title: Cycling to work in London and inhaled dose of black carbon.
abstract: Modelling studies suggest that urban cycling is associated with an increased inhaled dose of fossil fuel-derived black carbon (BC). Using the amount of black material in airway macrophages as a marker of long-term inhaled BC, we sought to compare inhaled BC dose in London (UK) cyclists and non-cyclists. Airway macrophage carbon was assessed in 28 (58%) out of 48 healthy adults (14 cyclists and 14 non-cyclists) who attended for induced sputum. Short-term (24 h) exposure to BC was assessed on a representative working day in 27 out of 28 subjects. Serum interleukin (IL)-1β, IL-2, IL-6, IL-8, granulocyte-macrophage colony-stimulating factor and tumour necrosis factor (TNF)-α were assessed in 26 out of the 28 subjects. Cyclists were found to have increased airway macrophage carbon when compared with non-cyclists (mean ± se 1.81 ± 0.21 versus 1.11 ± 0.07 μm(2); p<0.01). Short-term monitoring showed no difference in 24 h BC exposure between the two groups. However, cyclists were exposed to higher concentrations of BC during commuting (p<0.01). Airway macrophage carbon was associated with monitored commute BC (n=28; r=0.47, p<0.05). TNF-α was found to be increased in cyclists (p<0.05), but no other cytokines were increased. Commuting to work by bicycle in London is associated with increased long-term inhaled dose of BC. Whether cycling per se increases inhaled BC dose remains unclear.
authors.affiliation: Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
authors.forename: Chinedu
authors.initials: C
authors.lastname: Nwokoro
authors.forename: Clare
authors.initials: C
authors.lastname: Ewin
authors.forename: Clare
authors.initials: C
authors.lastname: Harrison
authors.forename: Mubin
authors.initials: M
authors.lastname: Ibrahim
authors.forename: Isobel
authors.initials: I
authors.lastname: Dundas
authors.forename: Iain
authors.initials: I
authors.lastname: Dickson
authors.forename: Naseem
authors.initials: N
authors.lastname: Mushtaq
authors.forename: Jonathan
authors.initials: J
authors.lastname: Grigg
mesh_terms: D000328:Adult; D000397:Air Pollution; D001642:Bicycling; D005260:Female; D006801:Humans; D001239:Inhalation; D008131:London; D016676:Macrophages, Alveolar / Q000737:chemistry; D008297:Male; D053260:Soot / Q000032:analysis; D014937:Work; D055815:Young Adult
chemical_list: D053260:Soot