Scientists since the early ’90s have seen the potential for cleaning up contaminated sites by growing plants able to take up nasty groundwater pollutants through their roots. Then the plants break certain kinds of pollutants into harmless byproducts that the plants either incorporate into their roots, stems and leaves or release into the air.
The problem with plants that are capable of doing this is that the process is slow and halts completely when growth stops in winter. Using plants in this way, a process called phytoremediation, often hasn’t made sense given the timetables required by regulatory agencies at remediation sites.
Scientists led by Sharon Doty say that genetically engineered poplar plants being grown in a laboratory were able to take as much as 91 percent of trichloroethylene, the most common groundwater contaminant at U.S. Superfund sites, out of a liquid solution. Unaltered plants removed 3 percent. The poplar plants — all cuttings just several inches tall growing in vials — also were able to break down, or metabolize, the pollutant into harmless byproducts at rates 100 times that of the control plants.
Because there is concern that transgenic trees might get into regular forests, Doty and her colleagues believe poplars may be a good choice, she said. Poplars are fast growing and can grow for several years without flowering, at which time they could be harvested to prevent seeds from generating. And unlike some other kinds of trees, branches of the hybrid poplar being studied do not take root in soils when branches fall to the ground.
Between superstition and ignorance, this nation has elevated fear of science to the level of political correctness. I wonder if this study can ever get to the pilot project stage – much less lead to implementation in pollution clean-up.
Don’t worry, I am sure the intelligent designer will clean up all the pollution for us…. 😀 😀 😀
[Message deleted – See Comment Guidelines. – ed.]
So regulators have been the source of the problem? They’ve been insisting on more expensive solutions to clean things up faster?
It’s not just this nation that has put political correctness ahead of science.
http://tinyurl.com/24d3sv
Having worked a lot in this field (phytoremediation), the results of this study need to be tempered with the reality of many of these sites. First off, the contaminant must be in the water for phytoremediation to work. Second, the plant must be using the groundwater, rather than tapping into shallow surface water.
Most organic contaminants (such as TCE) have greater affinity for the soil than the water. Additionally, most plants rely more on surface water than ground water. The poplar is a good choice, since it can tap directly into the groundwater. However, when storms occur, even the poplar is more likely to grab the easy water closer to the surface.
Also, these hybrid poplars are already being used in field studies.
To 3. Regulators insist on solutions that are likely to work. Much of the time consulting engineers advise that nature will take care of the contamination prior to exposure to receptors (people or animals). This is the least expensive solution in many cases, but can be expensive, since you must continuously monitor the site.
Nate, nice and mostly appropriate comment. But – let me know when the bureaucrats in charge really start to give a damn about “receptors” over budget.
Receptors lived at Love Canal. I had a “late” niece who went to high school and enjoyed her recreational sports on a ballfield constructed on donated landfill laced with asbestos. The lawsuit over the deaths of her classmates has only been frittering along for a couple of decades. There is no shortage of examples.
Remediation is still the last resort in a nation that honors profits before people.
This sounds interesting but what do they then do with the toxic timber? Presumably the “phytoremediation” relocates the toxic substance into the tree timber, so what do they then do with it? Is it milled and made into Ikea dining tables?
#7 – edwin – click the link and you’ll see one of the reasons this works is that poisonous substances are converted to harmless in the process. Otherwise, I imagine they might kill the trees early on.
In my neck of the woods, they’d make firewood. Let people cut cords at no cost to the project. Or make a few bucks from it. I burn aspen to heat the house.
#8. I did read it and I wondered about trichlor and benzene. They are very stable, enduring and severe carcinogens. The article implies they are rendered into some inert form. Whether this means they are molecularly altered into something benign (which is difficult) or bonded into a structure which safely contains them, isn’t clearly explained.
#6 – Most of the regulations regarding remediation are in response to events like Love Canal. I agree with the profits comment though. In many cases, remediation should be undertaken, but there are too many concerns about cost. Superfund has been a disaster, in that so much time/money is spent chasing responsible parties rather than cleaning up the environement.
#9 – TCE and Benzene readily photodegrade, due to the double bonds in the molecular structure. The basic idea behind phytoremediation is that the contaminant either moves out of the plant into the air or it is sequestered into the plant. Very little metabolism of the contaminant occurs. In air, TCE and benzene should be completely degraded within days. In soil though, they will be stable. They will not be inert in a plant though, simply unavailable.
Also, to say that TCE and Benzene are severe carcinogens would be a mistake. They are generally classified as suspected carcinogens or known carcinogens. Severe carcinogen is not a good term, since concentration comes into play here as well.
#6 You really don’t know a damn thing about EPA and regulators do you?
Love Canal predated EPA regulation. In fact, Love Canal is what led to passage of the Resource Conservation and Recovery Act (RCRA) which governs handling and disposal of hazardous waste.
#11 – Gee, I’m sorry if my concern about people doesn’t weigh as heavily as your concern for bureaucrats. I hope I didn’t hurt the feelings of some pencil-pusher.
Or maybe I did?
“Between superstition and ignorance, this nation has elevated fear of science to the level of political correctness. I wonder if this study can ever get to the pilot project stage”
I believe that christians at least will take this study into consideration whereas their atheist, tree huggin’ European counterparts will yap like the bitches they are and demand that soil should be cleansed by scrubbing it against an organic hand-made washboard.
Interesting article. At least the world is aware of some natural ways of natural cleaning, than the harmful chemicals that are used these days. I hope people (we) discover more ways to clean up ‘naturally’.