Gladiatorial games, part 12

(… continued from Gladiatorial games, part 11, posted on 25 Jan 2016).

The expert witness on acoustics for Chiltern District Council (CDC), Rick Methold, told the HS2 Select Committee that the lowest observed adverse effect level (LOAEL) threshold was “a relatively new concept” that those working in his field were “grappling with” (see footnote 1). So you will search in vain for a mention of LOAEL in the World Health Organisation (WHO) publication Guidelines for Community Noise, which was published in 1999.

General use of the concept by acousticians also postdates the noise policy development for HS1, so there is no precedent for HS2 to draw on for its use in a UK high speed railway project (see footnote 2). Instead, where following the HS1 precedent would lead is, as I mentioned in part 9, to employ increase in the noise environment as the indicator of the impact that results.

By the time that the WHO’s Night Noise Guidelines for Europe (NNGL) was published, the concept was well-enough established to be employed as a principle yardstick, although LOAEL was very much a last-minute addition to the document (see footnote 3). As Rupert Thornely-Taylor told the HS2 Select Committee when he presented his overview on noise way back in July 2014, LOAEL “is an established concept in toxicology”, which acousticians have adopted (see footnote 4). Unsurprisingly, especially in view of its remit to advise on threats to international health, the WHO interprets the reference to “adverse effects” in LOAEL as being solely effects that present a risk to public health. LOAEL, so the NNGL tells us (see footnote 5):

“can be considered a health-based limit value … necessary to protect the public, including most of the vulnerable groups such as children, the chronically ill and the elderly, from the adverse health effects of night noise.”

Defra’s Noise Policy Statement for England (NPSE) came along in March 2010. This document, to which I referred in part 10 of this blog series, is typical of the new trend in government policy statements in that the policy is set out in only the broadest terms; in the case of the NPSE it barely occupies two sides of paper. However, the document also includes a further four sides of explanatory notes, which fortunately include the following definition of LOAEL (see footnote 6):

“… the level above which adverse effects on health and quality of life can be detected.”

Unfortunately, the NPSE gives no guidance whatsoever on what suitable values for LOAEL might be in any given circumstance. The view is expressed in the NPSE that “it is not possible to have a single objective noise-based measure that is mandatory and applicable to all sources of noise in all situations” (see footnote 7). Whilst this is undoubtedly true, the absence of any clear guidance leaves, to my mind, rather too much latitude in deciding what an appropriate value for LOAEL. As Mr Methold put it to the Select Committee, members of his profession “were left scratching [their] heads” on what they “were supposed to do with national policy” (see footnote 8).

What is clear is that the NPSE requires, as its second aim, that a noise polluter should seek, as far as is “reasonable”, to “mitigate and minimise” noise that would give rise to “adverse” impacts and that, for this purpose, LOAEL is regarded as the onset of such impacts.

It is significant that the NPSE broadens out the description of adverse effects from the purely health related effects considered by the NNGL; the NPSE requires “adverse effects on health and quality of life” to be investigated. That this is a considered move is evident from the NPSE advising that the “distinction that has been made between ‘quality of life’ effects and ‘health’ effects recognises that there is emerging evidence that long term exposure to some types of transport noise can additionally cause an increased risk of direct health effects” (see footnote 9).

According to Mr Methold, the confusion about how to interpret the NPSE was “clarified quite clearly” when the Government published the Planning Practice Guidance (PPG) website in March 2010 (see footnote 8). Whilst Mr Methold acknowledged that this publication post-dated the deposit of the HS2 Phase 1 hybrid Bill, he advised the Select Committee that the Promoter had been furnished with access to a beta version of the website when the Environmental Statement was in the final stages of preparation (see footnote 10).

Mr Methold produced, as his exhibit A1571(20), a table presenting advice from the “noise” section of the PPG (see footnote 11). He told the Committee that LOAEL was shown in this table as marking the level at which noise that is “noticeable and not intrusive” becomes “intrusive”. Drawing upon the description in the Examples of Outcomes column of the table he explained that LOAEL marked the point at which the noise begins to cause “small changes in behaviour and/or attitude”, or as he put it the “point at which it starts to disturb activities”. It was Mr Methold’s submission that, consequently, LOAEL could be taken to be “the point at which annoyance starts to occur” (see footnote 12).

The Promoter’s Lead Counsel, Tim Mould QC, did not appear to share Mr Methold’s upbeat assessment that the PPG resolves the ambiguity inherent in the NPSE. He ventured that there may be “room for judgement and difference of opinion” in choosing an appropriate level for LOAEL and that “experts may disagree as to where that level should be set” (see footnote 13).

It was certainly the case that differences between the CDC and the Promoter regarding the appropriate value for the HS2 LOAEL threshold were all too evident during the petition hearing, but I will look at that in the next posting.

(To be continued …)


  1. Mr Methold appeared as an expert witness for Chiltern District Council (CDC): the evidence presented on behalf of CDC occupied the whole of the morning session held on Wednesday 4thNovember 2015 (video) and the Promoter’s response, including evidence from expert witness for the Promoter Rupert Thornely-Taylor, was given in a shorter than usual afternoon session (video). Mr Methold’s comment on LOAEL is recorded in paragraph 489 of the transcript of morning session of the HS2 Select Committee that was held on Wednesday 4th November 2015.
  2. See paragraphs 113 to 119 of the transcript of morning session of the HS2 Select Committee that was held on Wednesday 4thNovember 2015.
  3. See the final paragraph of section 1.1.3 of Night Noise Guidelines for Europe, World Health Organization (WHO) Regional Office for Europe, October 2009. The last-minute nature of the addition of LOAEL to the NNGL is evidenced, perhaps, by the omission of the acronym from the Glossary in Appendix 1 to the document.
  4. See paragraph 52 of the transcript of the morning session of the HS2 Select Committee that was held on Tuesday 8thJuly 2014.
  5. See the paragraph immediately below Table 5.5 on page 109 of the NNGL.
  6. See paragraph 2.20 of Noise Policy Statement for England (NPSE), Defra, March 2010.
  7. See paragraph 2.15 of the NPSE.
  8. See paragraph 92 of the transcript of the morning session of the HS2 Select Committee that was held on Wednesday 4th November 2015.
  9. See paragraph 2.14 of the NPSE.
  10. See paragraph 93 of the transcript of the morning session of the HS2 Select Committee that was held on Wednesday 4th November 2015.
  11. The table is drawn from the How to recognise when noise should be a concern? Section of the PPG website. Mr Methold has redrawn the table, but the original text has been faithfully reproduced in its entirety.
  12. For a fuller explanation of Mr Methold’s interpretation of the PPG table refer to paragraphs 95 to 106 of the transcript of morning session of the HS2 Select Committee that was held on Wednesday 4thNovember 2015. One point that was not brought out in this discourse is that the comments in the table are “based on the likely average response”.
  13. See paragraphs 484 and 488 of the transcript of the morning session of the HS2 Select Committee that was held on Wednesday 4thNovember 2015.


I wish to thank Michael Woodhouse for his suggestions and comments, which I have found invaluable in preparing this series of blogs.

Exhibit A1571(20) has been extracted from the bundle of evidence submitted to the HS2 Select Committee by Rick Methold and published on the website of the HS2 Select Committee.

Important Note: The record of the proceedings of the HS2 Select Committee from which the quotes reproduced in this blog have been taken are uncorrected transcripts of evidence, which are not yet an approved formal record. Neither witnesses nor Members have had the opportunity to correct the record in such instances, and it may therefore be subject to changes being made in the light of any such corrections being requested.


2 responses to this post.

  1. Posted by Mike on February 1, 2016 at 7:36 pm

    From my perspective as a resident living near the proposed HS2 station at Toton, for a project that will only destroy local jobs & rail services, if it’s audible, it’s adverse. (And that includes additional road traffic.) It’s already destroyed my health over the past three years.


  2. Posted by Les Fawcett on February 2, 2016 at 11:47 am

    Sorry to hear of your suffering Mike, even before construction is due to start. You have the same pain with no gain that we face in my area (Coventry). It’s a mystery why the gov’ment is steaming on with this delusional project. On the positive side, there is a better alternative HS rail plan and substantial financial backers to get it into the public consciousness. Expect an announcement soon.


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