2013 Environment and Health - Basel
Effects of studded tire restrictions on the public health in Stockholm, Sweden.
Background: In northern Europe, coarse particle concentrations are generally elevated during winter and spring. In Stockholm, road pavement wear increases drastically during the winter due to the use of studded tires. Together with increased use of traction sand on streets, this contributes to high emissions of coarse particles and the exceedances of the EU limit values for PM10. In order to improve air quality with respect to PM10, a ban of studded tires on Hornsgatan, a densely trafficked street in the inner city of Stockholm, was introduced from 2010.
Aims: The aim of this study was to quantify the importance of the ban of studded tires on the public health in the Greater Stockholm (approx. 1.63 million inhabitants). As health outcome we used number of premature deaths. In addition, we have calculated what a potential extension of restrictions could mean for the public health in the studied population.
Methods: The effect from different situations on the air quality was modeled using a non-exhaust traffic emission model (the NORTRIP model) and a Gaussian dispersion model. We then used an exposure-response function for coarse particles of 1.68 % increase in daily mortality per 10 µg m-3 increase in coarse fraction, as obtained earlier for the studied population. Results: The ban has led to reduced use of studded tires not only on Hornsgatan but also other streets in the inner city and along arterial roads. The current situation is that 50% of cars have studded tires in the inner city and 60% along arterial roads, respectively. We estimated that 8 premature deaths per year were avoided in the Greater Stockholm metropolitan area due to the ban on one single street. For a potential future situation with fees on using studded tires resulting in 10% of all cars having studded tires on inner city streets and 50% on arterial roads, we estimated 15 fewer premature deaths per year in the study area.
Conclusions: This study demonstrates the importance of making quantitative estimates of health impacts in order to justify actions to reduce air pollution.