Safer plants to grow where plastic contamination is a problem

Unfortunately, the best potential vegetable gardening area around the house—south facing wall, warm early in spring, close to the front door—is contaminated with paint chips from a previous house-washing. I tried to pick up everything I could, all the larger flecks, but in some very embarrassing lapse of consciousness, didn’t think of removing the top layer of soil to somewhere more convenient prior to digging. The only consolation is that it surely isn’t the first time it has happened. But now that it is done, what is to be done? My plans so far have been using it as a nursery space, but it still seems like such a shame not to grow herbs and greens there.

Any thoughts?
Thank you.

(Original title mentions microplastics specifically. But it holds for any other associated toxins as well.)

I might have some good news, I'm not sure.

A big issue related to paint chips from houses is actually lead. Lead can accumulate in the soils directly around houses and fences that at one time had lead paint and it has a tendency not to wash away. The good news is that lead does not tend to bioaccumulate in plants. Source

Microplastics is a bit trickier. I don't know a lot of literature on the subject specifically towards remediation of contaminated soil but I'd be willing to think that there might be some plants that are known to bioaccumulate the plastics more than another. That plant could be used for a season or two and then disposed of to reduce the amount of microplastics in the area. How to quantify the effectiveness? I'm not so sure.

An idea that I think might be a good middle of the road is to create raised beds and bring in soil to create a 'clean layer'. A big worry is the splash of soil onto vegetables that are not cleaned off for lead and that can be eliminated by this height increase. I would assume microplastics will require avoiding root systems penetrating down into the contaminated soil but a high walled raised bed would do a good job. Perhaps building something that you could garden while standing?

Sunflowers are often used to purify land.  The bigger the variety,  the better.

But disposal is tricky as they don't transform every toxin.  Mostly they absorb it and the biomass is decomposed with a specific fungus that eats toxins or mineral.

Sunflowers are a good choice because they are bright and cheery.

Bracken fern is another though some folks don't see their value:

https://permies.com/t/217581/Bracken-Fern-deadly-enemy

Here is a post I wrote way back in 2018 for a similar situation, and I will second the suggestion for growing mushrooms:

Anne wrote: It seems to me that the easiest way to solve the problem would be to bury it in lots of leaves and wood chips.  I mean deep.  Maybe putting a layer of cardboard down first.  Then plant something.  Maybe grow mushrooms.

While this article goes into toxic stuff I reference it to give you an idea of what plants can do.

http://www.resilience.org/stories/2014-08-11/using-plants-to-clean-contaminated-soil/

https://permies.com/t/85144/Worst-Decision-rid-pieces-landscape#702010

What do we know about microplastics and bio-uptake by plants?  I know zilch about biochemistry but all the popular-press level articles I've seen about microplastics danger have focused on their ingestion by animals, specifically fish and mammals.  

When I think about the hazards of plastics I imagine them in two buckets. The first is volatiles -- the various hydrocarbon chemicals that make plastics flexible and soft, which can outgas or seep into the environment and be bioavailable and thus dangerous like any other petrochemicals.  The second is particles, which used to be assumed inert, the stable parts left behind after volatiles were leached/outgassed and gone. Science in recent years has begun to suggest that the smallest particles are tiny enough to fool animal biology and thus pose health hazards after ingestion into mammalian/piscene/avian bodies.  

But the next step -- the idea that plants might uptake microplastics from the soil and store them in tissues that we later eat -- is new to me.

Medical Medium has a tea recipe for removing micro plastics from the bloodstream. It consists of mullein, lemon balm, fenugreek, and olive leaf. Perhaps you could grow some of these things in your contaminated area. Or drink the tea to combat your exposure!

And I barley can remove some metals from the soil. Also calendula can purify soil.

So the biggest problem with contaminants is that when you dig and weed the area, it creeates alot of dust that ends up in your lungs immediately or on your clothes then you then track into your house then then ends up in your mouth/nose/etc at a later date when you sweep or dust the house. So planting herbs that require minimal soil disturbance is actually a wonderful idea. I would also cut and eat the herbs, because you don't have to eat alot per week and the plant itself doesn't absorb much plastic. I would cover the area with wood chip so that some fungi can show up and start breaking down the paint, esp oyster mushroom.