UBC Reports | Vol.
50 | No. 10 | Nov.
Old Computers and Toxic Waste
A UBC chemical engineer hunts for the link between discarded
electronics and toxic chemicals in our bodies
By Michelle Cook
Toxic chemicals used as flame retardants are building up
in the bodies of people and animals worldwide and a UBC chemical
engineer suspects that your old computer monitor, keyboard
and mouse may be to blame.
Monica Danon-Schaffer, a professional engineer working on
her PhD in the department of chemical and biological engineering,
has launched a study to try to find out how these chemicals,
polybrominated diphenyl ethers or PBDEs, are migrating from
discarded consumer electronics -- or e-waste -- into human
First developed in the 1970s, PBDEs are widely used as fire
retardants in an array of plastic and foam products including
consumer electronics such as computers and TVs. They’re
also found in furniture, industrial textiles and other household
products such as TV cabinets and coffee makers.
Several recent studies have shown these harmful organic
pollutants increasing in fish stocks and other wildlife where
they disrupt hormone systems and impair memory. They are also
accumulating in high levels in human breast milk. A Health
Canada survey released earlier this year found that women
in Canada had levels of PBDEs five to 10 times higher than
women in other industrial countries.
“There’s a lot of scientific research about
what’s happening at the end of the pipe -- what’s
accumulating at the top of the food chain and in women’s
breast milk,” says Danon-Schaffer. “What is not
so well understood is how these chemicals are getting into
our waste stream -- solid, water and air -- in the first place.
What I’m trying to do is characterize and source these
flame retardants up-stream.”
PBDEs are close chemical cousins of PCBs. Like PCBs and
the pesticide DDT, substances now banned, PBDEs are slow to
break down and, in a process called bio-magnification, their
strength and resistance increases as they move up the food
chain. What troubles Danon-Schaffer is that they are spreading
globally at a faster rate than older pollutants like PCBs.
Danon-Schaffer thinks the main source of PBDEs may be the
tons of computer parts dumped into landfills every year. Although
computer manufacturers are starting to phase PBDEs out of
newer generations of electronics, older models containing
substantial quantities -- up to 30 per cent of the final product
in some cases -- are now coming to the end-of-useful-life
All the plastic components of these computer products --
monitors, circuit boards, printers, scanners -- amount to
“only a sliver” of products containing the contaminant,
she adds, but that “sliver” adds up to 70,000
tons of computer garbage in Canada annually. In the U.S.,
the figure is even more staggering. An estimated 55 million
computers will be tossed into landfills in 2005.
By analysing how the plastic parts are breaking down in
landfills, Danon-Schaffer hopes to determine how the flame
retardants are being released into the environment as well
as the volume of waste being distributed.
Flame retardants are added to computer parts in one of two
ways -- during the initial production of the plastic or afterwards,
when the finished plastic is being moulded into a product.
Danon-Schaffer suspects the latter method may be causing chemicals
to leach out faster.
For her study, she will monitor and analyse computer parts
packed into cylinders with landfill leachate (treated garbage)
supplied by a Vancouver-area landfill. She hopes to be able
to compare this to samples of landfill from the 1960s and
70s -- decades preceding the boom in home and office electronics.
“PBDEs are so ubiquitous now that they are all over
the place. The challenge is trying to isolate computers when
landfills have lots of waste containing these flame retardants,”
To date, there is no comprehensive information on landfill
leach rates for flame retardants. What scientists do know
is that the pollutants are making their way around the world.
This past summer, Danon-Schaffer travelled to several isolated
communities in the Canadian Arctic to try to find out just
how far PBDEs are being distributed in landfills there.
“These are communities without a lot of e-waste or
landfill, and if we find flame retardants in the water stream
up there, we might be able to interpret that this is long-range
transport,” she explains. “The theory is that
when these compounds move from warmer climates to colder climates,
they volatize, and jump, and then condense, and come down.
So a ‘grasshopper’ effect is moving them long
Her goal is to model what happens to PBDEs once they hit
The “mass balance” model would become a tool
for regions, municipalities and governments to use to measure
the volume of retardants going in and the volume spreading
out. This information could be then used to inform government
policies on e-waste and, she hopes, to effect changes to the
regulations governing the use of these compounds and get them
This year, the European Union banned two PBDE compounds
but, to date, no action has been taken to regulate their use
in Canada or the United States. “I think it is critical
to understand that many environmental contaminants are not
just carcinogenic, but endocrine disruptors, as many brominated
flame retardants are proving to be,” Danon-Schaffer
says. “As such, we need to create mechanisms to find
alternative products that are less harmful to human and animal
Danon-Schaffer is the 2004 recipient of the Claudette MacKay-Lassonde
Graduate Scholarship Award from the Canadian Engineering Memorial
Foundation. The award is given to one Canadian woman annually
for recognition of her efforts to promote engineering as a
career to young women by acting as a role model for the profession,
and for exemplary work in the field of engineering.