In addition to emitting exhaust fumes, traffic produces street dust, lifting loose materials from street surfaces, sanding materials, and materials from brakes, tires, studded tires and other. Street dust is one of the main air-quality problems in Helsinki. Construction sites and street work also cause street dust, spreading dust from the sites to the environment.
Street dust worsens air quality in spring
Street dust is most evident in spring. Most street dust particles are so fine – less than 10 micrometres (PM10) – that they cannot be detected by the eye. Such air pollution is called particulate matter. Particles enter people’s airways. Levels of particulate matter are especially high in spring, when particles accumulated in winter are lifted to air from drying streets by traffic and wind.
The City of Helsinki has drawn up an air protection programme to reduce street dust concentrations in the city. The plan includes the city’s long-term measures for controlling street dust. The cities in the Helsinki metropolitan area also have a joint emergency plan in case of a sudden weakening of air quality, according to which the Environment Services can make an irrigation request if street dust concentrations are high.
Particles of all sizes are very hazardous to health
Particles of all sizes have been found to cause adverse health effects, especially among vulnerable population groups. People in most danger include those suffering from asthma, small children, the elderly and those suffering from the coronary artery disease or emphysema. Apart from causing adverse health effects, street dust weakens the quality of life and spoils the environment.
Fine particles (less than 2.5 micrometres) are particularly hazardous to health. They are produced in combustion processes such as those of diesel vehicles, small fireplaces and energy production. The highest fine particle concentrations in the Helsinki region are usually transported from outside the Finnish borders.
Calcium chloride is used to suppress dust.