[The health impact of woodsmoke]

Biomass is an important renewable resource of primary energy. Wood burning is expected to expand in future as a cheap means of residential heating, especially in wood-producing rural areas. The health consequences of wood smoke are taken in account far less actively in Europe than in North America, where stringent limitations have been introduced, such as those of the EPA Burnwise project. Recently, wildfires were estimated to release 2 petagrams of carbon into the atmosphere worldwide, contributing to more than 300 000 deaths annually. More effective measures are thus needed to prevent indoor and outdoor exposure to wood smoke. Ultrafine particles are the biggest concern, but the volatile phase also contains many toxicants. Ultrafine particles are among the most dangerous carbonaceous particles found in polluted atmospheres. They can be identified by using C14, levoglucosan, crystallography and spectrometry. Any expansion of the use of wood as a fuel source should take into account its health impact, which is similar to that of fossil fuels.