North American Fruit Explorers mailing list at ibiblio

[Ginda Kaplan Fisher <list@ginda.us>]

On Oct 25, 2006, at 10:59 AM, Jim Fruth wrote:
. . .
    As for spreading sludge, that is a definite no - no.  Don't do 
it!(!)
> Whether municipal or industrial, sludge has a concentrated amount of 
> heavy
> metals.  Many (most?) plants absorb heavy metals and you could get an 
> unsafe
> amount in your diet, not unlike the many warnings to not eat fish 
> because of
> mercury build-up within the bodies of the fish.  >The solution to 
> pollution
> is dilution<  Around here, sludge, and septic tank waste, is spread on
> agricultural lands, hay fields mostly.  The cows eat the hay and we 
> eat the
> cows; European farmers have been doing this for 'eons' with no 
> (apparent)
> ill effect.
> . . .

I read some figures on lead uptake in plants several years ago, when I 
was shopping for a house and testing soil for lead.  Plants take up 
lead, but disperse it differentially though their tissues.  As a rule 
of thumb, dark green leafy vegetables have the most lead, and fruit has 
the least lead.  (My guess is it moves like calcium.)  There's some 
kind of kale or something that's grown on purpose in lead-heavy soil to 
clean up the soil.  (The crop is disposed of as hazardous waste.)  Root 
veggies vary a lot, but can also have high lead loads, maybe just 
because they are so close to the source?

Ginda