Dear Damon,
We have used source signatures occasionally when undertaking risk
assessments with regard to whether a source is coal based (natural coal
fragments) compared to an anthropomorphic source - petroleum/processed
organic matter. Being in the Northwest we tend to be affected by the
Lancs/N Wales coalfields.
Although the source signatures are a tool for assessing the potential
source of the PAH compounds, it is often useful to have the
chromatograms analysed (by a professional chemist with plenty of
experience who knows what he's looking for - we use Jim Jones!!!). This
usually means that the PAH results should when required be backed up by
TPH analysis.
Where the BaP result is very marginal - sometimes boulder clay contains
coal fragments - it may be suitable to complete a qualitative assessment
on top of the forensic tool to come to an appropriate judgement on the
results obtained.
It should be noted that on occasion, even though natural coal has been
determined as the source of the PAH, this material still is condemned
(for certain landuses) as potentially contaminated/requiring further
work as the concentration present is beyond reasonable values which may
be further risk assessed.
I think it is important to attempt to understand the reasoning behind
sources of contamination, especially on fill strata which appears to
have laid dormant for many decades.
With regards to is coal bad for you, that is another question which has
gone on for a while!!! My father in law is a coalman in Mid Wales and
covered in coal dust from September - April (gas for remainder of season
- been a coalman for 30yrs and no sign of cancer), pregnant women eat
coal allegedly (not caught the wife doing that yet, but there are still
a few weeks left!), and people have lived on coal fields ad infinitum.
Think there's a few PhD's in this subject!!!
Reduced cover thicknesses are addressed in the BRE document Cover
Systems for Land Regeneration (which has a calc sheet for assessing
cover thicknesses based on intermixing with lower concentration cover
soils).
Regards
Nik
Mr N Reynolds
BSc(Hons), MSc, CGeol, FGS, MIEnvSc, EurGeol
Senior Environmental Geologist
This e-mail requires acknowledgement to ensure the sender that the
correct recipient has received all information requested/necessary.
*: Cooper Associates
2 Vicars Lane,
Chester
CH1 1QX
(: (01244) 348787 (: Direct Dial No. (01244) 305786
7: (01244) 348788
*: [log in to unmask] <mailto:[log in to unmask]>
Web: http://www.coopers.co.uk <http://www.coopers.co.uk/?link=NR>
Private and Confidential
This message may contain private and confidential Information. If you
are not the intended recipient, please inform us and delete the message
immediately. Cooper Associates believes that this email and any
attachments are free of any virus or other defect which may adversely
affect a computer, however it is your responsibility to carry out
appropriate virus and other checks to ensure that this message and any
attachments do not affect your systems and Cooper Associates does not
accept any responsibility from any loss or damage arising in any way
from its use.
Privileged and confidential information and/or copyright material may be
contained in this e-mail. The information and material is intended for
the use of the intended addressee only. If you are not the intended
addressee you may not copy or deliver it to anyone else or use it in any
unauthorised manner. To do so is prohibited and may be unlawful. If you
receive this e-mail by mistake, please advise the sender immediately by
return e-mail and destroy all copies.
Cooper Associates promotes a sustainable environment. Please only
print this email if necessary. Where possible please store and record
this e-mail electronically rather than on paper.
________________________________
From: Contaminated Land Management Discussion List
[mailto:[log in to unmask]] On Behalf Of Damon
Pearson
Sent: 06 May 2010 14:09
To: [log in to unmask]
Subject: Benzo(a)Pyrene in Topsoil
Hi All,
I would appreciate any opinions you have on the use of the double ratio
plot developed by Jones Forensics Laboratories' to assess the origin of
BaP and how this relates to risk to human health. I'm unfamiliar with
this approach so not entirely sure on its suitability or if this is
widely used.
Situation
- Planning Context
- 4 Dwellings erected and retrospective planning application
submitted
- Brownfield Site
- Unorthodox approach to risk assessment, however;
Chemical analysis has shown BaP in the topsoil of gardens to be around
3.4mg/kg.
The consultant has used the double plot ratio to determine the nature of
BaP and concludes that its natural (most likely to be coal fragments)
and will not be mobile or available in such fragments and the fact that
any coal would have to be below 0.25mm to adhere to all exposed skin for
dermal adsorption to be a relevant pathway.
Many thanks,
Damon
Damon Pearson
Environmental Protection Officer
Barrow Borough Council
Tel: 01229 876382
Fax: 01229 876411
Email: [log in to unmask]
