Air quality in Tampere is mostly good – reduced road traffic has improved air quality in the city centre

Using dispersion modelling, the report examined the impacts of emissions from transport, energy production, industry and building-specific heating on air quality in 2021 and 2040. The results indicate that direct transport emissions, road dust and wood burning in residential buildings are the greatest factors impacting air quality. The assessment found that the impact of energy production and industry on air pollution concentrations at nose level was minor due to the fact that these emissions are released from tall stacks.

The ambient concentrations in Tampere are mainly below the air quality reference values. Nitrogen dioxide concentrations from road traffic emissions, in particular, are lower throughout the city than the current limit values and the stricter values to be introduced in 2030, with the exception of busy intersections – the limit values do not apply to traffic areas. The concentrations decrease as the distance from roads increases. The modelling predicts that ambient concentrations will have decreased by 2040 due to emission trends and electrification of vehicles.

Road dust caused by traffic and wood burning in private houses increase concentrations

There is little variation in concentrations of fine particulate matter between different districts of Tampere, as a large share of this matter originates from further afield. The fine particulate matter concentrations are clearly below the limit values at the moment and will remain so, regardless of the stricter values that will be introduced in the future.

However, the concentrations of inhaled particulate matter may be high at times, especially in the vicinity of busy traffic routes during the road dust season in spring. The concentrations are below the current limit values for inhaled particles and those that will enter into force in 2030, with the exception of busy traffic routes. However, there is a risk that the stricter 24-hour guideline value may be exceeded. Road dust emissions can be effectively controlled by local measures. Efficient and timely road maintenance will also be important to avoid exceeding the limit values in the future.

The modelling shows that the benzo(a)pyrene concentrations caused by burning wood to heat houses exceed the current target value in some compact residential areas. There is a risk that the limit value entering into force in 2030 will be exceeded in a significant part of residential areas with detached housing in Tampere. The report recommends conducting benzo(a)pyrene measurements in Tampere to check the concentration levels. The highest black carbon concentrations are currently found along busy traffic routes. As road traffic emissions are reduced in the future, the relative impact of building-specific heating emissions on ambient concentrations will increase. There are no air quality reference values for black carbon.

Air quality measurement stations in Tampere offer good representativeness

The assessment also evaluated the spatial representativeness of air quality measurement stations in Tampere. These stations are located in Epilä, Pirkankatu street, the bus station and Kaleva. The evaluation was based on dispersion modelling results, spatial distribution of emissions and the dispersion environments.

It found that the current measurement stations describe the air quality in Tampere well and represent different types of urban environments. Kaleva urban background station covers the largest are of all the stations. It is well placed to describe residents' exposure to pollutant concentrations in the urban environment.  The spatial representativeness areas of the measurement stations in Pirkankatu street and at the bus station, which are located in the city centre traffic environment, overlap in many respects.

While the air quality limit values that will enter into force in 2030 may affect the need to measure air quality, the report indicates that the current measurement network in Tampere meets the current needs of air quality monitoring well. The report recommends supplementing the measurement network in Tampere with a measuring station that represents a residential area with detached housing, and benzo(a)pyrene measurements to verify their concentration levels. The plan consequently is to conduct benzo(a)pyrene measurements for one calendar year during the next joint agreement period of air quality monitoring (2026–2030), which will begin at the turn of the year.