by Seshata on 25/12/2013

Hemp and the Decontamination of Radioactive Soil


Hemp Hemp science is now advancing in leaps and bounds compared to the stagnation of the previous few decades. One significant area of research that is currently receiving particular attention is phytoremediation, or decontamination of soil—although the discovery that hemp leaches contaminants from soil has been known for some time.



Hemp science is now advancing in leaps and bounds compared to the stagnation of the previous few decades. One significant area of research that is currently receiving particular attention is phytoremediation, or decontamination of soil—although the discovery that hemp leaches contaminants from soil has been known for some time.

Hemp and the Decontamination of Radioactive Soil

The Chernobyl phytoremediation project

For over a decade, industrial hemp growing in the environs of the abandoned Chernobyl nuclear power plant in Pripyat, Ukraine has been helping to reduce soil toxicity. Now, the Japanese are considering following the same course in order to rectify the environmental damage caused by the Fukushima meltdown—however, due to the Cannabis Control Law forced into Japanese law by the occupying U.S. powers in 1948, hemp may only be grown under license—which are highly restricted and difficult to obtain.

In 1989, just three years after the initial explosion, the Soviet administration of the time requested that the International Atomic Energy Agency (IAEA) assess the environmental situation. In the 30km exclusion zone surrounding Chernobyl, high concentrations of various toxic metals including iodine, cesium-137, strontium-90 and plutonium were found in the soil, as well as in plants and animals themselves.

Hemp has been found to absorb heavy metals from soil at a very high rate
Hemp has been found to absorb heavy metals from soil at a very high rate

Which Plants are Useful in Phytoremediation?

In response, it was decided that a concerted effort to reduce soil contamination through the use of beneficial plants would be undertaken. This process, known as phytoremediation, began immediately, and used various plants to take up specific contaminants—two brassica varieties to remove chromium, lead, copper and nickel, maize to take up lead (various researchers have demonstrated the remarkable lead-uptake capability of this important crop), and more recently, sunflower and hemp.

Sunflower plantings began in 1996 subsequent to the development of a variety that promised hitherto unheard-of efficiency of decontamination; hemp plantings soon followed, in 1998. Slavik Dushenkov, a research scientist with Phytotech, one of the organisations behind the hemp plantings, stated that “hemp is proving to be one of the best phyto-remediative plants we have been able to find”.

As well as in the Ukraine, much rural land in neighbouring Belarus was affected by the explosion, and authorities there are also pursuing the use of hemp as a decontaminant. The harvest produced will be turned into ethanol, as increased production of biofuel is a key target for increasing the overall economic and environmental health of the region.

The Chernobyl exclusion zone, site of the world's worst nuclear disaster, is slowly being returned to health as plants and animals begin to reclaim the land
The Chernobyl exclusion zone, site of the world’s worst nuclear disaster, is slowly being returned to health as plants and animals begin to reclaim the land

Differences in Metal Uptake From Soil

In 2012, a Romanian study investigated the nutritional safety of hemp seed produced from plants grown in soils rich in calcium, magnesium, potassium and iron. The study determined that five distinct Romanian hemp strains developed different nutritional profiles according to uptake of the various metals in the soil. For example, the Zenit strain exhibited highest rates of calcium uptake, while the Armanca absorbed least calcium; the Diana, Denise and Silvana strains absorbed magnesium at the highest rates, and the Zenit variety showed the highest concentrations of iron.

Despite the differences, the seeds and oil of all five strains exhibited high levels of magnesium, calcium, iron, manganese, zinc and potassium, all highly beneficial dietary metals. However, all varieties also tested above the safe legal limit for cadmium, a toxic heavy metal that may cause various health complications—despite the soil being within the safe limit for cadmium concentration. The Armanca and Silvana strains showed particularly high cadmium levels.

Hemp and Cadmium Absorption

Excessive consumption of foodstuffs high in cadmium can lead to joint and bone deformities, respiratory illness, anaemia, and kidney failure. In areas where cadmium is present in the soil, in order to be safe for human or animal consumption, hemp varieties should be selected on the basis of poor cadmium uptake.

According to a study into Chinese hemp strains conducted in 2011, many hemp strains have the ability to absorb and accumulate even large quantities of cadmium in soil without detriment to the plant itself. While this does throw up various implications for selection of sites for cultivation of food-safe hemp, it also indicates that cadmium-contaminated sites will particularly benefit from phytoremediation schemes that make primary or exclusive use of hemp. Furthermore, even if hemp used to decontaminate soil is unsafe for consumption, it can still be used in a number of industrial applications, such as for biofuel.

As vegetation slowly reclaims formerly inhabited areas, adding species known to be effective extractors of soil-based heavy metals can aid in ecosystem rejuvenation
As vegetation slowly reclaims formerly inhabited areas, adding species known to be effective extractors of soil-based heavy metals can aid in ecosystem rejuvenation

Hemp is Mostly Unaffected by Heavy Metals in Soil

Hemp’s resilience to contaminants in soil is well-documented. Even as early as 1975, a study published in the Agronomy Journal described how soil characteristics influenced elemental uptake and could even affect final cannabinoid profile in psychoactive strains. To illustrate this, fifteen sites with varying soil profiles were planted with the same strain of Afghan cannabis, and their harvests tested for metal content. Researchers concluded that differences could be used to determine geographic origin of cannabis through foliar analysis.

In 1995, the Polish Institute of Natural Fibres released a study demonstrating that tested varieties were able to withstand high levels of heavy metals in soil without impacting plant growth, yield or fibre quality. However, little research has been done into the safety of using fibres in clothing or other forms of industry, and this issue must be investigated fully in order to establish the possible uses for hemp grown in such conditions.

As a proven, valuable tool in the fight to repair human-inflicted damage to our soils and ecosystems, hemp could potentially benefit hundreds of thousands of sites across the globe—it is estimated that in the USA alone there are 30,000 sites requiring remediation. As is so often the case, US restrictions on hemp cultivation preclude any large-scale operations from being implemented, and the contaminated sites are largely left unremediated, through lack of both funding and interest on the part of the government.

Comment Section

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Kay

Excellent article Seshata! Paired with Paul Stamets use of fungi as a bio-remediation tool, this looks to be an excellent way to teach stewardship of our land and resolve the mistakes we have made as a species so far. Thanks for the research!

30/12/2013

Moseley Putney, AIA

I am founder of Kentucky Hemp Industries and am looking for scientific data/studies on hemp utilized for phytoremediation. Any assistance will be gratefully received.
Thanks,
MP

10/03/2014

Scarlet Palmer

Hello Moseley, thank you for your comment.
It is possible that articles on the Hemp Industries Association website might be useful for you (www.thehia.org) and the Hemp Cleans initiative was also doing research into phytoremediation last year (hempcleans.com). If we find any studies dedicated to this, I will get in touch again. Good luck with Kentucky Hemp Industries, more power to your elbow! With best wishes, Scarlet

14/03/2014

MOhemp Energy

Mr Putney the local team is working on StLouis nuclear decontamination of the old Manhattan Project Nuclear waste burried in a landfill (Westlake and Bridgeton) as well as along the Cold Water Creek areas. see: blog.mohempenergy.org for pot testing info and future plans.

21/02/2016

Joey

This is great information and it suprises me that legislation is preventing the clean up in Japan as that is an environmental disaster according to some intelligent physicists. Has anyone done any research on what happens when you burn the hemp in bio diesel? Wouldn't the chemicals the plants absorb in the ground cause these metals to be released into the air? I am not a scientist and hope I don't sound ignorant on the subject. The reason for my questions is that I am interested in cleaning up a large piece of ground I have from high levels of arsenic from farming. Thanks in advance for responding:)

11/08/2014

Seshata

Hi Joey, apologies for the delay in responding. Disposal of accumulator plants is a tricky issue, and if levels of heavy metals are beyond a certain threshold they are considered toxic waste and must be disposed of accordingly. How this applies to hemp has not been ascertained, as far as I'm aware, although I will update if I find anything specific to it. This article (http://www.energyjustice.net/biomass/phyto) has some interesting links to further reading.

14/11/2014

Lo Jarl

Working partly in the field of functional medicine it is sometimes demonstrated through Hair Tissue Mineral Analysis that people who are keen on hemp in all its forms jave high levels of heavy metals such as Cadmium, Uranium, Arsenic and Lead and possibly other metsls as well. This may imply that those manufacturers involved in hemp produce have poor control of the soil conditions where the hemp used for human consumption and clothing is being cultivated. Does anyone know of certification labels setting the standards for hemp produce low in heavy mrtals? We have to remember that some soils may naturally be high in heavy metals, or various natural soil improvement rock products. So simply avoiding industrially polluted soils will not guarantee that hemp (very often) labelled as organic or environmental friendly, will have acceptable levels of heavy metals.

14/11/2014

Seshata

Hey, this is interesting, thank you for bringing it to my attention. I will have to look into the existing guidelines, I haven't come across anything regarding levels of heavy metals in soil yet but there could be some non-specific guidelines that still apply. These results of the Hair Tissue analysis - are they available to source online in any form, or could you make them available?

Thanks,

Seshata

14/11/2014

philip

I don't understand why this information isn't more available.
I have researched some things online about hemp and cancer killing properties and it got me to thinking about the rise in the legalization of Marijuana in some states and the growing of hemp threw the farm bill soon after the fukushima incident call me crazy but I really think there may be a connection here

01/03/2015

Curlybird

I have also wondered about the accumulation of heavy metals during the bio-remediation process. Have there been any experiments attempted? Conceptually, much could be learned using spectrum analysis processes. There is also the possibility of re-processing as a bio-fuel. Would the metals break down further under combustion or would they remain as airborne contaminants? Much science to be accomplished here.

Excellent article, BTW.

14/03/2015

Frank

Where do the radioactive plants go once they've absorbed the radio nucleotides? Another
potential problem? In a debate: hemp deactivates radiation. I say hogwash.

19/03/2015

Seth Hartley

two questions come up for me, and I'm more just throwing them out there instead of looking for answers.

1. Could repeated remediations spread and diffuse heavy metal levels until they are balanced and under toxicity threshold levels? for example, planting in a toxic area, using the biomass produced for compost fodder or wormery feed, then re-planting until the metals are dispersed over a less concentrated area?

2. There was some mention about toxic ash from burning, but would you have the same results from pyrolysis (gasification)? Would heavy metals transfer to syngas, or would they stay with the bio char, and thus once again be used as an additive to diffuse the metals in small amounts into non-toxic soils?

3. I also saw mention of stamets and mycoremediation. Perhaps use hemp to isolate metals from the soil into biomass, then mushrooms to further process them until either more stable or uniformly distributed?

My interests would specifically be in bio-remediation of fly ash in desert conditions. It would be helpful for presenting to the local college's agroforestry branch as a project.

23/03/2015

Bella

Thats great news, it seems to be a versatile plant that can do good.

05/10/2015

Real Lehoux

I have serious doubt that any plant could effectively decontaminate a area highly radiactive.
Explanation: I do agree that plants have different absorption rate of different elements.
What must be understand is some Radiactive elements decay rapidly and loose their radioactivity in weeks , months and years dependant of their activity and molecular weight as example Radioactive Iodine decays fast in days and week but Plutonium takes 100 thousands of years to decay from dangerous level to more natural one. When a plant absorb a radioactive substance it maybe a low level one or a high level but in both case absorption does not change the rate of decay. An advantage is that plant could fixe into their cells the elements therefore in large quantity of plants the radioactive dust is not spreading elsewhere/everywhere.

05/10/2015

Guadalupe Rivera

I would lije to know whrre can i get seeds
i live plants any kind and love to grow them

08/10/2015

gowri

Excellent information. Why the big nations are not taking any initiative to reclaim the soil.? People are more worried about their personal gains than this. Soil contamination is a serious problem that too with radioactive materials.

10/10/2015

Janine boguslawski

Thanks for the research. Very interesting artcle.

12/10/2015

Dave Hicks

Great article.

I'm working with my KS state rep to pass a hemp bill this session legalizing the plant.

How are plants used for phytoremediation disposed of? I assume they are not useable in any manner.

Thanks

21/03/2016

Kevin

Yes this is something we are just starting to put together. I feel that one bio remediated product such as hemp could be remediated by mycoremediation. Exciting times! Unfortunately there is a lot of toxic soil out there. Most organic soil could be first remediated by hemp.

12/04/2016

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