© Danielle StevensonMushrooms growing at a brownfield site in Los Angeles
An environmental toxicologist in California is cleaning up areas contaminated with heavy metals or other pollutants using fungi and native plants in a win-win for nature.
Where once toxic soils in industrial lots sat bare or weed-ridden, there are now flowering meadows of plants and mushrooms, frequented by birds and pollinators: and it's thanks to Danielle Stevenson.
Founder of
DIY Fungi, the 37-year-old ecologist from UC Riverside recently spoke with Yale Press about her ongoing work restoring 'brownfields,' a term that describes a contaminated environment, abandoned by industrial, extraction, or transportation operations.
A brownfield could be an old railway yard or the grounds of an abandoned oil refinery, but the uniting factor is the presence of a toxic containment, whether that's a petrochemical, heavy metal, or something else.
Noting that she had read studies about mushrooms growing around the Chernobyl nuclear plant, she came to understand further, through her work, that fungi are an extraordinarily resilient species of life that consume carbon, and even though petroleum products are toxic to plants, to mushrooms they are essentially a kind of carbon.
In fact, mushrooms break down several categories of toxic waste with the same enzymes they use to consume a dead tree. They can also eat plastic and other things made out of oil, like agrochemicals.
At the Los Angeles railyard, as part of a pilot project, Stevenson and colleagues planted a variety of native grass and flower species alongside dead wood that would incubate specific fungi species called arbuscular mycorrhizal fungi, which assists plants in extracting heavy metals like lead and arsenic from the soil.
Alongside traditional decomposer fungi, the mixture of life forms demonstrated tremendous results in this brownfield.
"In three months we saw a more than 50 percent reduction in all pollutants. By 12 months, they were pretty much not detectable," Stevenson
told Yale 360
.Decontaminating soil like this typically involves bringing in a bulldozer and digging it all up for transportation to a landfill. This method is not only hugely expensive, but also dangerous, as contaminated material can scatter on the winds and fall out of the backs of trucks carting it away.
By contrast, the plants that draw out the toxic metals can be harvested and incinerated down to a small pile of ash before cheap transportation to a hazardous waste facility.
The technique, which Stevenson says has some scaling issues and issues with approval from regulators, is known officially as bioremediation, and she's even used it to safely break down bags of lubricant-soaked rags from bicycle repair shops.
"People who live in a place impacted by pollution need to have a say in how their neighborhood is being cleaned up. We need to empower them with the tools to do this," she said.
Comment: The humble fungi family seems to have many good uses beside their medicinal value.