Metal Eating Mushrooms Maybe?

One of the first principles that I learnt, when I completed a Permaculture Design Course, was to Observe and Interact. I’ve heard of many projects taking a year to observe their land, and a year is what you need to watch a full change of the seasons. I’ve also heard of lots of projects taking less time, but still making sure that they do lots of observation and thinking, before they jump in the deep end and build anything that they would later want to move.

I moved to my new home in Tavistock two months ago, and I specifically bought it because it gave me the biggest garden that I could get with my budget. As an end of terrace cottage, the garden is three times bigger then the other cottage’s gardens. I have one of 66 Duke of Bedford cottages, built in parallel terraces in 1850, to home the miners and their families. Each one comes with a piggery, a kitchen garden, and I’ve recently learnt that they also used to have allocated allotments on the other side of the road. Not surprisingly, the allotments have now been built over!

When I moved in, I base mapped my garden. I sat in it for hours and hours, and wondered around. I met all my neighbours, and made connections with those who had chickens, or fancied growing fruit trees. I asked for help in identifying the species of the mature trees, and I took a soil sample – I put some soil in a jam jar with water, shook it, and left it to settle so that I could see what type of soil I had by the layers of sediment that settled out. I watched the sun and the shade. Preparing myself for the possibility that the lead levels could be high, because I am next to a road, I researched plants that would be safer to grow. I learnt that fruit trees are good at absorbing toxins into their bark, and not so much into their fruit. So I made lists of forest garden species that I fancied eating, and lists of fruit trees that were hardy and native to Devon.

With the offer of a month of help, from a wonderful young lady, I decided to get stuck in after only a month in my home. A little too soon maybe? I made an initial map of what I wanted, but decided not to do anything too drastic. Charlie and I have been working hard. We sent a soil sample off to a lab to be analysed for heavy metals. We built a chicken run all the way along the side of the garden that was next to the road, and built raised beds on the other side. We sifted through a mountain of compost. We planted seeds, and prepared the green house. I guess I figured that if my soil turned out to be too high or low in pH, then I would just add whatever I needed to it, to bring it back into balance…..

I got my soil test back from the lab the other day. Lead is nearly twice the EU guidelines. Zinc is about one and a half times, and copper is nearly twice the guidlines….Big deep breath. Breathing? Arsenic is over ten times the EU maximum safe level (My level is 516.07mg/kg, the EU guideline is 50 mg/kg). I had a glass of wine.

I called the soil scientist, who spoke to me for close to an hour. He told me not to grow food unless it was in containers. Not even fruit trees. He told me to contact my neighbours. I finished my wine, and knocked on some doors. Not many people were in, so this will have to be an ongoing project. One neighbour, Jane, was in her garden, and I sat down with her and had a long chat. She has lived in her cottage for 20 years, and told me that she hasn’t been able to grow anything except trees. She always assumed that the pH was too high. She told me that she had done some research years ago, and found out that the council had done soil tests on the toll house, a building just on the other side of the road. They had found high levels of arsenic in their soil, and it was because back in the day, the people of Tavistock were mining arsenic, and this is where they dumped all of their spoilings (the waste material after the “majority” of the arsenic had been removed). Apparently a lot of land around here is contaminated. I believe that our cottages may have been built on top of arsenic spoilings.

I didn’t sleep, while I tried to process all of this. I have brainstormed everything I think I need to do, such as contacting my neighbours to see who else will do soil tests. I need to contact the council to find out what they know. I need to say yes to the neighbour who offered me an old bath to use for container growing. I need to chuck away the dandelion wine that I was busy brewing.

But maybe there is a light. Maybe there is a reason why I have spent the last month reading a book called Mycellium Running. I’ve been reading it because I wanted to inoculate some logs with mushroom spores, to grow them under a hedge at the end of my garden. I didn’t know that it would teach me all about Mycoremediation – a technique of using specific fungi in mats, spread across contaminated land. Particular fungi thrive on heavy metals. They absorb the metals and can then be picked off, dried, and dealt with in a concentrated form. It’s a new science with an incredible scope for research, but maybe there is a fungi that eats arsenic. I have a lot more reading to do – I found an article about someone who died from arsenic poisoning from eating morels, and another article that my friend Peter sent me on Bioremediation of Arsenic and Selenium. I have no idea what the cost could be, but maybe my arsenic problem is the fungi solution? I have the permaculture tool box at my side.

Any help, advice, and support on this would be appreciated – If you know anyone who might know anything that could help me, please let me know.

I’m still breathing.


About thehouseofjam

I am a Trustee/Director of the Permaculture Association of Britain, and I make jam with wild food. Lots of it!
This entry was posted in Arsenic, Food, Gardening, Low Impact living, morrels, mushrooms, mycoremediation, Permaculture, philosophy, Tavistock, Uncategorized and tagged , , , , , , , , , , , . Bookmark the permalink.

14 Responses to Metal Eating Mushrooms Maybe?

  1. Rachel Woodisse says:

    Hi Rebecca, what a shock for you! But as you say they maybe a solution in mushrooms? I wish you all the best as you have worked so hard, how awful for you. I love the blog. I am currently doing my diploma and been into Permaculture for a number of years. Best of luck with everything!

    • Thank you! I’m really feeling the emotional support, and I need it! I now have a bathtub in the middle of my lawn. I won’t fill it until in sure of where I want it to go, but I think it will make a great container garden!

  2. Euugggcchh! I feel for you Rebecca. That said, you’re now in a great position to do something about it – with the knowledge of what’s in your soil & the desire to grow food. The primary strategy for dealing with heavy metals is accumulator plants. They still need to be taken somewhere else & processed afterwards, but plants tend to be the primary means of remediating such soils.
    Now the slightly complicated bit; lead, copper & zinc are all cationic metals, which means they are more soluble & thus more easily absorbed by plants in acidic soils. The reverse is the case for arsenic which is anionic & more easily absorbed in alkaline soils. The classic accumulator plant for arsenic is the Chinese Brake Fern, though I’ve herd that all ferns are good at this. Look up phytoremediation on the net for more info. Here’s one paper on the subject:
    That said, I know that mycellium are know to lock up some heavy metals, preventing them from getting into the food chain. You certainly wouldn’t eat them afterwards though. Wishing you all the best with this Rebecca! You can do it!

    • 🙂 Thank you!
      Someone asked me the other day “So, how come you did a soil test anyway?”
      I said “because I did a Permaculture Design Course, and Aranya told me to.”

      I’m in the situation with my eyes open. Thank you for the reading list.

  3. Denise says:

    I can’t help, Rebecca but I do sympathise! I wish you the best of luck sorting it out/finding answers. xxx

  4. planthoarder says:

    Scary stuff. It’s so sad that your garden dreams won’t be realized, but I have seen amazing container gardens. Good luck with whatever you decide to do.

  5. Silcoe says:

    Hi Rebecca,
    While the accumulator plants and fungi are doing their stuff you can still grow in old discarded containers such as fertiliser bags, car tyres, plus the bathtub!. Make sure you use a ground barrier under tyres. I use a mixture of stable manure which i get free, plus some eco-compost which I buy in 50 litre sacks at about £3.65 a bag, mixed together it bulks up nicely. Good luck with the project – its still viable!

    • Thanks. I have now filled the bath tub, and have grow bags in the green house. I have found a free source of wood chip, which is fabulous, but I expect I’ll be spending more then I thought on compost this year. Stating positive!

  6. Harriet says:

    Hi Rebecca
    I’ve only just heard this news – its very serious for you as a grower and homeowner and as others have said, my heart goes out to you. I found a pdf about soil remediation with a case study of an arsenic-contaminated site, produced by Veolia, which I’ll send to you by email. It also got me thinking in another way. Are there other households in your town affected by the contamination, who might be interested in a full scale remediation scheme? It might be possible to form a group which would work on behalf of its members. The estate who built on the spoil profited from the mining activity that has caused the poisoning of the land – would it now be interested in supporting a group to consider the issues around remediation? If the town is in an area covered by Veolia funding, it might be worth asking if they would fund a group to commission an options appraisal or similar.

    • Thank you Harriet! I will look into veolia. The duke of Bedford built the cottages in 1850, and i don’t think he would have anything to say on the issue. However there are 64 of the cottages, and I’m sure plenty more people with contaminated land in the area. I think it’s going to become increasingly important that there are ways of remediating the soil without just removing it all. My mushroom search has now become a fern search. Pteris Vitatta is a fern which has been widely used to cleanse soil of arsenic, but it’s apparently not very hardy, I can’t find documentation of its use in the UK and I can’t find anyone willing to sell me the seed… search goes on. I’d love to find someone to give me funding to use my garden to study morels, shaggy manes, and ferns to see what is the best option to carry out in the rest of the area. We shall see where my search takes me! Thank you for the direction pointer! X

  7. Harriet says:

    Here’s one more bit of reading material – some practical info in it about how the pH of the soil affects uptake of arsenic and lead into plants – I’ve not found anything about what to do with the arsenic-loaded ferns and mushrooms outputs – it’s a design challenge…

  8. Todd says:

    Found some good studies on arsenic that could help provide a path toward remediation:

    1) Fern that hyper accumulates arsenic:

    This plant is concentrating arsenic of multiple forms and placing it in the frons. Being that it is a perennial and the frons could be harvested and removed from the site, this could be a great long term solution.

    2) Effects of phosphorus and compost amendments on fern hyper accumulation.

    This has a part in it that is a cause for great hope. In a 12 month period it was shown that >8% of the arsenic in the soil was taken up into the frons on the fern. Phosphorus was used as a soil fertilizer and this helped in the uptake.
    This makes sense because arsenic and phosphorus fall in the same column on the periodic table. This is also what makes arsenic so toxic. It tends to fit into the cellular machinery that uses phosphorus (ATP, kinases, etc).

    This is by no means anything close to a solution but a in situ site remediation may have a place for ferns and phosphorus.

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