[sdiy] Future SYNTH-DIY

[Bob Weigel]

Re: lead in the ladfills..and a proposal that we form a petition out of 
this if there are REALLY people trying to nix lead solder on the basis 
of this....

.I think I'm looking realistically when I say that

1) landfills are usually a vast array of things; a very small percentage 
of which are solder joints in junk electronics.  Very..very small 
percentage...nearing the 'infinitessimal' classification in terms of 
volume of ground vs. realistically "leachable" lead from the 
contribution of such.  So...right from the get go..this thought just 
seems crazy to me. I mean nature has a way of absorbing stuff in the 
soil LONG before it hits the water table anyway...and then the water 
tables  ** (See below...I threw in a worst case scenario calculation 
example to help put some substance behind these statements.)

2) multiply that by the fact that in 100 years, most of those solder 
joints will STILL be setting there with a Pb02/ Sn0/Sn2o3/H20 coating of 
some kind around them.  I mean..think with me. It's REALLY hard for that 
lead to get out of those joints when most of them are in some kind of 
closed container in the first place.  They are nearly always separated 
from a lot of the erosional aspects of nature save the few boards that 
have been ripped out of things.

3) I've got better things to worry about in a world where vast numbers 
of people hate each other.  We all have to pick our battles.  SO that's 
probably all I should say about that.  If someone is really worried 
about a landfill that is supposed to be somewhat isolated from water 
table that is in use by humans....let 'em worry.  The earth is amazingly 
good about purifying things.  I GUARANTEE that if I had funding and 
could actually perform a study on this, I would find that, statistically 
speaking, not a single ATOM of Pb from the ENTIRE mass of electronics in 
the worst case landfill scenario in the country will be likely to find 
it's way into anyone's used water.   I'd literally bet my life that no 
level classified as harmful can potentially arise from such 'abuses' in 
the worst case landfill scenario.  However I'm full aware that other 
things potentially can contribute to harmful levels of other things. I 
really...really wish that 'environmentalists' would have to provide 
bonafide research papers before anyone listens to them though on things 
like this...and that if they mess with the results that they would go to 
jail :-).   -Bob


**Ok welcome to Bob's 'worst case scenario estimate's inc......let's say 
a landfill from a city of 100,000 has 10 junk pieces of 
electronics/person in there...10^6 pieces...PER "degredation cycle" 
which is the total time for the contribution of the average piece to 
decay to near nothing in terms of leaching.   Ok..so let's start with 
the worst case scenario where if anything gets into the water table at 
all, it's evil.  Typical landfill for a town...100M square? Probably 
bigger but let's say that.  Water table at 100'?  30M say.  3x10^5 cubic 
meters of volume.  Potentially leachable lead in each piece of 
electronics..say they're all big TV's or something.  2,000 solder joints 
or some crazy amount just to be overkeel for an average.  And so we have 
a total solder joint volume of an average 2mm cube lets say.  Ought to 
be plenty for an average.  Say roughly .8-^-8cubic meters per joint. x 
2000=1.6x10^-5 cubic meters total per device X the percentage of each 
joint that is potentially leachable.  This is where the calculations get 
sketchy because some deviced are going to have that electronics crushed 
between stuff that keeps it sealed..hence no leaching...until the 
protection totally decays which might take several hundred or thousands 
of years or when the next volcano pops up there :)  Anyway let's just be 
wild and crazy and say that a tenth of each joint's lead can leach out.  
That's totally unrealistic I'm sure but let's just say. Something around 
10^-6 cubic meter per device time 1,000,000 devices gives us 1 cubic 
meter of lead. OUch..that's a lot of lead!...but...we're talking over a 
very very long period AND...we are only seeing one part in 300,000 or so 
and that's before it even makes it to the water table.  WILL ANY OF IT 
ACTUALLY MAKE IT TO THE WATER TABLE with that kind of slow/weak 
dillution?  No.  Every danged atom of it will wind up trapped in some 
kind of chemical bond with the soil.
Richard Wentk wrote:

> At 23:12 22/05/2005, Rainer Buchty wrote:
>
>> Besides, it's not like the lead in there would slowly creep out and harm
>> people like e.g. polychlorated biphenyls and the likes.
>
>
> I thought the issue was landfill? A lot of electronics end up in 
> landfill, which is a polite way of saying that it's in a hell's 
> kitchen of all kinds of biochemical decay and corrosion. This is far 
> from a chemically inert environment, and the last thing anyone wants 
> is (e.g.) lead salts seeping into the water table.
>
>> Another thing which IIRC will be ruled out are NiCd accumulators.
>
>
> Same reasons.
>
>> That might help the hobbyist, but not the one who wants to do business.
>
>
> I think that's what I meant about the death of Synth DIY. This is a 
> major pain for hobbyists, but it's potentially lethal for small-scale 
> companies like Doepfer and Moog and the rest.
>
> Richard
>
>
>
>