Ask A Scientist© General Science Archive

name        Charles J.
status      other
age         40s

Question -  Could you please help me for a question about lead
poisoning? --- If a 9-volt battery is dropped into a well, can the well
water still be used for my garden where we grow vegetables to feed the
family? In other words, does the battery have the lead component, will
the lead be dissolved into the well water, and will it finally get into
the vegetables? Many thanks!

-----------------------

Charles,

You pose a difficult question because the situation is fraught with so many
unknowns.

First, is there any chance that you could fish out the battery with a
powerful magnet dangling from a string? The case and terminals atop a 9 volt
battery are ferrous and would be attracted to the magnet?

I don't think there is much lead in such a battery. Also, the volume of water
in the well would have a bearing on the actual concentration of lead that
could arise should any actually dissolve in the water. Finally, it is more
likely that one would get more lead pollution in a garden from sources other
than the one about which you have concern. Leaded paints and the former use
of leaded gasoline have been a significant source of lead in soils.

If it were me, and I couldn't recover the battery, I would forget about it
and go ahead and use the water anyway. I'm not suggesting there is no basis
for concern. It's just that there are other pollution sources that would
concern me more than the one you posed.

Regards,
ProfHoff
=========================================================
Charles,

You pose a difficult question because the situation is fraught with so many
unknowns.

First, is there any chance that you could fish out the battery with a
powerful magnet dangling from a string? The case and terminals atop a 9 volt
battery are ferrous and would be attracted to the magnet?

I don't think there is much lead in such a battery. Also, the volume of water
in the well would have a bearing on the actual concentration of lead that
could arise should any actually dissolve in the water. Finally, it is more
likely that one would get more lead pollution in a garden from sources other
than the one about which you have concern. Leaded paints and the former use
of leaded gasoline have been a significant source of lead in soils.

If it were me, and I couldn't recover the battery, I would forget about it
and go ahead and use the water anyway. I'm not suggesting there is no basis
for concern. It's just that there are other pollution sources that would
concern me more than the one you posed.

Regards,
ProfHoff
=========================================================
Nine volt batteries are not based on lead chemistry. They are based on
zinc / manganese oxide chemistry. The battery will eventually corrode and
some zinc and manganese will be released, but I would estimate that the
dilution by the well water will lower the concentration to a safe level. For
an excellent demo on alkaline batteries go to: www.duracell.com

Vince Calder
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