Vertical concentration gradients of volatile organic compounds in two NS-oriented street canyons.

Diffusive samplers were used to measure the vertical concentrations of benzene, toluene, n-hexane, cyclohexane, ethylbenzene and o-, m- and p-xylenes on both sides of two NS-oriented street canyons in Murcia (Spain) during a 5-day period. Non-dimensional relationships of concentration and height were calculated in order to study the behaviour of their concentration vertical profiles. The results show that the vertical profiles of benzene, toluene, n-hexane and cyclohexane concentrations were similar in both streets and on both sides of each street.