[Terrapreta] char & vascular systems (lead and arsenic)

[Lloyd Helferty]

Thank you very much Mark.  This should come in handy.
  Page 7 contains some guidelines for contamination levels ("residential
soil cleanup standards of ... 20 mg/kg for arsenic.. (and) concentrations
below 37 mg/kg should protect the health of children having frequent
exposure to contaminated soils... 175 mg/kg as safe for adults having
occasional exposure to contaminated soil.").
 
Also: "Concentrations of lead and arsenic in soil may be 10 to 1000 times
greater than their concentrations in plants growing on that soil." "Seeds
and fruits typically have lower lead and arsenic concentrations than do
leaves, stems or roots. Roots and tubers usually have the highest lead and
arsenic concentrations, with the skin having higher lead and arsenic
concentrations than does the inner flesh. The lead content of roots
correlates more closely to soil lead than does lead in leaves or stems,
possibly because roots tend to retain absorbed lead and not transport it
higher up into the plant. Tree fruits such as apples and apricots contain
very low lead and arsenic concentrations."
 
    Lloyd Helferty
    Thornhill
 


  _____  

From: Mark Ludlow [mailto:mark at ludlow.com] 
Sent: June 13, 2008 11:36 PM
To: 'Philip Small'; 'Richard Haard'
Cc: 'Lloyd Helferty'; 'terra pretta group'; biochar-ontario at googlegroups.com
Subject: RE: [Terrapreta] char & vascular systems (lead and arsenic)



Philip,

 

Following your suggestion I found
http://cru.cahe.wsu.edu/CEPublications/eb1884/eb1884.pdf which speaks to the
issue of gardening in lead and arsenic contaminated soils.

 

Thanks!

 

Mark

 

From: e.philip.small at gmail.com [mailto:e.philip.small at gmail.com] On Behalf
Of Philip Small
Sent: Friday, June 13, 2008 4:33 PM
To: Richard Haard
Cc: mark at ludlow.com; Lloyd Helferty; terra pretta group;
biochar-ontario at googlegroups.com
Subject: Re: [Terrapreta] char & vascular systems

 

 

On Fri, Jun 13, 2008 at 2:40 AM, Richard Haard <richrd at nas.com> wrote:

 

 There must be a body of research on uptake.....

I am at my daughter's college graduation (go Gooey Ducks!) so short
response: WSU has extensive studies on arsenic and plant uptake, Soil sci
Frank Peryea at WSU in wenatchee wa is the primary source.  I will google
when  get a chance... -philip

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