Indoor air pollution of polycyclic aromatic hydrocarbons emitted by computers

We investigated the polycyclic aromatic hydrocarbons (PAHs) emitted from computers to evaluate the characteristics of indoor air pollution and the potential levels of human exposure. Gaseous naphthalene and phenanthrene were the dominant compounds in the indoor environment. The levels of sigma(16) PAHs in an office, a computer room, and a server room were 2-25 times higher than those in outdoor air or in a room without a computer. The PAH profiles inside the computers were similar to those in the indoor air, suggesting that the PAHs released from computers contribute to indoor air pollution. The PAH emissions from computers had a positive relationship with the age of the computer, the operating time, the internal temperature, and the size of the computer. Moreover, this study is the first to identify that computers are an indoor PAH source by confirming PAH emissions from computer components in an enclosed space. Adults are potentially exposed via inhalation to PAHs at a concentration of 1.9 ng TEQ/day in their office. The non-carcinogenic and carcinogenic risks of PAHs inhaled in an office were lower than the risk threshold set by the US EPA. However, in addition to PAHs, other volatile compounds that may be emitted from computers need to be considered.