Health impacts from particles and NO2 cause significant welfare losses. Photo: Hey Paul Studios/flickr.com/CC BY
Every year over 5,000 people in Sweden die prematurely due to air pollution, and the annual cost to society of health damage due to nitrogen oxides and particulate matter is estimated at SEK 42 billion.
A new study by the Swedish Environmental Research Institute and Umeå University has calculated the exposure of the Swedish population to some of the main air pollutants in 2010, and estimated the resulting health impacts.
The study focussed on nitrogen dioxide (NO2) and particles in the size categories 2.5 and 10 microns or less (PM2.5 and PM10). It was found that most of the PM2.5 at urban background stations is transported over long distances, largely from emission sources outside of Sweden. Road wear resulting from the use of studded tires is the largest source of locally generated PM. The high levels of nitrogen dioxide are caused largely by local traffic emissions, with an increased proportion of diesel vehicles exacerbating the problem.
Exposure to PM2.5 was estimated to cause approximately 3,500 premature deaths per year when assuming no division between sources and using an exposure-response coefficient of 6.2 per cent per 10 μg/m3.
Alternatively, when assuming a division between sources, it was estimated that non-local sources caused just over 3,000 premature deaths per year (exposure-response coefficient 6.2% per 10 μg/m3), and that residential wood burning caused just over 1,000 premature deaths per year. A higher exposure-response coefficient of 17 per cent per 10 μg/m3 was used for these primary combustion particles.
In addition, approximately 1,300 annual premature deaths were estimated to be caused by locally generated vehicle exhaust (using NO2 as an indicator), and another 200 deaths per year from road dust. Particulate matter should, according to the study, probably be added to the impact of local traffic in Sweden.
In summary, the total number of premature deaths was estimated at approximately 5,500 per year when taking into account differences in exposure-response for different PM sources.
For morbidity effects, the study included only a few important and commonly used endpoints, to allow comparisons with other health impact assessments and health cost studies.
The socio-economic costs (welfare losses) related to population exposure to air pollutants as indicated by NO2 were calculated both with and without a threshold of 5 μg/m3. Health effects related to annual mean levels of NO2 in 2010 were valued at between SEK 7 and 25 billion, depending on whether a threshold of 5 μg/m3 was included or not.
Moreover, welfare losses resulting from exposure to PM pollutants from road dust, residential wood burning and other sources were valued at SEK 35 billion, of which approximately 6.5 billion were linked to productivity losses, i.e. days when people are limited in their normal activities causing a loss of work days. The amount of work and study days lost constituted about 0.3 per cent of the total amount of such days in Sweden in 2010.
Using the division between PM sources and NO2 (with a 5 μg/m3 cut-off) as an indicator of traffic combustion, the total annual socio-economic cost was approximately SEK 42 billion.
Christer Ågren
Study: “Quantification of population exposure to NO2, PM2.5 and PM10 and estimated health impacts in Sweden 2010” (December 2014). By M. Gustafsson, B. Forsberg, H. Orru, S, Åström, H. Tekie, K. Sjöberg. Swedish Environmental Research Institute IVL Report B 2197. Find the full report on ivl.se under Publications.
