For people who care about the environment, few products are more important than energy-saving, compact fluorescent light bulbs. But there is one flaw; each bulb contains a tiny amount of toxic mercury that shouldn’t be disposed of in most landfills.

Last Saturday, Wal-Mart stores, Supercenters and Sam’s Clubs in Rhode Island and four other states took part in a pilot program to address that flaw by accepting and recycling old CFL bulbs. Steven P. Hamburg, the Brown University environmental studies professor who first advised Wal-Mart to make a big commitment to CFLs, called it a good first step.

Saturday’s effort also was praised by W. Michael Sullivan, director of the state Department of Environmental Management, who said it would help complete the life cycle of the bulbs by enabling consumers to return them for recycling.

For eight hours Saturday, Wal-Mart accepted old compact fluorescent bulbs and fluorescent tubes at special kiosks outside their stores in Rhode Island, California, Massachusetts, Minnesota and Oklahoma — the states were selected for their geographic diversity.

To handle the bulbs, Wal-Mart enlisted the LampTracker program offered by Waste Management, the giant Houston-based waste disposal and recycling company. LampTracker helps companies safely dispose of fluorescent bulbs and tubes by encasing them in foil bags so they can be safely transported to a recycling center in Minnesota. There, the mercury is removed and the materials recycled.

“At our stores, the kiosks used were very safe for our customers, associates and handlers because all bulbs were placed into VaporLok containment bags,” said Christopher N. Buchanan, a senior manager for public affairs for Wal-Mart in Plymouth, Mass. “These bags were specially engineered and custom manufactured to safely contain mercury residue and vapors during storage and transportation. Additionally, all kiosks had educational materials on the benefits of CFLs, and safe handling and disposal instructions.”

The story of how Wal-Mart embraced compact fluorescents is often told in both business and environmental circles.

In the fall of 2005, H. Lee Scott Jr., Wal-Mart’s chief executive officer, began approaching some environmental groups. Regarded as an environmental offender because of the enormous resources the stores sell and consume, Scott wanted to use the stores’ influence to improve the environment and become a leader on issues such as fuel efficiency and greenhouse gas emissions.

At the same time, he hoped to improve the stores’ image, and sales.

Scott and Andy Ruben, Wal-Mart’s vice president for strategy and sustainability, met at the Mount Washington Observatory in September 2005 with Hamburg and Fred Krupp, president of Environmental Defense, an advocacy group.

Hamburg pushed CFLs. If everyone in the United States made use of the bulbs, says Hamburg, Americans would save $10 billion in energy costs annually.

A story in The New York Times last January about Wal-Mart’s new commitment to the environment after that meeting used this metaphor: “It turns out that the long-lasting, swirl-shaped light bulbs known as compact fluorescent lamps are to the nation’s energy problem what vegetables are to its obesity epidemic: a near-perfect answer, if only Americans could be persuaded to swallow them.”

Two years ago, Wal-Mart wasn’t selling many CFL bulbs. Although they use 75-percent less electricity and last 10 times longer than incandescent bulbs, they cost as much as eight times more and give off a somewhat different light.

But Scott announced that he wanted to sell 100 million bulbs by 2008, one for each Wal-Mart customer.

Wal-Mart used its marketing expertise to make the bulbs more palatable. It displayed them at the ends of aisles and offered educational material. Each bulb saves $30 in electricity costs and prevents the consumption of more than 110 pounds of coal, the store said.

Last month, Wal-Mart used its purchasing clout to set a new standard for its suppliers to reduce the amount of mercury in each bulb it sold by 33 percent. The giant retailer has also launched wide-ranging efforts to reduce the energy consumed by its thousands of stores and to make more use of recycled products.

Hamburg said that by reducing the burning of coal, a leading source for the dispersal of toxic mercury, each bulb caused less mercury to be set free in the atmosphere than was contained in the bulb itself.

Still, he said he urged Wal-Mart to do more.

The solution, Hamburg said, is in-store recycling. It is tricky, Hamburg said, because the moment a CFL bulb is discarded, it is considered a hazardous waste governed by numerous state and federal laws.

But Hamburg said it was important to start now and work out the bugs and lower the costs, because the crunch will come in several years, when the bulbs are being fully used and then start wearing out in vast numbers.

“If we recycle every bulb that will burn out in America, that would cost $40 to $100 million,” Hamburg said. “But that is the cost of recycling 400 to 500 million bulbs a year.”

If you remember that the bulbs are saving $10 billion annually in energy use, the cost to recycle is a good investment, Hamburg said.

Wal-Mart spokesman Buchanan said he couldn’t estimate this week how many bulbs were recycled.

“As a company, we are now reviewing the results of our recycling days held in these states,” Buchanan said. “In addition, we are working to determine sites and timelines of additional recycling events in the future, but do not have that specific information at this time.”

So until the next recycling day, Hamburg suggests, store burned-out CFL bulbs in a safe place in your basement.

plord@projo.com