Study: Pedestrians’ exposure to street dust in Helsinki depends on route choice
Based on measurements by THL, pedestrians walking in Helsinki, especially near busy roads, are exposed to high concentrations of fine particles and coarse inhalable particles during the street dust season. However, route choices allow pedestrians and cyclists to impact how much they are exposed to street dust.
“Going through the Helsinki Central Park, concentrations of coarse inhalable particles were lower by almost half compared to average levels observed in the other examined areas. Exposure levels were also about a third lower along the pedestrian path Baana when compared to stretches where people walk right next to the road with cars driving on it”, says THL researcher Taina Siponen.
Street dust is in the air all year round, but especially in the spring
There is street dust in the air all year round. Street dust mainly consists of finely ground asphalt and street gritting material. However, street dust occurs especially in spring when fine dust trapped under the snow and ice over the winter is released into the air once surfaces start to dry.
“In the spring, high concentrations of dust occur especially along busy streets and roads. The amount of street dust in the air can be reduced by efficiently cleaning the streets as early as possible and by doing dust suppression with calcium chloride solution. Drivers can also reduce the formation of street dust by favouring studless winter tyres and by changing into summer tyres sooner than later”, says Hanna Manninen, Head of Air Quality Unit at HSY.
Especially vulnerable population groups should protect themselves against street dust
People who are especially sensitive to the more serious side effects of street dust include people with asthma, small children, elderly people and people with coronary artery disease or chronic pulmonary obstructive disease. These people should avoid exposure during the worst of the street dust season and manage their health condition in the proper way.
You can reduce exposure to street dust by
- avoiding being outdoors next to busy roads on dusty days
- favouring quieter streets and green areas on the way to school or work and back
- keeping windows closed at home and in the car
- drying your laundry indoors and cleaning away dust off floors and surfaces
- buying efficient filters for incoming air for your apartment and maintaining them appropriately
- using room-specific indoor air purifiers.
The THL study in spring 2021 measured pedestrians’ exposure to inhalable particles, fine particles and black carbon. Concentrations of the pedestrian measurements were compared with the readings of air quality measurement stations maintained by Helsinki Region Environmental Services HSY in traffic environments. The study was funded by THL and HSY.
Reference:
Siponen T, Pulkkinen A-M, Taimisto P, Yli-Tuomi T. Kävelijän altistuminen katupölylle Helsingissä. Hankkeen loppuraportti. [Exposure of pedestrians to street dust in Helsinki. Final project report.]. Finnish institute for health and welfare (THL). Discussion Paper 24/2022.
Further information
Street dust (HSY)
Taina Siponen
Researcher
THL
tel. +358 29 524 6465,
[email protected]
Hanna Manninen
Head of Air Quality Unit
Helsinki Region Environmental Services Authority HSY
tel. +358 50 401 7826
[email protected]
