Nevertheless, the new estimate is significant because it marks the first time the department has made such information public.
"We have no clue how much of this stuff is circulating around the globe because it's largely under the table; it's off the books. Now we have some more data, but quantities and destinations are still a gray area at best," said University of California San Diego sociologist David N. Pellow, co-editor of "Challenging the Chip" (Temple University, $25.95), a book about environmental justice in the electronics industry.
Each year, an estimated 100 million computers, monitors and televisions become obsolete in the United States, making e-waste the fastest-growing portion of the nation's garbage.
These products typically are loaded with toxic metals such as barium, cadmium and mercury. For example, a computer monitor can contain 4 pounds of lead, which can cause birth defects and mental retardation.
Malaysia was the clear favorite of e-waste exporters, accounting for nearly 40% of reported shipments from California. Brazil, China, Vietnam and India also were on the department's list of top e-waste destinations.
But all of those nations are prohibited from importing e-waste from the United States because they have ratified the Basel Convention, a 1992 agreement to control the international movement and disposal of hazardous waste. The pact bans member countries from accepting such material from nonmembers, including the United States.
Mexico and South Korea, two other nations on California's ranking of e-waste destinations, are Basel participants but have made separate agreements with the United States to allow for the shipments.
"People that I have talked to have simply said that it's the law of the jungle. The U.S. appears to be able to do whatever it wants to do," Pellow said.
It's up to other countries to police their own imports, and some of them have different definitions of hazardous waste, said Roxanne Smith, a spokeswoman for the U.S. Environmental Protection Agency.
EPA officials don't calculate the national quantity of e-waste exports or track where those shipments go. As long as U.S. companies say the junked items will be fixed or reused, the goods are not tracked as hazardous products.
"Exporting material for reuse or refurbishment is a business or economic issue, not an environmental one," Smith said.
However, countries such as China "don't have anywhere near the resources to enforce" their import restrictions, said Ted Smith, senior strategist at the Silicon Valley Toxics Coalition, an environmental group in San Jose, Calif.
Like many environmentalists, Smith is perturbed that EPA officials don't take a more proactive approach to e-waste. "It's just see no evil, hear no evil, pretend it doesn't exist," he said of the agency's culture.
Electronic castoffs have been a blessing and a curse for developing nations.
Sometimes, broken computers and other devices from the United States are refurbished for use by people who can't afford to buy new machines. Also, several global manufacturing companies have overseas plants that safely turn e-waste - such as glass from TV screens - into other products.
"There are facilities in all these countries ... that handle things in state-of-the-art and responsible ways, but there's plenty of opportunity for port hopping, dumping and disposal in irresponsible ways," said Elizabeth Grossman, author of "High Tech Trash" (Island, $25.95), a book about the effects of digital devices on human health.
Environmentalists and advocates for the poor note that many nations receiving e-waste shipments lack the United States' child-labor laws and pollution regulations. Their groups have documented cases of foreign workers, including children and pregnant women, taking apart computers, televisions and other electronics while fully exposed to toxins in those machines.
In addition, "e-scrap in developing countries is (often) incinerated, not only wasting needed resources but adding toxic chemicals to the environment," said a recent statement by a global, public-private partnership called Solving the E-Waste Problem.
E-waste processors in the United States typically say they're doing everything possible to ensure that their shipments are handled properly abroad.
At E-World Recyclers in Vista, Calif., President Cindy Erie said the company's chief executive has made several trips to Asia to verify that business partners there are environmentally responsible.
E-World currently has only domestic shipments, Erie said. She added that her company separates lead-free, or "clean," glass from computer monitors so it can be exported as a commodity and thus is not subject to the same restrictions as hazardous materials.
"As the general public becomes more aware of e-waste, it's going to ask what is happening to it," Erie said. "Hopefully, it ends up as a raw commodity, not a trash item."
In California, regulators have long recognized the need for better oversight of e-waste and taken some steps to address the issue. For instance, the state's toxics control agency asks exporters to state where they are shipping e-waste.
But the system has many holes.
For instance, it doesn't fully account for e-waste that is broken down into parts before shipping. It also doesn't track e-waste that is sent to another state and then shipped abroad.
Officials at the toxics agency said they're powerless to control interstate and global trade, which are under the federal government's jurisdiction.
That hasn't stopped opponents of e-waste dumping from criticizing state as well as federal regulators. They want government officials to beef up their export tracking system and close loopholes for overseas shipments of e-waste.
"It's much easier to control exports than to control imports," said Sarah Westervelt, a toxics analyst for the Seattle-based Basel Action Network.
The network obtained several of California's export notifications from 2005 and 2006 through the Public Records Act. Some of the forms included detailed information about the overseas companies that would receive the scrap and listed their recycling standards.
But other notices troubled Westervelt.
For example, Blue Star Electronics Inc. in Fremont, Calif., provided little more than the street address of a destination in India along with a note that said it would send two large shipping containers of monitors and computers there each month for "resale purposes."
Based on such scant reporting, Westervelt said, it wasn't possible to know whether the company was shipping products that could be refurbished or foisting hazardous goods on recyclers in India.
Early this year, California put its e-waste reporting system online. The change makes it easier for companies to comply with rules for export notices, and state officials say the added convenience will encourage better reporting.
As a result, regulators said, they can more quickly spot potential problems and contact regulators in popular foreign destinations for e-waste.
"We are seeing more issues and nuances that may ultimately need more attention," said Rick Brausch, a deputy director for the toxics control agency. "Gathering the information gets us one step closer to knowing where (e-waste) is going."
