I contacted the Cornell Extension
(http://www.css.cornell.edu/soiltest/soil%5Ftesting/index.asp) and learned that they have two tests for metals in the soil. The first R2070 just tests only for lead and costs $20.00. The second, R2020, tests for 16 different heavy metals, including arsenic, lead, cadmium, nickel, zinc and nitrate and costs $35.00.
In New York City, a "lead belt" runs from Williamsburg-Bushwick, through Bedford-Stuyvesant and East Flatbush, and into West Queens. Bushwick is considered to be the most contaminated. I've had clients in Crown Heights, Ft. Greene and Prospect Park concerned about their children playing in their yards because of high levels of lead. One of the surest ways to get the lead out is to remove layers of topsoil and add new soil; however, this is labor intensive and costly. If the toxins run deep, it's best to combine taking off a layer of dirt, and then using phytoremediation, or plants that naturally clean toxins from the soil
Some plants have evolved to be able to process metals from the soil. Plants that grow in metal rich soils are known as metal-hyperaccumulators. Most of them are in the mustard and broccoli family, but scientists are trying to find bigger, heartier plants to study. In South Africa, botanist are working with sunflowers, as their size allows them to absorb large amounts of metals from the soil. After the 1986 accident at the Chernobyl nuclear plant in the former Soviet Union, sunflowers grown on floating Styrofoam were used to clean up contaminated water. The roots of the sunflower plants remove 95% of the radioactivity by pulling contaminants out of the water. Now scientists are looking into the commercial potential of these plants to clean up polluted mining areas; it's hoped that one-day they could be harvested and processed for metals themselves.
Other plants also clean toxic metals; ferns remove arsenic from the soil. Poplar trees suck out dry cleaning solvent. Alpine pennycress, a wild European herb, takes care of zinc. Reed Canary grass, switch grass, tall fescue, alfalfa and sweet clover also process metals.
This coming spring, I'll come up with a plan for cleaning metals out of yards in New York City, for now, I'm trying to figure out how to get on the construction sites to get my 1.5 cups of soil to send Cornell.
Comments (7)
The confirmation that Cornell's CNAL can address metal toxins is timely. Do you know if mercury is included in R2020? What's the best way to contact them, as this information is not readily available on their Web site.
I've never heard of the "lead belt" before. The geography sounds like it could be a natural distribution. Where can I find more information?
Once the plants uptake the metals, how are they disposed of? They've now become toxic waste themselves.
PS: The link is missing a leading "www".
Posted by Xris (Flatbush Gardener) | November 20, 2007 1:36 AM
Posted on November 20, 2007 01:36
The confirmation that Cornell's CNAL can address metal toxins is timely. Do you know if mercury is included in R2020? What's the best way to contact them, as this information is not readily available on their Web site.
I've never heard of the "lead belt" before. The geography sounds like it could be a natural distribution. Where can I find more information?
Once the plants uptake the metals, how are they disposed of? They've now become toxic waste themselves.
PS: The link is missing a leading "www".
Posted by Xris (Flatbush Gardener) | November 20, 2007 1:37 AM
Posted on November 20, 2007 01:37
The lead is primarily from lead based paints. Just Google "Lead Belt" and you'll get lots of articles. Here's one by the Sierra Club. http://www.sierraclub.org/comunidades/ingles/brooklyn.asp
You'll have to call to find out about Mercury. They were supposed to send me a list, but I haven't gotten it yet. I know they don't test for asbestos.
As for getting rid of the plants, and soil they would have to go to a landfill. I have no idea what they did with those sunflowers from Chernobyl, but that's a good question. Soil can be tricky to get rid of. I've heard gardeners talk about dumps that won't take topsoil. Another question is if you plant ferns, poplars, etc. that phytoremediate the soil, but aren't meant to be disposed of, are they then toxic? Some insects have been co-evolving with metal hyperacculumators, but what does that mean for the rest of the eco-system?
Posted by Maria | November 20, 2007 10:22 AM
Posted on November 20, 2007 10:22
The lead is primarily from lead based paints. Just Google "Lead Belt" and you'll get lots of articles. Here's one by the Sierra Club. http://www.sierraclub.org/comunidades/ingles/brooklyn.asp
You'll have to call to find out about Mercury. They were supposed to send me a list, but I haven't gotten it yet. I know they don't test for asbestos.
As for getting rid of the plants and soil, they would have to go to a landfill. I have no idea what they did with those sunflowers from Chernobyl, but that's a good question. Soil can be tricky to get rid of. I've heard gardeners talk about dumps that won't take topsoil. Another question is if you plant ferns, poplars, etc. that phytoremediate the soil, but aren't meant to be disposed of, are they then toxic? Some insects have been co-evolving with metal hyperacculumators, but what does that mean for the rest of the eco-system?
Posted by Maria | November 20, 2007 10:25 AM
Posted on November 20, 2007 10:25
I would be interested in helping with some of the design and implementation of bioremediation plantings,I teach and implement Permaculture design and have worked with native species gardening for over 20 years,please visit my website for more background.Sincerely,
Andrew Faust
www.homebiome com
Posted by Andrew faust | November 29, 2007 2:13 PM
Posted on November 29, 2007 14:13
i want to know what r the on going projects going onphytoremidiation
Posted by G.Raghavendra | November 4, 2008 9:36 AM
Posted on November 4, 2008 09:36
We at Brooklyn College can do heavy metal analysis for soils (in fact metals in anything, including Hg) with negotiable pricing. We are also interested in working with you on the phytoremediation studies. Please send me an email at zcheng@brooklyn.cuny.edu
Posted by Joshua Cheng | January 16, 2009 12:05 PM
Posted on January 16, 2009 12:05