Abstract
On two occasions (in October and in March) during the snow season, the authors collected suspended particles near roads with heavy traffic of cars equipped with spiked tires. Using a scanning analytical electron microscope, we observed the characteristic particles.
The characteristic particles observed during the “spike season” were sulfur and halogen in addition to calcium carbonate compound free of other metals. The calcium carbonate which is present in the asphalt pavement is clearly distinguishable from the calcium particles (mostly Ca-Si-Ti mixed particles) derived from the white lines painted on the road (white paint). In addition, these calcium carbonate particles are absent in normal soil and combustionable particles made from coal and heavy oil, etc.
The calcium concentrations in suspended particles do not vary that much from season to season. As for calcium compounds, however, there are large differences.
Spiked tires which dig deep into the asphalt pavement may cause the release of asphalt particles in calcium carbonate.
