Interview with the study director Prof. Maria Klatte
Did any of the results of the NORAH Child Study surprise you?
There is already a whole range of studies on this issue. The children in those studies, however, were subject to much higher levels of exposure to aviation noise, spectacularly higher levels. Nonetheless, only very minor effects could be identified.
With this pre-knowledge we were not sure at the start of the study whether we would even be able to detect any effects on the reading performance of the children. We had not expected that statistically significant effects could be verified despite the low levels of exposure.
Were the other results as you expected them to be?
No, for example the increased frequency of medically diagnosed speech and language disorders and intake of medication: that is a result of the parent survey. We did not expect that this would show up so clearly. This is something we really need to pursue further to find out what exactly is behind it.
In your opinion, how serious are these speech and language disorders?
We do not know exactly which type of disorders led to the differences shown in our study. But we did examine whether the children who, according to their parents, had a speech or language disorder differ from the other children in terms of their reading performance. This is not the case. This is why we do not believe that we are looking at very serious disorders here. But we do not know exactly, and this is why there have to be follow-up investigations.
If parents hear about your study and start asking themselves whether their child is worse off than children in quieter areas: what would you tell them?
We asked the parents and the children about the physical and mental wellbeing of the children. This was represented as very positive by both groups. Children exposed to aviation noise do not feel bad, but they do feel a tiny bit less good. Other factors certainly have a greater influence on the wellbeing of the children. Nonetheless, the effect is statistically significant. And we cannot tell how that will develop in the long term if the children have to live and learn under the influence of aviation noise.
You identified a delay in learning to read of up to two months in second-grade pupils. Does this mean that children living near an airport are less likely to complete secondary school or generally have fewer chances?
It is not possible to answer that with any certainty because we do not know how the relatively small difference in the second-grade pupils will turn out in the long term. First we have to say that the identified statistical effect on the reading performance is small. There are other influencing factors that are far more important. But we do not know how that will develop. We also surveyed the school directors of the participating schools. We asked them which proportion of the children in their school go on to secondary school from primary. We did not find any difference here: in the schools exposed to high levels of aviation noise that participated in the study, on average the same proportion of children went on to secondary school as in the schools with lower exposure.
You also spoke to teachers …
Yes, the clarity of the results of the teacher survey were a surprise. We know that interruptions of the teaching flow are very unfavourable for children at this age. Up to now, research has focused mainly on reading performance. But these frequent interruptions can, of course, also have an unfavourable effect on other subjects.