, but in summer there was little correlation. The minimum sample size estimates varied more among TMEs in summer versus winter because of the differences in PM_2.5 concentration distributions related to changes in ambient PM_2.5 concentrations and ventilation practices. This study provides a feasible protocol on the calibration and application of portable monitors in TME air quality measurement and develops a method for estimating minimum sample size.

Decreased blood pressure associated with in-vehicle exposure to carbon monoxide in Korean volunteers

Background

Carbon monoxide (CO) is one of the primary components of emissions from light-duty vehicles, and reportedly comprises 77% of all pollutants emitted in terms of concentration. Exposure to CO aggravates cardiovascular disease and causes other health disorders. The study was aimed to assess the negative effects by injecting different amounts of CO concentration directly to human volunteers boarding in the car.

Methods

Human volunteers were exposed to CO concentrations of 0, 33.2, and 72.4 ppm, respectively during the first test and 0, 30.3, and 48.8 ppm respectively during the second test while seated in the car. The volunteers were exposed to each concentration for approximately 45 min. After exposure, blood pressure measurement, blood collection (carboxyhemoglobin [COHb] analysis), medical interview, echocardiography test, and cognitive reaction test were performed.

Result

In patients who were exposed to a mean concentration of CO for 72.4 ± 1.4 ppm during the first exposure test and 48.8 ± 3.7 ppm during the second exposure test, the COHb level exceeded 2%. Moreover, the diastolic blood pressure was decreased while increasing in CO concentration after exposure. The medical interview findings showed that the degree of fatigue was increased and the degree of concentration was reduced when the exposed concentration of CO was increased.

Conclusion

Although the study had a limited sample size, we found that even a low concentration of CO flowing into a car could have a negative influence on human health, such as change of blood pressure and degree of fatigue.

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.

Ambient Air Pollution and Morbidity in Chinese

The rapid economic growth in China is coupled with a severe ambient air pollution, which poses a huge threat to human health and the sustainable development of social economy. The rapid urbanization and industrialization over the last three decades have placed China as one of countries with the greatest disease burden in world. Notably, the prevalence rate of chronic noncommunicable diseases (CND), including respiratory diseases, CVD, and stroke, in 2010 reaches 16.9%. The continuous growth of the incidence of CND urgent needs for effective regulatory action for health protection. This study aims to evaluate the impact of rapid urbanization on status of ambient air pollution and associated adverse health effects on the incidence and the burden of CND and risk assessment. Our findings would be greatly significant in the prediction of the risk of ambient air pollution on CND and for evidence-based policy making and risk management in China.