[Terrapreta] char & vascular systems

[Philip Small]

On Sun, Jun 8, 2008 at 7:39 PM, Lloyd Helferty <lhelferty at sympatico.ca>
wrote:
>
>
> I've looked up Health Canada's guidelines for Canadian Drinking Water
> Quality, and they have established levels of Arsenic at 0.010 milligrams per
> litre (kg), based on lifetime exposure to arsenic from drinking water, which
> is 1000X more stringent than the Dynamotive char, so I'm not certain that
> the water flowing through this biochar would be drinkable nor whether any
> veggies that might grow in the medium could be certified organic.
>
We should all be concerned about arsenic in
soil<http://www.aehs.com/conferences/international/glance/tuesday/arsenic.htm>because
it is a carcinogen even at the natural background levels at which
arsenic occurs. The regulatory cleanup standard for arsenic contaminated
soil can calculate to between 0.1 and 0.5 ppm (varies with the regional
calculation).  Yet it is very likely that everyone reading this lives in an
area with natural soil arsenic levels above this standard. That doesn't mean
that the veggies grown in your garden soil can't meet organic standards.
That doesn't mean the groundwater percolating through your garden soil will
fail Canada's arsenic standard for drinking water.

I consider natural soil arsenic to be the most impossibly problematic
"contaminant" that environmental regulators are required to make sense of.
The Dynamotive charcoal arsenic levels look natural to me.  I respectfully
suggest we cut Dynamotive char some slack on the arsenic.
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