New research shows wood smoke's impact on health

Small-scale wood burning is a significant source of air pollution. However, there is limited knowledge as to the effects that wood burning has on people's health. SMHI has cooperated with IVL Swedish Environmental Research Institute and Umeå University to map the situation in and around Umeå.

The research project, which aims to increase the level of existing knowledge regarding wood-burning's impact on health was conducted on behalf of the Swedish Environmental Protection Agency. The work included measurements, calculations of levels, and people's exposure in and around Umeå.

Health risks despite low levels

As an initial measure, the IVL Swedish Environmental Research Institute measured levels of air pollution from wood burning in Umeå in Northern Sweden, and four smaller communities close by; Vännäs, Vännäsby, Sävar and Taveliden, which is a residential suburb to Umeå. The pollution that was included in the study were particulate matter (PM2.5), polyaromatic hydrocarbons (PAH) and soot.

Information regarding fire places and burning habits were also collected, after which SMHI carried out model calculations of levels and exposure. The final calculation of health impact was conducted by Umeå University and SMHI.

"The results demonstrate that air quality is good in the areas studied, that is to say that it is below the environmental quality standard that has been set", says Gunnar Omstedt, researcher in urban air quality at SMHI.

"This means that wood burning is being done in an acceptable manner, based on the environmental quality standards and environmental quality aims. The problem is that even these low levels can have an impact on people's health", says Gunnar Omstedt.

Four people die prematurely each year

"Our calculations show that on average four people per year are at risk of dying prematurely due to pollution from wood burning in the areas studied", Gunnar Omstedt adds.

The estimated mortality due to PM2.5 from local wood burning is about 4 people per year for Vännäs, Vännäsby, Sävar and Umeå, with a total population of about 100,000 people. This corresponds to approximately 0.4 per cent of the total number of people who die (except through injuries) per year in these cities.

Meeting environmental goals is not enough

"One conclusion we have drawn from this project is that we need to continue working with air quality even when meeting the environmental goals. In the long term, the impact wood burning has on health will be improved through the introduction of the Ecodesign Directive which requires newer and improved boilers and stoves", says Gunnar Omstedt.  

Wood smoke has less impact of health than other sources of pollution. The estimated mortality due to PM2.5 from wood smoke in urban Umeå is 2.5 persons per year, which can be compared with the mortality due to traffic pollution in the same area, which is estimated to be around four per year. The background levels, which come from pollution outside Umeå, is estimated to account for less than 17 persons per year, but this cannot be influenced locally.

"Much can be done locally to improve air quality, but it is also necessary to work on a national and European level", says Gunnar Omstedt.