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  1. Andrew P Prayle1,2
  1. 1 Division of Child Health, Obstetrics and Gynaecology, University of Nottingham, Nottingham, UK
  2. 2 Nottingham Children's Hospital, Nottingham University Hospitals NHS Trust, Nottingham, UK
  1. Correspondence to Dr Andrew P Prayle, Division of Child Health, Obstetrics and Gynaecology, University of Nottingham, Nottingham NG7 2RD, UK; andrew.prayle{at}

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Ambient air quality and asthma development in children

The link between poor air quality and paediatric asthma exacerbations is well-established. Surprisingly, this is less clear for ambient air pollutants and asthma incidence. Garcia et al (JAMA 2019;321:1906) undertook a longitudinal epidemiological study and found that as air quality improved, the incidence of childhood asthma reduced. Using data from three cohorts of school children, recruited between 1993 and 2014 from California, USA, they analysed trends in incidence of asthma, exploring the influence of air pollution (estimated using community-level data). Children in the cohort were followed-up annually, and the primary outcome was when the parents/guardians answered yes to the question ‘Has a doctor ever diagnosed this child with asthma?’. Air pollution decreased over time, and in parallel, asthma incidence decreased. In the fully adjusted model, the incidence risk ratio (IRR) for each 4.3ppb drop in nitrogen dioxide was 0.80 (95% CI 0.71 to 0.90), and for a drop of 8.1 µg/m3 in the levels of PM2.5 (particulate matter less than or equal to 2.5 diameter), the IRR was 0.81 (95% CI 0.67 to 0.98). Relationships with PM10 (particulate matter unde 10μm diameteand ozone were not statistically significant. Whether the pollutants are causal, or are markers for other factors, is, of …

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  • Funding Andrew Prayle is supported by a NIHR Academic Clinical Lecturer post.

  • Competing interests None declared.

  • Patient consent for publication Not required.

  • Ethics approval Not required.

  • Provenance and peer review Commissioned; internally peer reviewed.

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