Valerie J. Brown, Environmental Health Perspectives, Volume 112, Number 13

 Click here to download a PDF of this article.

Ironically, some of our most advanced technologies, when
discarded, may represent a rapidly expanding and sometimes unregulated exposure
to a toxicant that plagued even the ancient Romans: lead. Almost all electronic
devices contain lead, and such devices are proliferating-and becoming
obsolete-at breathtaking speed. A University
of Florida environmental
engineer is researching the potential environmental fate of the lead found in
electronics sent to landfills. In a report sponsored by the U.S. Environmental
Protection Agency (EPA) and issued 15 July 2004, Timothy G. Townsend described
his study of 12 different types of electronic items and his finding that the
items leached lead at concentrations exceeding the EPA threshold for categorizing
a waste as hazardous.

Townsend's goal is to help landfill regulators and managers
decide how to allocate scarce resources. He explains, "Maybe they have to
choose what type of waste to recycle- tires or electronics?" By discovering
whether electronics leach toxic chemicals, he says, "we might help a community
decide." He focused on testing for lead because it happens to extract well
under the test procedure he used-which is modeled on landfill conditions-and
thus may be likely to leach from a landfill.

Townsend's report, RCRA
Toxicity Characterization
of Computer CPUs and Other
Discarded Electronic Devices, expanded
on his earlier research on cathode ray tubes (CRTs) used in computer monitors
and televisions. CRTs contain an average of about four pounds of lead. There
are smaller quantities in the solder used in other electronic devices.

Townsend performed an EPA test known as the toxicity characteristic
leaching procedure (TCLP) on a variety of electronic items including computer
CPUs (central processing units), televisions, videocassette recorders,
printers, cellular phones, remote controls, computer mice and keyboards, and
smoke alarms. The TCLP test determines the mobility of analytes present in
waste. Following the protocol, the devices were ground up, mixed with an acetic
acid-based simulated leachate fluid, and rotated in a drum container for 18
hours, after which the leachate was tested for metal concentrations. In the
TCLP, lead concentrations above 5 milligrams per liter are considered
hazardous. All the devices Townsend tested leached lead over this threshold
under some conditions.

But is the lead that is actually in landfills a health threat?
"It has never been shown that lead is actually leaching out of landfills," says
Fern Abrams, director of environmental policy at IPC-Association Connecting
Electronics Industries, an industry group based in Northbrook, Illinois.
And although lead is known to be present in landfills, some of it may come from
other constituents. "Electronics in general are one percent of the waste that
goes into a landfill," says Jan Whitworth, a policy analyst with the Oregon
Department of Environmental Quality. So if lead were to be found in leachate,
it would be very hard to say for sure whether it had come from electronics.

Even so, the European Union has banned lead solder in
certain electronic devices beginning in 2006, due to landfill concerns. California already bans
disposal of CRTs and televisions in household waste landfills. Oladele
Ogunseitan, an associate professor of social ecology at the University of California,
Irvine, who is
evaluating the phaseout of lead solder, thinks it makes sense to allow manufacturers
to use hazardous materials when alternatives are not available, but to require
recycling. Today, many computer manufacturers will recycle discarded computers,
but often will charge a fee.

Others believe hazardous substances must be removed from products
altogether. Mamta Khanna, pollution prevention program manager at the nonprofit
activist Center for Environmental Health in Oakland, California,
would like electronics manufacturers to take cradle- to-grave responsibility
for their products. "Once they have to bear the burden of disposal, they will
use less hazardous materials," says Khanna. "Why wait for years of study to
determine when these toxic materials will start leaching and poisoning us, when
electronics makers can start using safer materials today?" Khanna also points
out that electronics waste is associated with other potentially toxic
chemicals, including mercury, chromium, and brominated flame retardants.

To simulate landfill
conditions more accurately than can be done in a lab with the TCLP, Townsend is
now conducting an experiment in which he has buried garbage and electronics
waste. Simulated rainfall is added periodically, with leachate forming as the
water percolates through the waste. Results will be available in about two
years. Next year the EPA expects to issue a rule limiting how CRTs can be
disposed of nationwide, according to agency environmental protection specialist
Marilyn Goode.