Air quality in Denmark

What is the air quality index in Denmark?

Denmark is officially known as the Kingdom of Denmark is situated in northern Europe tothe south of Norway and Sweden. It consists of a peninsula and 43 islands. In2020 the population was estimated to be in the region of 5.8 million people.

In December 2020, Denmark’s air quality index showed the air quality to be “Good”,according to the suggested figures by the World Health Organisation (WHO). Inthe capital city of Copenhagen, the air quality was “Good” with a reading of 18US AQI. The levels of the main pollutants were as follows: - PM2.5 - 4.4 µg/m³,PM10 - 8.9 µg/m³, sulphur dioxide (SO₂) - 0.1 µg/m³ and carbon monoxide (CO) - 0.2 µg/m³.

In the world ranking of dirtiest cities in 2019, Denmark was ranked as 84 out of a total of 98 countries.

Is Denmark improving its air quality?

A new overview of air quality in Copenhagen shows many particles that are harmfulto health on some roads and in the Inner City. It shows the results of a new collaborationbetween Google and the City of Copenhagen, which has had a car driving aroundthe streets of Copenhagen to measure and map air pollution.

The results already show a pattern in Copenhagen. They show that there is asignificantly higher level of ultrafine particles on the busiest roads and inthe inner city. Ultrafine air particles are considered to be the most harmfulparticles to health and originate especially from the combustion and exhaustfrom diesel engines. The project provides for the first time the opportunity tomeasure this type of particles which have not been mapped before. The E20motorway south of the city in particular and access roads such as Lyngbyvejenand Folehaven have a high level of ultrafine particles. In the central part ofthe city, HC Andersens Boulevard, Børsgade and Nørre Voldgade also stand out.

Aarhus University estimated in a statement last year that 3,200 Danes die a year dueto poor air quality. In Copenhagen alone, about 550 people die prematurelyevery year due to air pollution.

From 1 January 2010, there was a supplement introduced to the weight and ownershiptax of DKK 1,000 annually. To avoid the surcharge, a car must emit a maximum of5 micrograms of particles per kilometer. It is thus a matter of having anefficient particulate filter fixed, or buying a newer car that stays below the limit.

At the street stations, the traffic immediately driving past the station is themain source of substances such as nitrogen oxides, carbon monoxide and to some extentPM10 (particles less than 10 microns). The street stations are in all caseslocated on the pavement immediately up to the carriageways on a busy street inthe city centre. The results give an impression of the pollution you areexposed to in "street spaces", as - depending on the meteorologicalconditions - there can be large variations over smaller distances.

Is the air in Denmark good enough for biking?

Because many people currently have to stay home and work or take time off altogether,cars are also increasingly allowed to stay in the garage. This can be clearlyread on measurements of the air quality in Copenhagen. Here, measuring stationson, among other places, the busy HC Andersens Boulevard register a markeddecrease in NOx, which is the harmful exhaust gas that cars emit. From a levelof 273.12 µg/m³ on Thursday, 27^th February at 7.30 am to thisWednesday morning to be all the way down to just 66 µg/m³. It should be notedthat there may be fluctuations from day to day depending on how much it blowsand the direction of the wind. But the trend is clear in recent weeks; thecurve has been sharply downward. There is a measurable decline in air pollution. It is actually as expected when cartraffic so much lower, which is one of the major local sources of airpollution. The interesting thing is that it can be seen here in black and white that it will make a huge difference if car traffic in Copenhagen is reduced.

But while the declining pollution may not be so surprising, the coming weeks with aDenmark on low gear during the corona crisis may, in turn, give researchers aunique opportunity to document the consequences of the normally dense cartraffic in the city. There is now the opportunity to document the effect over alonger period of time under many different meteorological conditions.

Ironically, while NOx emissions from cars have fallen during the corona pandemic, theparticulate pollution from, for example, wood-burning stoves can converselyincrease because more people are at home during the day. How the two factors outweigh each other is still too early to say.

There are an estimated 7,000 kilometres of dedicated cycle tracks and lanes inDenmark. In Copenhagen a system of interconnected green cycle routes iscurrently under construction. The ultimate goal is to provide a safe and pleasant, yet fast network across thecity. It is hoped to reach at least 100 kilometres on completion. One problemthat this will bring will have to be solved. There is a general lack of dedicated spaces where bicycles can safely be left.

What are some environmental issues in Denmark?

Air pollution with NO_x gases comes primarily from local traffic and is especially achallenge in cities. NO_x is a collective term for nitrogen oxide (NO)and nitrogen dioxide (NO₂). Nitrogen dioxide is harmful to health initself. In addition, NO_x can react with ammonia in the air to formsecondary particles that are harmful to health in line with directly emittedparticles. Nitrogen from the air is deposited on surfaces where it has afertilizing effect. Air pollution with nitrogen compounds can thereforecontribute to over-fertilization (eutrophication), which can lead to algaeblooms in water areas and loss of biodiversity in nutrient-poor habitats.

In order to reduce pollution by NOx from cars, trucks and other vehicles using internal combustionengines could be retrofitted with NOx cleaning systems. There are alsorequirements for NOx purification of new ship engines, work machines and power plants.

From 2008-2010, environmental zones were established in the five largest Danish cities(Copenhagen, Frederiksberg, Aalborg, Aarhus and Odense). In the environmentalzones, requirements are set for emissions of NOx and other air pollutants fromlorries. In May 2019, the Folketing adopted stricter environmental requirementsfor trucks, buses and vans. Today, there are strict environmental requirementsfrom the EU for new vehicles. The EU has introduced new measurement methodswhere car emissions are measured under real driving conditions (RDE realdriving emissions) to prevent tampering with car emissions.

In the EU, a limit value of 40 µg/m³ has been set for the annual average of the air content of NO₂.The limit value is set to protect human health. HC Andersens Boulevard inCopenhagen is considered to be one of the most polluted places in Denmark andis therefore used as a reference for compliance with the EU limit value.

All Danish cities comply with the NO₂ limit value. The highest concentrations aremeasured on the busiest roads; the annual average at HC Andersens Boulevard in2017 was 38.4 µg/m³ and in Banegårdsgade in Aarhus 28 µg/m³. The concentrationsof NO₂ measured at the street stations in 2017 have decreasedcompared to the concentrations measured in 2016.

What causes air pollution in Denmark?

Particle pollution is the biggest problem for health, and those particles come, among otherthings, from the exhaust emissions from cars, trucks and ships, coal-firedpower plants and from wood smoke. In addition, there are also particles thatcome from tyres and brakes, wear of roads, salt water spray and dust from rooftops.

There are approximately 750,000 wood-burning stoves in Denmark, making them the largestsource of air pollution. In Denmark, the particles from these stoves, accordingto DCE, are responsible for approximately 550 annual deaths. Especially the oldwood-burning stove from before 2005 which emit far more harmful particles than others.

In 2005, the total particle emission was about 27,787 tonnes of PM2.5 in Denmark of which about17,665 tonnes were from residential wood combustion. Another major source isroad traffic, which contributes with about 20 per cent of the total emission of PM2.5.

What is the cleanest city in Denmark?

According to figures released by the reputable air monitoring company IQAir.com the cleanest city in Denmark is thecapital, Copenhagen. Only during the month of April did figures show a“Moderate” reading for PM2.5 (between 12.1 and 35.4 µg/m³). June, July, Augustand November returned a “Good” reading between 10 and 12 µg/m³. For theremaining seven months, Copenhagen achieved the target figure as suggested by the WHO (0 – 10 µg/m³).

Does the exclusion of traffic from city centres in Denmark help to reduce air pollution?

It has been proposed that car-free districts and car-free streets should becreated, that the environmental zones must be expanded and tightenedconsiderably, and that the number of parking spaces must be reduced. Alsosuggested was the creation of shortcuts for electric cars, buses and bicyclesby closing roads for transit with petrol and diesel cars.

What are the health hazards from breathing in the dirty air?

The World Health Organisation (WHO) study also shows that 90 per cent of theworld's population breathes polluted air. And while it is often a major threatto the poorest countries of the world, there are actually 400,000 deaths within the EU's borders each year.

A report from the University of Copenhagen and the Danish Heart Association fromJanuary 2018 shows a rather disappointing result. 2140 Danes die every yearfrom heart disease caused by air pollution.

The concentration often rises across large cities, and is known as smog. However,the problem is already alarming before it becomes the visible smog. Therefore,since 2007, “The World Air Quality Index” has collected data from measuringstations around the world, located in cities around the world.

Firewood smoke contains a complex mixture of pollutants such as particulate matter,inorganic gases (e.g. carbon monoxide, nitrogen oxides, and sulphur dioxides),polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs),which have the potential to harm the environment and human health. Many studieshave been conducted on the monitoring of both individual gaseous pollutant and a combination of mixes.

Volatile organic compounds are chemicals that contain carbon, hydrogen and oxygen andare gases at room temperature. VOCs are organic chemical compounds whosecomposition makes it possible for them to evaporate under normal indoor atmosphericconditions and pressure, this excludes carbon monoxide, carbon dioxide,carbonic acid, metallic carbides and ammonium carbonate.

Many diseases can be related to air pollution. This applies to both cardiovasculardiseases such as heart attacks and blood clots, and lung diseases such asbronchitis, asthma and coughs as well as lung cancer. It is estimated thatapproximately 6,000 Danes die from air pollution every year and in Europe thereare hundreds of thousands who die prematurely because they inhale polluted air.An analysis shows that Danes live on average one year and three months shorterdue to air pollution and noise, but with large geographical differences.

The dirty air is also expensive for society's common fund. Every year, more than 10,000 Danes become seriously ill, and havemillions of sick days, which are as a direct result of the pollution. Accordingto the Ecological Council, air pollution costs the Danish economy NOK 30-40 billion every year.

Particles with a diameter of up to 2.5 microns are called fine particles and are known asPM2.5. The largest source of fine particles are emissions from traffic andsmoke from wood-burning stoves, as well as so-called secondary particles, whichare formed from sulphur oxides and nitrogen filters from combustion plants andtraffic. The fine particles are characterized by the fact that they can betransported over long distances. The pollution of the air with fine particlesis dominated by foreign sources that contribute 75 per cent. The contribution fromwood-fired plants to the discharge of PM2.5 from Danish sources amounts to up to 2/3 of Danish sources.

Particles with a diameter of up to 10 microns arereferred to as PM 10. Particles between PM2.5 and PM 10 are depositedrelatively quickly to surfaces due to gravity and originate to a large extentfrom local sources such as the vortex of dust from soil, brakes, asphalt and tyres as well as sea salt.