Consumers saddled with old cell phones, TVs and computers are flocking to electronics recycling events, which have sprung up in more than 1,000 communities over the past four years.

But don't be fooled, activists warn. Items collected at free events are sometimes destined for salvage yards in developing nations, where toxins spill into the water, the air and the lungs of laborers paid a few dollars per day to extract materials.

"If nobody is paying (the collectors) to take this stuff, especially if they're getting a lot of televisions, then they are very likely exporting because that's how they make the economics work," says Barbara Kyle, national coordinator of the Electronics TakeBack Coalition, a San Francisco-based advocacy group.

"E-waste," or electronics trash, is piling up faster than ever, according to the Environmental Protection Agency. Americans discarded 47 million computers in 2005, up from 20 million in 1998. Factor in other forms of electronics, and the nation now dumps between 300 million and 400 million electronic items per year, according to estimates from the EPA and the TakeBack Coalition.

E-waste disposal rates are poised to accelerate in the run-up to a nationwide switch to digital television signals in February. Less than 20 percent of all electronic waste is recycled, according to the EPA. The rest ends up in landfills.

Still, recycling rates are rising. Free drop-off events, designed primarily to keep lead, mercury, barium and other e-waste toxins out of local landfills, have attracted overflow crowds in the past year. Last fall, organizers at a Bloomington, Minn., event planned to fill 34 trailers but ended up filling 85.

In April, a Washington, D.C., event snarled traffic for hours as some 4,000 people lined up to drop off items.

When recyclers cart away e-waste, what happens next can vary widely, says Bruce Parker, president of the National Solid Waste Management Association, a trade association that includes electronics recyclers. Some separate glass, metal and plastics, and then make sure that most reusable materials find their way into new products. Others bring their loads to brokers, who ship contents overseas to salvagers, who pay to mine mountainous piles for precious metals and other valuables.

This tapestry of approaches is possible because recyclers don't have to be certified. U.S. law (unlike Europe) permits the export of electronic waste to developing nations.

Meanwhile, salvage yards, once concentrated primarily in Guiyu, China, are proliferating. Last month, Consumers International, a London-based advocacy group, reported that Ghana and Nigeria are receiving hundreds of tons of e-waste from the developed world each month. According to the Basel Action Network, a Seattle-based nonprofit, much of the e-waste generated in the U.S. also ends up in Pakistan and India, where children often do the sorting and toxic circuit boards are burned in residential areas.

The challenge for consumers who use free drop-off events is to know when to be concerned and when to feel at ease about their gadgetry's final resting place.

"People really should ask questions about where the material is going," says Elizabeth Grossman, author of "High Tech Trash: Digital Devices, Hidden Toxics and Human Health "(Island Press, 2006).

Being responsible about e-waste disposal isn't as simple as making sure a recycler does no exporting whatsoever, says Kim Holmes, executive editor of "E-Scrap News," a trade magazine for electronics recyclers.

For instance, recovering certain types of plastics is too labor-intensive to be practical in the U.S., where labor rates are substantially higher than in China. "If we didn't have that market in China, all that (plastic) would end up in landfills," Holmes says.

What's more, both the EPA and NSWMA challenge activists' claims that e-waste in landfills poses risks to groundwater. "We believe the disposal of electronics ... in municipal solid waste landfills is protective of human health and the environment if that disposal occurs in modern, properly managed municipal solid waste landfills," says EPA spokeswoman Roxanne Smith.

The TakeBack Coalition's Kyle counters that not all landfills are modern and properly managed. Either way, landfill diversion programs are getting encouragement. Ten states and New York City have taken steps to ban certain categories of e-waste from landfills.