Effects of Air Pollution and the Introduction of the London Low Emission Zone on the Prevalence of Respiratory and Allergic Symptoms in Schoolchildren in East London: A Sequential Cross-Sectional Study

Positive impact of the introduction of low-emission zones in Antwerp and Brussels on air quality, socio-economic disparities and health: a quasi-experimental study

Low emission zones (LEZ) manage traffic entering cities by granting access only to vehicles that meet certain emission standards. This study evaluated if implementation of LEZs in Antwerp (2017) and Brussels (2018) improved air pollution within the boundaries of the defined zones, if spatial spillover effects occurred, if socioeconomic inequality in air pollution exposure changed over time, and if health was affected. The study population comprised 420,007 individuals living within the LEZs, within seventeen control cities or within adjacent areas of these cities. Annual residential air pollution (PM2.5, PM10, NO2, BC) was calculated for 2016-2022. Individual-level health outcomes (diabetes, cardiovascular disease, obstructive airway diseases, antidepressants, antithrombotic agents) were available for 2014-2023. Random effect models were constructed to assess the impact of LEZs on air pollution and socioeconomic disparities, and a comparative interrupted time series analysis was conducted to evaluate the health impact. Findings suggest that with the introduction of the LEZ, all pollutant concentrations declined significantly more rapidly in both Antwerp and Brussels and adjacent areas compared to other Belgian cities and adjacent areas. Socioeconomic disparities in BC and NO2 concentrations decreased over time. Findings for the evolution of diabetes suggested a positive impact of the LEZ for this particular outcome. This study suggests that LEZ implementation holds strong advantages that may extend beyond the boundaries of the defined zones. As air pollution concentrations in European cities are still high, policies such as LEZs are required to attain the World Health Organisation Global Air Quality Guidelines.

Investigating the impact of London's ultra low emission zone on children's health: children's health in London and Luton (CHILL) protocol for a prospective parallel cohort study

BACKGROUND

Air pollution harms health across the life course. Children are at particular risk of adverse effects during development, which may impact on health in later life. Interventions that improve air quality are urgently needed both to improve public health now, and prevent longer-term increased vulnerability to chronic disease. Low Emission Zones are a public health policy intervention aimed at reducing traffic-derived contributions to urban air pollution, but evidence that they deliver health benefits is lacking. We describe a natural experiment study (CHILL: Children's Health in London and Luton) to evaluate the impacts of the introduction of London's Ultra Low Emission Zone (ULEZ) on children's health.

METHODS

CHILL is a prospective two-arm parallel longitudinal cohort study recruiting children at age 6-9 years from primary schools in Central London (the focus of the first phase of the ULEZ) and Luton (a comparator site), with the primary outcome being the impact of changes in annual air pollutant exposures (nitrogen oxides [NOx], nitrogen dioxide [NO2], particulate matter with a diameter of less than 2.5micrograms [PM2.5], and less than 10 micrograms [PM10]) across the two sites on lung function growth, measured as post-bronchodilator forced expiratory volume in one second (FEV1) over five years. Secondary outcomes include physical activity, cognitive development, mental health, quality of life, health inequalities, and a range of respiratory and health economic data.

DISCUSSION

CHILL's prospective parallel cohort design will enable robust conclusions to be drawn on the effectiveness of the ULEZ at improving air quality and delivering improvements in children's respiratory health. With increasing proportions of the world's population now living in large urban areas exceeding World Health Organisation air pollution limit guidelines, our study findings will have important implications for the design and implementation of Low Emission and Clean Air Zones in the UK, and worldwide.

CLINICALTRIALS

GOV: NCT04695093 (05/01/2021).

Ambient air pollutants increase the risk of immunoglobulin E-mediated allergic diseases: a systematic review and meta-analysis

Immunoglobulin E (IgE)-mediated allergic diseases, including eczema, atopic dermatitis (AD), and allergic rhinitis (AR), have increased prevalence in recent decades. Recent studies have proved that environmental pollution might have correlations with IgE-mediated allergic diseases, but existing research findings were controversial. Thus, we performed a comprehensive meta-analysis from published observational studies to evaluate the risk of long-term and short-term exposure to air pollutants on eczema, AD, and AR in the population (per 10-μg/m3 increase in PM2.5 and PM10; per 1-ppb increase in SO2, NO2, CO, and O3). PubMed, Embase, and Web of Science were searched to identify qualified literatures. The Cochran Q test was used to assess heterogeneity and quantified with the I2 statistic. Pooled effects and the 95% confidence intervals (CIs) were used to evaluate outcome effects. A total of 55 articles were included in the study. The results showed that long-term and short-term exposure to PM10 increased the risk of eczema (PM10, RRlong = 1.583, 95% CI: 1.328, 1.888; RRshort = 1.006, 95% CI: 1.003-1.008) and short-term exposure to NO2 (RRshort = 1.009, 95% CI: 1.008-1.011) was associated with eczema. Short-term exposure to SO2 (RRshort: 1.008, 95% CI: 1.001-1.015) was associated with the risk of AD. For AR, PM2.5 (RRlong = 1.058, 95% CI: 1.014-1.222) was harmful in the long term, and short-term exposure to PM10 (RRshort: 1.028, 95% CI: 1.008-1.049) and NO2 (RRshort: 1.018, 95% CI: 1.007-1.029) were risk factors. The findings indicated that exposure to air pollutants might increase the risk of IgE-mediated allergic diseases. Further studies are warranted to illustrate the potential mechanism for air pollutants and allergic diseases.

Indoor air pollution effects on pediatric asthma are submicron aerosol particle-dependent

The school environment is crucial for the child's health and well-being. On the other hand, the data about the role of school's aerosol pollution on the etiology of chronic non-communicable diseases remain scarce. This study aims to evaluate the level of indoor aerosol pollution in primary schools and its relation to the incidence of doctor's diagnosed asthma among younger school-age children. The cross-sectional study was carried out in 11 primary schools of Vilnius during 1 year of education from autumn 2017 to spring 2018. Particle number (PNC) and mass (PMC) concentrations in the size range of 0.3-10 µm were measured using an Optical Particle Sizer (OPS, TSI model 3330). The annual incidence of doctor's diagnosed asthma in each school was calculated retrospectively from the data of medical records. The total number of 6-11 years old children who participated in the study was 3638. The incidence of asthma per school ranged from 1.8 to 6.0%. Mean indoor air pollution based on measurements in classrooms during the lessons was calculated for each school. Levels of PNC and PMC in schools ranged between 33.0 and 168.0 particles/cm³ and 1.7-6.8 µg/m³, respectively. There was a statistically significant correlation between the incidence of asthma and PNC as well as asthma and PMC in the particle size range of 0.3-1 µm (r = 0.66, p = 0.028) and (r = 0.71, p = 0.017) respectively. No significant correlation was found between asthma incidence and indoor air pollution in the particle size range of 0.3-2.5 and 0.3-10 µm.   Conclusion: We concluded that the number and mass concentrations of indoor air aerosol pollution in primary schools in the particle size range of 0.3-1 µm are primarily associated with the incidence of doctor's diagnosed asthma among younger school-age children. What is Known: • Both indoor and outdoor aerosol pollution is associated with bronchial asthma in children. What is New: • The incidence of bronchial asthma among younger school age children is related to indoor air quality in primary schools. • Aerosol pollutants in the size range of 0.3-1 µm in contrast to larger size range particles can play major role in the etiology of bronchial asthma in children.

Association between exposure to air pollution and risk of allergic rhinitis: A systematic review and meta-analysis

BACKGROUND

Allergic rhinitis (AR) is one of the most common allergic diseases in the world, and usually persists throughout the activity. Epidemiological studies have shown a positive association between air pollution and allergic rhinitis. However, we could not find any meta-analysis of the risk of air pollutants (PM_2.5, PM₁₀, NO₂, SO₂, O₃ and CO) on the prevalence of AR in people of all ages.

OBJECTIVES

Carry out a meta-analysis on the results of recent studies (up to 2020) to present valid information about exposure to air pollution and risk of prevalence of AR.

METHODS

We systematically searched three databases for studies up to December 17, 2020, including air pollution and AR. Random effect models were conducted to estimate the pooled odds ratios (ORs) and 95% confidence intervals (95% CIs). Subgroup analysis, funnel plot, Egger's test, and the trim-and-fill method were also conducted.

RESULTS

Thirty-five studies across 12 countries, including a total of 453,470 participants, were included. The OR per 10 μg/m³ increase of pollutants was 1.13 (1.04-1.22) for PM₁₀ and 1.12 (1.05-1.20) for PM_2.5. The OR per 10 μg/m³ increment of gaseous pollutants were 1.13 (1.07-1.20) for NO₂, 1.13 (1.04-1.22) for SO₂ and 1.07 (1.01-1.12) for O₃. No significant association was observed between CO and AR. Children or adolescents are more sensitive to air pollution than adults. The effects of PM₁₀ and SO₂ were significantly stronger in Europe than Asia. The effects of air pollutants were more significant and higher in developing countries than in developed countries, except for PM₁₀. A significant difference of subgroup test was found between developed and developing countries of NO₂.

CONCLUSION

This meta-analysis showed a positive association between air pollution and the prevalence of allergic rhinitis, and identified geographic area and economic level as the potential modifiers for the association.

Loss of E-cadherin due to road dust PM2.5 activates the EGFR in human pharyngeal epithelial cells

Exposure to road dust particulate matter (PM) causes adverse health impacts on the human airway. However, the effects of road dust on the upper airway epithelium in humans remain unclear. We investigated the involvement of the epidermal growth factor receptor (EGFR) after PM with an aerodynamic diameter of < 2.5 μm (PM_2.5)-induced E-cadherin disruption of human pharyngeal epithelial cells. First, we collected road dust PM_2.5 from 10 Chinese cities, including Wuhan, Nanjing, Shanghai, Guangzhou, Chengdu, Beijing, Lanzhou, Tianjin, Harbin, and Xi'an. Human pharyngeal FaDu cells were exposed to road dust PM_2.5 at 50 μg/mL for 24 h, cytotoxicity (cell viability and lactate dehydrogenase (LDH)) was assessed, and expressions of the proinflammatory interleukin (IL)-6 and high-mobility group box 1 (HMGB1) protein, receptor for advanced glycation end products (RAGE), occludin, E-cadherin, EGFR, and phosphorylated (p)-EGFR were determined. The E-cadherin gene was then knocked down to investigate EGFR activation in FaDu cells. Exposure to road dust PM_2.5 resulted in a decrease in cell viability and increases in LDH and IL-6. Our data suggested that PM_2.5 could decrease expressions of occludin and E-cadherin and increase expressions of EGFR and p-EGFR, which was confirmed by E-cadherin-knockdown. Our results showed a negative association between the alterations in E-cadherin and total elemental components in correlation analysis, especially S, Cl, K, Ti, Mn, Fe, Cu, Zn, and Pb. Exposure to metals in PM_2.5 from road dust may lead to loss of the barrier function of the upper airway epithelium and activation of the EGFR. Our study showed the adverse effects of road dust PM_2.5 on pharyngeal epithelial cells of the human upper airway.

Effect of particulate matter exposure on the prevalence of allergic rhinitis in children: A systematic review and meta-analysis

Among various air pollutants, particulate matter (PM) is the most harmful and representative pollutant. At the same time, allergic rhinitis (AR) is getting more and more attention, so we explore the relationship between PM and the prevalence of AR among children. Then, PubMed, Web of Science, Google Scholar was used to search for relevant studies up to January 2020. Literature quality assessment was processed using the Newcastle-Ottawa Scale (NOS) evaluation scale. Adjusted odds ratio (OR) with corresponding 95% confidence interval (CI) was retrieved from individual studies and pooled to generate a summary effect via STATA software. Besides, we test the result stability by Egger's test and funnel plot, and using the trim-and-fill method to modify the possible asymmetric funnel graph. 21 studies were included in the meta-analysis. 9 articles reported about PM_2.5 on childhood AR (1.09, 95%CI: 1.01, 1.17, per 10 μg/m³ increase). 15 articles reported about PM₁₀ on childhood AR (1.06, 95%CI: 1.02,1.11, per 10 μg/m³ increase), PM_2.5 exposure has a bigger effect on children AR than PM₁₀. In addition, a series of subgroup analysis was performed, and we found that PM_2.5 and PM₁₀ have different performances in different subgroups. In addition to this, we analyzed the sources of heterogeneity of the study. Apart from the results we got all have good stability without publication bias. Therefore, it can be concluded that exposure to PM may increase the prevalence of AR among children.

Air pollution control and the occurrence of acute respiratory illness in school children of Quito, Ecuador

Because of air quality management and control, traffic-related air pollution has declined in Quito, Ecuador. We evaluated the effect of a city-wide 5-year air pollution control program on the occurrence of acute respiratory illness (ARI). We compared two studies conducted at the same location in Quito: in 2000, 2 years before the policy to control vehicle emission was introduced, and in 2007. Each study involved ~ 730 children aged 6-12 years, observed for 15 weeks. We examined associations between carboxyhemoglobin (COHb) serum concentration-an exposure proxy for carbon monoxide (CO)-ambient CO, and ARI in both cohorts. In 2007, we found a 48% reduction in the ARI incidence (RR 0.52; 95% CI 0.45-0.62, p < 0.0001), and 92% decrease in the percentage of children with COHb > 2.5% as compared to the 2000 study. We found no association between COHb concentrations above the safe level of 2.5% and the ARI incidence (p = 0.736). The decline in air pollution due to vehicle emissions control was associated with a lower incidence of respiratory illness in school children.

Interventions to reduce ambient particulate matter air pollution and their effect on health

BACKGROUND

Ambient air pollution is associated with a large burden of disease in both high-income countries (HICs) and low- and middle-income countries (LMICs). To date, no systematic review has assessed the effectiveness of interventions aiming to reduce ambient air pollution.

OBJECTIVES

To assess the effectiveness of interventions to reduce ambient particulate matter air pollution in reducing pollutant concentrations and improving associated health outcomes.

SEARCH METHODS

We searched a range of electronic databases with diverse focuses, including health and biomedical research (CENTRAL, Cochrane Public Health Group Specialised Register, MEDLINE, Embase, PsycINFO), multidisciplinary research (Scopus, Science Citation Index), social sciences (Social Science Citation Index), urban planning and environment (Greenfile), and LMICs (Global Health Library regional indexes, WHOLIS). Additionally, we searched grey literature databases, multiple online trial registries, references of included studies and the contents of relevant journals in an attempt to identify unpublished and ongoing studies, and studies not identified by our search strategy. The final search date for all databases was 31 August 2016.

SELECTION CRITERIA

Eligible for inclusion were randomized and cluster randomized controlled trials, as well as several non-randomized study designs, including controlled interrupted time-series studies (cITS-EPOC), interrupted time-series studies adhering to EPOC standards (ITS-EPOC), interrupted time-series studies not adhering to EPOC standards (ITS), controlled before-after studies adhering to EPOC standards (CBA-EPOC), and controlled before-after studies not adhering to EPOC standards (CBA); these were classified as main studies. Additionally, we included uncontrolled before-after studies (UBA) as supporting studies. We included studies that evaluated interventions to reduce ambient air pollution from industrial, residential, vehicular and multiple sources, with respect to their effect on mortality, morbidity and several air pollutant concentrations. We did not restrict studies based on the population, setting or comparison.

DATA COLLECTION AND ANALYSIS

After a calibration exercise among the author team, two authors independently assessed studies for inclusion, extracted data and assessed risk of bias. We conducted data extraction, risk of bias assessment and evidence synthesis only for main studies; we mapped supporting studies with regard to the types of intervention and setting. To assess risk of bias, we used the Graphic Appraisal Tool for Epidemiological studies (GATE) for correlation studies, as modified and employed by the Centre for Public Health Excellence at the UK National Institute for Health and Care Excellence (NICE). For each intervention category, i.e. those targeting industrial, residential, vehicular and multiple sources, we synthesized evidence narratively, as well as graphically using harvest plots.

MAIN RESULTS

We included 42 main studies assessing 38 unique interventions. These were heterogeneous with respect to setting; interventions were implemented in countries across the world, but most (79%) were implemented in HICs, with the remaining scattered across LMICs. Most interventions (76%) were implemented in urban or community settings.We identified a heterogeneous mix of interventions, including those aiming to address industrial (n = 5), residential (n = 7), vehicular (n = 22), and multiple sources (n = 4). Some specific interventions, such as low emission zones and stove exchanges, were assessed by several studies, whereas others, such as a wood burning ban, were only assessed by a single study.Most studies assessing health and air quality outcomes used routine monitoring data. Studies assessing health outcomes mostly investigated effects in the general population, while few studies assessed specific subgroups such as infants, children and the elderly. No identified studies assessed unintended or adverse effects.The judgements regarding the risk of bias of studies were mixed. Regarding health outcomes, we appraised eight studies (47%) as having no substantial risk of bias concerns, five studies (29%) as having some risk of bias concerns, and four studies (24%) as having serious risk of bias concerns. Regarding air quality outcomes, we judged 11 studies (31%) as having no substantial risk of bias concerns, 16 studies (46%) as having some risk of bias concerns, and eight studies (23%) as having serious risk of bias concerns.The evidence base, comprising non-randomized studies only, was of low or very low certainty for all intervention categories and primary outcomes. The narrative and graphical synthesis showed that evidence for effectiveness was mixed across the four intervention categories. For interventions targeting industrial, residential and multiple sources, a similar pattern emerged for both health and air quality outcomes, with essentially all studies observing either no clear association in either direction or a significant association favouring the intervention. The evidence base for interventions targeting vehicular sources was more heterogeneous, as a small number of studies did observe a significant association favouring the control. Overall, however, the evidence suggests that the assessed interventions do not worsen air quality or health.

AUTHORS' CONCLUSIONS

Given the heterogeneity across interventions, outcomes, and methods, it was difficult to derive overall conclusions regarding the effectiveness of interventions in terms of improved air quality or health. Most included studies observed either no significant association in either direction or an association favouring the intervention, with little evidence that the assessed interventions might be harmful. The evidence base highlights the challenges related to establishing a causal relationship between specific air pollution interventions and outcomes. In light of these challenges, the results on effectiveness should be interpreted with caution; it is important to emphasize that lack of evidence of an association is not equivalent to evidence of no association.We identified limited evidence for several world regions, notably Africa, the Middle East, Eastern Europe, Central Asia and Southeast Asia; decision-makers should prioritize the development and implementation of interventions in these settings. In the future, as new policies are introduced, decision-makers should consider a built-in evaluation component, which could facilitate more systematic and comprehensive evaluations. These could assess effectiveness, but also aspects of feasibility, fidelity and acceptability.The production of higher quality and more uniform evidence would be helpful in informing decisions. Researchers should strive to sufficiently account for confounding, assess the impact of methodological decisions through the conduct and communication of sensitivity analyses, and improve the reporting of methods, and other aspects of the study, most importantly the description of the intervention and the context in which it is implemented.

Estimating the health impact of air pollution in Scotland, and the resulting benefits of reducing concentrations in city centres

Air pollution continues to be a key health issue in Scotland, despite recent improvements in concentrations. The Scottish Government published the Cleaner Air For Scotland strategy in 2015, and will introduce Low Emission Zones (LEZs) in the four major cities (Aberdeen, Dundee, Edinburgh and Glasgow) by 2020. However, there is no epidemiological evidence quantifying the current health impact of air pollution in Scotland, which this paper addresses. Additionally, we estimate the health benefits of reducing concentrations in city centres where most LEZs are located. We focus on cardio-respiratory disease and total non-accidental mortality outcomes, linking them to concentrations of both particulate (PM₁₀ and PM_2.5) and gaseous (NO₂ and NO_x) pollutants. Our two main findings are that: (i) all pollutants exhibit significant associations with respiratory disease but not cardiovascular disease; and (ii) reducing concentrations in city centres with low resident populations only provides a small health benefit.

The effects of particulate matters on allergic rhinitis in Nanjing, China

Particulate matter pollution is a serious environmental problem. Individuals exposed to particulate matters have an increased prevalence to diseases. In the present study, we performed an epidemiological study to investigate the effects of particulate matter less than 10 μm in aerodynamic diameter (PM₁₀) and particulate matter less than 2.5 μm in aerodynamic diameter (PM_2.5) on allergic rhinitis in Nanjing, China. Daily numbers of allergic rhinitis patients (33,063 patients), PM₁₀, PM_2.5, and weather data were collected from January 2014 to December 2016 in Nanjing, China. Generalized additive models (GAM) were used to evaluate the effects of PM₁₀ and PM_2.5 on allergic rhinitis. We found that the interquartile range (IQR) increases in PM₁₀ (difference of estimates, 5.86%; 95% CI, 3.00-8.81%; P = 4.72 × 10^-5) and PM_2.5 (difference of estimates, 5.39%; 95% CI, 2.73-8.12%; P = 5.67 × 10^-5) concentrations were associated with the higher increased numbers of allergic rhinitis patients with 3-day cumulative effects in single-pollutant model. In addition, we found that the IQR increase in PM₁₀ (age ≥ 18 years: 7.37%, 3.91-10.96%, 2.14 × 10^-5; 0-17 years: 0.83%, - 4.00-5.91%, 0.740) and PM_2.5 (age ≥ 18 years: 7.00%, 3.78-10.32%, 1.40 × 10^-5; 0-17 years: 0.40%, - 4.10-5.10%, 0.866) increased the number of allergic rhinitis patients in adults, but not in children. In summary, our findings suggested that exposure to PM₁₀ and PM_2.5 was associated with the risk of allergic rhinitis.

Changes in the relationship between childhood asthma and ambient air pollution in Taiwan: Results from a nationwide survey repeated 5 years apart

BACKGROUND

Childhood asthma is a common disease whose prevalence is changing. Shift in environmental exposure was one of the plausible explanations. This study investigated changes in the association between childhood asthma and ambient air pollution occurring over time.

METHOD

A nationwide questionnaire survey concerning respiratory illness and symptoms was administered to Taiwanese elementary and middle school students in 2011 and repeatedly in 2016-2017. During the study period, the concentrations of ambient air pollutants were obtained from the Environmental Protection Administration (EPA) monitoring stations. Generalized estimating equation models were applied to examine the association between air pollution in the past year and the risk of current asthma.

RESULTS

A total of 6346 children from the 2011 survey and 11 585 children from the 2016-2017 survey attended schools located within a 1-km radius of Taiwan EPA monitoring stations. The prevalence of childhood current asthma (children with physician-diagnosed asthma and persistent asthma symptoms in the past year) increased from 7.5% to 9.6% during this period. The level of exposure to particulate matter with an aerodynamic diameter of ≤2.5 μm (PM_2.5 ) in the past year was found to be associated with current asthma both in the 2011 survey (odds ratio (OR): 1.90, 95% confidence interval (CI): 1.41-2.57) and in the 2016-2017 survey (OR: 1.24, 95% CI: 1.04-1.48).

CONCLUSION

Improved air quality has reduced the effect of PM_2.5 on childhood asthma, but air quality remains a health concern in Taiwan.

Neighborhood air pollution and household environmental health as it relates to respiratory health and healthcare utilization among elderly persons with asthma

Objective: The study investigated the associations between fine particulate matter (PM_2.5; <2.5 μm in diameter), indoor environment, pulmonary function, and healthcare utilization in a vulnerable group of elderly persons with asthma. We hypothesized that environmental conditions were associated with adverse pulmonary health outcomes. Methods: The study involved elderly (n = 76; mean age 64.6 years; 48 women) vulnerable persons in Detroit, Michigan, USA, with physician-diagnosed asthma. Exposure variables included measured outdoor PM_2.5, self-rated outdoor and household environmental pollutants. Outcome variables were self-rated and measured pulmonary function, and asthma-related healthcare utilization. Results: Mean ambient PM_2.5 concentrations during the study was 14.14 ± (S.D. 6.36) µg/m³ during the summer and 14.20 (6.33) during the winter (p = 0.95). In multiple regression analyses, adjusting for age and gender, mean 6-month concentration of PM_2.5 was related to shortness of breath (SHOB; standardized β = 0.26, p = 0.02) and inversely with self-rated respiratory health (SRRH; β = 0.28, p = 0.02). However, PM_2.5 did not predict lung function (FEV₁% predicted and FEV₁/FVC). However, PM_2.5 was related to use of asthma controller drugs (β = 0.38, p = 0.001). Participants' air pollution ratings predicted total healthcare utilization (β = 0.33, p = 0.01). Conclusions: In elderly persons with asthma, living near heavy industry and busy highways, objective and perceived environmental pollution relate to participants' respiratory health and healthcare utilization. Importantly, air pollution might increase use of asthma controller drugs containing corticosteroids with implication for elderly persons' risk to develop osteoporosis and cardiovascular disease.

The potential of omics approaches to elucidate mechanisms of biodiesel-induced pulmonary toxicity

BACKGROUND

Combustion of biodiesels in place of fossil diesel (FD) has been proposed as a method of reducing transport-related toxic emissions in Europe. While biodiesel exhaust (BDE) contains fewer hydrocarbons, total particulates and carbon monoxide than FD exhaust (FDE), its high nitrogen oxide and ultrafine particle content may still promote pulmonary pathophysiologies.

MAIN BODY

Using a complement of in vitro and in vivo studies, this review documents progress in our understanding of pulmonary responses to BDE exposure. Focusing initially on hypothesis-driven, targeted analyses, the merits and limitations of comparing BDE-induced responses to those caused by FDE exposure are discussed within the contexts of policy making and exploration of toxicity mechanisms. The introduction and progression of omics-led workflows are also discussed, summarising the novel insights into mechanisms of BDE-induced toxicity that they have uncovered. Finally, options for the expansion of BDE-related omics screens are explored, focusing on the mechanistic relevance of metabolomic profiling and offering rationale for expansion beyond classical models of pulmonary exposure.

CONCLUSION

Together, these discussions suggest that molecular profiling methods have identified mechanistically informative, novel and fuel-specific signatures of pulmonary responses to biodiesel exhaust exposure that would have been difficult to detect using traditional, hypothesis driven approaches alone.

Impact of London's low emission zone on air quality and children's respiratory health: a sequential annual cross-sectional study

BACKGROUND

Low emission zones (LEZ) are an increasingly common, but unevaluated, intervention aimed at improving urban air quality and public health. We investigated the impact of London's LEZ on air quality and children's respiratory health.

METHODS

We did a sequential annual cross-sectional study of 2164 children aged 8-9 years attending primary schools between 2009-10 and 2013-14 in central London, UK, following the introduction of London's LEZ in February, 2008. We examined the association between modelled pollutant exposures of nitrogen oxides (including nitrogen dioxide [NO₂]) and particulate matter with a diameter of less than 2·5 μm (PM_2·5) and less than 10 μm (PM₁₀) and lung function: postbronchodilator forced expiratory volume in 1 s (FEV₁, primary outcome), forced vital capacity (FVC), and respiratory or allergic symptoms. We assigned annual exposures by each child's home and school address, as well as spatially resolved estimates for the 3 h (0600-0900 h), 24 h, and 7 days before each child's assessment, to isolate long-term from short-term effects.

FINDINGS

The percentage of children living at addresses exceeding the EU limit value for annual NO₂ (40 μg/m³) fell from 99% (444/450) in 2009 to 34% (150/441) in 2013. Over this period, we identified a reduction in NO₂ at both roadside (median -1·35 μg/m³ per year; 95% CI -2·09 to -0·61; p=0·0004) and background locations (-0·97; -1·56 to -0·38; p=0·0013), but not for PM₁₀. The effect on PM_2·5 was equivocal. We found no association between postbronchodilator FEV₁ and annual residential pollutant attributions. By contrast, FVC was inversely correlated with annual NO₂ (-0·0023 L/μg per m³; -0·0044 to -0·0002; p=0·033) and PM₁₀ (-0·0090 L/μg per m³; -0·0175 to -0·0005; p=0·038).

INTERPRETATION

Within London's LEZ, a smaller lung volume in children was associated with higher annual air pollutant exposures. We found no evidence of a reduction in the proportion of children with small lungs over this period, despite small improvements in air quality in highly polluted urban areas during the implementation of London's LEZ. Interventions that deliver larger reductions in emissions might yield improvements in children's health.

FUNDING

National Institute for Health Research Biomedical Research Centre at Guy's and St Thomas' National Health Service (NHS) Foundation Trust and King's College London, NHS Hackney, Lee Him donation, and Felicity Wilde Charitable Trust.

Particulate matter and childhood allergic diseases

Particulate matter (PM) is a ubiquitous air pollutant that is a growing public health concern. Previous studies have suggested that PM is associated with asthma development and exacerbation of asthma symptoms. Although several studies have suggested increased risks of atopic dermatitis, allergic rhinitis, and allergic sensitization in relation to PM exposure, the evidence remains inconsistent. The plausible mechanisms underlying these effects are related to oxidative stress, enhancement of sensitization to allergens, inflammatory and immunological responses, and epigenetics. This review discusses the effect of PM on childhood allergic diseases, along with plausible mechanisms. Further studies are required to understand the role of PM exposure on childhood allergic diseases, to reduce these diseases in children.

Students’ Decision-Making in Education for Sustainability-Related Extracurricular Activities—A Systematic Review of Empirical Studies

Equipping students with the capability to perform considerate decision-making is a key competence to elaborate socio-scientific issues. Particularly in the socio-scientific context of sustainable development, decision-making is required for the processing of information and the implementation of sustainable action. Extracurricular activities in education for sustainable development (ESD) offer a suitable format to promote decision-making due to their multidisciplinary and more informal structure. The purpose of this literature review is therefore to analyze empirical studies that explore students’ (1) decision-making in (2) ESD-related (3) extracurricular activities. Following the preferred-reporting of items for systematic reviews and meta-analyses (PRISMA) guidelines, a systematic search yielded 19 out of 365 articles, each of them addressing all three components. Despite the theoretical relationship, hardly any empirical enquiry is found examining the trinomial interrelation with an equal consideration of all components. Contrarily, we argue that each is positioned in favor for only one component with the others serving as a backdrop. It follows that the full potential of an equal distribution between all three foci has not been explored yet; even though integrating sustainability-related issues in extracurricular activities displays a promising learning opportunity to optimally foster students’ decision-making. Instead, studies that concentrate primarily on decision-making as a quantitatively measurable competence were predominant.

Exposure to air pollution and risk of prevalence of childhood allergic rhinitis: A meta-analysis

OBJECTIVES

Allergic rhinitis (AR), a common chronic inflammatory disease in the upper airways. The prevalence of AR in children seems to be increasing recently, and the most significant causes of the increase are thought to be changes in environmental factors, especially air pollution. However, we could not find any meta-analysis on the risk of air pollution exposure on the prevalence of AR in childhood. The aim of this research was to carry out a meta-analysis on the results of recent studies (21 s t century) to present valid information about exposure to air pollution and risk of prevalence of childhood AR.

METHODS

PubMed, Science, Google Scholar, Elsevier and MDPI web database were searched up to January 1, 2000 to February 28, 2018. Including of air pollution and AR in childhood related to the observation of literature. Meta-analysis, study quality assessment, heterogeneity analysis and publication bias test were using Stata-MP 14.1 and Review Manager version 5.3 software.

RESULTS

13 studies will be included in the meta-analysis (8 cross-sectional studies, 5 cohort studies). Exposure to NO₂ (OR_Europe = 1.031, 95%CI [1.002,1.060], P = 0.033; OR_Asia = 1.236, 95%CI [1.099,1.390], P = 0.000; OR_overall = 1.138, 95%CI [1.052,1.231], P = 0.001); Exposure to SO₂ (OR_Europe = 1.148, 95%CI [1.030,1.279], P = 0.012; OR_Asia = 1.044, 95%CI [0.954,1.142], P = 0.352; OR_overall = 1.085, 95%CI [1.013,1.163], P = 0.020); Exposure to PM₁₀ (OR_Europe = 1.190, 95%CI [1.092,1.297], P = 0.000; OR_Asia = 1.075, 95%CI [0.995,1.161], P = 0.066; OR_overall = 1.125, 95%CI [1.062,1.191], P = 0.000); Exposure to PM_2.5 (OR_Europe = 1.195, 95%CI [1.050,1.360], P = 0.007; OR_Asia = 1.163, 95%CI [1.074,1.260], P = 0.000; OR_overall = 1.172, 95%CI [1.095,1.254], P = 0.000).

CONCLUSIONS

Exposed to air pollution probable is a risk of prevalence of childhood AR. And the prevalence of AR will be increase when exposed to NO₂, SO₂, PM₁₀ and PM_2.5, but maybe the relationship between SO₂/PM₁₀ and prevalence of AR are not closely in Asia.

T-Helper Type 1-T-Helper Type 2 Shift and Nasal Remodeling after Fine Particulate Matter Exposure in a Rat Model of Allergic Rhinitis

Background

Exposure to fine particulate matter (particulate matter ≤2.5 μm [PM2.5]) increases the risk of allergic rhinitis (AR), but the underlying mechanisms remains unclear. Thus, we investigated the roles of T-helper (Th)1–Th2 cytokines and nasal remodeling after ambient PM2.5 exposure in a rat model of AR.

Methods

Female Sprague-Dawley rats were randomized into six groups: a negative control group, a group of healthy rats exposed to 3000 μg/m3 PM2.5, an ovalbumin (OVA) induced AR model, and three PM2.5-exacerbated AR groups exposed to three different concentrations (200, 1000, and 3000 μg/m3) of PM2.5 for 30 days via inhalation. Nasal symptoms, levels of Th1–Th2 cytokines, the degree of eosinophilia in nasal lavage fluid (NLF), and the messenger RNA (mRNA) expressions of transcription factors GATA-3 and T-bet in the nasal mucosa were measured in each individual rat. Hyperplasia of globet cells and collagen deposition were examined by histology.

Results

PM2.5 significantly increased the number of sneezes and nasal rubs in rats with AR. PM2.5 also significantly decreased interferon gamma and increased interleukin (IL) 4 and IL-13 expressions as well as the number of eosinophils in NLF. The mRNA expression of GATA-3 in the nasal mucosa of rats with AR was upregulated by PM2.5, whereas T-bet was significantly downregulated. Statistically significant differences in OVA-specific serum immunoglobulin E, goblet cell hyperplasia, collagen deposition, and transforming growth factor beta 1 levels were observed between the PM2.5-exacerbated AR groups and the AR model group.

Conclusion

Analysis of our data indicated that an increase in the immune response with Th2 polarization and the development of nasal remodeling may be the immunotoxic mechanisms behind the exacerbation of AR after exposure to PM2.5.

'Every breath we take: the lifelong impact of air pollution' - a call for action

Air pollution has become one of the major risks to human health because of the progressive increase in the use of vehicles powered by fossil fuels. While the risks of air pollution to health were thought to have been brought under control by the Clean Air Acts of the 1950s and 1960s, the situation of air pollution in the UK has now deteriorated to a point where it is contributing to 40,000 excess deaths each year. Here the findings of the RCP/RCPCH's 2015/16 Working Party on Air Pollution and Health are described and what actions now need to be taken. The UK needs to take a lead and introduce a new Clean Air Act that deals with the vehicle sources of pollution recognising that the toxic particles and gases emitted are effecting individuals from conception to death. This mandates urgent action by government both central and local, but also by all of us who have now become so dependent on road transport.

Land use, transport, and population health: estimating the health benefits of compact cities

Using a health impact assessment framework, we estimated the population health effects arising from alternative land-use and transport policy initiatives in six cities. Land-use changes were modelled to reflect a compact city in which land-use density and diversity were increased and distances to public transport were reduced to produce low motorised mobility, namely a modal shift from private motor vehicles to walking, cycling, and public transport. The modelled compact city scenario resulted in health gains for all cities (for diabetes, cardiovascular disease, and respiratory disease) with overall health gains of 420-826 disability-adjusted life-years (DALYs) per 100 000 population. However, for moderate to highly motorised cities, such as Melbourne, London, and Boston, the compact city scenario predicted a small increase in road trauma for cyclists and pedestrians (health loss of between 34 and 41 DALYs per 100 000 population). The findings suggest that government policies need to actively pursue land-use elements-particularly a focus towards compact cities-that support a modal shift away from private motor vehicles towards walking, cycling, and low-emission public transport. At the same time, these policies need to ensure the provision of safe walking and cycling infrastructure. The findings highlight the opportunities for policy makers to positively influence the overall health of city populations.

Air pollution, ethnicity and telomere length in east London schoolchildren: An observational study

BACKGROUND

Short telomeres are associated with chronic disease and early mortality. Recent studies in adults suggest an association between telomere length and exposure to particulate matter, and that ethnicity may modify the relationship. However associations in children are unknown.

OBJECTIVES

We examined associations between air pollution and telomere length in an ethnically diverse group of children exposed to high levels of traffic derived pollutants, particularly diesel exhaust, and to environmental tobacco smoke.

METHODS

Oral DNA from 333 children (8-9years) participating in a study on air quality and respiratory health in 23 inner city London schools was analysed for relative telomere length using monochrome multiplex qPCR. Annual, weekly and daily exposures to nitrogen oxides and particulate matter were obtained from urban dispersion models (2008-10) and tobacco smoke by urinary cotinine. Ethnicity was assessed by self-report and continental ancestry by analysis of 28 random genomic markers. We used linear mixed effects models to examine associations with telomere length.

RESULTS

Telomere length increased with increasing annual exposure to NO_x (model coefficient 0.003, [0.001, 0.005], p<0.001), NO₂ (0.009 [0.004, 0.015], p<0.001), PM_2.5 (0.041, [0.020, 0.063], p<0.001) and PM₁₀ (0.096, [0.044, 0.149], p<0.001). There was no association with environmental tobacco smoke. Telomere length was increased in children reporting black ethnicity (22% [95% CI 10%, 36%], p<0.001) CONCLUSIONS: Pollution exposure is associated with longer telomeres in children and genetic ancestry is an important determinant of telomere length. Further studies should investigate both short and long-term associations between pollutant exposure and telomeres in childhood and assess underlying mechanisms.