Interview with Prof. Rainer Guski, head of the NORAH study
There will be a lot of discussion on the NORAH-study. If you could choose: what should people talk about?
About the results, of course! Some were less surprising, such as the high annoyance effect of flight noise. Others were, such as the strong connection between noise and depression. The negative influence of flight noise on children learning to read also had not been expected to be so clear. Vice versa, we see that there only is a trend in the connection between blood pressure and noise, where we expected a clear effect. We can discuss this now.
What do you think are some central insights?
There are important insights from all sub-studies. I think the disturbance results are essential. We originally thought that Frankfurt as a change airport had a very different disturbance than airports that have not been developed. This seems to be wrong. The disturbance in Cologne and Stuttgart also is much higher than ten years ago. The so-called flight noise standard curves of the EU are out of date. A second insight for me is that we cannot conduct the debate about noise and cardiovascular diseases as we used to. Before NORAH, everyone assumed that the risks clearly increased with the noise level because literature said so – even though it was never all that clear, if we look more precisely. Now we can see that the cardiovascular effects are less than reported. At the same time, another aspect that has hardly been examined before comes to focus: depression. Both will play a role in the scientific discussion. I’m sure of that.
Do you have any explanation of why disturbance by flight noise is rising not just in Frankfurt, but also at other airports?
Maybe the continuous noise level is no longer the right measure to predict flight noise effects. The total continuous noise level in the area of almost all German airports has dropped slightly. The number of flight movements, however, has increased. The continuous noise level does not seem to consider this.
Do the different traffic noise types have to be reassessed after NORAH?
Yes, at least flight and rail traffic noise. The latter seems less harmless today. We found the highest risks for cardiovascular diseases in rail traffic noise. The annoyance curve also does not correspond to the EU standard curve. This matches the results of the rail noise study in the Middle Rhine Valley, by the way. The disturbance from flight noise has increased in the last years. Both EU standard curves need to be revised. NORAH forms a good basis for this. For road traffic, we do not have as clear indications, but there are relatively few examinations that suggest a change. Do you perceive the results as more reassuring or disconcerting? Neither nor. The effect of noise has changed. It has not become “better” or “worse.” I no longer see cardiovascular risks that are also discussed intensely in the region as being so extremely dangerous, at least regarding flight noise. All in all, the risks of flight noise have change from physical effects towards psychological ones, and specifically depression.
What does this mean for residents?
Maybe we could put it like this: I can be less afraid of a heart attack, but I should know clearly that flight noise is a high psychological burden. Especially if I am psychologically sensitive, it may be harmful for me to live near the airport.