Impact of the wood combustion in an open fireplace on the air quality of a living room: Estimation of the respirable fraction

Presently, both in rural areas and in cities open fireplaces are still present and large quantities of wood are combusted every year. The present study aims to characterize aerosol size distribution, chemical composition and deposition in the human respiratory tract of particles emitted during the combustion of logs of oak in an open fireplace installed in the living room of a typical village house. CO2 and CO levels and aerosol size distribution have been continuously monitored and a PM10 sampler with two types of filters for chemical and microscopic analysis was also installed. The increment, between the operating periods and the indoor background, in the organic carbon and PM10 concentration due to the use of the fireplace is 15.7±0.6 (mean±standard deviation) and 58.5±6.2μgm-3, respectively. The two main polluting processes during the operation of the fireplace are the ignition with the subsequent refueling and the final cleaning of the residual ashes. In both phases mean values around 1800 particles cm-3 with CMD of 0.15μm were measured. However, while PM10 levels of 130±120μgm-3 were estimated for the ignition stage, values of 200±200μgm-3 were obtained during the final cleaning step. Assessment conducted according to ISO standard 7708:1995, demonstrated that a person who stays in a living room when an open fireplace is lit will inhale, on average, 217μgm-3 and 283μgm-3 during the ignition and the refueling stages, respectively. Subsequent refueling proved to be much less polluting. The ashes removal can also be very polluting and dangerous to health if there are hidden small incandescent embers among the ashes (estimated PM10 of 132μgm-3), reaching a CO2 level of 1940ppm and a dangerous level of CO of 132ppm.