The use of studded tyres causes considerable pavement wear, estimated at 15-30 g per km driven. The total annual pavement wear on roads and streets amounts to 450,000 tonnes in Sweden. 300,000 tonnes in Finland and 250,000-300,000 tonnes in Norway. These figures are decreasing due to improving pavement quality and less abrasive stud types. The emitted particles are greatly dominated by coarse particles (>50 um diam.) and most of the particles are deposited within 10 or 20 m of the roads. Considerable amounts of particles accumulated during the winter can occasionally be remobilized under dry and windy weather conditions in the spring. Under normal conditions, pavement wear contributes less than automobile exhaust emissions to the concentration of particles in the air. Japanese studies show a distinct connexion between the use of studded tyres and the concentration of particles in the air and in human as well as dogs' and pigeons' lung tissues. Japanese studies also indicate a possible association between airborne particles and upper respiratory symtoms. The remarkably few reported biological toxicity tests of pavement-generated particles indicate merely limited acute effects on hamsters, lizards, salmon, protozoa, algae, bacteria and fungi. Relevant long-term field studies in terrestrial environments are almost lacking. Lakes receiving highway runoff can show disturbance in the structure of the benthic fauna. Studs may raise the snow-tyre noise from free-flowing traffic by 4-6 dB (A). The report identifies the need for further research on environmental and health effects of the use of studded tyres. (A)
Samenvatting