How do
Interesting plot. I am guessing that it is not just wood (totally untreated and all) that is burnt on the fires. Maybe that could add a few things of interest or mix up the results a bit. Not sure I'd consider 16.8mg/kg to be high though.
I totally agree that it would make a great project, especially comparison of soils from around the world including those on volcanic ash derived soils and also places such as here in/around Coal Measures with all of our PAH rich coaliferous soils too. The question then is are wood ash derived PAHs that much worse for you than naturally high soil PAHs?
Blimey. The hits just keep on coming.
Russell
-----Original Message-----
From: Taylor, Christopher [mailto:[log in to unmask]]
Sent: 24 April 2015 10:32
To: 'Russell Corbyn'; [log in to unmask]
Subject: RE: Wood ash / Allotment BaP
Right, I have done the double ratio plots, and the source is coal derived. I have attached the plot.
This must be a legacy of historic practices, as I don't know of any plot holders who bring ash from their fireplaces/coal burning stoves to their allotments. Just how persistent are PAHs in soil that is regularly worked for growing veg?
Also, plant derived ash is definitely present, but if the PAHs detected in the lab analysis are coal derived, does this imply that the PAH concentrations of the wood ash are negligible in comparison, i.e. do we have a mixture of the two ash types where a dominant more highly concentrated coal derived PAH is dominating the results?
This is all I have found on the composition of wood ash, from the following paper: http://www.forestry.gov.uk/pdf/use_of_ash_in_forestry.pdf/$FILE/use_of_ash_in_forestry.pdf (thanks to Jonathan Parry for the link)
Polyaromatic hydrocarbons (PAHs)
Data quoted by Someshwar from Diebel et al. (1992) indicate that the types of PAHs found in wood ash are those of the two and three ring constituents, which are less toxic than the four and five ring compounds.
Naphthalene proved the most plentiful in his study (1.6 mg/kg), but many compounds were below detection levels in the samples. In a recent study in Switzerland wood ash derived from a pure burn at 550 – 650 ºC was added to mineral soils, and monitored for both PAH and PCB compounds (Bundt et al., 2001). The wood ash was found to have high concentrations of PAHs (the sum of 20 types equated to 16.8 mg/kg). However, the PCB addition to soils from the wood ash was low (totalling 14 types which equated to 3.4μg/kg) . The exact nature of the wood burned was not recorded.
I imagine that the temperature of the fire, type and age of plant material etc, all have a role to play in the PAH composition. Seems like a great MSc/PhD project to investigate the PAH composition of purely plant derived ash.
Regards
Christopher Taylor
Enforcement Officer
Regulatory Services
Brent Council
Tel: 020 8937 5159
www.brent.gov.uk
-----Original Message-----
From: Contaminated Land Management Discussion List [mailto:[log in to unmask]] On Behalf Of Russell Corbyn
Sent: 23 April 2015 16:28
To: [log in to unmask]
Subject: Re: Wood ash / Allotment BaP
Now there is a sensible scientific approach, not just an idea!
Not that they (double ratio plots) are at exceptionally accurate but there are so many other sources of deposition for PAHs and their attachment to fugitive dusts from exhausts, fire depositions, weathered macadam dust, spilt oils and so on. They are ubiquitous and it would give an approximation and the grouping of data would become immediately apparent.
I now have several hundred macadam PAH analyses and there is good agreement with the vast majority of data. It also becomes apparent what level of PAH is noise. With the levels of most environmental soil PAH analysis being quite noisy due to the distribution being in reality quite close to the limit of detection of tests (and let us not forget the lab error bars that must be applied to that) I feel sure that there would be substantially more noise than in my macadam samples.
I don't like the "let's just look at BaP level" approach to PAH provenance assessment because it is a very narrow view and tells us not very much.
Cheers
Russell
-----Original Message-----
From: Contaminated Land Management Discussion List [mailto:[log in to unmask]] On Behalf Of Mark Henderson
Sent: 23 April 2015 11:42
To: [log in to unmask]
Subject: Re: Wood ash / Allotment BaP
It would be interesting to see the whole BaP set with fluoranthene, pyrene, BaA and chrysene. You could then plug them into a double ratio plot and see if they point to a single source.
Just an idea
Regards
Mark C Henderson BSc(Hons) MSc DIC MIEnvSc Technical Director
Mobile: 07736 058 007
Office: 01223 632800
Email: [log in to unmask]
W: www.mlm.uk.com
M L M
Buildings and Infrastructure ∙ Environment Planning and Development ∙ Compliance ∙ Sustainability
Follow us online:
Facebook: https://www.facebook.com/mlmgrp
Twitter: https://twitter.com/mlm_group
LinkedIn: http://www.linkedin.com/company/mlm-group
Emails are sent on behalf of the MLM company which is named in the relevant signed appointment or if none exists, in our fee proposal or (if MLM is acting as client) in our order. Companies Act information for MLM Group companies is available at http://www.mlm.uk.com/about_company.php.
-----Original Message-----
From: Contaminated Land Management Discussion List [mailto:[log in to unmask]] On Behalf Of Taylor, Christopher
Sent: 23 April 2015 07:57
To: [log in to unmask]
Subject: Re: Wood ash / Allotment BaP
Hi Chris
Sure. Here are the BaP results from 7 random allotments.
3.44 17.70 26.30 5.97 7.20 2.93 9.45 15.12 12.25 14.73
1.58 2.17 0.64 2.56 3.20 7.14 2.85 0.85 0.85 6.37
0.83 <0.05 <0.05 0.98 8.72 0.59 3.47 0.32 3.16 0.70
3.48 1.87 5.40 2.54 3.71 2.34 0.67 8.56 1.73 1.96 2.02 11.67 2.52 10.86
2.69 1.95 8.11 12.43 7.73 0.58 8.99 8.69 14.17 5.65 3.56 5.86 3.32 3.62 7.46 6.13 7.63 6.54 9.59 3.52 3.20 3.78 0.83 7.42 4.74 3.55 9.95 4.19
3.60 3.13 5.33 5.13 3.96
1.02 0.99 1.38 2.32 1.02 2.44 2.44 3.16
Regards
Christopher Taylor
Enforcement Officer
Regulatory Services
Brent Council
Tel: 020 8937 5159
www.brent.gov.uk
-----Original Message-----
From: Contaminated Land Management Discussion List [mailto:[log in to unmask]] On Behalf Of Chris Dainton
Sent: 22 April 2015 23:33
To: [log in to unmask]
Subject: Re: Wood ash / Allotment BaP
Neil & Chris
Can you share the BaP results (just the numbers will do) from the allotment testing you've undertaken so the List can get a feel of the range of BaP numbers encountered, rather than just min - max etc.
Cheers
Chris Dainton
--
The use of Brent Council's e-mail system may be monitored and communications read in order to secure effective operation of the system and other lawful purposes.
If you have received this transmission in error, we apologise. Please notify us immediately and permanently delete this message, keeping its contents confidential. We monitor email correspondence for security and management purposes. We will rely on any instructions to us or data that you include in your emails. We scan emails for malicious code but you should also take steps to protect your IT systems. We will not accept email disclaimers which differ from this one.
--
The use of Brent Council's e-mail system may be monitored and communications read in order to secure effective operation of the system and other lawful purposes.
|