At least 10,000 healthy life years are lost every year due to noise pollution in Western Europe. A piece of information so disturbing, yet so underestimated. Unfortunately, we have limited means today to understand the effects of noise pollution. In a worldwide perspective, it’s mostly done by noise mapping, which, as we know now is not always the most accurate assessment. Not all countries do it and if they do, they do not cover the whole country, so to see the real impact is very hard. We’ll talk about all things noise pollution with Gunn Marit Aasvang, who is a senior scientist at the Norwegian Institute of Public Health focusing on air and noise pollution. She does both research and counselling for local and central authorities in Norway.

Noise pollution is a serious problem, yet not many people talk about it or even acknowledge it, what is your perspective on that as a researcher who studies the effects of noise pollution on people?

I think the perception has changed a bit in the last 20 years. We get a lot of questions and inquiries at the Norwegian Institute of Public Health about noise. Noise is one of the main things that people complain about, especially living in the cities. But of course, there was this notion before that noise is only a nuisance that leads to  immediate and short-term disturbances, and most of the focus was on that. However, in the past 10 years there has been more and more research on the long-term effects of noise pollution on health. Research from Nordic countries, as well as the rest of the world shows associations between environmental noise and cardiovascular diseases, as well as cancer. In light of that, the attention to noise pollution as a health problem worldwide has increased.

Noise pollution is mentioned in the press, but not as substantially as air pollution, for example – why do you think that is?

I guess you’re right in some ways. Air pollution has been acknowledged as a health problem for many years . While you do not necessarily see air pollution, it is something that you breath in, and something that affects your health. There’s been a great amount of research on air pollution effects on health in the US, yet noise research is neglected there. And because the research projects promoted in the US have a big impact on what is researched everywhere else, noise pollution has been put on the backseat. Noise as well, for a long time, has been looked upon  as a nuisance rather than a health problem, so that might have added on the issue.

You’ve done a project about how noise pollution affects children – what do the results show?

Yes, we saw that most of the research on noise effects has been done on adults, so we thought it was about time to do some studies on children. We estimated residential noise level outside the houses of the children in the project, from pregnancy until the age of 7-8.  We looked at several health outcomes, from sleep disturbances to reduced attention to BMI (body mass index). The association with all of these was pretty inconsistent and not that strong. We found some associations only in boys, and some associations only in girls. For example, regarding sleep disturbances we only found associations with girls and not the boys, while the exposure during pregnancy found an association with inattention only with boys. This is a very complex analysis, so the results were not very strong and we need to take into the account so many other factors that might influence the associations. We found indications that noise can affect the child already during pregnancy as it works as a stressor. Regarding other research, there’s been some done with aircraft noise and schools, and it showed to be very consistent. When there’s an increase of aircraft noise near schools, the reading abilities of children reduce.

We can hear comments such as ‘if you don’t like living in a noisy city, move to the countryside’ all the time. Should we really just ‘deal with it’ or are there ways to change this?

To some extent, I think we need to cope with some noise. On the other hand, noise is quite highly regulated by the authorities, it’s included in the pollution act. There are also recommendations when building new houses, schools and kindergartens and it’s also possible to insulate houses. But when it comes to noise outside, of course it becomes more complicated. You need to reduce noise by the source or increase the distance between the receiver and the noise source, there have been some improvements regarding emissions from cars and aircrafts, but it’s still too high for many people.

Is a relatively quiet city a utopia?

For me, a silent city is a dead city; so perhaps we could aim for improved soundscape, better sound environment, focusing also on some recreational areas where sound would be kept as low as possible. You see, noise is an unwanted sound, but some sounds are actually quite pleasant.

Is there a difference in noise pollution levels between Norwegian cities and other European cities?

Good question. I think when comparing the mappings based on the Environmental Noise Directive, Oslo, for example stands neither very high, nor very low on the chart in terms of the percentage of people exposed to environmental noise. However, these noise mappings are not always accurate.

An example of noise mapping

What impact do each of us have on the noise problem – what can we do to have a positive impact?

Many people already think about climate change and take action, reducing their use of transport for example, so that way, you also reduce your input to the noise pollution. Cycling or walking to work definitely helps, also using electric cars, which tend to be quite silent at lower speeds. But ultimately, I think what needs to change most is the attitude towards the noise problem. A lot of people are reporting the annoyance of neighbourhood noise, so I think each one of us should be more considerate.

What are the biggest sources of noise pollution?

In terms of the number of people exposed, it’s definitely road traffic, but it’s not in terms of the highest levels.

Road traffic

There are a lot of health related consequences from noise pollution; obesity is one of them for example. Are there any other ones that we don’t know about?

Yes, some studies have reported associations with obesity. Noise pollution has shown to increase central obesity in some studies and the hypothesis behind that is that noise works as a stressor that increases stress hormones, which disturbs your metabolic system and the weight increases as a consequence of that. Especially noise at night that disturbs your sleep can have detrimental effects on health. Thus, noise as a stressor can potentially increase the chances for other diseases to develop. There are some studies that show some association with dementia. That particular study looked at both air and noise pollution and they found a stronger association with road traffic noise than air pollution when it came to dementia. Sleep disturbance, created by noise, in the long term will display some effects in the brain. However, more studies, including both air pollution and noise are needed to get more knowledge on the contribution on health from these to traffic related exposures. I have to point out that all these associations between noise and the more detrimental health effects are not very strong, but long term exposure to noise can contribute together with several other risk factors to the development of diseases.

Are there any known mental health problems connected with noise pollution?

Well, sleep disturbance is strongly linked to mental health issues such as depression and anxiety. Noise acting as a stressor also adds on that, however, the research in this particular topic is very limited. The WHO report on noise pollution was a huge effort to do systematic reviews on all health outcomes, including mental health and well-being. The studies are mostly cross-sectional, so the quality of the knowledge is very low. We still need to get more knowledge about that people are very different, some are more susceptible to noise, some are less, but the ones that are more susceptible suffer from noise pollution far more, which sometimes can be masked in larger studies.