Absorption of arsenic by edible plants

Alf Christophersen alf.christophersen at basalmed.uio.no
Tue Apr 4 10:24:34 EST 2000


On Tue, 04 Apr 2000 02:03:03 -0300, Planter <nospam at nospam.com> wrote:


>"A horticulture Extension agent for Texas A&M University has conducted a
>detailed study on the use of treated wood in raised bed gardens. In the
>April 15, 1993 issue of American Nurseryman, he reported that the amount
>of arsenic in soil samples 1 inch and 12 inches away (6 inches deep)
>from the treated wood in gardens between 6 months and 9 years old was
>between 6.2 and 14 ppm, which is considered to be within the normal
>range of 1-20 ppm. According to the Institute for Environmental
>Toxicology, plants growing within 6 inches of treated wood might absorb
>more arsenic than plants growing farther away from the wood."

Sorry to say, these concentrations are within ranges where arsenic is
an essential trace element.

It is possible that it might be essential even in higher
concentrations, depending on how effective the plant is to take up As.

It seems like As deficiency and Se deficiency in diet might give the
same diseases, most of them deadly in the end (CVD, cancers and other
diseases)

It seems like your diet should not have LESS than 0,1 ppm As, most
probably as an unknown organic compound, not As2O3.

Most trace elements are poisons if you get too much of them, but, they
are even better killer when you get too little of them. (Maybe not all
of them, I have never heard someone die from iron deficiency, because
the deficiency symptoms are so clear long time before you get a
disease, but Se-deficiency is very known to be deadly (eg. Keshan
disease in China). As-deficiency is just in the beginning of being
realized is of concern and since the diseases are very alike, it might
be that many described as Se-deficiency in reality has As deficiency.
It might perhaps be known that As and Se follows each other in many
minerals. Often they are together with phosphor. Unrefined raw
phosphate from New Zealand contain lots of Se and As and is since
around 1930 being purified for As, which also removes Se. That was the
start of an deadly epidemy in domestic animals in New Zealand and it
did turn out that the removal of Se from raw phosphate possibly was
the reason. With the research of several researchers, it might be that
the removal of As also might be partially be the reason for the
disease.

Maybe growing vegetables in As-enriched soil might be healthy for you
?? (Unless the concentration get up in acute toxic doses)


Another faulty thing is that you believe that As is a heavy metal.
Look in the periodical table. Do you find As together with Pb, Hg and
Cd ?? Those are the heavy metals that is difficult to get rid of.

As is quickly methylated and is excreted as that via lungs and urine,
in addition, if you increase the intake, your body will start making
enzymes increasing the rate of methylation. 

Since methylation is also needed in other places, like methylating
homocysteine to recover methionine, if your methyl group precursor
intake is bad (folate deficiency, methinone intake deficiency, betaine
deficiency etc.) the increased methylation of As might be giving you
disease because maybe other methylation processes may fail (needed to
protect against HIV replication and replication of other viruses,
needed to protect against mutations, which might end up with cancer)





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