WASHINGTON — America is getting cleaner, litter experts say.
They estimate that deliberate trash-tossing has fallen about 2 percent a year since the mid-'70s in communities where it's been measured.
On U.S. beaches, cigarette butts, beverage cans and Styrofoam peanuts for packaging are down, cleaners say. In most communities, pooper-scooper laws now make carefree strolls possible. Even along roadsides, more of what's visible today is grass.
Remarkably, the improvements come despite an increase of 90 million in the U.S. population since widespread trash surveying began in 1974.
If you haven't picked up on litter's decline, don't be surprised. People raise their standards as places get cleaner, so they're never impressed, according to John Doherty, New York City's sanitation commissioner. "The more you improve the cleanliness level, the higher people's expectations are."
Doherty, 69, who started out as a city street-sweeper in 1960, has lived the progress.
Thirty years ago, independent assessors rated nearly half of New York's streets and sidewalks as filthy. "A sweeper'd go out and there'd be mounds of steaming dog waste," Doherty said. "That was tolerated then."
Twenty years ago, New York was still so dirty that humorist Dave Barry accused the mayor of having appointed a Commissioner for Making Sure the Sidewalks Are Always Blocked by Steaming Fetid Mounds of Garbage the Size of Appalachian Foothills.
Today, the same independent assessment system used 30 years ago rates 95 percent of New York's streets and sidewalks as clean. Once-rare litter penalties now are the second biggest source of the city's revenue from fines, after parking violations.
As New York goes, so goes the nation, albeit by fits and starts, since litter curbs are almost entirely a local or state matter. For example:
Beyond enforcement, many factors aligned against litter. Recycling, for example, has made people more conscious of solid waste of all kinds. Tourist destinations discovered that it paid to be litter free. The same schoolchildren who pulled cigarettes out of their parents' mouths got on them when they littered.
It isn't that U.S. attitudes toward litter changed, said P. Wesley Schultz, a social psychologist at California State University at San Marcos. "People never had a very favorable attitude toward litter," Schultz said. "What we HAVE seen is a fairly dramatic change in people's norms about how appropriate it is to litter.
"People now feel littering is inappropriate and that others will disapprove of them if they litter. The norm about what's right and wrong changed."
The result is a dramatic shift in the nature of the U.S. litter problem, according to Steven Stein of Gaithersburg, Md., a professional litter and marine debris surveyor and analyst.
Litter that's intentional — tossing an empty Gatorade bottle, for example — used to be the bulk of the problem. Today, however, it's mainly unintentional or negligent, according to Stein: the bag of trash that flies out of a pickup's bed when it hits a bump or the tread that peels off an overinflated tire.
Stein, 54, should know. He's the director of operations at MSW Consultants of New Market, Md., a trash-surveying company. For eight years, he's strolled randomly selected but representative stretches of U.S. roadsides counting and classifying litter for local or state authorities.
Early spring is best, Stein said, before adopt-a-highway volunteers or sanitation workers disrupt the samples. He counts and analyzes litter within 3 feet of roads, then counts trash that he encounters on a standardized meandering walk up to 20 feet from the road.
"It's challenging. I love it," Stein said. "The source is the big question, and there's a lot of detective work to it.
"You take a corrugated box. If it's got a lot of dust, it's likely to be from a construction site. If it's crushed and it smells terrible, it's probably from a garbage truck. If it's crushed and it doesn't smell terrible, it's probably from a recycling truck."
Knowing litter's source helps focus prevention efforts, Stein said. It's key for sanitation departments, which can collect trash for $20 to $30 a ton but spend hundreds of dollars a ton to pick up litter.
Why does a litter count matter? Sometimes it's to document a trend. In Georgia, for example, litter-fighting Gov. Sonny Perdue wants measurable reductions. In Kansas City, Mo., where littering is down, and in Charlotte, N.C., where it's been up and down, surveys help grade local Keep America Beautiful campaigns.
The only attempt thus far to establish a national litter trend, issued in 2006 by prominent waste consultant Dan Syrek of Sacramento, Calif., found declines of roughly 2 percent annually. The figure is based on the results of 62 surveys that Syrek or others have conducted using his methodology since 1974.
The findings have two flaws: One is that the surveys don't add up to a national result. Second, only communities that are concerned about litter pay for surveys, so they're probably exceptionally eager to clean up. Nonetheless, based on his research, Stein also concludes that there's been a decline in litter.
He and his partners will test that proposition starting in March, when they launch the first serious national litter survey in 40 years. It'll compare current levels to benchmark national litter data compiled by the National Academy of Sciences in 1968. Keep America Beautiful, a nonprofit based in Stamford, Conn., is sponsoring the research under a grant from Philip Morris USA.
Until their survey is complete, the most telling evidence is probably the amount of litter that washes up on beaches, summing up all inland efforts. Those results are encouraging, too, said Seba Sheavly, a marine litter consultant for the nonprofit Ocean Conservancy and for the United Nations Environment Program.
At many U.S. sites with repeated beach surveys or cleanups, Sheavly said, "The number of things people pick up is declining." Worldwide, she added, "Things are level to downward, not on the rise."
Keep America Beautiful, the nation's biggest nonprofit cleanup group, is at www.kab.org. It's funded mainly by Waste Management Inc., the nationwide hauling and landfill company, and by producers of consumer goods implicated in litter.