UBC Reports | Vol. 50 | No. 10 | Nov. 4, 2004

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 tissue.

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 phase.

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,” Danon-Schaffer explains.

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 distances.”

Her goal is to model what happens to PBDEs once they hit the landfill.

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 phased out.

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 health.”

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.