title: High resolution exposure modelling of heat and air pollution and the impact on mortality.
abstract: BACKGROUND
  Elevated temperature and air pollution have been associated with increased mortality. Exposure to heat and air pollution, as well as the density of vulnerable groups varies within cities. The objective was to investigate the extent of neighbourhood differences in mortality risk due to heat and air pollution in a city with a temperate maritime climate.
  
  
  METHODS
  A case-crossover design was used to study associations between heat, air pollution and mortality. Different thermal indicators and air pollutants (PM10, NO2, O3) were reconstructed at high spatial resolution to improve exposure classification. Daily exposures were linked to individual mortality cases over a 15year period.
  
  
  RESULTS
  Significant interaction between maximum air temperature (Tamax) and PM10 was observed. During "summer smog" days (Tamax>25°C and PM10>50μg/m(3)), the mortality risk at lag 2 was 7% higher compared to the reference (Tamax 15°C and PM10 15μg/m(3)). Persons above age 85 living alone were at highest risk.
  
  
  CONCLUSIONS
  We found significant synergistic effects of high temperatures and air pollution on mortality. Single living elderly were the most vulnerable group. Due to spatial differences in temperature and air pollution, mortality risks varied substantially between neighbourhoods, with a difference up to 7%.
authors.affiliation: Air Quality Department, DCMR Environmental Protection Agency Rijnmond, P.O. Box 843, 3100 AV Schiedam, The Netherlands; Department of Public Health, Erasmus MC, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands. Electronic address: saskia.willers@dcmr.nl.
authors.forename: Saskia M
authors.initials: SM
authors.lastname: Willers
authors.affiliation: Department of Public Health, Erasmus MC, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands. Electronic address: m.jonker@erasmus.nl.
authors.forename: Marcel F
authors.initials: MF
authors.lastname: Jonker
authors.affiliation: Netherlands Organisation for Applied Scientific Research TNO, Princetonlaan 6, 3584 CB Utrecht, The Netherlands. Electronic address: e.j.klok@hva.nl.
authors.forename: Lisette
authors.initials: L
authors.lastname: Klok
authors.affiliation: Netherlands Organisation for Applied Scientific Research TNO, Princetonlaan 6, 3584 CB Utrecht, The Netherlands. Electronic address: menno.keuken@tno.nl.
authors.forename: Menno P
authors.initials: MP
authors.lastname: Keuken
authors.affiliation: Municipal Public Health Service Rotterdam-Rijnmond, Postbus 70032, 3000 LP Rotterdam, The Netherlands. Electronic address: j.odink@rotterdam.nl.
authors.forename: Jennie
authors.initials: J
authors.lastname: Odink
authors.affiliation: Air Quality Department, DCMR Environmental Protection Agency Rijnmond, P.O. Box 843, 3100 AV Schiedam, The Netherlands. Electronic address: sef.vandenelshout@dcmr.nl.
authors.forename: Sef
authors.initials: S
authors.lastname: van den Elshout
authors.affiliation: School of Geographical Sciences, University of Bristol, University Rd, Bristol BS8 1SS, UK. Electronic address: c.sabel@bristol.ac.uk.
authors.forename: Clive E
authors.initials: CE
authors.lastname: Sabel
authors.affiliation: Department of Public Health, Erasmus MC, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands. Electronic address: j.mackenbach@erasmus.nl.
authors.forename: Johan P
authors.initials: JP
authors.lastname: Mackenbach
authors.affiliation: Department of Public Health, Erasmus MC, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands. Electronic address: a.burdorf@erasmus.nl.
authors.forename: Alex
authors.initials: A
authors.lastname: Burdorf
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000393:Air Pollutants / Q000032:analysis*; D002947:Cities; D018592:Cross-Over Studies; D004781:Environmental Exposure / Q000032:analysis* / Q000706:statistics & numerical data; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D009026:Mortality / Q000639:trends*; D009426:Netherlands; D012621:Seasons; D013997:Time Factors; D014505:Urban Population / Q000706:statistics & numerical data*
chemical_list: D000393:Air Pollutants
keywords: Air pollution; Case-crossover study; Heat stress; Mortality; Spatial variation; Vulnerable groups