Properly ventilating and frequently cleaning our homes and offices are both important to our health, concludes a new European study published in the Journal of Environmental Science and Health. Researchers analyzed bacterial and fungal counts and suspended particulate matter in indoor air samples of 40 homes and offices. They determined that 45 percent had indoor pollution levels greater than that recommended by the current European Concerted Action Report on air quality standards.

An analysis of a Canadian government Health Measures Survey discovered 47 different indoor volatile organic compounds (VOC) among more than half of the 3,857 households surveyed throughout Canada. Most of the VOCs identified there have also been present in separate European and U.S. studies.

According to the U.S. Environmental Protection Agency (EPA), VOCs are carbon chemical compounds that can evaporate under normal indoor atmospheric conditions. The concern with indoor VOCs is their potential to react with indoor ozone to produce harmful byproducts that may be associated with adverse health effects in sensitive populations.

Benzene, trichloroethylene, tetrachloroethylene and xylene top the list of common VOCs inside U.S. households, according to an EPA report. Typical sources comprise common household chemicals, furnishings and décor, as well as indoor activities such as unventilated cooking, heating and smoking.