DENVER -- The countdown to the digital switch has brought big business to electronics recycling plants as people unload their old analog televisions.

But electronics recyclers worry some televisions are winding up in landfills, spreading toxins that many consumers don’t even know about, reported KMGH-TV in Denver.

Guaranteed Recycling Xperts (GRX) President Mike Wright said foot traffic at his recycling warehouse in Denver has doubled in the past few months, and there has been a spike in the number of old televisions coming in.

Wright said most of his customers have done their homework and know that throwing a television, computer monitor or other electronics away can be dangerous.

But there are others out there who don't know. Interviewed on Denver's 16th Street Mall, a number of passers-by said if their television stopped working, they would simply dump it. Wright said that would be a big mistake.

"Electronics do have toxins in them. Primarily it's going to be lead and mercury," Wright said. But there are also cadmium, lithium and a host other toxic chemicals inside televisions and computers that can be harmful once they are taken apart.

Left sitting in a landfill, Wright said the chemicals can leach out and possibly get into groundwater.

Depending on a television's size, Wright said televisions and other e-waste can be recycled relatively cheaply, for between $15-$45.

The City of Denver has partnered with GRX to offer discount coupons for people turning old televisions over.

But Wright said more needs to be done to make sure toxic electronics don't end up sitting in landfills.

Wright and the Colorado Association for Recycling are backing legislation that would make it illegal to dump a television or other electronics.

Other recyclers are urging large electronics manufacturers to develop "take back" programs, allowing consumers to return old televisions to be recycled at the manufacturer's expense.

Already Sony and Samsung have developed such programs.