Heavy Metals in Fertilizers

[Purple Monster]

That depends on the plant. Unfortunately, heavy metals are more available to cannabis than almost any other plant. Combine that with the typical methods of ingestion and the fact that they accumulate in the body and I believe it represents a genuine cause for concern.

Have you looked at your local water municipal analysis? Do you drink tap water?

 

[Azeotrope]

BerndV - I'd like to see some evidence/data to support the statement that heavy metals are more 'available' to cannabis..... Fill me in here. Plant biology varies by species, but mobility of ions, salts and such doesn't vary much by the type of plant. More the PH and other factors of the medium......

 

[BerndV]

Have you looked at your local water municipal analysis? Do you drink tap water?

While the tap water here is free of any detectable levels of heavy metals according to their latest published water report, there are thousands of other potential contaminants for which municipal drinking water is not tested. These include various organic solvents, pesticides, and many other nasties. That is why my home drinking and cooking water is filtered through a three stage carbon block filtration system and then through a reverse osmosis membrane prior to being consumed. My plants get the same good stuff. Obviously, when I am in a restaurant or traveling, I drink what is available. However, Aquafina tests squeaky clean and is my choice when traveling.

 

[BerndV]

BerndV - I'd like to see some evidence/data to support the statement that heavy metals are more 'available' to cannabis..... Fill me in here. Plant biology varies by species, but mobility of ions, salts and such doesn't vary much by the type of plant. More the PH and other factors of the medium......

Actually, certain species of plants are known as hyper-accumulators of metal ions. These represent <0.2% of all angiosperms, totaling approximately 400 species in all. Cannabis falls in this category. There are numerous scholarly articles available that discuss this but require a fee to view. However, many users of this site have access to the classic "Hemp Diseases and Pests" by J.M. McPartland, et al. The following selected quotes are from page 165:

"Cannabis absorbs many heavy metals from the soil, without ill effects. These toxins deserve mention for their effects on us. Ingesting plants laced with lead (a contaminant found in chemical fertilizers) causes anaemia and brain damage. Ingesting mercury, another cumulative toxin, also causes neurological deficits. Mercury is released from combustibles such as coal and volcanoes. Siegel et al. (1988) measured 440 ng mercury per gram of marijuana grown on Hawaii's volcanic soil. They noted that mercury is absorbed ten times more efficiently by the lungs than by the gut, and calculated that smoking 100 g of volcanic marijuana per week would lead to mercury poisoning.

Jurkowski et al. (1990) found high levels of lithium in hemp (1.04 mg/kg), higher than any other crop plant tested.

Hemp's ability to hyper-accumulate metals may prove useful for decontaminating toxic waste sites. In Silesia, Cannabis is deliberately cultivated on wasteland contaminated with cadmium and copper. The crop efficiently extracts the toxic metals from the soil and accumulates the metals in the seeds."

The following link discusses accumulation of heavy metals in cannabis leaves versus seeds:

http://www.pjbs.org/pjnonline/fin356.pdf

 

[Azeotrope]

BerndV - Thanks, I'll keep reading on the subject.

Regards,

Azeo

 

[BerndV]

The Oregon Department of Agriculture recently performed independent analysis of several Advanced Nutrient products and found them in violation of manufacturer submitted certificates of analysis. Their product "Big Bud", for example, was found to contain far more lead, arsenic, mercury, and cadmium than AN had purported. I really have to wonder to what extent the deleterious effects marijuana may have on memory and learning are related to the heavy metal content of the marijuana as opposed to the THC and other cannabinoids.

 

[Purple Monster]

While the tap water here is free of any detectable levels of heavy metals according to their latest published water report, there are thousands of other potential contaminants for which municipal drinking water is not tested. These include various organic solvents, pesticides, and many other nasties. That is why my home drinking and cooking water is filtered through a three stage carbon block filtration system and then through a reverse osmosis membrane prior to being consumed. My plants get the same good stuff. Obviously, when I am in a restaurant or traveling, I drink what is available. However, Aquafina tests squeaky clean and is my choice when traveling.

I guess what im saying is, you're really making a health conscious decision to avoid anything with heavy metals, when most people are not even aware that they encounter heavy metals on a daily basis through tap water, foods, emission sources. People are exposed to heavy metals every single day. That's great that you don't want to encounter or drink or smoke or have anything that contains any sort of heavy metals, but you've got to realize that millions of people everyday are exposed to these metals at acceptable levels, and they continue to do so. They wont be shutting down the water municipals or emission sources or anything of the like, anytime soon! What I am saying is, they have have established safe levels of heavy metals, so if we're below those levels, what is the concern?

Do we know for sure how these heavy metals affect plants? I for one do not, and there's not a lot of literature on the subject. Do you know of any complete studies on plants with different lines of nutes and pre and post analysis? I haven't yet found anything in this regard, but I do applaud your efforts in bringing this to everyones attention. I'll be smoking some of my maxibloom nugs in a few weeks and we'll see if I survive!

 

[Purple Monster]

I really have to wonder to what extent the deleterious effects marijuana may have on memory and learning are related to the heavy metal content of the marijuana as opposed to the THC and other cannabinoids.

It would be interesting to see some more literature on the subject!

 

[Purple Monster]

Actually, certain species of plants are known as hyper-accumulators of metal ions. These represent <0.2% of all angiosperms, totaling approximately 400 species in all. Cannabis falls in this category. There are numerous scholarly articles available that discuss this but require a fee to view. However, many users of this site have access to the classic "Hemp Diseases and Pests" by J.M. McPartland, et al. The following selected quotes are from page 165:

"Cannabis absorbs many heavy metals from the soil, without ill effects. These toxins deserve mention for their effects on us. Ingesting plants laced with lead (a contaminant found in chemical fertilizers) causes anaemia and brain damage. Ingesting mercury, another cumulative toxin, also causes neurological deficits. Mercury is released from combustibles such as coal and volcanoes. Siegel et al. (1988) measured 440 ng mercury per gram of marijuana grown on Hawaii's volcanic soil. They noted that mercury is absorbed ten times more efficiently by the lungs than by the gut, and calculated that smoking 100 g of volcanic marijuana per week would lead to mercury poisoning.

Jurkowski et al. (1990) found high levels of lithium in hemp (1.04 mg/kg), higher than any other crop plant tested.

Hemp's ability to hyper-accumulate metals may prove useful for decontaminating toxic waste sites. In Silesia, Cannabis is deliberately cultivated on wasteland contaminated with cadmium and copper. The crop efficiently extracts the toxic metals from the soil and accumulates the metals in the seeds."

The following link discusses accumulation of heavy metals in cannabis leaves versus seeds:

http://www.pjbs.org/pjnonline/fin356.pdf

Not to pick this apart too much, but

"The presence of lead in cannabis sativa may be attributed to oil wells locations around the cultivated area. "

This study doesn't exactly sound well thought out, and its 20 years old to boot.

"These high levels of chromium may have adverse effects on smokers of cannabis. These high levels of chromium can also be attributed to the humus nature of soil around the cultivated area"

Here we have another direct statement in the pdf you linked which references other causes for high levels of metals.

"It is clear, from this study, that the implications of addictive habits of smoking and chewing the leaf or seed of cannabis sativa. The effect on the human brain is made manifest in the heavy content of this plant especially those cultivated in southern Nigeria. Indulgence in the use and abuses of this substance can endanger the individual involved. It has caused many students their studies and life’s"

Really? This sounds like propaganda. Lol.

Anyways, my point is, you're referencing a 20 year old study comparing metal content in a leaf to metal content in a seed, that in itself references other causes for the heavy metals. It doesn't refer to or argue that specific nutrients heavy in metals should not be used, or that they infact increase heavy metal uptake.

The conclusion(per your own pdf):
The results obtained in this study revealed that As, Cd., Cr, Fe, Ni, Ph and Hg levels in cannabis leaf exceeded those of the cannabis seed.

How does this really tell us anything? This only means that the leaves contained more metals than the seeds. It doesn't specifically reference heavy metal nutrients, anywhere.

What did I miss? I like this topic. While the PDF is educational, it doesn't offer any facts or data that would suggest using nutrients that contain heavy metals would increase the plants heavy metal contents in leaves.

Puff

 

[Sam the Caveman]

How does this really tell us anything? This only means that the leaves contained more metals than the seeds. It doesn't specifically reference heavy metal nutrients, anywhere.

If the heavy metals are never made available to the plants, they (the heavy metals) won't be present in the leaves (and bud) or seeds. So by using nutrients that have undetectable levels of heavy metals, the plants grown with those nutrients are unable to contain heavy metals.

I thought this whole discussion was about cannabis' especially high affinity for heavy metals, and about how cannabis grown using nutrients with undetectable levels of heavy metals is healthier to smoke than cannabis grown with nutrients containing heavy metals.

 

[Purple Monster]

If the heavy metals are never made available to the plants, they (the heavy metals) won't be present in the leaves (and bud) or seeds. So by using nutrients that have undetectable levels of heavy metals, the plants grown with those nutrients are unable to contain heavy metals.

I thought this whole discussion was about cannabis' especially high affinity for heavy metals, and about how cannabis grown using nutrients with undetectable levels of heavy metals is healthier to smoke than cannabis grown with nutrients containing heavy metals.

Right, I understand that.

Yeah this discussion has sort of twisted all sorts of ways, but the bottom line is I think everyones interested in the effects on heavy metals on cannabis plants. But where are the figures? What amounts, types, and concentrations of these heavy metals can/will make it to the final product? If at all?

Tons of speculation, thats the problem. I would love to find some more documentation.

Puff

 

[B.C.]

Try a search for phyto-extractors. BC

 

[Sam the Caveman]

While an exhaustive study on the health effects of smoking cannabis containing heavy metals would answer our concerns perfectly, nobody had done that yet. So the references to other studies may provide some background info for us to speculate how the results of an exact study would turn out. So at this point, its all pure speculation.

There are so many other factors that come into play that an appropriate study would need to address several different smoking methods (bong, joint, vaporizer, glass pipe, metal pipe, apples containing heavy metals-j/k) as well as heavy metal affinity of a diverse cross section of cannabis genetics.

 

[Sam the Caveman]

Hey I found a test kit that can test for heavy metals here

http://www.heavymetalstest.com/

its the last product on the page

I sense a side by side comparison grow, then we can at least test heavy metal affinity using different nutrients.

 

[BerndV]

If the heavy metals are never made available to the plants, they (the heavy metals) won't be present in the leaves (and bud) or seeds. So by using nutrients that have undetectable levels of heavy metals, the plants grown with those nutrients are unable to contain heavy metals.

I thought this whole discussion was about cannabis' especially high affinity for heavy metals, and about how cannabis grown using nutrients with undetectable levels of heavy metals is healthier to smoke than cannabis grown with nutrients containing heavy metals.

Well stated. The essence of my thoughts in this thread are that cannabis is a known hyper-accumulator of heavy metals, that the usual method of ingesting cannabis is via the lungs, and that this method provides an efficient means of transporting heavy metals into the body. In order to avoid this unfortunate potential, it is optimum to grow marijuana in a medium/nutrient environment free of detectable levels of heavy metals, thereby ensuring that the end product is as healthy to consume as possible. For some people, this may be of no concern whatsoever. However, given the choice, my guess is that most consumers of marijuana would prefer that it is free of heavy metals, all other things being equal.

 

[spurr]

Hey BrendV,

Sorry for not responding sooner, I have been basically offline for a couple of weeks and very busy lately.

I haven't read the whole thread yet, I will tomorrow, but I wanted to upload a few cannabis heavy metal papers now. I hope you find these useful, they probably do not tell you anything you do already know, but it's always nice to read studies with quantified data. I have good info about heavy meatals and plants/flowers I can post soon.


attached studies:

"Cannabis sativa L. growing on heavy metal contaminated soil: growth, cadmium uptake and photosynthesis"
P. LINGER, A. OSTWALD and J. HAENSLER
BIOLOGIA PLANTARUM 49 (4): 567-576, 2005
(re: cadmium)


"Monitoring of heavy metals and selected micronutrients in hempseeds from North-western Turkey"
Kursat Korkmaz, S. Metin Kara, Faruk Ozkutlu and Volkan Gul
African Journal of Agricultural Research Vol. 5(6), pp. 463-467, 18 March, 2010
(human toxicity issues are discussed from eating hemp seed, etc., I thought that might offer some insights you seem to be asking about)

 

[TrueGangsta148]

i followed the links on the first post and then through a few links and a search, i found the data for ionic, sorry i closed the page before saving the link. it has pretty low #'s for all of them, not 0, but lower than at least some of the others i looked at i dont remember all of them. i do remember that the HG seemed super watered down compared to the amount of heavy metals.

 

[mershman]

If I understand this formula right, it says to multiply 6.0 to the amount on the chart. Arsenic: 6.0 x 13 = 78 ppm allowable concentration of each metal.

http://www.aapfco.org/aapfcorules.html#InterpSUIP25

 

[spurr]

One more, it's recent (three years ago) and worth reading:

"Effect of soil contamination on some heavy metals content of Cannabis sativa"
M.A. Khan, A. Wajid, S. Noor, F.K. Khattak, S. Akhter and I.U. Rahman
J. Chem. Soc. Pak., vol. 30, no. 6 (2008)

 

[ScrubNinja]

Sorry for the length, but I found this interesting

Chemical makeup of the human body

Elements needed for Life

The human body is a combination of elements and compounds. The average adult (a 70 kilogram adult) is composed of:

Element %
Oxygen 65
Carbon 18
Hydrogen 10
Nitrogen 3
Calcium 1.5
Phosphorus 1
Sulfur 0.25
Potassium 0.2
Chlorine 0.15
Sodium 0.15
Magnesium 0.05
Iron 0.006
Fluorine 0.0037
Zinc 0.0032
Silicon 0.002
Zirconium 0.0006
Rubidium 0.00046
Strontium 0.00046
Bromine 0.00029
Lead 0.00017
Niobium 0.00016
Copper 0.0001
Aluminum 0.000087
Cadmium 0.000072
Boron 0.000069
Barium 0.000031
Arsenic 0.000026
Vanadium 0.000026
Tin 0.000024
Mercury 0.000019
Selenium 0.000019
Manganese 0.000017
Iodine 0.000016
Gold 0.000014
Nickel 0.000014
Molybdenum 0.000013
Titanium 0.000013
Tellurium 0.000012
Antimony 0.000011
Lithium 0.0000031
Chromium 0.0000024
Cesium 0.0000021
Cobalt 0.0000021
Silver 0.000001
Uranium 0.00000013
Beryllium 0.000000005
Radium 0.00000000000000001

Also, from the WSDA site

The "Total Metals in Product" is the concentration of each listed metal found using the analysis required by WSDA. The Washington standard for metals is based on the concentration of metals in the product and the application rate of the product. To accurately compare products, you need to consider the use rate on the product label.

So if the maxibloom label says 1 to 2 teaspoons per gallon, what rate did they use for the test to obtain the results they give?

Cheers.