The exposure of cyclists,car drivers and pedestrians to traffic-related air pollutants

Volunteers provided with personal air sampling (PAS) equipment covered concurrently, by car or bicycle, various selected routes. These comprised two inner city routes in Amsterdam (ICR 1 and 2) as well as a route including a tunnel on a busy highway (TR) and a rural route just south of Amsterdam (RR). A third inner city route, a busy narrow street, was subsequently also selected, and covered by bicycle or walking (ICR 3). Each run lasted about 1 h; the sampling time on the TR route was approximately 30min. The sampling periods in January and May lasted 2 weeks with four sampling days per week. In August only ICR 3 was covered, this sampling period lasted 2 days. CO, NO₂, benzene, toluene and xylenes were measured in the personal air samples. A monitoring vehicle covered the routes concurrently and measured CO, NO₂ and pm₁₀ (semi) continuously. Lead and PAH content in pm₁₀ was determined. The ventilation of the volunteers was measured while they were using a car or a bicycle. The route and the type of transport influenced (P < 0.001) the concentrations of CO, benzene, toluene and xylenes. The daily average temperature was positively associated with the exposure of car drivers and cyclists to most compounds measured. A volunteer exhaled on average 2.3 times more air as a cyclist than as a car driver. Despite the much higher concentrations in the personal air samples of car drivers, the uptake of CO, benzene, toluene and xylenes of cyclists sometimes approached that of the car drivers. The uptake of NO₂ of cyclists was clearly higher than that of car drivers.