title: Quantifying the impact of current and future concentrations of air pollutants on respiratory disease risk in England.
abstract: Estimating the long-term health impact of air pollution in a spatio-temporal ecological study requires representative concentrations of air pollutants to be constructed for each geographical unit and time period. Averaging concentrations in space and time is commonly carried out, but little is known about how robust the estimated health effects are to different aggregation functions. A second under researched question is what impact air pollution is likely to have in the future.
  
  
  
  We conducted a study for England between 2007 and 2011, investigating the relationship between respiratory hospital admissions and different pollutants: nitrogen dioxide (NO2); ozone (O3); particulate matter, the latter including particles with an aerodynamic diameter less than 2.5 micrometers (PM2.5), and less than 10 micrometers (PM10); and sulphur dioxide (SO2). Bayesian Poisson regression models accounting for localised spatio-temporal autocorrelation were used to estimate the relative risks (RRs) of pollution on disease risk, and for each pollutant four representative concentrations were constructed using combinations of spatial and temporal averages and maximums. The estimated RRs were then used to make projections of the numbers of likely respiratory hospital admissions in the 2050s attributable to air pollution, based on emission projections from a number of Representative Concentration Pathways (RCP).
  
  
  
  NO2exhibited the largest association with respiratory hospital admissions out of the pollutants considered, with estimated increased risks of between 0.9 and 1.6% for a one standard deviation increase in concentrations. In the future the projected numbers of respiratory hospital admissions attributable to NO2in the 2050s are lower than present day rates under 3 Representative Concentration Pathways (RCPs): 2.6, 6.0, and 8.5, which is due to projected reductions in future NO2emissions and concentrations.
  
  
  
  NO2concentrations exhibit consistent substantial present-day health effects regardless of how a representative concentration is constructed in space and time. Thus as concentrations are predicted to remain above limits set by European Union Legislation until the 2030s in parts of urban England, it will remain a substantial health risk for some time.
authors.affiliation: School of Mathematics and Statistics, University of Glasgow, Glasgow, G12 8QW, UK. francesca.pannullo@glasgow.ac.uk.
authors.forename: Francesca
authors.identifier: 0000-0001-8779-7638
authors.initials: F
authors.lastname: Pannullo
authors.affiliation: School of Mathematics and Statistics, University of Glasgow, Glasgow, G12 8QW, UK.
authors.forename: Duncan
authors.initials: D
authors.lastname: Lee
authors.affiliation: Met Office, FitzRoy Road, Exeter, EX1 3PB, UK.
authors.forename: Lucy
authors.initials: L
authors.lastname: Neal
authors.affiliation: Met Office Hadley Centre, FitzRoy Road, Exeter, EX1 3PB, UK.
authors.forename: Mohit
authors.initials: M
authors.lastname: Dalvi
authors.affiliation: Met Office, FitzRoy Road, Exeter, EX1 3PB, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Agnew
authors.affiliation: Met Office Hadley Centre, FitzRoy Road, Exeter, EX1 3PB, UK.
authors.forename: Fiona M
authors.initials: FM
authors.lastname: O'Connor
authors.affiliation: Mathematical Sciences, University of Southampton, Highfield, Southampton, SO17 1BJ, UK.
authors.forename: Sabyasachi
authors.initials: S
authors.lastname: Mukhopadhyay
authors.affiliation: Mathematical Sciences, University of Southampton, Highfield, Southampton, SO17 1BJ, UK.
authors.forename: Sujit
authors.initials: S
authors.lastname: Sahu
authors.affiliation: Met Office, FitzRoy Road, Exeter, EX1 3PB, UK.
authors.forename: Christophe
authors.initials: C
authors.lastname: Sarran
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D001499:Bayes Theorem; D004739:England / Q000453:epidemiology; D004784:Environmental Monitoring; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D009585:Nitrogen Dioxide / Q000032:analysis*; D010126:Ozone / Q000032:analysis; D052638:Particulate Matter / Q000032:analysis; D012140:Respiratory Tract Diseases / Q000453:epidemiology*; D012306:Risk; D013458:Sulfur Dioxide / Q000032:analysis
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D013458:Sulfur Dioxide; D010126:Ozone; D009585:Nitrogen Dioxide
keywords: Air pollution; Present day and future health effects; Spatio-temporal ecological study