Seattle-based Basel Action Network documented scenes of e-waste dumping and burning in Lagos, Nigeria, in its report, ``The Digital Dump: Exporting Re-Use and Abuse to Africa.'' The group said as many as 500 shipping containers filled with discarded computers enter the port of Lagos primarily from North America and Europe every month. Most of this material is not reusable and gets dumped or burned, posing environmental and human health hazards, the report said.

Lagos' e-waste dumping is ``representative of developments rapidly taking place in other port cities of Africa,'' according to the group's investigation.

``We've talked to the recycling exporters who say the computers are repairable and that technology will help lift Africans out of poverty,'' said Jim Puckett, executive director of Basel Action Network or BAN. ``But the material isn't tested, and there's no infrastructure to do the repair. So as much of 75 percent of it is dumped and burned.''

``If good intentions turn into an e-waste dump, it's a crime, not charity,'' Puckett said.

Puckett's BAN, working with Greenpeace China, investigated hazardous practices of e-waste recycling in southern China and released the 2002 report ``Exporting Harm.'' That report criticized the U.S. government for not adopting the Basel Convention -- a treaty that controls traffic in hazardous waste. Public concern raised by media coverage of that report helped groundbreaking e-waste legislation gain passage in the California Legislature in 2004.

Dumping and burning e-waste can release a host of toxic substances into the environment, including lead, cadmium, mercury and brominated flame retardant, activists and scientists agree.

``This new report about dumping in Africa is important for Silicon Valley because we're the birthplace of the computer and we have a responsibility to prevent the harm that's going on here,'' said Ted Smith, chairman of the Computer Take-Back Campaign. The group advocates producer responsibility for the hazards posed by computers at the end of their useful life.

The report, which is available at www.ban.org, cited ``asset tags'' that identified owners and brand names of products found in the Lagos dump sites. The report said many of the asset tags can be traced back to U.S. government and educational organizations in the United States.

One asset tag identified the San Mateo Union High School District, the report says. A spokesman for the school district did not return a call for comment.