Particles in indoor environment:: Sources and health outcomes

This paper summarizes the indoor air particle sources and their health effects according to human exposure data available. Smoking and cooking are considered as the main sources for indoor particles. Resuspension of settled particles due to human indoor activities increases the concentration of coarse particles. Other sources influencing indoor particle levels are outdoor air, heating, pets, microbes and secondary organic aerosols. Indoor events generating particles are often of short duration, but they may considerably increase particle concentration in the indoor air. Human exposure studies give proof of eye, nose and throat irritation after house dust inhalation. Mild inflammation and obstructive effects on the airways are also reported. Ultrafine particles may be more harmful than larger particles, because they deposit deeper to the respiratory track. So far, the evidence is inadequate and more information is needed to demonstrate the health effects according to particle source, size and mass.