Table 1

Summary of time-series studies of NO2 and mortality and hospital admissions available for review

TotalMulticity studySingle-city study
OutcomeMortality*Hospital admissionMortalityHospital admissionMortalityHospital admission
WHO region
 American A2423651818
 European A564116114030
 Western Pacific B3117222915
 American B750075
 Western Pacific A571344
 South East Asia B202000
Averaging time
 24 h1078221178665
 Maximum 1 h27255102215
  • *One multicity study on mortality used multiple WHO regions, that is, South East Asia B and Western Pacific B.

  • †Respiratory includes all respiratory diseases, asthma, COPD (including asthma), lower respiratory infections and upper respiratory diseases; cardiovascular includes all cardiovascular diseases, cardiac disease, heart failure, ischaemic heart disease, dysrhythmia and stroke.

  • COPD, chronic obstructive pulmonary disease.