You likely have an opinion on the City of Austin’s proposed ban on some single-use plastic bags. Opponents say the ban will reduce consumer choice, make shopping less convenient and cut the supply for recyclers. To proponents, the ban means less litter, less trash in our landfills and reduced use of oil.

A ban could also mean less plastic will end up in our environment; wherever you stand on the issue, that should be good news.

Plastic, whether in the form of bottles, bags, chairs or anything else, does eventually break into smaller and smaller parts, but it essentially remains the unique combination of chemicals it started as. Given long enough, it becomes tiny particles, sort of like plastic sand. This isn’t a good thing. In parts of the ocean, The Algalita Marine Research Foundation has documented up to six times more bits of plastic by weight than zooplankton.

Zooplankton are tiny marine creatures that anchor the marine food chain; they’re eaten by small fish, which are eaten by larger fish, which still larger fish eat, on up the chain, perhaps right to your dinner plate. Plastic is also now found in the bodies of most marine organisms, scientists say, where it can cause injury, malnutrition and death, primarily by blocking the intestinal tract.

Of the 1 billion plastic bags distributed every day on our planet, 0.2 to 0.3 percent — millions, in other words — end up in the ocean. Bags, along with other forms of plastic, float on the surface, where they’re often mistaken for food by turtles, birds and other marine life.

Several studies have investigated plastic ingestion by sea turtles, including one in 1993 that found debris in the digestive tracts of 51 percent of examined loggerheads. Some necropsies (animal autopsies) have found turtles whose entire digestive tract was packed solid with pieces of plastic bags. In fact, more than 260 marine species have been documented as ingesting or becoming entangled in plastic.

Much floating plastic trash eventually washes up on beaches. Marc Ward of Sea Turtles Forever recently documented more than 14,000 items of marine plastic debris along a single beach in Costa Rica. Next time you’re in Port Aransas, catch the ferry over to St. Joe’s island. All of the trash and plastic you see there washed ashore from somewhere else.

Padre Island National Seashore, the primary nesting beach for endangered Kemp’s ridleys, is what is known as a "sink," or a place where winds, currents and tides cause debris to accumulate. On Padre Island, Ward’s beach in Costa Rica and others around the globe, plastic debris makes it difficult for female sea turtles to successfully nest and for hatchlings to make it to the ocean.

You may not care about sea turtles or other marine animals, but presumably your own health matters to you. Remember that microscopic plastic working its way up the food chain? Studies show that plastic particles in the ocean absorb various toxic chemicals, says Ward, including PCBs, DDT, polycyclic aromatic hydrocarbons and BPA. Some of these chemicals are known to cause cancer. Some of the chemicals already in plastic are endocrine disruptors, which means they affect our hormones and reproductive systems.

Wallace J. Nichols, PhD, a research associate at the California Academy of Sciences, notes that a paper in a prestigious scientific journal way back in 1972 identified the threat of micro-plastics in the ocean. The problem has relatively clear-cut solutions, he adds, including reducing single-use plastics (including bags) and cleaning up debris.

In 2009, the United Nations Environment Program called for a worldwide ban on plastic bags. More than nine countries have already banned plastic bags — including South Africa, Eritrea, Rwanda, Somalia, Tanzania, Kenya and Uganda. Bags are taxed or customers must pay for them in Ireland, Italy, Belgium, Switzerland, Holland, Germany, Taiwan and a number of cities in India. U.S. cities with some sort of ban on single-use bags include San Francisco, Los Angeles, Seattle and Brownsville, Texas. Galveston is currently considering a bag ban.

“In my experience,” Nichols says, “when you tell people ‘no more plastic bags,’ a few complain for a while and then everybody adapts and life goes on. We accepted single use bags quickly and easily when they came into our lives, and we’ll accept their leaving quickly and easily now that they’re a problem. We can move on to better design and less waste, quickly and painlessly, and someone will make money from that transition.”

Banning single-use plastic bags in Austin would be a good start — especially if you don’t like the idea of eating plastic.