Ask the federal Environmental Protection Agency, for example, to resolve the "paper or plastic" debate once and for all — which one uses the most energy and creates the most pollution to produce and recycle? — and you get an e-mail like this one: "EPA is currently performing a literature review/data search on paper and plastic and then we plan to make that information available to the public so citizens can reach their own conclusion. We don't have an anticipated time frame of when the literature search will be ready — we are still looking for the data," wrote the EPA's Roxanne Smith to the Deseret News recently.

That doesn't stop people on both sides of the paper-plastic debate from quoting outdated data to prove that their favorite kind of shopping bag is more environmentally friendly. Ashby weighs in on the side of plastic.

Plastic bags have become the poster child for consumption and waste, from Africa to Anchorage. At the Web site reusablebags.com, the digital tally of worldwide plastic shopping bag consumption ticks away at a dizzying rate: about 100,000 bags every 10 seconds.

According to the Algalita Marine Research Foundation, more than 1 million birds and more than 100,000 sea mammals, amphibians and fish are killed annually by plastic rubbish, including plastic bags, through entanglement, suffocation and starvation after ingesting plastic — a phenomenon that Salt Lake artist Carol Sogard represented in her art piece "Bagging Birds" earlier this year. Scientists worry that chemicals from all that ingested plastic then gets into the food chain, perhaps causing havoc with animal and human endocrine systems.

Some grocery store chains are encouraging their customers to bring reusable bags. Whole Foods Markets no longer uses any petroleum-based plastic shopping bags, but does use biodegradable plastic bags, which can be composted.

Ashby audibly sighs at the mention of biodegradable bags, which sometimes end up being recycled by mistake. "They do not play very well with the other polymers," he says. They don't melt at the same temperature, and the corn-based polymers, if mixed with other plastic bags, have a tendency to catch fire. "And they fall apart. So now you have millions of little pieces of plastic. ... I know there's a place for it and it makes us feel better because it's made from a renewable resource, but it's messing up a pretty good recycling program."