Hi All!
The paragraphs Chris mentions in the two new SGV reports quite clearly
indicate that there is an order of magnitude difference between DEFRA's
SGV's for toluene and ethylbenzene when comapred to the equivalent Dutch
figures, even when soil organic matter is adjusted to UK generic guidance
levels. Utilising the levels of the Dutch isnt authoritative and in line
with UK policy, and it also comes way down the hierarchy of sources within
CLR9 (UK, European (meaning EU, not other countries within Europe),
International (i.e. WHO), and finally other countries (all the Dutch list
and USEPA screening levels and everything else) and those bu authoritative
bodies but used for different purposes) With this in mind it would seem
impossible to defend the use of Dutch levels within the UK. The only safe
way around this is for the consultant to undertake a DQRA and deriving
SSAC's using SNIFFER.
This may well be asking a lot but at then end of the day, as regulators, it
is partly our responsibility to drive up the standards of SI's within the
land contamination industry and to protect the public health.
Also made public for the first time is that the EA have now adopted the
Johnson and Ettinger model for modelling inhalation of indoor vapour, and
dropped the Krylov and Ferguson model. The implications for this with
regard to Organic compounds are important; you can't use CLEA 2002 anymore
as the Governments Policy has changed and CLEA 2002 is out of date. Also to
be brought to attention is the changing of building parameters, also meaning
CLEA 2002 is out of date. In light of this we should all really be using
SNIFFER to do DQRA's where an SGV does not exist for a site. CLEA-UK cant
come along too soon!!!!!!!!
Controversial I know but there you go!!!!!!!!!!!!!!!!!
Jon
Jonathon Parr
Public Protection Officer (Contaminated Land)
Blackpool Borough Council
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(01253) 478318
-----Original Message-----
From: Allison, John DCCS [mailto:[log in to unmask]]
Sent: 21 January 2005 12:38
To: [log in to unmask]
Subject: Re: Rejection of Dutch Intervention Values
Hello Christiaan,
The Dutch values are perfect for use in The Netherlands given their
particular policies on risk assessments and as you spotted different soil
types. Even if you correct for soil, the last time I looked at them the
human health side was based on average human receptors and not the most
sensitive receptor as current UK policy requires.
The Dutch do tend to revise their values much more frequently than we do
which personally I believe is no bad thing.
Strictly speaking I would say that the use of the Dutch values is
inappropriate in this country for risk assessment as they don't comply with
UK policy on risk assessment. Having said this the toxicology and modelling
behind the values may be useful and there may be times when it is
appropriate to have a look through the values and their calculation for
guidance as they do cover a wide range of contaminants. As ever though an
"eyes open" approach is necessary when doing this.
regards
John Allison BSc(Hons) MRSC SiLC
Scientific Officer (Contaminated Land)
Environmental Health & Consumer Protection
Knowsley Metropolitan Borough Council
Municipal Buildings
Cherryfield Drive
Kirkby
Merseyside
L32 1TX
Tel: 0151 443 2796
Fax: 0151 289 7488
-----Original Message-----
From: Contaminated Land Management Discussion List
[mailto:[log in to unmask]] On Behalf Of
Christiaan Wilkinson
Sent: 21 January 2005 11:18
To: [log in to unmask]
Subject: Rejection of Dutch Intervention Values
Hello All,
Before I take a new stance on the use of the Dutch Intervention Values in
GQRA could you give me some feedback on my thoughts.
Thanks,
Christiaan
Lancaster CC
Recent publication of the first organic SGV's (Toluene & Ethylbenzene)
show that the Dutch values contain large variations in their values. For
example, the current DVI for Toluene in soil is 339 mg kg-1. If this were
adjusted from 10% soil organic matter to 2.5% the intervention value would
be 84.8 mg kg-1. The Dutch have recently proposed to replace the human
health IV with new Serious Risk Concentrations (SRC) guidelines. The
proposed SRC for Toluene is 32 mg kg-1. The proposed SRC is a ten-fold
decrease from the current DVI. (SGV 15, 2004)
A further example of DVI variance is also in evidence in SGV16
(Ethylbenzene). Current DVI for Ethylbenzene in soil is 50mg kg-1. The
corrected soil organic matter from 10% to 2.5% would be 12.5 mg kg-1 which
is a factor of two lower. However, the proposed SRC is 111mg kg-1 which
shows a two-fold increase.(SGV 16, 2004)
UK policy requires the assessor to adopt the most conservative approach
when carrying out a Tier 1-risk assessment. The guidelines used must
be "appropriate, authoritative and scientifically based" (DETR Circular
02/2000). Based on this policy and the above evidence the LA does not view
the Dutch Intervention Values as being appropriate or authoritative.
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