Severe noise pollution could affect thousands of people in Buckhamshire if HS2 is built, according to the HS2 Action Alliance.

HS2 locomotives will roar past at 200mph less than every two minutes, taking the 400-metre-long trains about four seconds to pass any given spot. This means the noise from each train could last up to 25 seconds in total.

And the impact of the controversial project will be magnified by the fact that trains will be running from 6am-11pm – meaning the noise on this stretch of the route along the Chilterns would be pretty much continuous.

In a nutshell, according to the Alliance, the noise levels of between 90 to 100 decibels for those living near the track could be double that recommended by the World Health Organisation.

A spokesperson for the Alliance said: "World Health Organisation Guidelines for community noise recommend less than 30 A-weighted decibels (dB(A)) in bedrooms during the night for a sleep of good quality and less than 35 dB(A) in classrooms to allow good teaching and learning conditions.

"The WHO guidelines for night noise recommend less than 40 dB(A) outside of bedrooms to prevent adverse health effects from night noise. The US Government estimates noise above 140dB(A) causes pain and negative health impacts occur from sustained exposure to noise above 85dB(A). To put these figures in context a vacuum cleaner at 3 metres distance will emit around 70 db(A) and a jet taking off at 100m will emit around 125dB(A).

"HS2 Ltd’s own figures state the Pass By Noise Values at 25 metres will be 95dB where no mitigation is in place or 76dB where three metre noise barriers are employed for mitigation when its trains are travelling at 362 km/h- extremely noisy under any measure. But even these figures don’t tell the full story. HS2 Ltd’s noise calculations are based on an 'equivalent continuous sound level' which requires that the noise energy from every train that passes during a specified period is added together and an average figure produced. But this approach ignores the sudden impact of a high speed train passing. "


The Alliance has recommended the following guidelines concerning to HS2 noise levels:

•Rather than HS2 Ltd setting its own noise limits, as is currently the case, these should be prescribed by an independent external body.

•HS2 Ltd should follow World Health Organisation advice on noise measurement, including considering the impacts of peak noise levels in addition to continuous sound levels.

•HS2 Ltd must develop a credible and detailed noise mitigation policy as a matter of urgency. It is simply not acceptable to pretend that the limited measures currently specified will be adequate or that it will be possible to control noise by improving rolling stock design to produce the appreciable reduction in noise levels as HS2 Ltd currently maintains.

•There should be an urgent review into whether operating speeds of 360 kph, rising to 400 kph in future, are feasible in the light of the view in Japan that 320 kph may represent the practical limit.

•If the noise levels cannot be mitigated/reduced below tolerance thresholds dictated by an external regulator, impacted households should be compensated accordingly.