Built environment and indoor air quality: The case of volatile organic compounds

A large number of studies indicated the presence of volatile organic compounds (VOCs) of various chemical classes in indoor environments (public buildings, homes). VOCs affect the air quality indoors having an impact on human health and wellbeing. They are the result of infiltration of polluted outdoor air and emissions from various indoor sources, including building materials, consumer products (fragrances, air fresheners), activities of the occupants (cleaning) and smoking. On average, people spend a great part of their time (85 to 90%) in confined spaces (homes, office buildings and schools) exposed to a complex mixture of air contaminants at concentration levels that are often several times higher than outdoors. For many chemicals present in indoor air (and their mixtures) the risk for human health and comfort is almost unknown and difficult to predict because of the lack of toxicological data and information on the dose-response characteristics in humans or animal models. Saving of energy for homes and public buildings becomes an additional and essential criterion for the overall quality of the built environment. The need to construct airtight buildings may lead to the accumulation of air contaminants indoors and thus changing the prevailing philosophy for a healthy indoor environmental quality. The necessity emerged, in particular, for low emitting construction and building materials along with the adaptation of appropriate ventilation regimes to ensure wellbeing and comfort for building occupants. The paper provides an overview of indoor/outdoor air concentrations of volatile organic compounds in buildings. It discusses the methodological approaches and procedures applied so far to assess VOC's presence indoors and outdoors, notably benzene and formaldehyde as model compounds for indoor air quality emphasizing the needs for future research and action plans to ensure a healthy and occupant friendly indoor environment.