The health impact of wood as domestic space heating in the city of Stuttgart

Abstract

Background Due to rising fossil fuel prices coupled with policy measures promoting biomass fuels, the number of installed pellet stoves has increased rapidly over the last decade years, so that at the end of 2013 will be over 300 000 installed pellet stoves in Germany. Although pellets stoves have lower emission than manually loaded single fireplaces or older wood boilers, they produce higher dust, CO and VOC emissions than modern oil and gas stoves due to incomplete combustion. Reliable data on pellets stove emissions would allow to assess the health impact related to this technology. Aims This work aims to provide reliable information to the dust emissions from pellet boilers for domestic space heating operating under realistic conditions and to assess the health impacts related to the pellet stoves emissions in the City of Stuttgart. Methods Particulate matter, CO and VOC emissions produced by pellet stoves in the City of Stuttgart for the year 2006 were estimated. Two scenarios were then defined for the year 2020: strong increase in newly installed pellets stoves; and a hypothetical legal ban of wood fuel in the inner city. Using the impact pathway approach, health impacts were estimated. Results The proportion of pellets in the energy supply in the Stuttgart region is very low compared to other sources. After wood stoves, pellet stoves were the second-largest source of emissions. The legal ban of wood fuel in the inner citywould reduce emissions from pellet combustion by 1% in the Stuttgart region and by 17% in the city of Stuttgart compared to the volume of emissions in a BAU scenario. The health impact followed the same trend. Conclusions The contribution of pellet stoves to the total emissions in the Stuttgart region is small. However, the proportion of the particulate matter emissions compared to gas or oil is higher by almost a factor of three. Fostering a wider dissemination of pellet stoves should favor the installation of modern combustion control equipment.