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.
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 (PM2·5) 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.
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 PM2·5 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).
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.
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.
The adverse effects of traffic-related air pollution on children's respiratory health have been widely reported, but few studies have evaluated the impact of traffic-control policies designed to ...reduce urban air pollution. We assessed associations between traffic-related air pollutants and respiratory/allergic symptoms amongst 8-9 year-old schoolchildren living within the London Low Emission Zone (LEZ). Information on respiratory/allergic symptoms was obtained using a parent-completed questionnaire and linked to modelled annual air pollutant concentrations based on the residential address of each child, using a multivariable mixed effects logistic regression analysis. Exposure to traffic-related air pollutants was associated with current rhinitis: NOx (OR 1.01, 95% CI 1.00-1.02), NO2 (1.03, 1.00-1.06), PM10 (1.16, 1.04-1.28) and PM2.5 (1.38, 1.08-1.78), all per μg/m3 of pollutant, but not with other respiratory/allergic symptoms. The LEZ did not reduce ambient air pollution levels, or affect the prevalence of respiratory/allergic symptoms over the period studied. These data confirm the previous association between traffic-related air pollutant exposures and symptoms of current rhinitis. Importantly, the London LEZ has not significantly improved air quality within the city, or the respiratory health of the resident population in its first three years of operation. This highlights the need for more robust measures to reduce traffic emissions.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Obesity affects ethnic minority groups disproportionately, especially in the pediatric population. However, little is known about the impact of obesity on health-related quality of life (HRQoL) in ...children and adolescents from mixed-ethnic samples. The purpose of this study was to: 1) measure HRQoL in a mixed-ethnic clinical sample of obese children and adolescents, 2) compare HRQoL assessments in obese participants and healthy controls, and 3) compare HRQoL in obese children and adolescents according to their pubertal status.
A clinical sample of children and adolescents with obesity (n = 96) and healthy children and adolescents attending local schools (n = 444) completed the Pediatric Quality of Life Inventory (PedsQL; UK version 4). Age-appropriate versions were self-administered by children and adolescents aged 8-18 years, and interview administered to children aged 5-7 years. Multiple regression analyses controlling for age, gender, pubertal status, and ethnicity were used to compare the PedsQL scores of the two samples.
The clinical sample of obese children and adolescents had poorer HRQoL scores on all dimensions of the PedsQL compared to the healthy controls (p < 0.005). Subsequent analyses also demonstrated that in this sample of mixed-ethnic children and adolescents, prepubescent obese children achieved the poorest scores in the emotional functioning dimension.
Obesity significantly impacts on physical, emotional, social and school functioning of mixed-ethnic children and adolescents. Clinicians need to be aware of the significant impact of obesity on all aspects of functioning. More effort is required to target interventions to improve the quality of life of children with obesity.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract Background Airway macrophages clear inhaled soot (black carbon) from traffic fumes. Macrophages from children with asthma have impaired phagocytosis of bacteria, and prostaglandin E2 (PGE2) ...is associated with impaired phagocytosis by macrophages. We sought to assess whether macrophage phagocytosis of soot was impaired, and to measure prostanoid metabolites, in children with asthma. Methods In this cross-sectional study, airway macrophages were obtained from 72 children aged 7–14 years by sputum induction with nebulised 4·5% saline. Children were classified as: healthy controls (n=39); mild asthma, defined as British Thoracic Society (BTS) step 1–2 (n=13); or moderate-to-severe asthma (BTS step 3–5) (n=20), and recruited from a UK paediatric outpatient clinic. Healthy controls were recruited as part of the London Low Emission Zone study. Macrophage black carbon was assessed with image analysis by an assessor masked to asthma severity. Exposure to air pollution was calculated by means of the London Air Quality Toolkit. Urinary PGE2 metabolites were measured with high performance liquid chromatography-tandem mass spectrometry. The effect of PGE2 on phagocytosis of black carbon by rat airway macrophages was assessed with an in-vitro phagocytosis assay using urban particulate matter collected from air filters placed at city centre sites in Leicester, UK. Written informed consent was obtained from children and parents (Research Ethics Committee reference 11-LO-1732 and 08/H0704/139). Findings Children with moderate-to-severe asthma had lower airway macrophage black carbon than did controls (median 0·19 mm2 IQR 0·11–0·26 vs 0·35 0·16–0·49, p<0·0366, Mann-Whitney U test). Airway macrophage black carbon in children with mild asthma was much the same as in controls. Air pollution exposure at the home address did not differ between groups. Moderate to severe asthma was associated with an increase in the urinary PGE2 metabolite, 13,14-dihydro-15-keto-tetranor-PGE2 (median 668 pg/mg creatinine IQR 293–937 vs 471 315–623, p<0·05, Mann-Whitney U test). In the 33 children with asthma, this urinary PGE2 metabolite was inversely associated with macrophage carbon (Spearman r =−0·47, p<0·0062). PGE2 suppressed phagocytosis by rat airway macrophages of urban particulate matter to 57% (IQR 41–95) of controls (p<0·0215, Wilcoxon signed rank test). Interpretation Macrophage phagocytosis of black carbon derived from fossil fuel is impaired in moderate-to-severe childhood asthma. This process is associated with raised urinary concentrations of 13,14-dihydro-15-keto-tetranor-PGE2. PGE2 also impairs phagocytosis of black carbon and urban particulate matter by rat airway macrophages in vitro, and is therefore a plausible mediator underlying the impaired phagocytosis seen in macrophages from children with asthma. We now aim to replicate these findings in differentiated human macrophages and to establish airway concentrations of PGE2 from exhaled breath condensate samples taken from these children. Our results suggest a possible mechanism underlying the observation that traffic-derived air pollution adversely affects children with asthma, because they may be less able to clear inhaled particles effectively. Funding Barts and The London Charity.
Modelling studies suggest that urban cycling is associated with an increased inhaled dose of fossil fuel-derived black carbon (BC). Using the amount of black material in airway macrophages as a ...marker of long-term inhaled BC, we sought to compare inhaled BC dose in London (UK) cyclists and non-cyclists. Airway macrophage carbon was assessed in 28 (58%) out of 48 healthy adults (14 cyclists and 14 non-cyclists) who attended for induced sputum. Short-term (24 h) exposure to BC was assessed on a representative working day in 27 out of 28 subjects. Serum interleukin (IL)-1β, IL-2, IL-6, IL-8, granulocyte-macrophage colony-stimulating factor and tumour necrosis factor (TNF)-α were assessed in 26 out of the 28 subjects. Cyclists were found to have increased airway macrophage carbon when compared with non-cyclists (mean ± se 1.81 ± 0.21 versus 1.11 ± 0.07 μm(2); p<0.01). Short-term monitoring showed no difference in 24 h BC exposure between the two groups. However, cyclists were exposed to higher concentrations of BC during commuting (p<0.01). Airway macrophage carbon was associated with monitored commute BC (n=28; r=0.47, p<0.05). TNF-α was found to be increased in cyclists (p<0.05), but no other cytokines were increased. Commuting to work by bicycle in London is associated with increased long-term inhaled dose of BC. Whether cycling per se increases inhaled BC dose remains unclear.
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.
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.
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.
Telomere length increased with increasing annual exposure to NOx (model coefficient 0.003, 0.001, 0.005, p<0.001), NO2 (0.009 0.004, 0.015, p<0.001), PM2.5 (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)
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.
•This is the first study on air pollution and telomere length in children.•Genetic ancestry is a major determinant of telomere length in children.•Continuous exposure to pollution is associated with telomere elongation.•Future research should investigate longitudinal effects on telomeres.
Airway macrophage (AM) phagocytosis is impaired in severe asthma. Prostaglandin (PG) E2 and D2 are increased in severe asthma and suppress AM phagocytic function in vitro. In this study, we sought ...evidence for PG-mediated impairment of phagocytosis of inhalable carbonaceous particulate matter (PM) by AM in children with severe asthma compared with mild asthmatics and healthy controls.
AM were obtained from children with asthma and healthy controls using induced sputum. AM carbon area (μm(2)) was assessed by image analysis. In a subgroup of asthmatics, urinary PGE2 and PGD2 metabolites were measured by high-performance liquid chromatography, and PM exposure at the home address was modelled. Phagocytosis of PM by human monocyte-derived macrophages and rat AM was assessed in vitro by image analysis.
AM carbon was 51% lower in children with moderate-to-severe asthma (n=36) compared with mild asthmatics (n=12, p<0.01) and healthy controls (n=47, p<0.01). There was no association between modelled PM exposure and AM carbon in 33 asthmatics who had a urine sample, but there was an inverse association between AM carbon and urinary metabolites of PGE2 and D2 (n=33, rs=-0.40, p<0.05, and rs=-0.44, p<0.01). PGE2 10(-6) M, but not PGD2 10(-6) M, suppressed phagocytosis of PM10 by human macrophages in vitro (p<0.05 vs control). PGE2 10(-6) M also suppressed phagocytosis of PM10 by rat AM in vitro (p<0.01 vs control).
Phagocytosis of inhaled carbonaceous PM by AMs is impaired in severe asthma. PGE2 may contribute to impaired AM phagocytic function in severe asthma.
Spirometry in the diagnosis of asthma in children Dundas, Isobel; Mckenzie, Sheila
Current opinion in pulmonary medicine,
2006-January, 2006-Jan, 2006-01-00, 20060101, Letnik:
12, Številka:
1
Journal Article
PURPOSE OF REVIEWTo review the diagnostic accuracy of lung function measurements made using spirometry for childhood asthma, recent guidelines for the measurement and interpretation of spirometric ...lung function tests and recent developments for diagnosing asthma.
RECENT FINDINGSMeasurements of lung function and bronchial lability made using spirometry may not perform any better than other tests such as skin prick testing, or measurements of exhaled nitric oxide for diagnosing asthma. New guidelines are available.
SUMMARYSpirometry is a simple, robust and widely available tool for investigating lung function. There are published guidelines for making measurements and their interpretation. The place of spirometry in the diagnosis of asthma, however, needs clarification. The diagnostic profiles of measurements of bronchodilator responsiveness and bronchial hyperreactivity made using spirometry, although reasonable, are not perfect. In schoolchildren, they are no better than knowledge of aeroallergen sensitization when considering a diagnosis of asthma.
The adverse effects of traffic-related air pollution on children's respiratory health have been widely reported, but few studies have evaluated the impact of traffic-control policies designed to ...reduce urban air pollution. We assessed associations between traffic-related air pollutants and respiratory/allergic symptoms amongst 8-9 year-old schoolchildren living within the London Low Emission Zone (LEZ). Information on respiratory/allergic symptoms was obtained using a parent-completed questionnaire and linked to modelled annual air pollutant concentrations based on the residential address of each child, using a multivariable mixed effects logistic regression analysis. Exposure to traffic-related air pollutants was associated with current rhinitis: NOx (OR 1.01, 95% CI 1.00-1.02), NO2 (1.03, 1.00-1.06), PM10 (1.16, 1.04-1.28) and PM2.5 (1.38, 1.08-1.78), all per Mg/m3 of pollutant, but not with other respiratory/allergic symptoms. The LEZ did not reduce ambient air pollution levels, or affect the prevalence of respiratory/allergic symptoms over the period studied. These data confirm the previous association between traffic-related air pollutant exposures and symptoms of current rhinitis. Importantly, the London LEZ has not significantly improved air quality within the city, or the respiratory health of the resident population in its first three years of operation. This highlights the need for more robust measures to reduce traffic emissions.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Extracorporeal membrane oxygenation (ECMO) improves survival in mature neonates with reversible lung disease. However, ECMO could result in survival of infants with severe respiratory dysfunction who ...would otherwise have died. Alternatively, infants receiving ECMO might be spared prolonged ventilation and consequent barotrauma, resulting in improved respiratory function. Our aim was to compare respiratory function at 1 yr of age in infants assigned to receive either ECMO or conventional management (CM). Seventy-eight surviving infants of the United Kingdom (UK) ECMO trial (51 in the ECMO group) were studied at 1 yr of age. Questionnaires provided details of respiratory symptoms, and laboratory measurements of respiratory function were made for respiratory rate, tidal volume, lung volume, airway conductance, specific airway conductance, and maximal expiratory flow at FRC (Vmax (FRC)). Data were exchanged on floppy disk for cross-analysis and to ensure that investigators were blinded to the status of the infants. There was a wide spectrum of respiratory function, from normal to markedly abnormal. There were few differences between the groups, but in the CM group lung volume was increased (95% confidence intervals CIs of the difference in ECMO versus CM subjects: -67; -4 ml), and inspiratory specific conductance was lower (95% CI: 0.03; 0.98 s(-)(1). kPa(-)(1)). There was a trend toward a lower V max(FRC) (95% CI: -2; 67 ml/s(-)(1) in the CM group. In addition to providing a survival advantage, ECMO did not worsen lung function in infants assigned to receive it. Indeed, their lung function appeared slightly better than that of infants treated conventionally.
PDF
