Gordon,
        Excellent summary of the fundamental issues re: LF alternatives.
     These conclusions are also supported by a study of ~150 municipal
     landfills circa 1992 by the Lead Industries Association (LIA). That
     analysis did not find any leachate over EPA's Diluent Attenuation
     Factor (DAF) model for groundwater contamination.
        Also, about five years ago, EPA proposed increasing the leachate
     level for a waste to be considered a hazardous waste from 5 mg/l to 12
     mg/l based on EPA's own risk assessment criteria.(never adopted)
        Switching away from lead may very well result in what we're now
     seeing w/EPA's mandate for gasoline to contain the oxygenate MTBE,
     which is contaminating GW & lakes.  Lee Wilmot,HADCO Corp,603/896-2424
______________________________ Reply Separator _________________________________
Subject: [LF] Is removing lead from electronics good for the environm
Author:  "Davy; Gordon" <[log in to unmask]> at smtplink-hadco
Date:    10/15/99 5:18 PM
Although the answer to the subject question appears to be a no-brainer, this
posting is in defense of a "no" answer, admittedly a minority position.
Since I'm coming from behind, I have had to make it rather long, but I hope
that it will be interesting and convincing.

The fundamental reason for the lead-free electronics effort is that an
electronic product containing lead is perceived as hazardous, not to the
user, but to the environment when it is discarded in a landfill. (I have not
seen any assertion that incineration of lead-bearing products is a concern
(i.e., because of fume going up the chimney), presumably because the low
vapor pressure of lead even at incineration temperatures is a
well-established fact. The lead remains with the ashes or slag which in turn
are disposed of in a landfill.) Another reason given for lead-free
electronics is that of market pressure, but this is not a fundamental
reason, as the market pressure derives from the perception of hazard.

However, in order for lead to be a hazard, it has to be not only toxic
(which it surely is), but there also has to be some way for people, or
animals, or plants to be exposed to it. The exposure mechanism is asserted
to come from leaching of the lead (in whatever form, including metallic in
solder and as the oxide in CRT's) by percolating rain water, thereby
contaminating the ground water that is a major source of drinking water.
Landfills all over the world surely contain lead, as people have been
discarding electronic products and car batteries in landfills - in some
countries for roughly 75 years and TV's for 50 years. Lead in paint in
building demolition debris has been going into landfills for even longer.
The first few inches of soil in a large fraction of the world also contains
lead because of its use in gasoline for many decades.

That should be long enough for lead to show up in the ground water if it is
going to at all, so I have been doing some research to try to establish the
extent to which lead is getting into the water supply. Everything that I have
found suggests to me that lead is not getting into the water supply, and that
the current concern about lead in landfills that is being expressed by some
is not even on the radar screen of those who are responsible for providing
safe water. It's not that they haven't looked - they are looking but are not
finding, as indicated in the excerpts below. (I include the links for those
who would like to pursue the matter further.) This phenomenological approach
is supported by a chemical approach, which suggests that lead cations will
react with a variety of anions (e.g., sulfate) that are readily available in
the soil to form highly insoluble, and hence immobile, products. This in turn
suggests that efforts to keep lead out of electronics so as to keep lead out
of landfills, so as to keep lead out of drinking water, however noble in
concept, is not supported by scientific evidence.

If this is true, then the result of the tens of millions of dollars that are
being spent removing lead from electronic products and bringing lead-free
electronic products to market will be no saved lives and no reductions in
the incidence of lead poisoning. In fact, the environmental impact of any
alternative to lead in electronics must be weighed quite carefully, because
it is entirely possible that the alternative will harm the environment. The
level of uncertainty will surely be higher, as we don't have so many decades
of experience to consider as we have for lead. How ironic it would be for
our industry to make a massive investment in lead-free electronics
technology only to have some official organization decree some years hence
that we will have to stop using the accepted substitute because of its newly
found (or asserted) environmental impact! Yet who can say that such a thing
is unlikely? It would be difficult indeed for our industry either to find
yet another substitute or to revert, then, to lead after having acquiesced
in abandoning it.

Here is an excerpt from a white paper by the American Water Works
Association (1995) http://www.awwa.org/govtaff/minpupap.htm. :

        The Centers for Disease Control recently reported that between the
late 1970s and the late 1980s, the average blood lead levels of persons in
the United States, aged 1 to 71 years, dropped 78 percent from 12.8 ug/dL to
2.8 ug/dL. The average blood lead level in American children (ages 1 to 5
years) dropped 75 percent from 14.9 to 3.6 ug/dL in the same period.
[Harmful effects of lead in children have been identified by epidemiological
studies at blood lead levels at least as low as 10 micrograms of lead per
decilitre of blood (ug/dL).]  This significant decrease in average blood
lead levels has been attributed to removal of lead from gasoline and
soldered cans.... Drinking water is one of several sources of lead exposure.
Its relative contribution to total lead exposure is usually low,
particularly in water systems where corrosion control has been optimized.
Lead in rivers, streams, and aquifers usually is found at low levels or
occurs at levels below detection. When present in a source water, lead is
typically removed during water treatment.

You can read the original CDC report tttp://www.leadinfo.com/media/booklet.html.
Quoting ..,
        The dramatic decline in BLLs in the U.S. population since the late
1970s is probably a direct consequence of the regulatory and voluntary bans
enacted during this period on the use of lead in gasoline, household paint,
food and drink cans, and plumbing systems. The effects of these changes
benefited all U.S. population groups studied. In addition, BLLs may have been
reduced in some groups as the result of childhood lead poisoning-prevention
efforts undertaken by public health agencies, lead paint-abatement programs,
and the promulgation of a standard for lead exposure in industry.
        Despite the recent and large declines in BLLs, the risk for lead
exposure remains disproportionately high for some groups, including children
who are poor, non-Hispanic black, Mexican American, living in large
metropolitan areas, or living in older housing.
        The risk for lead exposure in children is primarily determined by
environmental conditions of the child's residence. The most common source
for lead exposure for children is lead-based paint that has deteriorated
into paint chips and lead dust. In the United States, approximately 83% of
privately owned housing units and 86% of public housing units built before
1980 contain some lead-based paint. In addition, soil and dust contaminated
with residual lead fallout from vehicle exhaust contribute to exposure;
concentrations of lead in soil and dust are highest in central urban areas.
For adults, the most common high-dose exposure sources are occupational.
Other exposure sources for adults and children can include lead dust brought
into the home on clothing from workplaces, lead used for some hobbies, lead
contained in some "folk" medicines and cosmetics, and lead in plumbing and
in crystal and ceramic containers that leaches into water or food.
Some people do have too much lead in their blood. The number is much smaller
today than 20 years ago, and is likely to continue to drop. Note that there
is absolutely no mention of lead from drinking water (other than via lead in
the plumbing). These excerpts suggest to me that lead in landfills is not
getting into the drinking water and that to the extent that people are
getting lead poisoning, they are getting it in ways that have nothing to do
with lead in electronics.
Here is a quote from EPA Office of Pollution Prevention and Toxics,
http://www.epa.gov/lead/:
        Current studies suggest that the primary sources of lead exposure
for most children are deteriorating lead-based paint, lead contaminated
dust, and lead contaminated residential soil.
Here is a quote from EPA Office of Ground Water and Drinking Water,
http://www.epa.gov/OGWDW/standard/lead&cop.html:
        What are the sources of lead in drinking water?
        Lead in drinking water results primarily from corrosion of materials
containing lead installed in building plumbing such as lead solder, brass,
bronze and other alloys containing lead in contact with the water. The
amount of lead attributable to corrosion by-products in the water depends on
a number of factors, including the amount and age of lead bearing materials
susceptible to corrosion, the way they were manufactured, how long the water
is in contact with the lead-containing surfaces, and how corrosive the water
is towards these materials. The corrosivity of water is influenced by a
number of factors, including acidity, alkalinity, dissolved solids and
hardness. In general, soft acidic waters are more corrosive to lead than
hard waters.

The AWWA, the CDC, and the EPA seem to agree that lead from discarded
products in landfills is not a source of lead in drinking water. Given its
low level today and the number of car batteries and lead pipes landfills
contain (one battery equals how many cell phones?), it seems unlikely that
even a greatly increased rate of disposal of electronics would produce a
noticeable increase in the lead level of ground waters.

Incidentally, soil contains some lead that is not of human origin
(non-anthropogenic). In a paper published in Science in 1985 and quoted by
Graedel and Allenby (p.46, see reference below), a plot of lead
concentration as a function of depth in sediments near the mouth of the
Mississippi River is given. The depth of 50 cm is ascribed to the year 1850.
The plot shows a concentration in 1850 of about 30 ppm, of which 5 - 8 ppm
is identified as "pollutant lead." The lead level increases with decreasing
depth up to about 15 cm, which is ascribed to be 1970. At that depth, the
pollutant lead level is a little over 20 ppm. The latest lead level is for
1982, just 12 years later, for which pollutant lead is just about 12 ppm -
not much higher than 130 years earlier and roughly one-half the naturally
occurring level. The fact that these lead levels can be traced at all by
taking a core sample indicates the immobility of lead even in a very wet
environment, as does the elevated levels of lead in the first few
centimeters of soil years after a virtual elimination of the arrival of lead
from burning of leaded gasoline.

As for the question of the environmental impact of alternatives, we have the
paper by Ed Smith and Kristine Swanger, which was given this Spring at the
Expo, and also published in the July 1999 SMT (pp. 76-79). They studied
seven lead-free solder alloys for toxicity and their environmental effects.
They state:

        Silver and silver compounds can cause biological effects such as
digestive tract irritation and agryria. Ecotoxicity, reproductive effects
and mutagenicity have been observed in laboratory studies; however,
toxicological data has not been fully investigated.
        Antimony and antimony compounds can cause biological effects such as
severe digestive tract irritation with abdominal pain, nausea, vomiting and
diarrhea. Toxicological data has not been fully investigated.
        Copper and copper compounds can cause biological effects such as
severe digestive tract irritation with abdominal pain, nausea, vomiting and
diarrhea. Ecotoxicity has been observed in laboratory studies, but
toxicological data has not been fully investigated.
        Indium and indium compounds have shown developmental toxicity in
rats and mice. Particular symptoms of this developmental toxicity include
fetal mortality, fetal malformation, reduced fetal weight, and malformations
in the tail, ribs, digits and kidneys. Ecotoxicity and mutagenicity have
been observed in laboratory studies; more toxicological studies are needed.
        Bismuth and bismuth compounds have been suggested to be a carcinogen
or a cocarcinogen in rats. Some studies have shown that bismuth can cause
chromosomal aberrations in rats. More epidemiological studies are required
for a more complete determination.

The authors go on to discuss the facts that silver and silver compounds,
antimony and antimony compounds, and copper and copper compounds, are
regulated under Superfund, SARA 313, RCRA, Clean Water Act, and other
regulations and comment "Lead-free replacement solder alloys may not provide
the electronics manufacturer any less regulatory burden than that imposed by
conventional lead-tin solders." They then present leaching experiments that
they conducted on the solders and conclude:

        These experiments show that most lead-free solders leach at levels
that would cause them to be classified as a hazardous waste, failing both
silver and antimony levels.

The most extensive analysis I am aware of, of the environmental impact of
switching away from solder containing lead to a substitute was done by
Braden Allenby for his Ph.D. thesis (Rutgers) in 1992. (Dr. Allenby's title
now is Vice President, Environment, Health, and Safety for AT&T.) For his
thesis, he developed a qualitative analytical system that he calls the
Design for the Environment Information System, or DFEIS. This DFEIS leads a
person to consider all the various aspects of proposed options in a
systematic fashion. The primary issues are toxicity/exposure (not just
toxicity!), environmental, manufacturing, and social/political. Each of
these issues is then analyzed for any one option in matrix form. For
example, for manufacturing, the row headings are process compatibility,
materials compatibility, component compatibility, performance, energy
consumption, resource consumption, availability, cost, and environment of
use. The column headings are the life stages: initial production, secondary
processing/manufacturing, packaging, transportation, consumer use,
reuse/recycle, and disposal. For each cell in the matrix, the respondent
enters a symbol that indicates two separate aspects of the impact: how
severe the impact is, and what the level of uncertainty is. With some
training (there is plenty of explanation in the thesis) and experience, a
person can learn to read these matrices and pick out the concerns readily.
Equally important is that each cell, in demanding a symbol, requires the
respondent to consider aspects that could otherwise have been totally
overlooked.

Dr. Allenby then applied his DFEIS to four options for joining electronic
circuits: lead solder (the status-quo baseline), a tin-indium solder, a
tin-bismuth solder, and a silver-filled epoxy. This analysis occupies about
half of his thesis - it is quite extensive. Part of his analysis made it
into a book which he co-authored with Dr. Tom Graedel, now a professor at
Yale: Industrial Ecology, Prentice Hall, 1995, ISBN 0-13-125238-0. I quote
now from the thesis (p.150):

        The results of the test case are counterintuitive. Of the four
alternatives evaluated, current lead-based solders are the preferable option,
primarily because of the environmental and social costs of exploiting reserves
of indium and bismuth and, to a lesser extent, silver. When the relatively
minor component of overall lead demand attributable to PWB assembly
applications (less than one percent) is considered, and contrasted with the
significantly expanded mining and processing activities the other option would
entail, lead-based solders are the least environmentally harmful choice. This
is especially true as data on environmental impacts and non-mammalian toxicity
are sparse for both bismuth and indium.

Quoting from the book (p.180):
        Lead poses clear and severe toxicity issues, especially in the
mammalian chronic category. However, the amount of exposure associated with
this particular use of lead is so low that it is not appropriate to rank
that risk as serious.... Thus, a systematic analysis has led to what, for
many people, is a counterintuitive result.

The lead-free solders that are being considered to allow abandoning
lead-containing solders have yet to be given a clean bill of health, or even
a conclusion that they are less of an environmental hazard. Again it must be
emphasized that just because something can cause health problems if it gets
in you - lead or one of the potential substitutes - doesn't mean that it
will cause health problems - it may not have any way to get in you. If you
are not exposed to a toxic material, it won't hurt you. People have looked
for elevated blood lead levels for people who solder for a living, and have
not found it. And of course, the prospect of eliminating copper from
electronics, regardless of any toxicity that may be asserted, is not very
likely. But if that is true for copper, why should things be any different
for lead?

While there are those who don't care where the bandwagon is going as long as
they are on board, I hope that there will be some people who will care.
Since the reason given for abandoning lead in electronics is for the benefit
of the environment, it seems appropriate for someone who believes this to
prepare an environmental impact statement in support of this belief. (Even
if they disagree with Dr. Allenby's conclusion, they can do no better than
to use his analysis as a starting point for their own.) As far as I have
been able to tell, no such statement (other than Dr. Allenby's) has ever
been prepared. The argument that I have presented here is basically that we
have sound scientific grounds for asserting that lead, though toxic, is not
a significant hazard in electronics because there is no exposure mechanism,
and certainly it is not significant enough of a hazard to warrant a switch
to an alternate for which there are significant environmental concerns that
have yet to be addressed. The prospect of removing from the biosphere all
toxic substances, which some are championing, without consideration of the
risk of exposure or of trade-offs is a very serious and far-reaching matter,
and any one step once taken will be politically difficult to reverse. One
doesn't have to be anti-environment to resist some proposals being labeled
as environmentally friendly.
     Gordon Davy Northrop Grumman ESSS 410-993-7399

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