Subclinical responses in healthy cyclists briefly exposed to traffic-related air pollution: an intervention study

The Association Between Air Pollution Exposure and White Blood Cell Counts: A Nationwide Cross-Sectional Survey in South Korea

Background: The effect of air pollution, a major global health issue, on the immune system, particularly on white blood cell (WBC) counts, remains underexplored. Methods: This study utilized data from 54,756 participants in the Korean National Health and Nutrition Examination Survey to investigate the effects of short- (day of examination and 7-day averages), mid- (30- and 90-day averages), and long-term (one-, three-, and five-year averages) air pollutant exposure on WBC counts. We assessed exposure to particulate matter (PM10, PM2.5), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), and carbon monoxide (CO). Results: Linear regression with log-transformed WBC counts, adjusted for confounders, showed that PM10 was positively associated with long-term exposure, PM2.5 was negatively associated with short- and mid-term exposures, SO2 was consistently negatively associated with short- and mid-term exposures, NO2 and CO were positive across most periods, and O3 was negatively associated with short- and mid-term exposures. Logistic regression analysis confirmed these findings, showing that short- and mid-term exposure to PM10, PM2.5, and SO2 was negatively associated with the risk of belonging to the high-WBC group, while long-term exposure to PM10, PM2.5, NO2, and CO showed positive associations with risk. Conclusions: Our findings highlight the time- and pollutant-specific associations between air pollution exposure and WBC counts, underscoring air pollution's potential impact on systemic inflammation.

Emerging concern on air pollution and health: Trade-off between air pollution exposure and physical activity

Air pollution is a major contributor to the global disease burden, especially affecting respiratory and cardiovascular health. However, physical activity is associated with improved lung function, a slower decline in lung function, and lower mortality. The public is more likely to be exposed to air pollution during outdoor physical activity. However, studies on how long-term and short-term exposure to air pollution interacts with physical activity yield inconsistent results, and the thresholds for air pollution and physical activity remain unclear. Thus, more studies are needed to provide sufficient evidence to guide the public to safely engage in outdoor physical activity when exposed to air pollution.

Multi-season mobile monitoring campaign of on-road air pollution in Bengaluru, India: High-resolution mapping and estimation of quasi-emission factors

Mobile monitoring can supplement regulatory measurements, particularly in low-income countries where stationary monitoring is sparse. Here, we report results from a ~ year-long mobile monitoring campaign of on-road concentrations of black carbon (BC), ultrafine particles (UFP), and carbon dioxide (CO2) in Bengaluru, India. The study route included 150 unique kms (average: ~22 repeat measurements per monitored road segment). After cleaning the data for known instrument artifacts and sensitivities, we generated 30 m high-resolution stable 'data only' spatial maps of BC, UFP, and CO2 for the study route. For the urban residential areas, the mean BC levels for residential roads, arterials, and highways were ~ 10, 22, and 56 μg m-3, respectively. A similar pattern (highways being characterized by highest pollution levels) was also observed for UFP and CO2. Using the data from repeat measurements, we carried out a Monte Carlo subsampling analysis to understand the minimum number of repeat measures to generate stable maps of pollution in the city. Leveraging the simultaneous nature of the measurements, we also mapped the quasi-emission factors (QEF) of the pollutants under investigation. The current study is the first multi-season mobile monitoring exercise conducted in a low or middle -income country (LMIC) urban setting that oversampled the study route and investigated the optimum number of repeat rides required to achieve representative pollution spatial patterns characterized with high precision and low bias. Finally, the results are discussed in the context of technical aspects of the campaign, limitations, and their policy relevance for our study location and for other locations. Given the day-to-day variability in the pollution levels, the presence of dynamic and unorganized sources, and active government pollution mitigation policies, multi-year mobile measurement campaigns would help test the long-term representativeness of the current results.

The acute effects of endurance exercise on epithelial integrity of the airways in athletes and non-athletes: A systematic review and meta-analysis

INTRODUCTION

Acute endurance exercise may induce airway epithelium injury. However, the response of epithelial integrity markers of the airways including club cell secretory protein (CC16) and surfactant protein D (SP-D) to endurance exercise have not been systematically reviewed. Therefore, the aim of this systematic review and meta-analysis was to assess the acute effects of endurance exercise on markers of epithelial integrity of the airways (CC16, SP-D and the CC16/SP-D ratio) in athletes and non-athletes.

METHODS

A systematic search was performed utilizing PubMed/Medline, EMBASE, Web of Science, and hand searching bibliographies of retrieved articles through to September 2022. Based on the inclusion criteria, articles with available data about the acute effects of endurance exercise on serum or plasma concentrations of CC16, SP-D and CC16/SP-D ratio in athletes and non-athletes were included. Quality assessment of studies and statistical analysis were conducted via Review Manager 5.4 software.

RESULTS

The search resulted in 908 publications. Finally, thirteen articles were included in the review. Acute endurance exercise resulted in an increase in CC16 (P = 0.0006, n = 13) and CC16/SP-D ratio (P = 0.005, n = 2) whereas SP-D (P = 0.47, n = 3) did not change significantly. Subgroup analysis revealed that the type (P = 0.003), but not the duration of exercise (P = 0.77) or the environmental temperature (P = 0.06) affected the CC16 response to endurance exercise.

CONCLUSIONS

Acute endurance exercise increases CC16 and the CC16/SP-D ratio, as markers of epithelial integrity, but not SP-D in athletes and non-athletes.

Using three statistical methods to analyze the association between aldehyde exposure and markers of inflammation and oxidative stress

BACKGROUND

Exposure to aldehydes has been linked to adverse health outcomes such as inflammation and oxidative stress, but research on the effects of these compounds is limited. This study is aimed at assessing the association between aldehyde exposure and markers of inflammation and oxidative stress.

METHODS

The study used data from the NHANES 2013-2014 survey (n = 766) and employed multivariate linear models to investigate the relationship between aldehyde compounds and various markers of inflammation (alkaline phosphatase (ALP) level, absolute neutrophil count (ANC), and lymphocyte count) and oxidative stress (bilirubin, albumin, and iron levels) while controlling for other relevant factors. In addition to generalized linear regression, weighted quantile sum (WQS) and Bayesian kernel machine regression (BKMR) analyses were applied to examine the single or overall effect of aldehyde compounds on the outcomes.

RESULTS

In the multivariate linear regression model, each 1 standard deviation (SD) change in propanaldehyde and butyraldehyde was significantly associated with increases in serum iron levels (beta and 95% confidence interval, 3.25 (0.24, 6.27) and 8.40 (0.97, 15.83), respectively) and the lymphocyte count (0.10 (0.04, 0.16) and 0.18 (0.03, 0.34), respectively). In the WQS regression model, a significant association was discovered between the WQS index and both the albumin and iron levels. Furthermore, the results of the BKMR analysis showed that the overall impact of aldehyde compounds was significantly and positively correlated with the lymphocyte count, as well as the levels of albumin and iron, suggesting that these compounds may contribute to increased oxidative stress.

CONCLUSIONS

This study reveals the close association between single or overall aldehyde compounds and markers of chronic inflammation and oxidative stress, which has essential guiding value for exploring the impact of environmental pollutants on population health.

Personal strategies to mitigate the effects of air pollution exposure during sport and exercise: a narrative review and position statement by the Canadian Academy of Sport and Exercise Medicine and the Canadian Society for Exercise Physiology

Air pollution is among the leading environmental threats to health around the world today, particularly in the context of sports and exercise. With the effects of air pollution, pollution episodes (eg, wildfire conflagrations) and climate change becoming increasingly apparent to the general population, so have their impacts on sport and exercise. As such, there has been growing interest in the sporting community (ie, athletes, coaches, and sports science and medicine team members) in practical personal-level actions to reduce the exposure to and risk of air pollution. Limited evidence suggests the following strategies may be employed: minimising all exposures by time and distance, monitoring air pollution conditions for locations of interest, limiting outdoor exercise, using acclimation protocols, wearing N95 face masks and using antioxidant supplementation. The overarching purpose of this position statement by the Canadian Academy of Sport and Exercise Medicine and the Canadian Society for Exercise Physiology is to detail the current state of evidence and provide recommendations on implementing these personal strategies in preventing and mitigating the adverse health and performance effects of air pollution exposure during exercise while recognising the limited evidence base.

Moderate aerobic training is safe and improves glucose intolerance induced by the association of high fat diet and air pollution

Obesity and exposure to fine particulate matter (PM_2.5) are risk factors for insulin resistance, to which physical exercise is the most powerful non-pharmacological strategy. However, public concern over whether exercise could be protective in a polluted environment exists. Therefore, evaluating the possible benefits of exercise in polluted conditions in different contexts (age, gender, and cardiometabolic health) is imperative. In this sense, muscle plays a major role in maintaining glucose homeostasis, and its oxidative status is closely affected during exercise. This study tested whether moderate aerobic training could alleviate the metabolic and oxidative impairment in the gastrocnemius induced by the combination of a high-fat diet (HFD) and PM_2.5 exposure. Female mice (B6129SF2/J) received HFD (58.3% of fat) or standard diet, intranasal instillation of 20 μg residual oil fly ash (ROFA: inorganic portion of PM_2.5), or saline seven times per week for 19 weeks. In the 13th week, animals were submitted to moderate training or remained sedentary. Trained animals followed a progressive protocol for 6 weeks, ending at swimming with 5% body weight of workload for 60 min, while sedentary animals remained in shallow water. Aerobic moderate training attenuated weight gain and glucose intolerance and prevented muscle and pancreatic mass loss induced by a HFD plus ROFA exposure. Interestingly, a HFD combined with ROFA enhanced the catalase antioxidant activity, regardless of physical exercise. Therefore, our study highlights that, even in polluted conditions, moderate training is the most powerful non-pharmacological treatment for obesity and insulin resistance.

The influence of air pollution exposure on the short- and long-term health benefits associated with active mobility: A systematic review

Active mobility (AM), defined as walking and cycling for transportation, can improve health through increasing regular physical activity. However, these health improvements could be outweighed by harm from inhaling traffic-related air pollutants during AM participation. The interaction of AM and air pollutants on health is complex physiologically, manifesting as acute changes in health indicators that may lead to poor long-term health consequences. The aim of this study was to systematically review the current evidence of effect modification by air pollution (AP) on associations between AM and health indicators. Studies were included if they examined associations between AM and health indicators being modified by AP or, conversely, associations between AP and health indicators being modified by AM. Thirty-three studies met eligibility criteria. The main AP indicators studied were particulate matter, ultrafine particles, and nitrogen oxides. Most health indicators studied were grouped into cardiovascular and respiratory indicators. There is evidence of a reduction by AP, mainly ultrafine particles and PM_2.5, in the short-term health benefits of AM. Multiple studies suggest that long-term health benefits of AM are not negatively associated with levels of the single traffic-related pollutant NO₂. However, other studies reveal reduced long-term health benefits of AM in areas affected by high levels of pollutant mixtures. We recommend that future studies adopt consistent and rigorous study designs and include reporting of interaction testing, to advance understanding of the complex relationships between AM, AP, and health indicators.

Habitual exercise, chronic exposure to fine particulate matter and high-sensitivity C reactive protein in Asian adults

OBJECTIVES

Exercise may increase the inhaled amount of air pollutants and exacerbate the adverse health effects. We investigated the combined effects of chronic exposure to fine particulate matter with an aerodynamic diameter less than 2.5 µm (PM_2.5) and habitual exercise on C reactive protein (CRP), a sensitive marker of inflammation.

METHODS

We selected 40 209 Taiwanese adults who joined a standard medical screening programme between 2001 and 2016. The PM_2.5 exposure was estimated at each participant's address using a satellite-based spatiotemporal model. Information on habitual exercise was collected using a standard self-administered questionnaire. Mixed-effects linear regression models were used to investigate the associations of CRP with PM_2.5 and exercise. An interaction term of PM_2.5 and exercise was introduced in the models to test the modifying effects.

RESULTS

A greater amount of habitual exercise was associated with a decreased level of CRP, while a higher concentration of PM_2.5 exposure was associated with an increased level of CRP. The inverse associations of habitual exercise with CRP were not modified by chronic exposure to PM_2.5. The participants in the group with a low level of exercise and a high level of PM_2.5 exposure exhibited a 19.1% higher level of CRP than those in the group with a high level of exercise and a low level of PM_2.5 exposure (95% CI: 13.7% to 24.8%; p<0.001). The longitudinal and sensitivity analyses yielded similar results.

CONCLUSIONS

Increased levels of exercise and reduced exposure levels of PM_2.5 are associated with a lower CRP level. Habitual exercise reduces CRP level regardless of the levels of chronic PM_2.5 exposure. Our results support that habitual exercise is a safe approach for reducing systemic inflammation to improve cardiovascular health even for people residing in relatively polluted areas.

Respiratory Deposition Dose of PM2.5 and PM10 Before, During and After COVID-19 Lockdown Phases in Megacity-Delhi, India

Considerable changes in particulate matter (PM) during COVID-19 lockdown in major cities around the World demand changes in exposure assessment studies of PM. The present study shows variations in respiratory deposition dose (RDD) of both fine (PM_2.5) and coarse (PM₁₀) particles before, during and after Covid-19 lockdown phases at three sites (with different pollution signatures) in Delhi—Alipur, Okhla and Pusa Road. Exposure assessment study showed mean PM_2.5 RDD (± S.D.) (µg/min) for walk and sit mode during before lockdown (BL) as 2.41(± 1.20) and 0.84(± 0.42) for Alipur, 2.71(± 1.60) and 0.94(± 0.56) for Okhla, and 2.54(± 1.28) and 0.88(± 0.44) for Pusa road, which decreased drastically during Lockdown 1(L1) as 0.85(± 0.35) and 0.30(± 0.12) for Alipur, 0.83(± 0.33) and 0.29(± 0.11) for Okhla, and 0.68(± 0.28) and 0.23(± 0.10) for Pusa road, respectively. Mean PM₁₀ RDD (± S.D.) (µg/min) for walk and sit mode during before lockdown (BL) as 3.90 (± 1.73) and 1.36 (± 0.60) for Alipur, 4.74 (± 2.04) and 1.65 (± 0.71) for Okhla, and 4.25 (± 1.69) and 1.48 (± 0.59) for Pusa Road, respectively which decreased drastically during Lockdown 1(L1) as 2.19 (± 0.95) and 0.76 (± 0.33) for Alipur, 1.73 (± 0.67) and 0.60 (± 0.23) for Okhla and, 1.45 (± 0.50) and 0.50 (± 0.17) for Pusa Road, respectively. Significant decrease in RDD concentrations (Both PM_2.5 and PM₁₀) than that of BL phase have been found during Lockdown 1(L1) phase and other successive lockdown and unlock phases—Lockdown 2(L2), Lockdown 3(L3), Lockdown 4(L4) and Unlock1 (UL1) phases. Changes in RDD values during lockdown phases were affected by lesser traffic emission, minimized industrial activities, biomass burning activities, precipitation activities, etc. Seasonal variations of RDD showed Delhites are found exposed to more fine and coarse particles’ RDD (walk and sit modes) before and after lockdown, i.e. during normal days than during lockdown phases showing potential health effects. People in sit condition found less exposed to fine and coarse RDD comparison to those in walk condition both during normal and lockdown days.

Estimation of Ground PM2.5 Concentrations in Pakistan Using Convolutional Neural Network and Multi-Pollutant Satellite Images

During the last few decades, worsening air quality has been diagnosed in many cities around the world. The accurately prediction of air pollutants, particularly, particulate matter 2.5 (PM2.5) is extremely important for environmental management. A Convolutional Neural Network (CNN) P-CNN model is presented in this paper, which uses seven different pollutant satellite images, such as Aerosol index (AER AI), Methane (CH4), Carbon monoxide (CO), Formaldehyde (HCHO), Nitrogen dioxide (NO2), Ozone (O3) and Sulfur dioxide (SO2), as auxiliary variables to estimate daily average PM2.5 concentrations. This study estimates daily average of PM2.5 concentrations in various cities of Pakistan (Islamabad, Lahore, Peshawar and Karachi) by using satellite images. The dataset contains a total of 2562 images from May-2019 to April-2020. We compare and analyze AlexNet, VGG16, ResNet50 and P-CNN model on every dataset. The accuracy of machine learning models was checked with Mean Absolute Error (MAE), Root Mean Square Error (RMSE) and Mean Absolute Percentage Error (MAPE). The results show that P-CNN is more accurate than other approaches in estimating PM2.5 concentrations from satellite images. This study presents robust model using satellite images, useful for estimating PM2.5 concentrations.

A Reusable Multiplayer Game for Promoting Active School Transport: Development Study

BACKGROUND

Most children and adolescents in Sweden do not meet the recommended daily physical activity levels of the World Health Organization. Active school transport (AST) and gamification are potential methods for increasing children's daily physical activity. We previously developed a game named Tic-Tac-Training for promoting active transport at workplaces; however, the game has not been applied to AST.

OBJECTIVE

The objectives of this study are to investigate how Tic-Tac-Training functions to promote AST among schoolchildren in northern Sweden, improve the game to be more suitable for schoolchildren, and construct a road map for future development based on children's ideas.

METHODS

First, we developed Tic-Tac-Training using the Scrum agile software development method. Second, we conducted a questionnaire-based formative evaluation of the game with schoolchildren (n=16; 9/16, 56% male; 6/16, 38% female; and 1/16, 6% other aged 11-12 years) in Luleå, Sweden. Third, we conducted focus group interviews with 33 children (13/33, 39% male and 20/33, 61% female aged 12-13 years) to gather ideas for gamifying AST. We mapped the interview results to the Octalysis gamification framework and established a road map for future development.

RESULTS

The formative evaluation revealed several issues, including a lack of interesting game features, lack of support for continuous engagement, disliked competitive features, and lack of incentives for discourse and participation. New features such as rewards, collectibles, and levels were implemented based on the results. The focus group interviews revealed additional ideas for gamifying AST, such as using avatars, in-game currency and trading, and context-sensitive tasks.

CONCLUSIONS

The results have several potential impacts on how reusable, gamified AST interventions can be developed and what kind of gamification elements schoolchildren in northern Sweden wish to see. These results can interest game researchers and teachers who wish to apply gamification in school contexts. Finally, we aim to continue developing the game based on the road map.

Childhood adversity, prenatal depression, and maternal inflammation across pregnancy

Background

To examine whether change in neutrophil-lymphocyte ratio, a marker of systemic inflammation, differs by childhood adversity and prenatal depression.

Methods

Prenatal complete blood count data were used to calculate neutrophil-lymphocyte ratio in first and third trimesters. The Adverse Childhood Experiences scale measured childhood adversity, and the Patient Health Questionnaire-9 measured depression. This is a secondary analysis of a study of predictors of risk for sleep-disordered breathing.

Results

Participants were 98 pregnant women, mean age 30 years (SD = 5), mean body mass index of 35 kg/m² (SD = 7), 61% identified as white, and 28% identified as Hispanic. Women who reported childhood sexual abuse history displayed greater increase in neutrophil-lymphocyte ratio over pregnancy relative to women without childhood sexual abuse. Change in neutrophil-lymphocyte ratio across pregnancy did not differ by prenatal depression.

Conclusion

Experiences of sexual abuse in childhood may impact markers of systemic inflammation in pregnancy.

Ultrafine particle exposure for bicycle commutes in rush and non-rush hour traffic: A repeated measures study in Copenhagen, Denmark

Ultrafine particles (UFP), harmful to human health, are emitted at high levels from motorized traffic. Bicycle commuting is increasingly encouraged to reduce traffic emissions and increase physical activity, but higher breathing rates increase inhaled UFP concentrations while in traffic. We assessed exposure to UFP while cycling along a fixed 8.5 km inner-city route in Copenhagen, on weekdays over six weeks (from September to October 2020), during morning and afternoon rush-hour, as well as morning non-rush-hour, traffic time periods starting from 07:45, 15:45, and 09:45 h, respectively. Continuous measurements were made (each second) of particle number concentration (PNC) and location. PNC levels were summarized and compared across time periods. We used generalized additive models to adjust for meteorological factors, weekdays and trends. A total of 61 laps were completed, during 28 days (∼20 per time period). Overall mean PNC was 18,149 pt/cm³ (range 256-999,560 pt/cm³) with no significant difference between morning rush-hour (18003 pt/cm³), afternoon rush-hour (17560 pt/cm³) and late morning commute (17560 pt/cm³) [p = 0.85]. There was substantial spatial variation of UFP exposure along the route with highest PNC levels measured at traffic intersections (∼38,000-42000 pt/cm³), multiple lane roads (∼38,000-40000 pt/cm³) and construction sites (∼44,000-51000 pt/cm³), while lowest levels were measured at smaller streets, areas with open built environment (∼12,000 pt/cm³), as well as at a bus-only zone (∼15,000 pt/cm³). UFP exposure in inner-city Copenhagen did not differ substantially when bicycling in either rush-hour or non-rush-hour, or morning or afternoon, traffic time periods. UFP exposure varied substantially spatially, with highest concentrations around intersections, multiple lane roads, and construction sites. This suggests that exposure to UFP is not necessarily reduced by avoiding rush-hours, but by avoiding sources of pollution along the bicycling route.

Effects of lubricant-fuel mixing on particle emissions in a single cylinder direct injection spark ignition engine

Gasoline direct injection (GDI) engines emit less carbon dioxide (CO₂) than port fuel injection (PFI) engines when fossil fuel conditions are the same. However, GDI engines emit more ultrafine particulate matter, which can have negative health effects, leading to particulate emission regulations. To satisfy these regulations, various studies have been done to reduce particulate matter, and several studies focused on lubricants. This study focuses on the influence of lubricant on the formation of particulate matter and its effect on particulate emissions in GDI engines. An instrumented, combustion and optical singe-cylinder GDI engine fueled by four different lubricant-gasoline blends was used with various injection conditions. Combustion experiments were used to determine combustion characteristics, and gaseous emissions indicated that the lubricant did not influence mixture homogeneity but had an impact on unburned fuels. Optical experiments showed that the lubricant did not influence spray but did influence wall film formation during the injection period, which is a major factor affecting particulate matter generation. Particulate emissions indicated that lubricant included in the wall film significantly affected PN emissions depending on injection conditions. Additionally, the wall film influenced by the lubricant affected the overall particle size and its distribution.

Immune cell targeting nanoparticles: a review

Immune cells are attractive targets for therapy as they are direct participants in a variety of diseases. Delivering a therapeutic agent only to cells that act on a disease by distinguishing them from other cells has the advantage of concentrating the therapeutic effect and lowering systemic side effects. Distinguishing each immune cell from other immune cells to deliver substances, including drugs and genes, can be achieved using nanotechnology. And also nanoparticles can ensure in vivo stability and sustained drug release. In addition, there is an ease of surface modification, which is an important characteristic that can be utilized in targeted drug delivery systems. This characteristic allows us to utilize various properties that are specifically expressed in each immune cell. A number of studies have delivered various substances specifically to immune cells through surface engineering with active target ligands that can target each immune cell and enzyme-responsive coating, and demonstrated high therapeutic effects compared to conventional treatments. Progress in research on target delivery has been suggested to be a breakthrough for the treatments of various diseases, including cancer treatment.

HSP70 as a biomarker of the thin threshold between benefit and injury due to physical exercise when exposed to air pollution

Physical exercise has acute and chronic effects on inflammatory balance, metabolic regulation, and redox status. Exercise-induced adaptations are mediated by enhanced 70-kDa heat shock protein (HSP70) levels and an improved heat shock response (HSR). Therefore, exercise could be useful against disease conditions [obesity, diabetes mellitus (DM), and exposure to atmospheric pollutants] marked by an impaired HSR. However, exercise performed by obese or diabetic subjects under pollution conditions might also be dangerous at certain intensities. Intensity correlates with an increase in HSP70 levels during physical exercise until a critical point at which the effort becomes harmful and impairs the HSR. Establishing a unique biomarker able to indicate the exercise intensity on metabolism and cellular fatigue is essential to ensure adequate and safe exercise recommendations for individuals with obesity or DM who require exercise to improve their metabolic status and live in polluted regions. In this review, we examined the available evidence supporting our hypothesis that HSP70 could serve as a biomarker for determining the optimal exercise intensity for subjects with obesity or diabetes when exposed to air pollution and establishing the fine threshold between anti-inflammatory and pro-inflammatory exercise effects.

Acute cardiorespiratory response to ambient air pollution exposure during short-term physical exercise in young males

BACKGROUND

Physical exercise in the presence of ambient air pollution may increase the absorbed dose of air pollutants. The combined effect of such exposure on cardiorespiratory function in young adults remains unclear.

AIM

To determine the acute cardiorespiratory responses in healthy young adults preforming submaximal physical exercise under exposure to high level winter-type ambient air pollution.

METHODS

Healthy young males (n=30) performed two separate 15-minute submaximal exercise trials on a cycle ergometer - when air pollutants' concentrations were increased (exposure trial) and when air quality was good (control trial). Each time blood pressure, pulse oximetry, spirometry and fractional exhaled nitric oxide (FeNO) were measured at baseline, directly after exercise and after 15-min of rest.

RESULTS

High air pollutants concentrations were observed during exposure trials (PM_2.5 24.0-157.0 μg/m³, SO₂ 8.7-85.8 μg/m³). Group-based correlation analysis showed statistically significant negative correlations between post-exercise declines in FEV₁/FVC and SO₂, PM₁₀ and PM_2.5 concentrations. In individual cases the decrease was recorded only in subjects who exercised under particularly high exposure, and was not related to their BMI, physical activity pattern or allergy status. In multivariate analysis SO₂ was a statistically significant predictor of both immediate (OR: 1.09, 95%CI: 1.01-1.17) and delayed decrease in airflow (OR: 1.08, 95%CI: 1.01-1.16), and PM_2.5 was also a statistically significantly explanatory variable of post-exercise decline in FEV₁/FVC (OR: 1.03, 95%CI: 1.00-1.06).

CONCLUSION

In young and healthy males exposure to ambient air pollution during short-term submaximal exercise is associated with a decrease in airflow (FEV₁/FVC) and the decrease is more apparent when the exercise takes place under particularly high exposure conditions.

The Association of White Blood Cells and Air Pollutants-A Population-Based Study

The links of air pollutants to health hazards have been revealed in literature and inflammation responses might play key roles in the processes of diseases. WBC count is one of the indexes of inflammation, however the l iterature reveals inconsistent opinions on the relationship between WBC counts and exposure to air pollutants. The goal of this population-based observational study was to examine the associations between multiple air pollutants and WBC counts. This study recruited community subjects from Kaohsiung city. WBC count, demographic and health hazard habit data were collected. Meanwhile, air pollutants data (SO₂, NO₂, CO, PM₁₀, and O₃) were also obtained. Both datasets were merged for statistical analysis. Single- and multiple-pollutants models were adopted for the analysis. A total of 10,140 adults (43.2% males; age range, 33~86 years old) were recruited. Effects of short-term ambient concentrations (within one week) of CO could increase counts of WBC, neutrophils, monocytes, and lymphocytes. However, SO₂ could decrease counts of WBC, neutrophils, and monocytes. Gender, BMI, and smoking could also contribute to WBC count increases, though their effects are minor when compared to CO. Air pollutants, particularly SO₂, NO₂ and CO, may thus be related to alterations of WBC counts, and this would imply air pollution has an impact on human systematic inflammation.

Application of high-resolution metabolomics to identify biological pathways perturbed by traffic-related air pollution

BACKGROUND

Substantial research has investigated the adverse effects of traffic-related air pollutants (TRAP) on human health. Convincing associations between TRAP and respiratory and cardiovascular diseases are known, but the underlying biological mechanisms are not well established. High-resolution metabolomics (HRM) is a promising platform for untargeted characterization of molecular mechanisms between TRAP and health indexes.

OBJECTIVES

We examined metabolic perturbations associated with short-term exposures to TRAP, including carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), fine particulate matter (PM2.5), organic carbon (OC), and elemental carbon (EC) among 180 participants of the Center for Health Discovery and Well-Being (CHDWB), a cohort of Emory University-affiliated employees.

METHODS

A cross-sectional study was conducted on baseline visits of 180 CHDWB participants enrolled during 2008-2012, in whom HRM profiling was determined in plasma samples using liquid chromatography-high-resolution mass spectrometry with positive and negative electrospray ionization (ESI) modes. Ambient pollution concentrations were measured at an ambient monitor near downtown Atlanta. Metabolic perturbations associated with TRAP exposures were assessed following an untargeted metabolome-wide association study (MWAS) framework using feature-specific Tobit regression models, followed by enriched pathway analysis and chemical annotation.

RESULTS

Subjects were predominantly white (76.1%) and non-smokers (95.6%), and all had at least a high school education. In total, 7821 and 4123 metabolic features were extracted from the plasma samples by the negative and positive ESI runs, respectively. There are 3421 features significantly associated with at least one air pollutant by negative ion mode, and 1691 features by positive ion mode. Biological pathways enriched by features associated with the pollutants are primarily involved in nucleic acids damage/repair (e.g., pyrimidine metabolism), nutrient metabolism (e.g., fatty acid metabolism), and acute inflammation (e.g., histidine metabolism and tyrosine metabolism). NO2 and EC were associated most consistently with these pathways. We confirmed the chemical identity of 8 metabolic features in negative ESI and 2 features in positive ESI, including metabolites closely linked to oxidative stress and inflammation, such as histamine, tyrosine, tryptophan, and proline.

CONCLUSIONS

We identified a range of ambient pollutants, including components of TRAP, associated with differences in the metabolic phenotype among the cohort of 180 subjects. We found Tobit models to be a robust approach to handle missing data among the metabolic features. The results were encouraging of further use of HRM and MWAS approaches for characterizing molecular mechanisms underlying exposure to TRAP.

Increasing cardiopulmonary effects of ultrafine particles at relatively low fine particle concentrations

Ultrafine particles (UFPs) are of concern because of their high pulmonary deposition efficiency. However, present control measures are generally targeted at fine particles (PM_2.5), with little effect on UFPs. The health effects of UFPs at different PM_2.5 concentrations may provide a basic for controlling UFPs but remain unclear in polluted areas. School children spend the majority of their time in the classrooms. This study investigated the different short-term effects of indoor UFPs on school children in Beijing, China when indoor PM_2.5 concentrations exceeded or satisfied the recently published Chinese standard for indoor PM_2.5. Cardiopulmonary functions of 48 school children, of whom 46 completed, were measured three times. Indoor PM_2.5 and UFPs were monitored in classrooms on weekdays. Measurements were separated into two groups according to the abovementioned standard. Mixed-effect models were used to explore the health effects of the air pollutants. Generally, UFP-associated effects on children's cardiopulmonary function persisted even at relatively low PM_2.5 concentrations, especially on heart rate variability indices. The risks associated with high PM_2.5 concentrations are well-known, but the effects of UFPs on children's cardiopulmonary function deserve more attention even when PM_2.5 has been controlled. UFP control and standard setting should therefore be considered.

Respiratory Effects of Exposure to Traffic-Related Air Pollutants During Exercise

Traffic-related air pollution (TRAP) is increasing worldwide. Habitual physical activity is known to prevent cardiorespiratory diseases and mortality, but whether exposure to TRAP during exercise affects respiratory health is still uncertain. Exercise causes inflammatory changes in the airways, and its interaction with the effects of TRAP or ozone might be detrimental, for both athletes exercising outdoor and urban active commuters. In this Mini-Review, we summarize the literature on the effects of exposure to TRAP and/or ozone during exercise on lung function, respiratory symptoms, performance, and biomarkers. Ozone negatively affected pulmonary function after exercise, especially after combined exposure to ozone and diesel exhaust (DE). Spirometric changes after exercise during exposure to particulate matter and ultrafine particles suggest a decrease in lung function, especially in patients with chronic obstructive pulmonary disease. Ozone frequently caused respiratory symptoms during exercise. Women showed decreased exercise performance and higher symptom prevalence than men during TRAP exposure. However, performance was analyzed in few studies. To date, research has not identified reliable biomarkers of TRAP-related lung damage useful for monitoring athletes' health, except in scarce studies on airway cells obtained by induced sputum or bronchoalveolar lavage. In conclusion, despite partly counteracted by the positive effects of habitual exercise, the negative effects of TRAP exposure to pollutants during exercise are hard to assess: outdoor exercise is a complex model, for multiple and variable exposures to air pollutants and pollutant concentrations. Further studies are needed to identify pollutant and/or time thresholds for performing safe outdoor exercise in cities.

A machine learning-based model to estimate PM2.5 concentration levels in Delhi's atmosphere

During the last many years, the air quality of the capital city of India, Delhi had been hazardous. A large number of people have been diagnosed with Asthma and other breathing-related problems. The basic reason behind this has been the high concentration of life-threatening PM2.5 particles dissolved in its atmosphere. A good model, to forecast the concentration level of these dissolved particles, may help to prepare the residents with better prevention and safety strategies in order to save them from many health-related diseases. This work aims to forecast the PM2.5 concentration levels in various regions of Delhi on an hourly basis, by applying time series analysis and regression, based on various atmospheric and surface factors such as wind speed, atmospheric temperature, pressure, etc. The data for the analysis is obtained from various weather monitoring sites, set-up in the city, by the Indian Meteorological Department (IMD). A regression model is proposed, which uses Extra-Trees regression and AdaBoost, for further boosting. Experimentation for comparative study with the recent works is done and results indicate the efficacy of the proposed model.

Exercising in the urban center: Inflammatory and cardiovascular effects of prolonged exercise under air pollution

The aim of this study was to investigate, in a well-controlled experimental environment, whether air pollution from an urban center would affect inflammatory and cardiorespiratory responses during prolonged moderate exercise (i.e., 90 min). Ten healthy men performed two experimental trials under filtered and polluted air, inside an environmental chamber located in Sao Paulo downtown, Brazil. Blood samples were obtained at rest, 30, 60, and 90 min of the exercise to determine the serum cytokines concentration, while arterial pressure was recorded immediately after the exercise. The serum cytokines were not altered until 60 min of exercise for both conditions (P > 0.05). Otherwise, at 90 min of exercise, the IL-6 (P = 0.047) and vascular endothelial growth factor (VEGF) (P = 0.026) were significantly higher and IL-10 tended to decrease (P = 0.061) in polluted air condition compared to filtered air condition. In addition, both systolic (P = 0.031) and diastolic (P = 0.009) arterial pressure were higher in polluted air condition than filtered air condition. These findings demonstrate that the exercise of longer duration (i.e., 90 min), but not of shorter duration (i.e., <60 min), performed in vehicular air pollution condition results in pronounced pro-inflammatory and increased arterial pressure responses.

Respiratory effects of road pollution in recreational cyclists: a pilot study

We sought to measure bicyclists' roadway exposures to particulate matter and assess whether those exposures are associated with reduced pulmonary function. Thirty-one (31) volunteer participants riding bicycles on selected routes were tracked using the Global Positioning System. Personal exposures to particulate matter (PM-10) were measured during the rides and pulmonary function tests were administered at baseline, immediately after the ride, and 2 and 6-24 hours later. Post-ride decrements in pulmonary function were observed for several outcome measures, with the largest differences immediately post-ride. Statistically-significant declines in FEV₁ (-38.42, 95% Confidence Interval (CI), -63.79 to -13.05 ml), FVC (-36.89, 95% CI, -62.96, -10.84 ml), and PEFR (-162, 95% CI -316.02 to -9.49 ml/sec) were observed for each increase in decile of peak exposure. PM-10 exposures encountered on roadways may put bicyclists at risk for pulmonary deficits.

Analysis of inflammatory markers in apparently healthy automobile vehicle drivers in response to exposure to traffic pollution fumes

Objective:

This study aimed to evaluate pattern of markers of inflammation in apparently healthy drivers who exposed to traffic fumes.

Methods:

This cross-sectional study was conducted from June 2016 to January 2017 at Liaquat University of Medical & Health Sciences (LUMHS), Jamshoro. It looked into the effects of traffic pollutants on markers of inflammation including CRP, Leukocytes count, IL-6, TNF-α, TNF-β of healthy human volunteers. Eighty-seven, apparently healthy, non-smoking automobile vehicle drivers, having daily contact of traffic exhaust for at least six hours, aged between 18-40 years recruited for this study. Levels of traffic-generated pollutants P.M_2.5, P.M_10, NO_x were recorded in different areas of Hyderabad City.

Results:

P.M_2.5 found to be positively correlated with markers of inflammation including IL-6 (r_s = 0.99), TNF-α (r_s = 0.41), CRP mg/dl (r_s = 0.99) , neutrophils (r_s = 0.29), lymphocytes (r_s = 0.31), eosinophils (r_s = 0.20), monocytes (r_s = 0.42) and basophils (r_s = 0.16). Positive correlation present among IL-6 (r_s = 0.21), TNF-α (r_s = 0.49) and CRP mg/dl (r_s = 0.22) % (r_s = -0.31), Leukocytes (r_s = 0.14) neutrophils (r_s = 0.31), lymphocytes (r_s = 0.21), monocytes (r_s = 0.50), basophils (r_s = 0.17) with P.M₁₀. NO_x showed positive correlation with IL-6 (r_s = 0.22), TNF-α (r_s = 0.48), CRP (r_s = 0.22), neutrophils (r_s = 0.31), lymphocytes (r_s = 0.13), basophils (r_s = 0.17) and monocytes (r_s = 0.48).

Conclusion:

Findings of our study suggest that almost all markers of inflammation are positively correlated with traffic pollutants and this condition might raise the risk of systemic diseases.

Exposure to organic and inorganic traffic-related air pollutants alters haematological and biochemical indices in albino mice Mus musculus

The relationship between air pollution exposure and haematology remains controversial. Evidences in the effect of trace organic air pollutants and in the impact of such exposure on lipid and protein levels are scarce. This work investigated the health effects of medium-term exposure to traffic-related air pollution on both haematological and biochemical indices in animal models. Two groups of albino mice (Mus musculus) were exposed to ambient air polluted by vehicle exhaust for three and six months, and one group was kept as control. Results found significant depletions (p < 0.05) in red blood cells, packed cell volume, neutrophils, eosinophils, monocytes, and total cholesterol after air pollution exposure. On the contrary, significant elevations (p < 0.05) were observed in platelet, lymphocytes, and serum albumin compared to control condition. Correlation data suggested that significant changes in blood parameters may be altered by the synergistic effect of several organic and inorganic air pollutants.

Effects of low-intensity and high-intensity cycling with diesel exhaust exposure on soluble P-selectin, E-selectin, I-CAM-1, VCAM-1 and complete blood count

BACKGROUND

Exposure to particulate matter 2.5 μm or less (PM2.5) that contains transition metals may play a role in systemic oxidative stress and inflammation. Exposure to diesel exhaust (DE) can increase adhesion molecules, which are important in the inflammatory response; however, it is unclear how exercising in DE affects adhesion molecules and how exercise intensity modulates this response.

AIM

To determine how DE exposure during exercise of varying intensities affects adhesion molecules and markers of systemic inflammation.

METHODS

Eighteen males performed 30 min cycling bouts at low intensity and high intensity (30% and 60% of power at VO2peak (peak oxygen consumption) and a control condition (rest)). Each trial was performed once breathing filtered air (FA) and once breathing DE (300 μg/m3 of PM2.5, six trials in total). Prior to, immediately post, 1 and 2 hours post exposure, blood was drawn to measure parameters of a complete blood count and soluble (s) platelet-Selectin, endothelin-Selectin, intracellular cell adhesion molecule (sICAM)-1 and vascular cell adhesion molecule (sVCAM)-1. Data were analysed using repeated-measures analysis of variance.

RESULTS

Two hours following high-intensity exercise, sICAM-1 was significantly less in DE compared with FA (p=0.008). Immediately following rest (p=0.013) and high-intensity exercise (p=0.042) in DE, sICAM-1 was significantly greater than immediately following low-intensity exercise in DE. There were no significant differences in other markers between DE and FA.

CONCLUSIONS

Based on this study, healthy individuals may not experience an acute increase in adhesion molecules and systemic inflammatory markers from exercising in DE compared with FA, and higher exercise intensities do not appear to increase the likelihood that DE will affect adhesion molecules and systemic inflammatory markers.

Blood pressure and pulmonary health effects of ozone and black carbon exposure in young adult runners

Physical activity has been shown to promote health and well-being, however, exercising in environments with high level of air pollution might increase the risk of cardio-respiratory impairments. In this crossover study, we constructed linear mixed models to investigate the impact of short-term exposure to black carbon (BC) and ozone on blood pressure and pulmonary functions among 30 healthy adult runners after 30-minute run on a clean and polluted route on separate days in August 2015 in Hong Kong. Runners were on average 20.6 years old, with mean body mass index of 20.3 kg/m². Air pollution concentrations were higher in the polluted route than in the clean route, with the highest difference in BC (5.4 μg/m³ versus 1.3 μg/m³). In single-pollutant models, no significant association was found between air pollution and changes in blood pressures, forced vital capacity, forced expiratory volume in 1 s, peak expiratory flow and fractional exhaled nitric oxide, after adjusting for gender, type of route, temperature and relative humidity. When further adjusting for both BC and ozone simultaneously, increment in BC became statistically significantly associated with increase in systolic blood pressure (relative risk = 3.18; 95% CI: 0.24, 6.13) after running exercise. Stratified analysis further shows that the significant adverse association between systolic blood pressure and BC was only observed in the polluted route (e.g., relative risk = 4.51, 95% CI: 0.75, 8.27 in two-pollutant). Our finding of BC is consistent with existing literature, while further studies with greater sample size and longer exposure time are needed to investigate the effects of ozone to cardio-respiratory functions in runners. Given that exercise has clear health benefits, one should consider ways to minimize the air pollution exposure.

Impact of short-term traffic-related air pollution on the metabolome - Results from two metabolome-wide experimental studies

Exposure to traffic-related air pollution (TRAP) has been associated with adverse health outcomes but underlying biological mechanisms remain poorly understood. Two randomized crossover trials were used here, the Oxford Street II (London) and the TAPAS II (Barcelona) studies, where volunteers were allocated to high or low air pollution exposures. The two locations represent different exposure scenarios, with Oxford Street characterized by diesel vehicles and Barcelona by normal mixed urban traffic. Levels of five and four pollutants were measured, respectively, using personal exposure monitoring devices. Serum samples were used for metabolomic profiling. The association between TRAP and levels of each metabolic feature was assessed. All pollutant levels were significantly higher at the high pollution sites. 29 and 77 metabolic features were associated with at least one pollutant in the Oxford Street II and TAPAS II studies, respectively, which related to 17 and 30 metabolic compounds. Little overlap was observed across pollutants for metabolic features, suggesting that different pollutants may affect levels of different metabolic features. After observing the annotated compounds, the main pathway suggested in Oxford Street II in association with NO2 was the acyl-carnitine pathway, previously found to be associated with cardio-respiratory disease. No overlap was found between the metabolic features identified in the two studies.

Exercise and air pollutants exposure: A systematic review and meta-analysis

This review aims to systematically review and synthesize scientific evidence for the influence of air pollution exposure and outdoor exercise on health. We conducted a literature search in the PubMed, Cochrane, EMBASE, and Web of Science for articles that evaluated the combination effect of air pollution exposure and exercise on health. Questionnaires regarding exposure history, or studies examining indoor air pollution were excluded. Each included study needs to have clear exercise intervention plan. The pooled estimates of the combination effect of air pollution exposure and outdoor exercise on health were calculated in the meta-analysis. The quality of each included study was assessed and the quality of evidence for each outcome assessed in the meta-analysis was also measured. Twenty-five studies were identified. Six studies addressed ozone exposure, four diesel exhaust exposure, six traffic-related air pollution, ten particulate matter (PM) exposure. Only peak expiratory flow (effect size [ES] = -0.238, 95% confidence interval [CI] = -0.389, -0.088) was found to be significantly decreased after exercise intervention in a polluted environment in the meta-analysis. Seven studies reported exposure to air pollutant during exercise was associated with an increased risk of airway inflammation and decrements in pulmonary function. Six studies discovered that exposure of traffic pollution or high PM during exercise may contribute to changes in blood pressure, systemic conduit artery function and micro-vascular function. The combination effect of air pollution and exercise was found to be associated with the increased risk of potential health problems of cardiopulmonary function, immune function, and exercise performance.

The pulmonary and autonomic effects of high-intensity and low-intensity exercise in diesel exhaust

BACKGROUND

Exposure to air pollution impairs aspects of pulmonary and autonomic function and causes pulmonary inflammation. However, how exercising in air pollution affects these indices is poorly understood. Therefore, the purpose of this study was to determine the effects of low-intensity and high-intensity cycling with diesel exhaust (DE) exposure on pulmonary function, heart rate variability (HRV), fraction of exhaled nitric oxide (FeNO), norepinephrine and symptoms.

METHODS

Eighteen males performed 30-min trials of low-intensity or high-intensity cycling (30 and 60% of power at VO_2peak) or a resting control condition. For each subject, each trial was performed once breathing filtered air (FA) and once breathing DE (300μg/m³ of PM_2.5, six trials in total). Pulmonary function, FeNO, HRV, norepinephrine and symptoms were measured prior to, immediately post, 1 h and 2 h post-exposure. Data were analyzed using repeated-measures ANOVA.

RESULTS

Throat and chest symptoms were significantly greater immediately following DE exposure than following FA (p < 0.05). FeNO significantly increased 1 h following high-intensity exercise in DE (21.9 (2.4) vs. 19.3 (2.2) ppb) and FA (22.7 (1.7) vs. 19.9 (1.4)); however, there were no differences between the exposure conditions. All HRV indices significantly decreased following high-intensity exercise (p < 0.05) in DE and FA. The exception to this pattern was LF (nu) and LF/HF ratio, which significantly increased following high-intensity exercise (p < 0.05). Plasma norepinephrine (NE) significantly increased following high-intensity exercise in DE and FA, and this increase was greater than following rest and low-intensity exercise (p < 0.05). DE exposure did not modify any effects of exercise intensity on HRV or norepinephrine.

CONCLUSIONS

Healthy individuals may not experience greater acute pulmonary and autonomic effects from exercising in DE compared to FA; therefore, it is unclear if such individuals will benefit from reducing vigorous activity on days with high concentrations on particulate matter.

Particulate matter exposure and health impacts of urban cyclists: a randomized crossover study

BACKGROUND

Cycling and other forms of active transportation provide health benefits via increased physical activity. However, direct evidence of the extent to which these benefits may be offset by exposure and intake of traffic-related air pollution is limited. The purpose of this study is to measure changes in endothelial function, measures of oxidative stress and inflammation, and lung function in healthy participants before and after cycling along a high- and low- traffic route.

METHODS

Participants (n = 38) bicycled for 1 h along a Downtown and a Residential designated bicycle route in a randomized crossover trial. Heart rate, power output, particulate matter air pollution (PM₁₀, PM_2.5, and PM₁) and particle number concentration (PNC) were measured. Lung function, endothelial function (reactive hyperemia index, RHI), C-reactive protein, interleukin-6, and 8-hydroxy-2'-deoxyguanosine were assessed within one hour pre- and post-trial.

RESULTS

Geometric mean PNC exposures and intakes were higher along the Downtown (exposure = 16,226 particles/cm³; intake = 4.54 × 10¹⁰ particles) compared to the Residential route (exposure = 9367 particles/cm³; intake = 3.13 × 10¹⁰ particles). RHI decreased following cycling along the Downtown route and increased on the Residential route; in mixed linear regression models, the (post-pre) change in RHI was 21% lower following cycling on the Downtown versus the Residential route (-0.43, 95% CI: -0.79, -0.079) but RHI decreases were not associated with measured exposure or intake of air pollutants. The differences in RHI by route were larger amongst females and older participants. No consistent associations were observed for any of the other outcome measures.

CONCLUSIONS

Although PNC exposures and intakes were higher along the Downtown route, the lack of association between air pollutant exposure or intake with RHI and other measures suggests other exposures related to cycling on the Downtown route may have been influential in the observed differences between routes in RHI.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01708356 . Registered 16 October 2012.

Seasonal trends in the composition and sources of PM2.5 and carbonaceous aerosol in Tehran, Iran

Currently PM_2.5 is a major air pollution concern in Tehran, Iran due to frequent high levels and possible adverse impacts. In this study, which is the first of its kind to take place in Tehran, composition and sources of PM_2.5 and carbonaceous aerosol were determined, and their seasonal trends were studied. In this regard, fine PM samples were collected every six days at a residential station for one year and the chemical constituents including organic marker species, metals, and ions were analyzed by chemical analysis. The source apportionment was performed using organic molecular marker-based CMB receptor modeling. Carbonaceous compounds were the major contributors to fine particulate mass in Tehran, as OC and EC together comprised on average 29% of PM_2.5 mass. Major portions of OC in Tehran were water insoluble and are mainly attributed to primary sources. Higher levels of several PAHs, which are organic tracers of incomplete combustion, and hopanes and steranes as organic tracers of mobile sources were obtained in cold months and compared to the warm months. The major contributing source to particulate OC was identified as vehicles, which contributed about 72% of measured OC. Among mobile sources, gasoline-fueled vehicles had the highest impact with a mean contribution of 48% to the measured OC. Mobile sources also were the largest contributor to total PM_2.5 (40%), followed by dust (24%) and sulfate (11%). In addition to primary emissions, mobile sources also directly and indirectly played an important role in another 27% of fine particulate mass (secondary organics and ions), which highlights the impact of vehicles in Tehran. Our results highlighted and quantified the role of motor vehicles in fine PM production, particularly during winter time. The results of this study could be used to set more effective regulations and control strategies particularly upon mobile sources.

Biomarkers of Human Cardiopulmonary Response After Short-Term Exposures to Medical Laser-Generated Particulate Matter From Simulated Procedures: A Pilot Study

OBJECTIVE

We conducted an exposure chamber study in humans using a simulated clinical procedure lasing porcine tissue to demonstrate evidence of effects of exposure to laser-generated particulate matter (LGPM).

METHODS

We measured pre- and post-exposure changes in exhaled nitric oxide (eNO), spirometry, heart rate variability (HRV), and blood markers of inflammation in five volunteers.

RESULTS

Change in pre- and post-exposure measurements of eNO and spirometry was unremarkable. Neutrophil and lymphocyte counts increased and fibrinogen levels decreased in four of the five subjects. Measures of HRV showed decreases in the standard deviation of normal between beat intervals and sequential 5-minute intervals.

CONCLUSION

These data represent the first evidence of human physiologic response to LGPM exposure. Further exploration of coagulation effects and HRV is warranted.

Urban Form, Air Pollution, and Health

PURPOSE OF REVIEW

Urban form can impact air pollution and public health. We reviewed health-related articles that assessed (1) the relationships among urban form, air pollution, and health as well as (2) aspects of the urban environment (i.e., green space, noise, physical activity) that may modify those relationships.

RECENT FINDINGS

Simulation and empirical studies demonstrate an association between compact growth, improved regional air quality, and health. Most studies are cross-sectional and focus on connections between transportation emissions and land use. The physical and mental health impacts of green space, public spaces that promote physical activity, and noise are well-studied aspects of the urban environment and there is evidence that these factors may modify the relationship between air pollution and health. Urban form can support efforts to design clean, health-promoting cities. More work is needed to operationalize specific strategies and to elucidate the causal pathways connecting various aspects of health.

Growth and reproductive traits of F1-generation transgenic goats for human granulocyte-colony stimulating factor

To ensure that animal welfare requirements and phenotypic characteristics of the newly produced transgenic lines are not compromised, an evaluation of all individuals is necessary. This can be inferred by the analysis of the growth and reproduction parameters. The present study was designed to determine the impact of the insertion of human granulocyte-colony stimulating factor (hG-CSF) transgene on growth and reproductive characteristics in first-generation (F1) goats from two transgenic lines. Bodyweight (BW) development (BW at birth, mean BW gain before weaning, BW at weaning, mean BW gain after weaning, BW at puberty), as well as reproductive parameters (age at puberty, ejaculate volume, concentration, total sperm per ejaculate, massal motility, progressive individual motility, major and minor defects) were similar (P > 0.05) between transgenic (T) and non-transgenic (NT) goats. Significant (P < 0.05) differences in mean (±s.d.) white blood cell count were observed between T and NT in first day of life (174.6 ± 14.7 × 103 and 15.0 ± 4.0 × 103 cells/µL), and during (66.8 ± 21.1 × 103 and 17.0 ± 4.6 × 103 cells/µL) and after (36.6 ± 4.0 × 103 and 15.5 ± 2.2 × 103 cells/µL) suckling, even though hG-CSF has not been detected in blood serum in any analysis. Although other cell counts were occasionally higher in T animals, differential counts showed that this difference was mainly due to an increased number of neutrophils, which represents 84.6%, 67.2% and 56.8% of total white blood cell count respectively, in the three time periods. Kidney and liver biochemical analyses indicated that all goats were healthy. Thus, it is possible to assume that all animals are normal and had no deleterious effects on either growth or reproductive parameters by the presence of transgene or as a consequence of leukocyte profile alteration.

Latent class analysis to model multiple chemical exposures among children

BACKGROUND

Children are exposed to multiple potentially harmful chemicals simultaneously. Efforts to understand the patterns and consequences of these exposures have been hampered by statistical limitations in estimations of higher order interactions.

OBJECTIVES

The current study uses latent class analysis, a form of person-centered modeling to identify unobservable subgroups within populations and examine relationships between latent classes and measures of immune function.

METHODS

Data from the National Health and Nutrition Examination Survey 2011-2012 were analyzed. A sample of 721 children aged 6-19 years were included who provided data on 47 chemicals of interest representing six chemical classes. Groups were identified using latent class analysis controlling for race/ethnicity, age, sex and poverty status.

RESULTS

Two alternative approaches to identifying latent classes each resulted in similar three class solutions, including one group of children characterized by low co-exposures across chemicals, a group with moderate co-exposure levels, and a group characterized by high co-occurring levels of polycyclic aromatic hydrocarbons, volatile organic compounds, phenols and phthalates. Under one of the approaches, latent classes were significantly associated with immune function as measured by lymphocyte and neutrophil counts.

CONCLUSIONS

Latent class analysis offers a potential approach to measuring and understanding interactions among multiple co-occurring chemical stressors. However, additional work is needed to test the ability of latent classes to predict health variables.

Pulmonary challenge with carbon nanoparticles induces a dose-dependent increase in circulating leukocytes in healthy males

Background

Inhalation of particulate matter, as part of air pollution, is associated with increased morbidity and mortality. Nanoparticles (< 100 nm) are likely candidates for triggering inflammatory responses and activation of coagulation pathways because of their ability to enter lung cells and pass bronchial mucosa. We tested the hypothesis that bronchial segmental instillation of carbon nanoparticles causes inflammation and activation of coagulation pathways in healthy humans in vivo.

Methods

This was an investigator-initiated, randomized controlled, dose-escalation study in 26 healthy males. Participants received saline (control) in one lung segment and saline (placebo) or carbon nanoparticles 10 μg, 50 μg, or 100 μg in the contra-lateral lung. Six hours later, blood and bronchoalveolar lavage fluid (BALF) was collected for inflammation and coagulation parameters.

Results

There was a significant dose-dependent increase in blood neutrophils (p = 0.046) after challenge with carbon nanoparticles. The individual top-dose of 100 μg showed a significant (p = 0.05) increase in terms of percentage neutrophils in blood as compared to placebo.

Conclusions

This study shows a dose-dependent effect of bronchial segmental challenge with carbon nanoparticles on circulating neutrophils of healthy volunteers. This suggests that nanoparticles in the respiratory tract induce systemic inflammation.

Trial registration

Dutch Trial Register no. 2976. 11 July 2011. http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2976

Electronic supplementary material

The online version of this article (10.1186/s12890-017-0463-x) contains supplementary material, which is available to authorized users.

Large-scale ex vivo generation of human neutrophils from cord blood CD34+ cells

Conventional high-dose chemotherapy frequently leads to severe neutropenia, during which patients experience a high risk of infection. Although support care with donor’s neutrophils is possible this choice is largely hampered by the limited availability of matched donors. To overcome this problem, we explored a large-scale ex vivo production of neutrophils from hematopoietic stem cells (HSCs) using a four-stage culture approach in a roller-bottle production platform. We expanded CD34⁺ HSCs isolated from umbilical cord blood (UCB) using our in-house special medium supplemented with cytokine cocktails and achieved about 49000-fold expansion of cells, among which about 61% were differentiated mature neutrophils. Ex vivo differentiated neutrophils exhibited a chemotactic activity similar to those from healthy donors and were capable of killing E. coli in vitro. The expansion yield as reported herein was at least 5 times higher than any other methods reported in the literature. Moreover, the cost of our modified medium was only a small fraction (<1/60) of the StemSpan^™ SFEM. Therefore, our ex vivo expansion platform, coupled with a low cost of stem cell culture due to the use of a modified medium, makes large-scale manufacturing neutrophils possible, which should be able to greatly ameliorate neutrophil shortage for transfusion in the clinic.

The effect of air pollution on diurnal variation of performance in anaerobic tests, cardiovascular and hematological parameters, and blood gases on soccer players following the Yo-Yo Intermittent Recovery Test Level-1

This study aimed to investigate the effect of air pollution on diurnal variation of performance in anaerobic tests, cardiovascular and hematological parameters, and blood gases on soccer players following the Yo-Yo Intermittent Recovery Test Level-1 (YYIRT1). In a randomized order, 11 healthy soccer players (mean age: 21.8 [range: 20-24] years; height: 178.00 [range: 1.64-1.83] cm; body mass index [BMI]: 23.57 [range: 20.45-28.03] kg.m^-2) performed a YYIRT1 at two different times of day (TOD) (08:00 h and 18:00 h) in two areas (i.e. polluted (PA) and non-polluted (NPA)) with a recovery period of ≥ 72 h in between, to determine the maximal oxygen uptake (VO2max). In each test session: resting oral temperature is measured, anaerobic performances (pre- and post-YYIRT1) were performed, cardiovascular parameters and blood samples were collected at: rest, 3 min and 60 min after the YYIRT1, to assess blood gases and hematological parameters. Our results showed that, agility performance, VO2max, red blood cells (RBC), hemoglobin (Hb), pH, and bicarbonate levels (HCO3^-) decrease significantly (p < 0.001) following the YYIRT1 in PA compared to NPA. Likewise, the heart rate (HR), systolic blood pressure (SBP), platelets (PLT), white blood cells (WBC), neutrophiles (NEUT), lymphocytes (LYM), and partial pressure of CO2 levels (P_vCO2) were significantly higher (p < 0.001) in PA. This effect was slightly accentuated at 18:00 h for some parameters (i.e. Agility, HCO3^-, HR, P_vCO2, RBC, SBP). However, performances of sprint and Sargent jump test (SJT), oral temperature, rate of perceived exertion scales (RPE), partial pressure of O2 (P_vO2), diastolic blood pressure (DBP), and monocytes (MON) were not affected by pollution (p > 0.05). In conclusion, pollution seems to be critical for health stability and performance in response to YYIRT1 especially in the evening and the winter season. Therefore, coaches and athletes should draw attention to the potential importance of land use planning in their training sessions and competitions in the morning in polluted area to minimize the risk of pollution exposure.

The mobile monitoring of black carbon and its association with roadside data in the Chinese megacity of Shanghai

High-level black carbon (BC) pollution is associated with traffic emissions in metropolitan areas with high vehicle density. Mobile monitoring was conducted to assess the in-vehicle BC exposure on three backbone ring roads (inner, middle, and outer ring roads) on October 14 and October 18, 2015 in Shanghai. Ambient BC monitoring was also simultaneously conducted in three fixed roadside stations from October 14 to October 20, 2015. Results of the mobile monitoring showed median BC personal exposure concentrations ranging from 5.0 μg m^-3 on the inner ring road to 13.5 μg m^-3 on the outer ring road. The ambient BC concentrations during the entire observation period showed an arithmetic mean and a standard deviation of 3.5 ± 2.9 μg m^-3. The correlation analysis of urban roadside monitoring (Caoxi Road and South Zhongshan Road) and personal data showed a high and significant correlation. The results of this study highlight the critical level of BC pollution in Shanghai and facilitate the development of evidence-based public health interventions and control strategies to prevent the adverse health effects of BC pollution.

Respiratory outcomes of ultrafine particulate matter (UFPM) as a surrogate measure of near-roadway exposures among bicyclists

BACKGROUND

Studies have shown a consistent association between exposure to traffic-related air pollution and adverse health effects. In particular, exposure can be high for cyclists who travel near roadways. The objective of the current study was to examine the relationship between short-term exposure of near-road traffic emissions and acute changes in lung function among individuals who frequently bike in the Sacramento and Davis areas in California. Ultrafine particulate matter (UFPM) was used as a surrogate for near-roadway exposure in this study since the main source of this pollutant is from motor vehicle exhaust.

METHODS

Thirty-two bicyclists were recruited and completed two rides on separate days during the study period of March-June, 2008. One ride was on a high traffic route paralleling a section of Interstate 80 (I-80)/Interstate Business 80 (I-80B), and a second one was on a low traffic route, such as bike paths away from major highways. The participant's lung function was measured before and after each ride, and UFPM exposure was measured during the rides using a condensation particle counter (CPC).

RESULTS

In the final linear mixed-effect model using median UFPM concentrations as the main exposure, we observed that lung function change (post-ride minus baseline measurements) shifted in the negative direction. Lung function changed by 216 mL for FVC and 168 mL for FEV₁, respectively, for an interquartile range (IQR: 12,225 to 36,833 number of particles/cm³) increase of UFPM concentration after adjusting for other covariates of age, sex, wind direction, and day of the week.

CONCLUSIONS

This study found significant associations between increased levels of UFPM concentrations as a proxy for near road traffic pollution, and decrements in lung function measurements. Our results are related to short-term exposures, and the long-term health effects of cycling near heavy traffic require further research. Our study suggests the need to reduce traffic pollution, particularly near roads. Cyclists should plan their route to reduce their exposure where possible and further research on built environment designs may help urban planners to reduce the potential health concerns of cyclists' exposure to traffic-related air pollution.

Effect of diesel exhaust inhalation on blood markers of inflammation and neurotoxicity: a controlled, blinded crossover study

CONTEXT

Epidemiological studies and animal research have suggested that air pollution may negatively impact the central nervous system (CNS). Controlled human exposure studies of the effect of air pollution on the brain have potential to enhance our understanding of this relationship and to inform potential biological mechanisms.

OBJECTIVES

Biomarkers of systemic and CNS inflammation may address whether air pollution exposure induces inflammation, with potential for CNS negative effects.

MATERIALS AND METHODS

Twenty-seven healthy adults were exposed to two conditions: filtered air (FA) and diesel exhaust (DE) (300 μg PM2.5/m(3)) for 120 min, in a double-blinded crossover study with exposures separated by four weeks. Prior to and at 0, 3, and 24 h following each exposure, serum and plasma were collected and analyzed for inflammatory cytokines interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-α), the astrocytic protein S100b, the neuronal cytoplasmic enzyme neuron-specific enolase (NSE), and serum brain-derived neurotrophic factor (BDNF). We hypothesized that IL-6, TNF-α, S100b and NSE would increase, and BDNF would decrease, following DE exposure.

RESULTS

At no time-point following exposure to DE was a significant increase in concentration from baseline seen for IL-6, TNF-α, S100b, or NSE relative to FA exposure. Similarly, no significant decrease in BDNF concentration from baseline was seen following DE exposure, relative to FA. Furthermore, the repeated measures ANOVA considered for all time-points and biomarkers revealed no significant time-exposure interaction.

DISCUSSION AND CONCLUSION

These results suggest that short-term exposure to DE amongst healthy adults does not acutely affect the systemic or CNS biomarkers that we measured.

Vertical and horizontal variability in airborne nanoparticles and their exposure around signalised traffic intersections

We measured size-resolved PNCs in the 5-560 nm range at two different types (4- and 3-way) of TIs in Guildford (Surrey, UK) at fixed sites (∼1.5 m above the road level), sequentially at 4 different heights (1, 1.5, 2.5 and 4.7 m), and along the road at five different distances (10, 20, 30, 45 and 60 m). The aims were to: (i) assess the differences in PNCs measured at studied TIs, (ii) identify the best fit probability distribution curves for the PNCs, (iii) determine vertical and horizontal decay profiles of PNCs, (iv) estimate particle number emission factors (PNEFs) under congested and free-flow traffic conditions, and (v) quantify the pedestrian exposure in terms of respiratory deposition dose (RDD) rates at the TIs. Daily averaged particle number distributions at TIs reflected the effect of fresh emissions with peaks at 5.6, 10 and 56 nm. Despite the relatively high traffic volume at 3-way TI, average PNCs at 4-way TI were about twice as high as at 3-way TI, indicating less favourable dispersion conditions. Generalised extreme value distribution fitted well to PNC data at both TIs. Vertical PNC profiles followed an exponential decay, which was much sharper at 4-way TI than at 3-way TI, suggesting ∼40% less exposure for people at first floor (4.7 m) to those at ground floor around 4-way TI. Vertical profiles indicated much sharper (∼132-times larger) decay than in horizontal direction, due to close vicinity of road vehicles during the along-road measurements. Over an order of magnitude higher PNEFs were found during congested, compared with free-flow, conditions due to frequent changes in traffic speed. Average RDD rate at 4-way TI during congested conditions were up to 14-times higher than those at 3-way TI (0.4 × 10(11) h(-1)). Findings of this study are a step forward to understand exposure at and around the TIs.