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 Soil Depollution: In Conversation at the World Living Soil Forum

At the beginning of June 2022, Moët-Hennessy held a two-day soil conference in Arles in Provence, the World Living Soils Forum. Over the two days, experts came together to explore what is known and unknown about the world beneath our feet.

Felicity Carter, representing ARENI, led a panel session on Soil Depollution. Joining her were Ludovic Vincent, the founder of BIOMEDE, a start-up that aims to develop ways to remediate heavy metal contamination using phytoextraction, or biological means; soil scientist Natalia Rodríguez Eugenio, who currently works at the Global Soil Partnership, Food and Agriculture Organization of the United Nations; and Johan De Fraye, head of Environmental Affairs at Signify where he is responsible for managing global environmental liabilities. He is also the chair of NICOLE, the European industrial network that groups industry, service providers and academics in solving contaminated land issues.

ARENI

I’m going to ask each speaker to introduce their work. And I’d like to start with Natalia. The floor is yours.

Natalia Rodríguez Eugenio:

Thank you very much. Actually, I think soil pollution is not such an attractive topic as others like biodiversity, but it’s really something that we need to deal with, especially in agriculture. I am very proud that I decided to start working on this topic in 2017. This topic has never been addressed at the United Nations level. So we managed to start organizing a big global event, bringing together all the experts from multidisciplinary areas. We started trying to understand what is the status of soil pollution globally. We really don’t have a clear picture.

We just launched the international network on soil pollution, trying to bring all the experts together to understand the status, and what data we need to collect. What are the gaps? And to set up guidelines and standards that can be applied in all parts of the world, especially the developing world, that does not have the technical capacity to do it by themselves.

ARENI

Next I’ll pass the baton to Ludovic Vincent, who’s going to speak in French. [The following transcript is an English approximation of what he said.]

Ludovic Vincent:

Good morning. As we have already said, pollution is an underestimated subject with regard to the consequences on the environment, on health, etc. I’m a co-founder of BIOMEDE, which is a startup working with wine growers, in particular, to try to extract heavy metals from soils with plants.

Well, how did this project arise? It was a problem faced by farmers and wine growers who had to abandon their plots because of excess quantity of copper in their soils, and this led to problems in terms of their production. So I thought that maybe this could be a place where we could work on this remediation of soils, you know, and correct this problem with regards to copper contamination, which is an element that’s used a great deal in agriculture and try to create an industry which could be involved in the extraction of these pollutants.

ARENI

Thank you. Johan, it’s your turn. Tell us about what you do.

Johan de Fraye:

When I was asked to come and present, I was wondering, what, what can I share, or what can I bring to the table in this discussion? As a network, we exist for 25 years and it’s quite unique in a sense that we bring together industry academics and service providers, and we’ve gone through some evolution in how we deal with pollution. And this is very generic. It’s chemical, it’s organic [as in organic chemistry] pollution as well as inorganic pollution. And there are two main trends, I think, that I can share. One is that we moved from an initial compliance perspective. So it’s a standard that is set. And if you exceed the threshold of that standard, you need to clean up. It’s very black and white, and it became very apparent early on that it didn’t lead to a lot of remediation because it’s too strict.

There were a lot of delays in implementing solutions. So we rapidly moved as an industry to risk-based remediation, where the concept of risk is extremely important. It made sure that, first of all, if it was economically achievable to clean up and that you had an actual impact. So that’s one big evolution. In the meantime, we’ve added elements of sustainability to it because if you have a very energy-consuming remediation technology, then obviously you have a CO2 impact.

And we’re now even heading into the concept of circularity or land stewardship—where we want to make sure that things like brown fields, that don’t evolve, that are contaminated, and nobody wants to touch them—that you visualize the value that that land may bring beyond economical value, so that it drives the redevelopment and the return of that land to beneficial reuse.

What we did was dig and dump. You excavate, you put it in a landfill, but it’s not really sustainable. You destroyed the soil. The soil is gone. Your problem, pollution, is gone as well, but you’re left with a hole.

So we’re heading into smarter solutions: in situ solutions using remediation, using local bacteria or augmenting the local population of bacteria to degrade, where that is possible. Now for metals, obviously that doesn’t really work. But remediation is one element that we look at.

We’re now even heading into the concept of circularity or land stewardship—where we want to make sure that things like brown fields, that don’t evolve, that are contaminated, and nobody wants to touch them—that you visualize the value that that land may bring beyond economical value, so that it drives the redevelopment and the return of that land to beneficial reuse.

Johan De Fraye, head of Environmental Affairs, Signify

ARENI

Can you give an example of phytoremediation?

Ludovic Vincent:

You have several examples of phyto-extraction and phytoremediation. With copper, for example, you can use calendula, which is a plant, which obtains good results for extracting a copper. You have plant species, which are known for accumulating heavy metals. We work to identify new species. We can use look at thousands of plants, screen them, see which ones are capable of absorbing certain elements and where we can use species which are adapted to an environment. And so we don’t have management problems afterwards. You have to find the right species for the right place for the right soil composition. You have to look at the bioavailability of elements, so it’s a synergy that has to work. You have to take all of these elements into account. It takes time, but it works. And this can give new life to these soils which, for example, were abandoned, after excavation.

ARENI

Am I right in thinking that there are some vegetables that are very good at extracting metals from the ground?

Ludovic Vincent:

Yes, you have brown mustard, you have artichoke, which is able to extract a number of heavy metals. You have plants that we eat that are capable of doing this, and which can be interesting because if a plant accumulates iron, that can be interesting for food consumption.

ARENI

Let’s go back to definitions. I’ll come to you, Natalia. What is the scale worldwide of soil pollution? And how do you classify whether a soil is polluted or not?

Natalia Rodríguez Eugenio:

We are not really sure about the magnitude of the impact, but what we know is that basically there is no pristine area anymore. Contaminants not only are in the soil directly or reach the soil directly, but they can also be transported through the atmosphere, through the air currents, through the oceans, through the rivers. For 100 years we have been releasing contaminants into the environment and they move from one place to the other.

There is no pristine area anymore. Contaminants not only are in the soil directly or reach the soil directly, but they can also be transported through the atmosphere, through the air currents, through the oceans, through the rivers. For 100 years we have been releasing contaminants into the environment and they move from one place to the other.

Natalia Rodriguez Eugenio, Global Soil Partnership

ARENI

There’s no place on planet earth that is free of contaminants.

Natalia Rodríguez Eugenio:

It is really difficult to find a place. Scientists have even found contaminants in the Arctic, in Antarctica.

ARENI

It’s really horrible to hear, but to go back to the question of classification. Are there different types of soil pollution?

Natalia Rodríguez Eugenio:

We can classify classify pollution as anthropogenic pollution or geogenic pollution. This is also another problem: there are many elements that are naturally part of rocks that become available when the rocks weather and become soil. We have natural contaminants like radon, or heavy metals of natural origin, particularly in volcanic areas.

We also have anthropogenic pollutants which are those produced by human activities. We can also classify pollution as diffused pollution or point source pollution. For example, diffuse pollution is more related to agriculture. When you have sprayed fertilizers, pesticides, they move freely in the environment and you cannot identify clearly what is the point source. You cannot go to the source and stop it there.

When we try to classify which is good, which is bad, and which is really bad, you need to go contaminant by contaminant, and there are different standards. But as I said, at the beginning, there are no standards for all the contaminants. And the problem is that we are now having many emerging contaminants, many pharmaceuticals, microplastics, new contaminants, or emerging contaminants that are new for us.

ARENI

When you talk about anthropogenic contaminants, pesticides and pharmaceuticals and so on, do they recombine in the environment in new ways? Or do they stay as discrete chemicals?

Natalia Rodríguez Eugenio:

This is one of the main problems. You have a mix of contaminants that are synergistic. They can be antagonists so they can mitigate each other. It is very complicated to really understand how they behave because soil metrics are really complicated.

ARENI

Let’s talk about remediation. Johan, can you talk about remediation and what we can do and what we can’t do?

Johan de Fraye:

Initially it was all about taking out the source [of pollution] and, and that was the solution, right? Because there was nothing else. It was quite grim actually, because you can’t always access the source. If it’s under a building then what do you do? But the positive news is that we found ways to do remediation and that’s a growing business or a growing science. It’s incredible what we’re finding that can work. You have bioremediation, where you stimulate bacteria, local bacteria, endogenous bacteria, to actually degrade organic pollution all the way to CO2.

Initially, it was thought that, in particular with organic pollutants, that they’re forever chemicals. We still have some of these. But nature actually finds a way and you can stimulate it to find a way. The most optimistic method that we have right now is that indirect methods, natural methods, can actually clean up. Can you clean up to pristine conditions? I don’t think we can go back to that. That is not possible.

ARENI

Can you give an example of a chemical that has been cleared up in a meaningful way?

Johan de Fraye:

Trichloroethylene is a greasing agent. It’s very toxic, it’s carcinogenic. This was a chemical that was used for a hundred years to degrease metals. We even have pictures from the past where in the back door of the plant, people just used to throw it out, and they assumed it would vaporise. It did for a part, but most of it went actually down into the soil. It’s heavier than water. It sinks. It goes as deep as it can, until it reaches a clay layer. It’s a difficult to treat chemical and it’s very deep, so we can’t dig a hole and take it out.

Initially the thinking was, you can’t do anything with it. It’s there forever. We’ve polluted drinking water and we’ll never do it again. And most industries have banned the chemical. What has now transpired by a lot of research is that you can actually degrade it. There’s three chlorine atoms and you take them out one by one, biologically.

ARENI

How do you remove the chlorine?

Johan de Fraye:

Bacteria. And you make it less toxic. And that’s a very good example of a chemical where initially people were desperate, right. That shows that with good research, you can accomplish a lot.

ARENI

Ludovic, can we have an example from you?

Ludovic Vincent:

Bioremediation and the use of bacteria is something that has been used with great results. We are working on totally new solutions, you know, and there are problems like cadmium, arsenic as well. We know that nature can find solutions. Nature can recycle and find pathways for that. So it can be bacteria, it can be fungi, it can be plants, but you need to find a systemic approach.

You know, we have 50, 60 years of pollution to deal with, and new pollution is arising as well. We need a kind of global rationale, so as not to constantly run after problems.

Bioremediation and the use of bacteria is something that has been used with great results. We know that nature can find solutions. Nature can recycle and find pathways. So it can be bacteria, it can be fungi, it can be plants, but you need to find a systemic approach.

Ludovic Vincent, founder of BIOMEDE

ARENI

Natalia, how much global willingness is there to tackle the problem?

Natalia Rodríguez Eugenio:

Many governments have realized that they have problems, especially well in developed countries. At a global level, countries have realized that we really need to act, because this is affecting our health, the health of the environment, and food security, because contaminants in the soil also reduce productivity in the soil.

At the United Nations level they are tackling problems. Maybe a bit slow, but with good decisions. Just this week they are discussing an agreement to control plastics in the environment.

Audience member:

Is there any plan to tackle microplastics in the soil?

Natalia Rodríguez Eugenio:

The plan is to try to establish a kind of global framework to address the problem with microplastic. The problem is that we still have many knowledge gaps and many organizations research centers are trying to fill those knowledge gaps on how microplastic react in the soil. To understand the real impact of microplastic in soil, because we just don’t know.

Plastics have an additional problem: in the end, they are organic molecules and they have the property of binding with other contaminants. So you don’t only have the plastic. You also have additional pesticides. Even heavy metals can be attached to the microplastic.

In water, you can develop the technology and try to make very tiny filters to remove that plastic. But in soil, it works completely differently, because this plastic can be attacked to organic molecules.

ARENI

So this is a problem from hell. Is there the political and academic and scientific will to solve this problem?

Natalia Rodríguez Eugenio:

Yes. We have microplastics in our body. It was recently discovered that even in human placenta, there are microplastics. It’s already in the whole food chain. What is not clear is the health impact of that plastic in our body, but we all have it. It has been seen that, for example, in earthworms, microplastics reduce the size of the earthworms and affect reproduction. So yes, there is a huge concern.

The World Health Organization is working on establishing standards in food and drinking water, but there is still a long way to go in understanding, because of the complexity and the huge amount of chemicals that are in the environment. And I think it’s worth it to mention also that practically every day we are releasing new contaminants.

Audience member 2:

You see how opaque the chemical industry is about the production of chemicals, notably in viticulture, meaning that at least 5% of what is in the product is totally unknown because of industrial secrets. We don’t know what the cocktail actually does with all the different things we use in the vineyard. How do you manage not knowing exactly what the chemical composition is?

Johan de Fraye:

There are so many chemicals out there, right? I think we have about 200,000 chemicals. It’s a number I’ve heard at some point. And a lot of those were never tested when they were developed 50 years ago, but they’re in the environment, right? There is very strong legislation these days in the EU. However, to catch up on those hundreds of thousands of chemicals and understand risks and impacts is going to take quite a while. You can move forward with risk assessments. You see exposure, you look at pathways, you look at retention and uptake and biodiversity. You indirectly measure whether your soil can cope or not and that’s all you can do right now, frankly.

This is a condensed and edited version of a much longer and livelier discussion, which you can watch HERE in English of French.


The World Living Soils Forum is an international forum organized by a private actor Moet Hennessy to: 

  • Connect people committed to soil regeneration
  • Share concrete actions for sustainable and regenerative viticulture/agriculture
  • Strengthen the link between Science, Innovation, and realities of the field
  • Gather Science-based KPIs and methodologies to champion soil health

The forum brought together researchers, experts, public institutions, journalists, trade associations and companies from the Food & Beverage industry for two days of conferences, round tables, masterclasses, and workshops

This first edition of the World Living Soils Forum took place on June 1 & 2, 2022 in Arles-en-Provence. You can watch all the replays of the sessions HERE in both English and French.