For those interested in knowing more about lead and the health risks
associated with it, the following is material I recently came upon.
The more I research the subject, the more it seems there was a lack of
diligence on the part of the EU parliament in its certainly well-meaning but
ultimately careless decision to ban lead from electronic solders. By doing so, (based
on recent and continuing discussions in these forums), it appears that they
are poised to cause a risk, to the European and World consumer population, much
more uncertain than the risk of continued use of traditional electronic
solders.
While this is a personal opinion, each of us needs to reach our own
conclusions based on the data we find and believe and the advice of the many technical
experts who kindly grace these forums.
Kind regards to all,
Joe
Reference:
K. Sexton, L. Needham, J. L. Pirkle "Human Biomonitoring of Environmental
Chemicals" American Scientist, Jan-Feb 2004 pp 38-45
The following table was extracted from a graph in the article. There may be
small errors in interpreting the exact values thus approximations are provided.
It shows the dramatic reduction in lead in blood with the removal of lead
from gasoline in the US. The authors state that, at present, blood lead levels
are less than 2µg/dL in the US. It is worth noting that lead in gasoline has not
been completely eliminated in the US but is still allowed for aviation
gasoline, farm and marine equipment (ironically for safety reasons) and racing fuel
for cars (for financial reasons ;-).
Lead in Gasoline (thousand of tons) Mean blood levels of
Pb (µg/dL )
1976 ~101
~16
1977 ~ 88
~14
1978 ~ 87
~13.5
1979 ~ 60
~12
1980 ~ 42
~9.5
(The following data point is not from the original graph but was constructed
from data from the article and the reference cited below.)
2003 ~ 7*
< 2
* this is an estimate extracted from - Decision Document on Lead under the
Process for Identifying Candidate Substances for Regional Action under the Sound
Management of Chemicals Initiative- PUBLIC CONSULTATION DRAFT
Prepared by the Substance Selection Task Force for the North American Sound
Management of Chemicals Working Group of the Commission for Environmental
Cooperation
June 2003
Blood levels of Pb (µg/dL) defined as toxic over time
1965 60
1970 40
1975 30
1980 30
1985 25
1990 25
1995 10
Following quotes from the article "Human Biomonitoring of Environmental
Chemicals"
================================================================
"... the CDC began measuring blood lead levels in the US population,
ironically enough, after the Food and Drug Administration voiced concerns about
possible exposures from eating food stored in soldered cans, which turned out to be
a very minor risk compared with leaded gasoline."
================================================================
"It is important to remember that detecting a chemical in a persons' blood or
urine does not by itself mean that the exposure causes disease."
================================================================
"The latest CDC report, in addition to listing current biomarker levels in
the population, also highlights some interesting exposure trends gleaned from
earlier NHANES findings. For example, from 1991-1994, 4.4% of children between
ages 1 to 5 had blood lead greater than or equal to 10µg/dL, the Federal action
level. By the second collection period 1999-2000, only 2.2% of this age group
exceed this threshold. This decrease suggests that efforts to reduce lead
exposure for children had been successful. It also serves as a reminder that some
children living in homes with lead-based paint or lead contaminated dust
remain at unacceptably high risk"
From Lead in the Inner Cities by Howard Mielke
"Lead in paint and gasoline together accounts for most of the lead now in the
human environment. In terms of raw tonnage, the amount of lead in gasoline
over only the 57 years of its use from 1929 to 1986 roughly equals all of the
lead in paints in 94 years of lead-paint production, from 1884 to 1978. The peak
use of lead-based paint came during the 1920s when the U.S. economy was
largely agrarian and rural. Most lead paints still exist as a thin mass on the
walls and structures of older buildings. Deteriorated or sanded and scraped paint
contributes to lead dust accumulation in the soil."
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