Air pollution costs the Nordic countries tens of billions of kroner every single year. "It has a negative impact on human health and leads to higher mortality and greater inequality in the distribution of welfare. In order to regulate air pollution effectively, we have to find out which chemical substances are the most harmful and which population groups are affected the most," says Jørgen Brandt, professor at the Department of Environmental Science at Aarhus University and project leader of the NordicWelfAir project.
Together, the 16 partners from five Nordic countries participating in the project will map out air pollution and its various components all the way down to a 1 km x 1 km resolution for all the Nordic countries. Project activities also include development of a common air pollution modelling framework which will, for the first time, make it possible to calculate air pollution levels in the Nordic countries from 1990 to the present with the same geographical resolution for all countries.
High costs and more disease
Although the air quality in the Nordic countries is relatively good compared with many other regions, the negative health effects of air pollution are significant. It can lead to respiratory disease, cardiovascular disease and cancer, as well as further complications for those already suffering from other illnesses.
"We have a problem with air pollution in the Nordic region. Our air may not be as bad as in Beijing, but it nonetheless poses a very serious health and socio-economic problem on a Nordic scale. We already know quite a bit about the consequences of air pollution exposure, and in Denmark alone there are close to 4 000 premature deaths related to air pollution each year. This is 20 times higher than the annual figures for traffic fatalities," Professor Brandt states.
"Air pollution is a significant cause of disease, and it costs society an enormous amount of money. Just for Denmark the cost is DKK 30 billion each year," he continues. "This includes costs associated with premature death, sickness absence and hospital admissions, for example."
Which substances are most harmful and who is most affected?
In the face of such a severe problem that leads to both serious illness and high societal costs, it is imperative to find the best, most effective means of mitigation. That is what the NordicWelfAir project is planning to help with.
"Air pollution consists of a combination of many different types of particles and gases that can adversely affect human health in a variety of ways. We don’t really know which substances are most harmful. Therefore, the project will see whether the answer is, for instance, soot particles from oil, wood and coal-burning stoves; NOx emissions from automobiles leading to nitrate particles; or ammonium particles from agriculture," the professor says, adding:
In short, we are going to determine which sources are the most damaging pollutants and who is most vulnerable.
Air pollution travels rapidly over great distances
Fine particles in the air are rapidly transported by wind across national borders and are deposited by rain and snow on surfaces below. Using different air pollution models, the NordicWelfAir project will identify where pollutants are coming from, and it may not necessarily be from a country close by.
"Pollutants in the air you breathe on the streets of Oslo or Copenhagen come from numerous sources," the professor explains. "Local traffic is an obvious source, but some are coming from other cities and countries, even distant sources like China and the US or a cloud of volcanic ash from Iceland. Our model allows us to perform detailed calculations, which in turn can identify which areas are most exposed to air pollution and where it comes from. This is unprecedented at this scale in air pollution research."
Hard to rule out other causes of disease
According to Professor Brandt, one of the most difficult aspects of the project will be proving that disease and health problems are in fact the result of air pollution as opposed to other factors.
“The epidemiological component of the project is looking at this issue. If you live near a highway it may well be noise pollution and not just emissions that cause health problems. Smoking and/or a poor diet are also potential causes of disease,” he says.
“It’s a difficult task, but here we will draw on data from the various registers in addition to other studies. For example, the University of Copenhagen has conducted a survey over many years asking nurses what they eat and drink, if they smoke and where they live. The Danish Cancer Society Research Center maintains a similar register of cancer patients. That is, they know a great deal about their lives.”
Ms Geels continues: “We can use this approach to compare information found in the national registers against other surveys, and attempt to rule out patients whose disease is rooted in other causes. We are also working together with the Department of Public Health at Aarhus University, where they have a research project where they take people into a chamber and expose them to air pollution. They measure how the subject’s body reacts in a wide variety of ways. This yields a better understanding of the physiological effects of polluted air when it comes to pulmonary and cardiovascular diseases, for example.”
