Indoor and outdoor concentrations of volatile organic compounds at two administrative buildings in the center of Tehran

Volatile organic compounds (VOCs) have been simultaneously measured at industrial cities and inside the buildings as well. These compounds are concerned for their influences on indoor air quality and thus on human health. This study was, therefore, aimed to determine the relationship between VOCs concentration in indoor and outdoor environments of two administrative offices in the center of Tehran.
In the present work, indoor/outdoor concentrations of VOCs were measured in totally 143 rooms of two Petroleum Industry Health Organization administrative buildings in winter. Ethical issues with regard to obtaining the required permits were considered. First Check (model 6000) was used to measure VOCs concentration. Natural ventilation was calculated using the rate of air changes per hour in the indoor environment. Tables given by authorized organizations were exploited as well.
The results indicated that indoor/outdoor concentration ratios for volatile organic compounds ranged from 1 to 2 for office building No.1. This ratio ranged from 0.5 to 1 for office building No.2. The indoor concentrations of totally measured VOCs in these two office buildings were 1006.23±179.39 ppb and 645.44±123.42 ppb, respectively.
Indoor concentrations of most studied volatile organic compounds were higher than their corresponding outdoor values. Office building No.1 experienced higher concentrations of measured VOCs as compared with office building No.2. The measured concentrations were higher in office rooms with 1 air change per hour than rooms having 1.5 air changes per hour.