EXPOSURE AND RISK CHARACTERIZATION IN EUROPEAN INDOOR ENVIRONMENTS RELATED TO BENZENE AND FORMALDEHYDE

The study focuses on exposure and risk assessment of two major organic compounds (benzene and formaldehyde) commonly found indoors, evaluating accordingly cancer and non-cancer risks posed by indoor exposure in dwellings and public buildings in European Union (EU) countries, considering them either as individual compounds or as a chemical mixture. The acquisition of data on indoor concentrations identified significant differences in indoor air quality within and among EU countries, as well as significant data gaps. Cancer risks for both of the compounds were one to two orders of magnitude higher than the one (10(-6)) proposed as acceptable by risk management bodies, while cumulative cancer risk was consistently in the range of 10(-3). For formaldehyde non cancer effects, risk characterization outcome relies significantly on the Exposure Limit (EL) value adopted, in any case average indoor formaldehyde levels are close to the ELs. The risk assessment evaluation process faces crucial difficulties, either due to the relative paucity of indoor air quality measurements in many EU countries, or by the lack of sampling consistency among the already existing studies, indicating the need for well-designed measurements of indoor air quality following a harmonized sampling and analytical protocol. The uncertainties embodied in the cancer potency factors and exposure limit values by the different scientific/regulatory bodies, alter the prioritization and risk management between these two abundant compounds.