Estimation of sources and factors affecting indoor VOC levels using basic numerical methods

Volatile Organic Compounds (VOCs) are a concern due to their adverse health effects and extensive usage. Levels of indoor VOCs were measured in six homes located in three different towns in epsilon anakkale, Turkey. Monthly indoor VOC samples were collected by passive sampling throughout a year. The highest levels of total volatile organic compounds (TVOC), benzene, toluene, and xylenes occurred in industrial, rural, and urban sites in a descending order. VOC levels were categorized as average values annually, during the heating period, and non-heating period. Several building/environmental factors together with occupants' habits were scored to obtain a basic indoor air pollution index (IAPi) for the homes. Bivariate regression analysis was applied to find the associations between the pollutant levels and home scores. IAPi scores were found to be correlated with average indoor VOC levels. In particular, very strong associations were found for occupants' habits. Furthermore, observed indoor VOC levels were categorized by using self-organizing map (SOM) and two simple scoring approaches, rounded average and maximum value methods, to classify the indoor environments based on their VOC compositions (IAPvoc). Three classes were used for both IAPi and IAPvoc approaches, namely good, moderate, and bad. There is an urgent need for indexing studies to determine the potential sources and/or factors affecting observed VOCs. This study gives a basic but good start for further studies.