Your Health / Motor vehicle pollutants can pose issues for cyclists
21 Dec 2012
In a report released by the National Institutes of Health (NIH), a study conducted in Amsterdam, The Netherlands, determined that cyclists are more exposed to nitrogen dioxide (NO2) more so than motorists.
In the study, volunteers were provided with personal air sampling (PAS) equipment to carry concurrently by bicycle and motor vehicle car on selected routes. The routes included two inner-city routes, a tunnel on a busy highway, and a rural route. Each run lasted about one hour for all routes except for the busy highway where it was for 30 minutes. Each study lasted two weeks with four sampling days per week.
The chemicals measured by the PAS units were NO2, carbon dioxide (CO), benzene, toluene, and xylenes. Lead and PAH content was determined. During these tests, each volunteer's ventilation was measured while they were on a bicycle or in a car. The daily average temperature was positively associated with the exposure of the cyclists and car drivers for most compounds that were measured.
The conclusion is that 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.
A Canadian study concluded that short-term exposures to traffic pollution may alter the heart and lung functions in cyclists. NO2 is toxic by inhalation. According to the EPA, scientific evidence links short-term NO2 exposures, ranging from 30 minutes to 24 hours, with adverse respiratory effects including airway inflammation in healthy people and increased respiratory symptoms in people with asthma.
How does Bexar County fair? According to the Texas Commission on Environmental Quality (TCEQ), the NO2 reading has been 38 parts per billion (ppb) for one hour. Here are the readings for other counties:
Harris (Houston) 46ppb
Tarrant (Fort Worth, Arlington) 37ppb
Travis (Austin, San Marcos) 14ppb
Jefferson (Port Arthur) 27ppb
El Paso 33ppb
From this data, Bexar sits right under Harris County.