Findings of the NORAH study in Frankfurt, on effect of aircraft noise on mental well-being and depression
At the event in the House of Commons on 4th July, exploring the relationships between exposure to aircraft noise and mental health, a presentation was given by Dirk Schreckenberg, from Hagen, Germany. He is one of the research psychologists who worked on the NORAH study (Noise-Related Annoyance, Cognition, and Health) carried out in Frankfurt, before and after the opening of the 4th runway. The NORAH study is the largest and most comprehensive to look at the impacts of aircraft noise on people’s health and quality of life, and also its impacts on children. One sub-study looked at mental well-being, and another looked at depression. It was clear from the data that people were more annoyed and more affected by noise from the new runway, and at lower noise levels, than had been expected. Though the links are complicated, and not entirely linear, there is a clear link between worsening mental well-being and more plane noise. There was a clear relationship between depression and aircraft noise, with more depression at levels of noise that are widely experienced. The data form an inverted “U” shape graph, indicating less depression at the highest noise levels. The reasons are unclear, but may be a “healthy resident” effect.
Seminar on Aircraft Noise and Mental Health, 4th July 2016
at the House of Commons, Westminster
The Aviation Environment Federation (AEF) and Heathrow residents’ group HACAN hosted a well attended event in Parliament, which explored the relationship between aircraft noise and mental health. The event was chaired by Twickenham MP, Dr Tania Mathias.
Dirk Schreckenberg, from the Centre for Applied Psychology, Environmental and Social Science in Hagen, Germany, provided a summary of the findings of the NORAH study. This major piece of research from around Frankfurt Airport examined a wide range of health impacts associated with aircraft noise before and after a fourth runway was built. The study included ground-breaking research on the links between aircraft noise and depression, and the impacts of a change in noise exposure (associated with expansion or new flight paths) on quality of life and community annoyance.
Summary of the Presentation by Dirk Schreckenberg
Centre for Applied Psychology,
Environmental and Social Research
D-58093 Hagen, Germany
Download the full presentation: Presentation by Dirk Schreckenberg on the NORAH study
Summary by Sarah Clayton, AirportWatch co-ordinator (with the approval of Dirk)
The NORAH Study (Noise-Related Annoyance, Cognition, and Health) is the most extensive study on the subject of aircraft noise impact done so far. It was carried out over several years, around Frankfurt airport, looking at a number of questions such as what impact does traffic noise have on people’s quality of life and health, and what impact does it have on the development of children?
With the 4th Frankfurt airport runway, that opened in October 2011, it was intended to increase the capacity for 200,000 more annual flights – up to a total of 700,000 per year by 2020.* New areas were over-flown for the first time, and other areas experienced differences in the way they were overflown.
The NORAH Study was commissioned by the Environment & Community Center (UNH), a wholly-owned subsidiary of the federal state of Hessen. It is a longitudinal study that took place between April 2011 and December 2015.
Between 2001 – 2007 there were Regional Planning and Zoning Procedures, with the official approval at the end of 2007 on the legitimacy of the requested airport expansion. The plan approval order looked at issues such as night flights.
In the year 2000, a regional mediation group agreed initially on a ban on night flights for the period of 11pm to 5am. By 2007 in the approval order this night flight ban was ignored.. The order allowed for up 17 scheduled flights between 11pm and 5am and 133 flights in the shoulder periods after the opening of the runway. Communities and citizens’ groups regarded this as a violation of the mediation agreement.
In October 2011 the 4th runway opened and a night flight ban was introduced (a voluntary ban till March 2012, when it was confirmed by a court decision).
The NORAH study looked at the year 2011 (before the runway opened – in October) and then the two years after it, in 2012 and 2013. These were compared with earlier data from 2005. For each address, the level of noise, the Leq, the maximum sound level, the number of noise events and the background of road traffic and railway noise were calculated (modelled).
There were several work packages (sub-studies) that made up the NORAH study. One was the Annoyance, health-related quality of life section (NORAH WP1), which looked at annoyance and reported mental well-being. There was a separate section, on Health risks, Depression (NORAH WP2), which looked at the risk of developing depression. That was carried out by Professor Andreas Seidler, University of Dresden.
A previous study (RDF study) carried out in 2005 showed results with regard to the percentage of people highly annoyed by aircraft noise. Its findings are comparable to the findings of the ANASE study in the UK. In both studies a higher percentage of people were annoyed by noise at lower levels as compared to the European standard dose-response curve for aircraft noise annoyance derived from meta-analysis (so-called Miedema curves).
The new NORAH results show an even higher percentage of highly annoyed people in the years 2011 to 2013. The difference in the annoyance between 2011 and 2005 is considerably larger than the difference before (2011) and after (2012, 2013) the opening of the new runway.
With the new runway there were winners and losers in terms of noise experienced. At the worst, some people could have experienced as much as 12 – 13 dB averaged noise more than before.
The study data showed that compared to the levels in 2005, in 2011, 2012 and 2013 many more people were highly annoyed by aircraft noise – at all levels. This is shown at other German airports (Cologne/Bonn and Stuttgart) as well as at Frankfurt, though the effect is stronger at Frankfurt.
At Frankfurt, for example, while in 2005 around 50% were highly annoyed by an average level of noise at 55 dB LAeq at daytime, in 2011, 2012 and 2013 this level of annoyance was reached at about 50 dB LAeq.
. Likewise in 2005 around 70% were highly annoyed at a noise level at 60 dB LAeq, by 2011, 2012 and 2013 about 70% were highly annoyed by 55 dB LAeq.
Based on previous scientific literature and on evidence of the NORAH study the NORAH scientists assumed a reciprocal relationship between noise reactions and mental health. That is, noise leads to stress reactions and in the long-term to reduced mental health. People who are already ill react worse to the noise stressor than people who are more healthy. The findings did not show an improvement in mental well being in those experiencing slightly less noise.
At Frankfurt 3,508 people took part in all stages, in 2011, 2012 and 2013. Interviews were conducted by telephone, or online.
There were also surveys at Berlin-Brandenburg (5,548 people), in 2012, and at Cologne/Bonn (2, 955 people) and at Stuttgart airports (1979 people), in 2013.
The non-acoustic factors influencing of noise annoyance include the perception of fairness, expectations, attitudes towards the noise source, trust in authorities and noise sensitivity. People’s perception of their ability to control or influence the situation was also important. People are even more upset and angry about the noise if there is inadequate communication with the airport or source of the noise.
In the graph above, the exposure-response curves for aircraft noise annoyance against LpAeq moved higher up in 2011, 2012 and 2013 compared to the RDF-Studie 2005. (This means people were more annoyed at lower noise levels). This is partly a ‘change’ effect due to the airport’s expansion, and perhaps partly a general trend in time?
The reactions to noise are complicated, and the NORAH study looked at groups experiencing an average 2 dB LAeq more or less averaged noise, and found mixed results. It did appear that when the groups experienced 2 dB LAeq more noise, they expressed higher levels of annoyance than expected.
The illustration above compares the extent of noise annoyance in 2012 and 2013 to the degree of annoyance as predicted for 2012 and 2013 (‘2012/2013 expected’) on the base of the exposure-response model of 2011. The “expected” values on the graph did not match well with the actual data obtained. The slope of the line indicates that people are more annoyed than expected at lower noise levels. This was particularly the case in 2012, the first year the runway operated (red line). The level of annoyance was very slightly lower in 2013, (blue line) when perhaps people had become slightly more resigned to the new aircraft noise situation at their home.
Factors influencing the change in aircraft noise annoyance
Judgements of health-related quality of life (HQoL) refer to general health, physical functioning and role, bodily pain, vitality, social functioning, emotional role, mental health. The judgments were summarized to two scores: MCS mental component and PCS physical component. In the analysis, the MCS and PCS scores were linked to address-related sound levels for aircraft, road traffic, and railway noise.
Models were adjusted for mode of survey, gender, age, period of residence, hours out of home, house ownership, socio-economic status, migration background, noise sensitivity, Body Mass Index, exercise, and sound levels of other transportation modes.
The study found changes in mental well-being since the opening of the new Frankfurt runway in October 2011, and its consequent changes in noise annoyance. The results showed the correlation between sound level and MCS was rather low, BUT particularly in the group that experienced an “Increase in LpAeq,24hrs,” mental well-being decreased with increasing sound levels. The relationship became stronger after the opening of the new runway in the group suffering from an increase in aircraft noise exposure due to its opening. It seems that noise becomes relevant for mental health particularly when the noise situation worsens.
The part of the NORAH study that looked at annoyance, and health-related quality of life (NORAH WP1) did not look at depression but only on self-reported mental well-being.
Those experiencing an increase in Leq after the opening of the 4th runway might also have experienced aircraft noise before, although on a lower level.
Considering depression and transport noise, the study looked at road noise, rail noise and aircraft noise. This section of the NORAH study looked at health insurance data (‘claims’ data) on ambulant patient and inpatient diagnoses from 2006 to 2010, and a survey of individual risk factors of insured people. This data was linked with address-related average and maximum sound levels for aircraft, road traffic, railway noise from 1996 – 2005. In total the study looked at 1,026,658 insured people, aged over 40 years. They found there were 77,295 people with depression, in this group.
Analysis of noise-related health risks included regression with sound levels, and data was adjusted for age, gender, education, occupation, social status (aggregated insurance data).
The study found that with road noise, there is a straight linear relationship, with more depression linked to more noise. The study found that for a 10dB Leq increase in averaged road traffic noise over 24 hours, there was a 4% increase in the chance of depression.
The picture for rail noise is a bit complicated – and not quite a linear link. For aircraft noise, the relationship with depression is an inverted U shape, with more depression at moderate levels, and less depression at lower and higher levels.
© Seidler et al. (2015). Source: http://www.laermstudie.de/fileadmin/files/Laermstudie/NORAH_Knowledge_12.pdf
The reasons for this are not known, but could include the “healthy resident” effect, and a mixture of people self-selecting to not live in those areas, or moving away, or being accustomed to the noise and accepting of it.
Aircraft noise annoyance is associated with mental health:
People who are more highly annoyed report less mental well-being (similar for road traffic and railway noise). Correspondingly, in NORAH and other recent studies an association between transport noise and the risk of developing a depression was found. The linearity of the relationship is unclear.
- Background info: The new runway was requested by Lufthansa and the airport to be able to increase the capacity. But so far, the total number of yearly movements didn’t change much since the opening of the runway (s. table for your information).
|after opening of 4th runway||before|
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