title: The health risks and benefits of cycling in urban environments compared with car use: health impact assessment study.
abstract: OBJECTIVE
  To estimate the risks and benefits to health of travel by bicycle, using a bicycle sharing scheme, compared with travel by car in an urban environment.
  
  
  METHODS
  Health impact assessment study.
  
  
  METHODS
  Public bicycle sharing initiative, Bicing, in Barcelona, Spain.
  
  
  METHODS
  181,982 Bicing subscribers. Main outcomes measures The primary outcome measure was all cause mortality for the three domains of physical activity, air pollution (exposure to particulate matter <2.5 µm), and road traffic incidents. The secondary outcome was change in levels of carbon dioxide emissions.
  
  
  RESULTS
  Compared with car users the estimated annual change in mortality of the Barcelona residents using Bicing (n = 181,982) was 0.03 deaths from road traffic incidents and 0.13 deaths from air pollution. As a result of physical activity, 12.46 deaths were avoided (benefit:risk ratio 77). The annual number of deaths avoided was 12.28. As a result of journeys by Bicing, annual carbon dioxide emissions were reduced by an estimated 9,062,344 kg.
  
  
  CONCLUSIONS
  Public bicycle sharing initiatives such as Bicing in Barcelona have greater benefits than risks to health and reduce carbon dioxide emissions.
authors.affiliation: Center for Research in Environmental Epidemiology, C Doctor Aiguader 88, 08003 Barcelona, Spain. drojas@creal.cat
authors.forename: David
authors.initials: D
authors.lastname: Rojas-Rueda
authors.forename: Audrey
authors.initials: A
authors.lastname: de Nazelle
authors.forename: Marko
authors.initials: M
authors.lastname: Tainio
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Nieuwenhuijsen
mesh_terms: D000063:Accidents, Traffic / Q000401:mortality*; D000293:Adolescent; D000328:Adult; D000393:Air Pollutants / Q000009:adverse effects / Q000032:analysis; D001334:Automobile Driving / Q000706:statistics & numerical data*; D001642:Bicycling / Q000502:physiology* / Q000706:statistics & numerical data; D002245:Carbon Dioxide / Q000032:analysis; D002423:Cause of Death; D004781:Environmental Exposure / Q000009:adverse effects* / Q000032:analysis; D015444:Exercise / Q000502:physiology*; D006293:Health Promotion; D006801:Humans; D008875:Middle Aged; D052638:Particulate Matter / Q000009:adverse effects / Q000032:analysis; D018570:Risk Assessment; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D015996:Survival Rate; D014504:Urban Health; D055815:Young Adult
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D002245:Carbon Dioxide