london’s soil chemistry: a continental scale anomaly

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London’s Soil Chemistry:A continental scale anomaly

Dee Flight, Andreas Scheib and the Geochemical Baselines Team

British Geological Survey, Keyworth, Nottingham, NG12 3NX

www.bgs.ac.uk


A tale of two soil geochemical mapping projects

GEMAS: European continental scale

•Agricultural soil quality

•Are anthropogenic impacts significant?

London Earth: city scale:•Urban soil quality;•What impact does the soil quality have on the population?


GEMAS UK

138 sites

1 sample per 2500 km2

London


London Earth

6300 sites1572 km2

4 samples per km2

London Earth – Source of Sample site map: http://www.bgs.ac.uk/downloads/start.cfm?id=1464


London Earth: Land use at soil sampling sites


London Earth


• Rigorous standardised methods based on established expertise and well tested, quality control;

• Undertaken contemporaneously;

• Multi-element/parameter topsoil geochemical mapping;

• Robust and reproducible outputs;

• Sample and data archive – lasting impact and future resource.

GEMAS & London Earth


London Earth – Source of As map: http://www.bgs.ac.uk/downloads/start.cfm?id=2020

London Earth – Source of Cd map: http://www.bgs.ac.uk/downloads/start.cfm?id=2021


• Geogenic signatures for Al, Cs, Ga, K, La, Mg, Mn, Nb, Rb, Ti, V most dominant.

• Very low geogenic control of As, Ba, Cd, Mo, Pb, Se, Sn, Zn in London urban domain.

• Strongest geogenic signatures survived 2000 year history of urban development

London Earth – statistical analysis and parent material mapping


London Earth – Source of Pb map: http://www.bgs.ac.uk/downloads/start.cfm?id=2026


(From Reimann et al., 2014, Fig. 11.41.5, p.339)


21 mg/kgGEMAS median


(From Reimann et al., 2014, Fig. 11.42.4, p.346)


Pb isotope ratios in London’s soil


500400300200100

14000

12000

10000

8000

6000

4000

2000

Borough median soil Pb (mg/ kg)

Censu

s 2011 p

opula

tion d

ensi

ty (

pers

on/km

2)

Inner LondonOuter London

Westminster

Wandsworth

Waltham Forest

Tower Hamlets

Sutton

Southwark

Richmond upon Thames

Redbridge

Newham

Merton

Lewisham

Lambeth

Kingston upon Thames

Kensington and Chelsea

Islington

Hounslow

HillingdonHavering

Harrow

Haringey

Hammersmith and Fulham

Hackney

Greenwich

Enfield

Ealing

Croydon

Camden

Bromley

Brent

Bexley

Barnet

Barking and Dagenham

City of London


London: soil Pb bioaccessibility


Lead in London Soil - a relationship with social deprivation?


The London effect: Precious metals

(From Reimann et al., 2014, Fig. 11.7.5, p.139) (From Reimann et al., 2014, Fig. 11.10.5, p.159)


A_Pd ppbX_Pd ppbA_Pt ppbX_Pt ppbA_Au ppbX_Au ppb

140

120

100

80

60

40

20

0

Data

Boxplot of X_Au ppb, A_Au ppb, X_Pt ppb, A_Pt ppb, X_Pd ppb, A_Pd ppb

GEMAS median soil Au concentration:1 ppb

X soil: 0-2 cmA soil: 5-20 cm

Gold in London’s soils


Conclusions

• GEMAS and London Earth are high quality robust soil geochemical surveys of differing scale and purpose.

• Used together they provide unique understanding of the magnitude and spatial influence of London’s urban soil contamination.

• High resolution geochemical data show that a wide range of elements have been modified in London’s urban soil.

• GEMAS shows that for Pb, Au, (Sn, Hg, Ag) the impact of London’s urban soil contamination is significant at the continental scale.


Thank you for listening

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ReferencesReferences

References

SLIDES 5, 6:Knights, K.V. and Scheib A.J., 2010. London Earth: details of field campaigns across the Greater London area, 2005 to 2009. British Geological Survey, Keyworth, Nottingham, UK. Open Report OR/09/056.

SLIDE 9:Ellison, R.A., Woods, M.A., Allen, D.J., Forster, A., Pharaoh, T.C. and King, C., 2004. Geology of London. Memoir of the British Geological Survey, Sheets 256 (North London), 257 (Romford), 270 (South London) and 271 (Dartford) (England and Wales). British Geological Survey, Keyworth, Nottingham.

SLIDE 11, 13, 19:Reimann, C., Demetriades, A., Birke, M., Filzmoser P., O’Connor, P., Halamic, J., Ladenberger, A. & the GEMAS Project Team, 2014. Distribution of elements/parameters in agricultural and grazing land soil of Europe. Chapter 11 In: C. Reimann, M. Birke, A. Demetriades, P. Filzmoser & P. O’Connor (Editors), Chemistry of Europe's agricultural soils – Part A : Methodology and interpretation of the GEMAS data set. Geologisches Jahrbuch (Reihe B 102), Schweizerbarth, 101-472.

SLIDE 12:Johnson, C.C., Ander, E.L., Cave, M.R. and Palumbo-Roe, B., 2012. Normal background concentrations (NBCs) of contaminants in English soils: Final project report. British Geological Survey Commissioned Report, CR/12/035, 40 pp.

SLIDE 16:Appleton, J.D., Cave M.R., Scheib, A. and Wragg, J., 2012. Modelling lead bioaccessibility in urban topsoils based on data from Glasgow, London, Northampton and Swansea, UK. Accepted for publication in Environmental Pollution.

SLIDE 17:Department for Communities and Local Government, Indices of Deprivation 2010. ONS Super Output Area Boundaries.

london’s soil chemistry: a continental scale anomaly

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