Assessment of daily variations of volatile organic compound in Tehran in 2010-2011

 In accordance with the Air Clean Act developed for ozone monitoring, the measurement of volatile organic compounds (VOCs) based on photochemical assessment monitoring stations (PAMS) was carried out. 

 Thirteen species of VOCs were measured on Enghelab square in Tehran by PhoCheck PID Detector at morning, noon, and afternoon for 3 months. The data were reported as descriptive statistics. 

 Most of the VOCs species showed diurnal variations with higher concentrations in the noon. The highest concentration of VOCs was aromatic group (AR: 0.549 ± 0.146 ppb). AR was the main contributor to photochemical smog. 

 The majority of the AR class and toluene may be followed by the impacts of heavy traffic and the peak values of VOCs concentrations occurred around mid-day which depends indirectly upon vehicles and emission of evaporations