[APD] RE: Ironite

[Laura Burbage <leuhrich at yahoo_com>]

OK; I know it's off topic but...

I too, am VERY skeptical of this sort of thing.  So,
as I was interested, I looked further than the ironite
lawsuit press release.  By looking at the Washington
State fertilizer ingredient webpage (given on the
press release) I found that Ironite contains 4380 ppm
arsenic.  So, I did some quick and dirty math.  Let's
assume that I broadcase Ironite in my garden at the
recommended rate (5 lbs per 1000 square feet), and
that it is mixed into the top 3 inches of soil (let's
assume I am mainly using it as a top dressing and not
mixing deeper than 3").  Therfore, I would be
increasing this soils arsenic concentration by 0.94
ppm.  Let's assume I do this every spring for 21 years
(not unheard of).  I have then increased the arsenic
concentration in my soil by 19.87 ppm.  Note that the
EPA Superfund cleanup level for arsenic is 20 ppm.  In
addition, soils contain background arsenic levels to
beging with, so my real time to reach this
concentration would be shorter than 20 years.

Ironite's website claims that vegetables grown on soil
treated with Ironite do not contain increased levels
of arsenic due to the type of arsenic in Ironite. 
However, from a health standpoint, that's not the
issue.  Most plants do not take up inorganic arsenic. 
The problem arises from direct contact with arsenic in
the soil, ingestion of the soil particles (e.g. on
veggies), and inhalation of the soil dust.  Children
are especially at risk; it is estimated that children
ingest about 200 mg/day of soil (100 mg/day for
adults)

So, learning this, I'm uncomfortable with the
following potential scenario:  I buy a house from an
80-year old retiree, who has gardened in the same spot
for 30 years.  I remove the garden and plant grass. 
Should I let my child play there?

Risk assessors have formulas to calculate risk based
on the amount of arsenic in the soil and the age of
the person there, as well as how often they are there
and other factors.  I don't know how to do this, but I
would not knowingly bring my child to a playground
with 20 ppm arsenic in the soil.  Never mind having it
in my back yard.

-Laura




	
		
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