Spring is in the air, and for many people in Finland that means heightened interest in air quality indicators. Not only is pollen is beginning to spread at this time of year, but dust from gravel spread on roads during the winter and studded winter tyres grinding against the tarmac can also cause breathing difficulties.
This week road maintenance teams in the capital city region are starting to clear the bigger pieces of gravel from the streets as part of the annual spring clean Finnish streets must undergo.
The more thoroughgoing wash Finnish roads experience each spring won't happen until the end of the month at least, however, as night time frosts may cause slippery road surfaces in the meantime.
Six weeks of cleaning
"Several contractors have scheduled the 27th of March as the first day for a full vacuum and wash of the streets," says Tarja Myller of Helsinki's Public Works Department.
The full cleanup takes around six weeks, so it won't be complete until mid-May. In towns and cities north of Helsinki, it could take even longer. There are around 60,000 tonnes of gravel to be collected from the city's streets.
According to Myller, there is more gravel than usual this year thanks to the lack of snow. Normally much of the gravel is taken away when streets are cleared of snow, but if it melts before it's cleared then the gravel remains.
The Finnish Allergy and Asthma Federation says that those suffering breathing difficulties should wear face masks, and if that doesn't help, stay at home.
Helsinki Region Environmental Services Authority (HSY) announced on Tuesday that February was the worst month of the winter for air quality in the region, and that air quality in the area was very poor at several points during the winter.