Helsinki Region Environmental Services Authority (HSY) has monitored the air quality of harbour areas in Katajanokka, West Harbour, Eteläranta and Vuosaari for several years, according to the company's release. The location of the measurement station varies each year. In 2021, the station was at Katajanokka. The air contained particulate matter, such as street dust, fine particles, sulphur dioxide, and nitrogen oxides, meaning exhaust emissions.
In 2021, the annual sulphur dioxide concentrations at Katajanokka were at 0.8 micrograms per cubic metre (µg/m3). In 2013, before the latest changes to the emissions standards, the concentrations were at 3.2 µg/m3. Besides emissions from ship traffic, the sulphur dioxide emissions from energy production have also been reduced.
Annual nitrogen dioxide concentrations have also decreased in Helsinki harbours in the long term. The reduction in concentrations is at least partially caused by the car population becoming increasingly modern and exhaust emissions becoming cleaner. Another reason is the COVID-19 pandemic reducing the number of ship passengers and the volumes of car traffic, which can be seen in the results for 2020 and 2021.
Last year, the World Health Organization (WHO) published increasingly strict threshold values for various air pollutants. In the Helsinki Metropolitan Area, these values are exceeded in various environments, including the harbours in terms of nitrogen dioxide and fine particles.
The air pollutant concentrations in harbours vary by the ships’ arrival and departure times. In Katajanokka, for example, the concentrations of nitrogen dioxide increase in the morning and evening.
Information about air pollutants:
• Nitrogen oxides (NOx) originate from traffic emissions, particularly from diesel vehicles and heavy traffic. Of nitrogen oxides, nitrogen dioxide is the most common cause of health hazards. In high concentrations, it contracts the bronchi and increases respiratory symptoms among children and persons with asthma, in particular.
• Sulphur dioxide (SO2) outdoors mainly originates from energy production and ship emissions. Sulphur dioxide emissions have decreased significantly over the past decades, which is why concentrations outdoors are low these days.
• Inhalable particles (particulate matter, PM10) mainly come from street dust raised by traffic, which may pose a health hazard. Increased amounts of street dust weaken the wellbeing of persons with respiratory illnesses, in particular.
• Fine inhalable particles (PM2.5) mainly come from emissions caused by traffic and the burning of wood. They also traverse to the Helsinki region from outside Finland. These particles are considered especially hazardous to health since they can enter the lungs’ most peripheral parts.
• The groups who are the most vulnerable to health hazards caused by air pollutants are small children, seniors, and persons with respiratory or cardiovascular illnesses.