Factors affecting the indoor concentration of ozone and ozone reaction products in school buildings and means to reduce exposure

摘要

Several epidemiological studies have reported that ozone and products of ozone reactions cause several acute and chronic health effects, and that even a slight amount of ozone is po-tentially deleterious to human health. Knowledge of the factors affecting the concentrations of ozone in different environments is important to define the means to reduce the exposure to ozone and to ozone reaction products. 'The literature review was performed using Web of Science, SCOPUS, Google Scholar, and PubMed. Altogether 34 search terms and their combinations were used to identify journal papers and reports. This study revealed that the following factors affect the concentration of ozone and ozone reaction products indoors: 1) Outdoor ozone penetrat-ing into the indoor environment; 2) Housing characteristics (e.g. type of ventilation, filters, decorations and finishing materials); 3) Indoor chemistry (e.g. ozone reactions with cleaning chemicals); 4) Occupants (ozone reactions with skin, clothes and hair) and their activities (e.g. use of copy machines, laser printers, air cleaning devices, and window opening); 5) Sea-sonality, temperature and relative humidity. The means for reducing exposure to ozone and ozone reaction products indoors include e.g. filtering ozone from the air supply using suita-ble filters, limiting the use of cleaning chemicals and ozone emitting devices, and avoiding window openings when the concentration of ambient ozone is high. Although the ambient ozone concentration constitutes an important part of the total individual ozone exposure, reducing outdoor ozone concentration is difficult. Thus, means to reduce the concentration of indoor ozone and its oxidation products are crucial in limiting exposure.