Thanks. The first time I saw this sheet at
www.nema.org I
thought that NEMA had produced it. Now I see it was
prepared by the EPA.
I do have a few concerns about the data presented.
1) The sheet states that an incandescent lamp will be
responsible for 10 mg of mercury emissions from coal-fired
power plants over a 10-year period, yet does not give the
power rating of the lamp or the number of hours burned per
year. I would prefer to see data that said "a 100-watt
incandescent lamp operating for 10,000 hours will cause X mg
of mercury to be released by coal-fired power plants."
2) The value of 10mg is far lower than I calculate for
typical incandescent lamps using published data on mercury
contamination of coal. Based on my calculations, 100-watt
incandescent lamps would create 40 mg of mercury emissions
from coal-fired power plants over a 10,000 hour period and,
since the emissions change linearly with lamp power, a
60-watt lamp would be responsible for 24 mg of mercury
emissions. So, where did the 10 mg value come from? I
don't think that EPA used a 25-watt lamp as typical.
However, their number is close to the average amount of
mercury emitted per kWh for power plants in the US using all
types of fuel - including those that don't emit any mercury
at all - when operating a 75-watt or 100-watt lamp for
10,000 hours. Yet their graph states "coal power plants."
Strange.
I prefer to use the value for coal-fired plants and then
state that not all electricity is produced by burning coal.
However, I do believe that when less electricity is needed
because more energy-efficient light sources are used, that
means we can hope the reduction in generating capacity will
occur first at those plants that produce the most pollution.
3) The mercury clean-up instructions given in this sheet are
at odds with the instructions given on the EPA web site, at
least for carpeted surfaces. I'm going to have to check
with EPA so I can understand this difference.
BTW - I'm also discussing mercury clean up recommendations
with a toxicologist who has published papers on mercury
contamination. and have found a number of low cost mercury
clean up kits for thermometer-size mercury spills, which
should work just as well with the much smaller amount of
mercury in a CFL.
However, the problem of what to recommend if a CFL breaks on
a carpet is unresolved. The EPA web site says that the
section of carpet must be cut out and disposed of, though
the EPA fact sheet you have referenced does not include this
warning. I'll try to find someone at the EPA who can
discuss this issue.
--
Vic Roberts
http://www.RobertsResearchInc.com
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