Bioavailability of heavy metals to urban agricultural food and biofuel crops and their remediation potential

Grantham Scholar Marta Crispo researches how soil black carbon affects the availability of heavy metals to food crops and the ability of willow to remediate contaminated urban soil.

The project

More than half the world’s population live in urban areas. Consequently, urban areas are drivers of global change and there is heavy reliance on imported food and energy. Increasing sustainable, own-grown food and biofuel production in urban areas could reduce this environmental impact.

However, urban soils can contain high concentrations of heavy metals. And these may pose a risk to human health if used for food production. But these heavy metals often co-occur with black carbon, a suite of molecules ranging from soots to biochar, reducing the pollutant bioavailability. Thus, this project will address 2 key questions:

◊ How does soil black carbon affect the availability of heavy metals to own-grown food crops?

◊ What is the potential of short rotation coppice willow, a biofuel crop, to remediate contaminated urban soil?

Because coppice willow naturally accumulates heavy metals it has been proposed as a sustainable way to remediate contaminated soils. Therefore coppice willow provides the opportunity to both remediate urban land unsuitable for food production, whilst also producing a biofuel. Moreover, biochar, which can be produced when short rotation coppice is used as a feedstock for energy production, has the potential to reduce pollutant bioavailability.

This project will establish an own-growing and short rotation coppice experiment in an urban allotment site, working with our collaborative partners Leicester City Council.

Outreach and impact

Climate Commission

Martha is a Student Commissioner at EAUC (the Alliance for Sustainability Leadership in Education). This is a unique partnership of higher and further education organisations. Specifically, it aims to bring the education sector firmly into the climate change debate. If you want to find out more, read Grantham Scholar and the Climate Commission.

And Martha’s work with the Commission was covered in University World News. In this piece Martha said: ‘Students make up 7% of the UK population. We will have a huge impact through our lives and careers on the sustainability of the world. We are the ones that are inheriting pollution, melting ices and extreme weather events.’ If you want to find out more, you can read Climate commission unveils toolkit for university leaders.

My Harvest

Marta is part of MyHarvest, which estimating the contribution of home-grown fruit and vegetable crops on UK food production.

a poster for the Time Is Now which 'reads there is no planet b' by Marta Crispo
Time Is Now

Time Is Now: mass lobby

In June 2019 a group of Grantham Scholars went to the Time Is Now protests in London, where they met with Sheffield Central MP Paul Blomfield. Before the event, Marta explained why she was attending. Read: The Time Is Now: Grantham Scholars at ‘mass lobby’.

Marta Crispo’s publications

Marta Crispo, Duncan D. Cameron, Will Meredith, Aaron Eveleigh, Nicos Ladommatos, Ondřej Mašek, Jill L. Edmondson, Opening the black box: Soil microcosm experiments reveal soot black carbon short-term oxidation and influence on soil organic carbon mineralisation, Science of The Total Environment, Volume 801, 2021, 149659, ISSN 0048-9697,

Marta Crispo, Miriam C. Dobson, Roscoe S. Blevins, Will Meredith, Janice A. Lake, Jill L. Edmondson,
Heavy metals and metalloids concentrations across UK urban horticultural soils and the factors influencing their bioavailability to food crops, Environmental Pollution, Volume 288, 2021, 117960, ISSN 0269-7491,


Dr Jill Edmondson

Department of Animal and Plant Sciences


Dr Manoj Menon

Department of Geography

Dr Janice Lake

Department of Animal and Plant Sciences