Qualité de l’air à Helsinki

Is Helsinki a polluted city?

Helsinki is a city located in Finland, being both the capital and most populous city in the entire country. Location wise it faces onto the Gulf of Finland, and is home to some 656 thousand people, with the extended urban area housing even more, with 1.26 million people living in the suburbs of the city. It finds itself very close to other major cities in Europe, among them being Tallinn in Estonia, Stockholm in Sweden and Saint Petersburg in Russia, having close historical ties with all of these cities.

Nowadays, Helsinki has a prominent IT based economy, as well as shipping industries and companies also keeping the employment rate up. As such, whilst Helsinki has a very good and almost model like level of pollution, there are still a few factors that drive up the yearly pollution averages due to anthropogenic activities.

In 2019, a year that will be referenced more prominently due to 2020 being a year that saw widescale lockdowns occurring across the world and therefore not entirely indicative of what the real pollution levels would be under more normal circumstances. In 2019, Helsinki came in with a yearly PM2.5 average of 6 μg/m³, placing it well within the World Health Organizations (WHO's) target goal for a great quality of air, a target grouping that requires 10 μg/m³ or less to be classified as such.

This reading of 6 μg/m³ also placed Helsinki into 4168^th place out of all cities ranked worldwide, as well as 3^rd place out of all cities ranked in Finland. Of note is that Finland was one of the cleanest countries air quality wise in 2019, meaning that despite a few pollution causing hiccups, has a great quality of air that many countries and cities could aspire to.

What are the main causes of pollution in Helsinki?

Even with such clean levels of air, the sources of pollution that arise are similar to many other cities and countries around the world, but due to protective initiatives in play as well as meteorological and geographic factors also playing a part, they would be much reduced.

With many government bourn incentives to get people onto public transport and other green forms of transportation such as bicycle commutes or walking when necessary, there will still be an abundance of personal vehicle usage, with cars, motorbikes and other similar automobiles inhabiting the roads. Heavy duty vehicles such as trucks, lorries and buses also have their own part to play, with many still running on diesel fuels, despite the countries efforts to see to the phasing out of their using entirely around 2030, as a rough estimate.

Alongside this, due to it being a port town, it would also see a large amount of pollution arising from boats, cargo and freight ships all docking there and moving in and out of the port. These vehicles often have higher levels of sulfur in their fuels due to different regulations regarding fuel usage in boats. As such this would be another contributing source of pollution.

Other sources would include ones such as factory emissions, with many of them relying on imported coal to power their stations. Once again whilst it is planned to be phased out and replaced by more sustainable methods, in the meantime the combustion of fossil fuels can add further to year round pollution readings.

When is the air at its cleanest in Helsinki?

Observing the data taken over 2019, whilst the entirety of the year manages to stay within the WHO's target bracket for best quality of air, there are certain portions of it where the air quality may differ by several units, with factors such as the weather (wind speed, humidity) and human based factors such as increased use of heating or cars skewing the readings somewhat.

It appears to be that the end of the year is when Helsinki saw its best levels of air quality. Around August the PM2.5 readings started to drop, coming in with a reading of 5.9 μg/m³ over August, and then going down further in September to 4.7 μg/m³, and then down furthermore to the cleanest month of the year, October, which came in with a reading of 4.1 μg/m³, giving it an exceptionally good quality of air. despite a sudden rise in November to 6.6 μg/m³, December also came in with a respectable reading of 4.5 μg/m³, indicating that the end of the year is indeed the time when Helsinki has its cleanest and least polluted air.

When are pollution levels at their highest in Helsinki?

Whilst the whole year remains a model that many cities would dream of attaining, there are months where the levels stay slightly elevated. As mentioned before, the cleanest months of the year were at the very end in October and November.

For the months that had somewhat heightened pollution levels, January through to June all came in slightly higher than their cleaner counterparts. January, May, June and July all came in with the worst readings of PM2.5, with numbers of 6.5 μg/m³, 9.8 μg/m³, 6 μg/m³ and 6.7 μg/m³.

This shows that May was the most polluted month of the entire year, with its surrounding months also having higher readings of pollution. Despite not breaking out of the best group ratings bracket, it still stands to reason that elevated levels of pollution often indicate that something may be going wrong, or better preventative measures may be put into place during such times.

What type of pollutants would be found in the air in Helsinki?

With much of its pollution coming from sources such as vehicular and ship emissions, as well as industrial smoke and particulate matter, the chemical pollutants would have a close relationship to these processes, as well as other pollutants being found on both the ground level and upper atmosphere.

Prominent ones would be nitrogen dioxide (NO₂) and sulfur dioxide (SO₂), with nitrogen dioxide being released in high volumes by cars and trucks, often to the point that high levels of it often correlate directly with larger volumes of traffic or rush hour areas.

Sulfur dioxide is also released by vehicles, but would find more prominence in release from ships due to the higher sulfur content present in their fuels. With such a clean quality of air year round, whilst there would no doubt be other pollutants found in the air, many of them would be in trace amounts and somewhat negligible, although still posing risk to human health if allowed to accumulate in certain areas. These would include fine particles or compounds such as ozone (O₃), carbon monoxide (CO), along with black carbon and volatile organic compounds, with more being salient in the air during the months that have higher PM2.5 readings, otherwise being quite free from the atmosphere, giving Helsinki a very good quality of air to breathe.