ORIGINAL ARTICLE Estimated health impact of a shift from light fuel to residential wood-burning in Upper Austria Daniela Haluza 1 , August Kaiser 2 , Hanns Moshammer 1 , Claudia Flandorfer 2 , Michael Kundi 1 and Manfred Neuberger ,1 The dependency on carbon-based fossil energy and growing awareness of climate change issues has induced ambitious policy initiatives to promote renewable energy sources for indoor heating. Combustion of regionally available material such as wood is considered a carbon-neutral alternative for oil and gas, but unregulated revival of wood stoves may cause detrimental health effects. For the prognosis of the health impact of air pollution due to the use of wood stoves, Upper Austria served for a case study. On the basis of recent measurements of particulate matter o10 mm in aerodynamic diameter (PM10) and nitrous gases (NO x ), we compared the air pollution attributable to present energy mix (termed scenario 1) with two alternatives: For scenario 2, we assumed replacement of light fuel oil by either fossil gas or biomass, and for scenario 3, replacement of light fuel oil by biomass only. Compared with the current exposure from scenario 1, the increased annual mean PM10 levels are estimated to lead to 101 (95% CI 56;146) and 174 (95% CI 92;257) additional deaths among 1.4 million inhabitants per year for scenarios 2 and 3, respectively. Without adequate strategies for reducing the emissions of domestic heating facilities, replacement of fossil energy sources could lead to an increased health risk. Journal of Exposure Science and Environmental Epidemiology (2012) 22, 339--343; doi:10.1038/jes.2012.27; published online 9 May 2012 Keywords: air pollution; particulate matter; biomass; domestic heating; health impact assessment INTRODUCTION Even though wood is considered a natural and ‘‘clean’’ energy supply, it is well established that burning timber of either outdoor sources such as large-scale fires or indoor stoves contaminate the ambient air with toxic substances. 1 Owing to the increasing world population, motorized traffic and industrialization power consumption is presently growing at a rate of approximately 2.3 terawatt per decade, of which 80% to 90% is derived from combustion of fossil fuels. 2 Therefore, non-renewable energy resources are the major producer of surplus carbon dioxide (CO 2 ), contributing to climate change. With reference to the potentially detrimental effects on the global climate, alternatives to fossil fuels have gained political and economical attention, as the use of biomass, for example, wood, as energy source is strongly growing. The public health impact of particulate matter derived from biomass combustion has been addressed predominantly with a focus on indoor wood smoke exposure. Especially in developing countries, biogenic materials are used for heating and cooking without sufficient ventilation and thus have noxious effects mainly in children and woman, who, compared to males, usually spend longer time indoors. 3,4 In addition, important diffuse sources of wood smoke such as accidental wild land fires or intentional burning of agricultural areas are responsible for increased air pollution --- and associated health hazards --- of vast regions, also due to the wind-driven transport of incineration particles over hundreds of kilometers. 5--7 So far, investigations of the environmental and health effects of fuel combustion in modern furnaces are rare. A possible reason for the neglect of this issue may be the difficulty to determine the location of these sources of exposure. 8,9 Experimental evidence of the toxicological effects of wood smoke was obtained predominantly from animal exposure studies and from in vitro and ex vivo assays. Both diesel exhaust and wood smoke PM act as cyto- and genotoxic agents in cell culture settings. 10 Inflammatory activity, which is regarded as a crucial mechanism of particle-related adverse cardio-respiratory effects, is also triggered by particles from wood smoke and traffic. 11 In addition, biomass combustion substances are found to be responsible for lung cancer in rodents. 12 In summary, even though a precise quantification of the risk is still missing, the capacity of wood smoke and its various components to cause adverse health effects is well documented. In this study, we evaluated the public health impact of air pollutants under various scenarios of energy use in Upper Austria, which is a highly industrialized region in the northern part of Austria in Central Europe with a population of 1.4 million inhabitants, a surface of 11,980 km 2 , and a population density of 117/km 2 . It is the fourth-largest Austrian county by area and the third largest by population. The capital is the city of Linz, the third- largest city of Austria, with a population of about 189,000 inhabitants. At present, the gross energy consumption in Upper Austria is about 300 petajoule, 30% of which are covered by renewable energy sources. 13 METHODS Scenarios for the Use of Energy Sources The emission data for scenario 1 correspond to the average energy mix for Upper Austria from the official national statistics of Austria. 14 The data for traffic and domestic fuel for scenario 1 are mean values from two Upper Received 1 September 2011; accepted 13 February 2012; published online 9 May 2012 1 Institute of Environmental Health, Center for Public Health, Medical University of Vienna, Kinderspitalgasse, Vienna, Austria; 2 Central Institute for Meteorology and Geophysics, Hohe Warte, Vienna, Austria. Correspondence to: Professor/Dr. Manfred Neuberger, Institute of Environmental Health, Center for Public Health, Medical University of Vienna, Kinderspitalgasse 15, 1095 Vienna, Austria. Tel.: þ 43 1 40160 34930. Fax: þ 43 1 40160 934903. E-mail: manfred.neuberger@meduniwien.ac.at Journal of Exposure Science and Environmental Epidemiology (2012) 22, 339 -- 343 & 2012 Nature America, Inc. All rights reserved 1559-0631/12 www.nature.com/jes