Creosote vs. Elm Oyster

I started off on a quest to find out how polluted my soil was and if there was a mushroom species that could clean it up.

First, I began Googling. I was having a hard time finding a mushroom that seemed to gobble up creosote in particular, although I did find one affectionately dubbed “The Train Wrecker” due to its ability to eat through railroad ties. Researchers are currently studying it as a strong candidate for mycoremediation.

I also discovered that the Elm Oyster Mushroom is a great mycoremediator for wood preservatives (creosote is certainly a wood preservative!). My first inclination was to try both mushrooms in adjacent spaces and see which one did a better job, but I quickly realized the Train Wrecker was, well, beyond my skill level…

For one thing, the best substrate (the material the mushroom needs to feed on) for the Train Wrecker is preferably fresh pine chips, which you can’t just go and order on Amazon. We also discovered it is difficult to get a single kind of wood chips from tree service companies because the wood is often mixed with other kinds of woods, which is less than ideal. Plus you can’t control when the wood might become available, and timing is important. Add in the fact that the Train Wreckers may only eat through railroad ties and is not yet a proven mycoremediator and it just seemed clear that we should go with the Elm Oyster mushroom instead.

The Elm Oyster is said to be one of the easiest mushrooms to grow outdoors as there is for beginners–there are varieties of substrates you can use, and it does well with a pretty good range of temperatures in case the weather is a little variable. Since other mycoremediation and garden projects have been done with it (it makes the soil absolutely yummy for veggies), there were some resources online I was able to draw from to help design our plan rather than being completely in the dark. With the Train Wrecker, I would have had no idea how to set it up. There are no guarantees here, but the Elm Oyster sure looks like our best bet!

When I started calling different soil testing companies to see if they tested for creosote, I figured out why ‘creosote’ is not really something you can target as a single entity. Here’s a recap of what one company told me on the phone:

About 300 chemicals have been identified in coal-tar creosote, and there may be 10,000 other chemicals present in the mixture. The major chemicals in coal-tar creosote that can cause harmful health effects are polycyclic aromatic hydrocarbons (PAHs), phenol, and cresols.1 Coal-tar creosote is usually a heavy, oily, liquid containing mainly alkylnaphthalenes, naphthalene, diphenyl, acenaphthalene, fluorene, plus small amounts of higher phenols, diphenylene oxide, quinoline base and indole.

http://www.beyondpesticides.org/programs/wood-preservatives/publications/poison-poles/no-title97

Whew! Well, that’s not pretty. Unfortunately, most places do not test for any of that. The county (which does offer free soil testing for mineral content and that sort of thing), did not offer testing for any kind of pesticides, and neither did the next three places I called.

Luckily, I finally got good news from Test America (they have locations around the U.S.). While they don’t test all of the chemicals in creosote, they do test for the phenols and cresol and they could also test for arsenic and other heavy metals that railroad ties are often holding onto as well.

So, with a soil sample in hand and a mushroom in mind, we are ready to move forward to the next step!