New study by Queen Mary University, London, indicates possible long-term effects of aircraft noise on children’s cognition
Research into the impact of noise on children have carried out a new study to follow up a study done between 2001 and 2003 into the impact of noise from road traffic and aircraft on children aged 9 – 10. That was called the RANCH study (Road traffic noise and Aircraft Noise exposure and children’s Cognition and Health). The new study, carried out in 2008, wanted to assess the effects of noise over time on cognition. The study did indicate that levels of aircraft noise experienced in primary schools might affect aspects of children’s cognition, even several years after they have left the primary school – even taking socio-economic factors into account. The study looked at the same children aged 15-16 years old, who had attended noisier primary schools six years earlier. They found aircraft noise was more disturbing or annoying to these children than to controls, even after accounting for aircraft noise at their current school.
Summary of the RANCH study by Hounslow council http://www.hounslow.gov.uk/ranch_study.pdf
Full RANCH Study (2005) at http://www.itp.wceruw.org/documents/MooreStansfeld05RanchLancet.pdf
7 November 2013
Source: Clark, C., Head, J. & Stansfeld, S. A. (2013).
Longitudinal effects of aircraft noise exposure on children’s health and cognition: A six-year
follow-up of the UK RANCH cohort. Journal of Environmental Psychology.
35: 1-9. DOI: 10.1016/j.jenvp.2013.03.002
Contact: firstname.lastname@example.org (at Queen Mary University of London http://www.qmul.ac.uk/)
Science for Environment Policy
Possible long-term effects of aircraft noise on children’s cognition
Levels of aircraft noise experienced in primary schools might affect aspects of
children’s cognition, even several years after they have left the school, new
research suggests. Researchers revealed that 15-16 year olds who had attended
noisier primary schools six years earlier found aircraft noise more disturbing or
annoying, even after accounting for aircraft noise at their current school.
Living in noisy environments has been linked to various negative impacts on human health, with studies showing associations with heart disease, sleep disturbance and stress.
Across Europe, 80 million people, 20% of the total population, are thought to be regularly exposed to noise levels considered unacceptable by health experts. A previous investigation into environmental noise’s effects on children, the EU RANCH project (1) , revealed negative effects of aircraft noise on several aspects of cognition, including reading comprehension and memory.
RANCH studied 2844 children in 2001-2003, aged between nine and ten, attending 89 primary schools near major airports in the UK, the Netherlands and Spain.
The current study provides a follow-up to this work by assessing whether these effects on cognition were still apparent in the same children in 2008, when they were aged 15 to 16 and attending secondary school.
Such ‘longitudinal’ studies, which follow individuals over long periods, are important to assess how the effects of noise change. For example, if children are not able to adapt to noise, its impacts on their cognition could increase over time.
This study focused on the UK children who had been part of the original RANCH study. 461 pupils were tested, and data on noise levels in the secondary schools as well as in their original primary schools were analysed. The children were tested for reading comprehension, given a psychological distress score (based on answers to a questionnaire) and asked to rate how much aircraft noise disturbed or annoyed them.
The researchers also accounted for other factors which may influence the results, such as socioeconomic background.
The results showed that noise annoyance was significantly related to noise levels that the teenagers had experienced when they were younger at primary school, even when the levels at secondary school had been taken into account.
Annoyance can be an important indicator of a poor quality of life, the researchers state, potentially leading to stress and associated illness.
Poorer reading comprehension scores in the teenagers were associated with higher noise levels at primary school. While this finding was not statistically significant, the researchers suggest that this may be a result of the relatively small number of people studied, rather than a lack of an effect.
Other, larger, studies have demonstrated a significant negative link between noise levels and reading comprehension.
Finally, they found no association between higher noise levels at primary school and higher psychological distress scores.
Taken alongside the RANCH findings, the researchers conclude that this study adds to evidence that high levels of noise might impair children’s cognitive development, particularly in terms of reading comprehension and noise annoyance.
1. RANCH (Road traffic noise and Aircraft Noise exposure and children’s Cognition and Health) project, was supported by the European Commission under the Fifth Framework Programme.
See also earlier:
Noise and children:
Aircraft noise ‘affects learning’
Exposure to high levels of aircraft noise may affect children’s reading skills, researchers claim.A team from Barts and the London NHS Trust looked at data on more than 2,800 children living near Heathrow and other airports in Spain and the Netherlands.
The Lancet study found each five decibel increase in noise level was linked to children being up to two months behind in their reading age.
A US expert said the study supported previous research findings.
The children, all aged nine or 10, attended schools near to London’s Heathrow Airport, Schiphol in the Netherlands and Barajas in Spain.
But the researchers said their findings applied to the area around any airport.
Exposure to aircraft noise was associated with impaired reading comprehension, even after factors such as socio-economic differences between schools were taken into account.
Reading age was delayed by up to two months per five decibel increase in noise levels in the UK children studied, who attended schools in the boroughs of Hounslow, Hillingdon and Slough, and up to one month in the Dutch children.
A similar comparison could not be made for the Spanish children studied as there is no national data on reading age available.
Long term effects ‘unknown’
Overall, the researchers found a difference of around 20 decibels between children exposed to the lowest and highest levels of aircraft noise.
This translates to a delay of up to eight months in a child’s expected reading age.
The researchers say that while this is significant, it is much lower than the two year reading age delay seen in children with learning difficulties.
They suggest that children exposed to noise learn to tune it out – but this can mean they also tune out other external noise, such as teacher’s instructions.
Increased levels of exposure to both aircraft and traffic noise was associated with additional stress in children and a reduced quality of life.
However, exposure to traffic noise alone did not have an effect on reading age and, unexpectedly, was found to improve recall in memory tests.
Professor Stephen Stansfeld, who led the research, said: “These exposure-effect associations, in combination with results from earlier studies, suggest a causal effect of exposure to aircraft noise on children’s reading comprehension.
“In practical terms, aircraft noise might only have a small effect on the development of reading, but the effect of long-term exposure remains unknown.”
He said the results were relevant to the design and placement of schools in relation to airports and to the formulation of policy on noise and child health as well as the wider consideration of the effect of environmental factors on children’s development.
Schools which already existed near to airports should be properly insulated to give children as much protection as possible from the effects of aircraft noise, said the researchers.
Writing in the Lancet, Dr Peter Rabinowitz of Yale University School of Medicine, said this latest research backed up previous analyses.
He highlighted one study which looked at children living near to the old Munich airport in Germany, before and after it was closed down.
“Children attending schools near the airport improved their reading scores and cognitive memory performance as the airport shut down, while children going to school near the new airport experienced a decline in testing scores.”
The London Borough of Hounslow said that, in light of the research, it had launched an investigation into the impact of aircraft noise on local schools.
Aircraft and road traffic noise and children’s cognition