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WHO Europe publishes tough guidelines and recommendations for policymakers to reduce aircraft noise

The World Health Organisation Regional Office for Europe (WHO Europe) has today published its long-awaited environmental noise guidelines, the first complete update to WHO’s community noise guidelines launched in 1999. Following a comprehensive review of the scientific evidence linking noise to health impacts, WHO Europe has made source-specific recommendations for noise from aviation, road traffic, rail, wind turbines and leisure (such as personal electronic devices). For aircraft noise, the relevant guidelines are as follows:

  • For noise exposure averaged across the day, evening and night (Lden), the guidelines strongly recommend reducing noise levels to below 45 dB Lden, as aircraft noise above this level is associated with adverse health effects. 
  • For night noise exposure, the guidelines strongly recommend reducing noise levels to below 40 dB Lnight, as aircraft noise above this level is associated with adverse effects on sleep. 
  • To reduce health effects, the guidelines recommend “that policy-makers implement suitable measures to reduce noise exposure from aircraft in the population exposed to levels above the guideline values for average and night noise exposure.”

Comparison of these recommended thresholds with the 1999 version is complicated by the fact that the new guidelines have used different metrics, switching to Lden to match the mapping requirements in the 2002 EU Environmental Noise Directive. Airports are required to produce action plans every 5 years based on Lden noise maps, which give additional weighting to noise during the evening and at night, intended to reflect the additional disturbance and more significant health impact caused by noise at these times. 

The tough guideline thresholds set for aviation reflect the strength of the evidence relating to annoyance and sleep disturbance. There is good evidence that 10% of the population are highly annoyed when exposed to noise levels around 45 Lden, rising to 26.7% at 55 Lden. At present, the Environmental Noise Directive (END) requires mapping at 55 Lden so little data is available to show the scale of the problem in the UK. However, data put together by the Airports Commission showed that over one million people experienced average aircraft noise at or above 55 Lden in 2014. The aircraft noise thresholds are also significantly lower than for road and rail noise, confirming that people are more sensitive to aircraft noise than to noise from other modes of transport at any given level.

WHO Europe recognises the scale of the challenge necessary to meet these recommendations and did consider whether there was a need to produce interim targets. But there was no consensus to set Europe-wide interim targets as situations vary from country to country, and it was noted that previous WHO advice had concluded that an interim target is “not a health-based limit value by itself” and that “vulnerable groups cannot be protected at this level”. Instead, the guidelines focus on how policy makers should reduce exposure to noise levels at or close to the limit values, identifying four general principles:

  • Reduce exposure to noise, while conserving quiet areas. 
  • Promote interventions to reduce exposure to noise and improve health. 
  • Coordinate approaches to control noise sources and other environmental health risks. 
  • Inform and involve communities potentially affected by a change in noise exposure.

The last point is an issue that’s particularly relevant to recent airspace change disputes.

The WHO Europe guidelines also recommend further research on the health effects of noise exposure from transport on both adults and children, including areas such as adverse birth outcomes, cognitive impairment and mental health.

While the guidelines have a European focus, today’s report argues, they also have global relevance as “the large body of evidence underpinning the recommendations was derived not only from noise effect studies in Europe but also from research in other parts of the world, mainly America, Asia and Australia”. 

So what does this mean for UK aviation policy?

Communities impacted by aircraft noise have long-argued the need to incorporate WHO’s advice into policy decisions. In fact, we came very close to making this a reality in 1999, when UK ministers signed the Charter on Transport, Environment and Health pledging to take the WHO’s advice into account and ensuring that “the wellbeing of our communities is put first when preparing and making decisions regarding transport and infrastructure policies”. Although the 1999 WHO guidelines were referenced subsequently in Department for Transport consultations on issues like the night noise regime at the London airports, they have long since been omitted from policy documents and there is no mention of WHO in the Government’s Aviation Strategy documents so far.

With the Government advocating an evidence-based approach to policy-making, AEF and communities will be keen to see how the Government intends to avoid adverse public health impacts when it publishes the Aviation Strategy green paper later this year. Understanding the scale of the problem would be a natural starting point, and we look forward to seeing noise data for UK airports using the metrics and limit values identified by WHO Europe. Given that most of the UK’s largest airports have recently produced noise maps using Lden, extrapolating national data for the population exposed at 45 Lden should not be too onerous.

AEF reaction

Reacting to the publication, AEF’s Director Tim Johnson said:

The fact that WHO has recommended tough limit values for aircraft noise should come as no surprise, as the guidelines acknowledge the existing evidence of health impacts for people living around airports and under flightpaths, especially those who have their sleep interrupted. Implementing these recommendations will present a significant challenge for the Government and the aviation industry, particularly if it continues to pursue growth without effective plans to protect communities.

The Government has the perfect opportunity to respond positively in its draft Aviation Strategy due later this year. Rather than electing to ignore the WHO’s advice on the basis that it is too challenging, it should use set out appropriate measures to tackle this issue.