Industries that underpin local economies can also overload olfactory nerves. Some people who live near paper mills, refineries, breweries, contained-animal lots, dog-food makers and other redolent sites get used to noxious odors. But others complain to their state or local government. And, depending on where they live, some level of government might be able to do something about it.

Air-quality control is mainly the province of federal regulators, but different states allow different measures to be taken against "nuisance" industries whose stench is offending the neighbors. In Washington State, for example, "one person complaining about one activity is enough to set us on an enforcement path," says Jim Nolan, director of the Puget Sound Clean Air Agency's compliance division. Across the country in Biddeford, Maine, city officials approved an "air toxic control ordinance" that allows them to perform inspections and random tests on local businesses to check their toxin emission levels. In nearby Portland and a few other places, the city sends out occasional smell patrols, strong-nosed folks testing the air for violations of the tough local odor ordinance.

In many localities, complaints about smells arise from the fact that former city dwellers and their sprawl are impinging on traditionally agriculture-dominated areas. The newcomers are sometimes too delicate to adjust to the smells associated with animals--especially on factory-style farms where just a couple of buildings can house animals that produce as much waste as a small city. "Most of the regulations I'm aware of are tied to specific industries that cause odors, such as hog farming," says Chris Cooper of the American Planning Association.

That's certainly the case in Colorado, where voters five years ago approved a ballot initiative giving the state authority to regulate hog farming and its effects on air and water quality. "We really didn't get involved until the voters said, 'Thou shalt regulate the hog industry,'" says Chris Dann of the Colorado Department of Public Health and Environment. The state takes care of offenders in the pork- producing world but still has no authority over cattle or chicken facilities. Odor in Colorado is mainly handled as a local concern.

In the metropolitan Denver area, complaints about odors from industrialized Commerce City facilities go to a local council made up of representatives from cities, local health departments and manufacturing companies and refiners. But odors don't respect political boundaries. There's not much agriculture left in the metro area, but Denver still sometimes smells of feed lots because of the way wind whips odors in from 60 miles away, out of the plains areas to the north and east, and cycles them around, trapped by the Front Range of the Rockies.

Increasingly, new technology is helping to mitigate noxious smells. David Soll, a University of Iowa biologist, has come up with an ultrasound wave technique that kills the toxic chemicals that cause odors in hog waste. His invention should soon be commercially available. "You see a problem that's a billion-dollar problem," he says, "and the intellectual basis for solving it is really trivial." Other breakthroughs have helped reduce odors in solid waste and heavy industry. "Our emissions have decreased at least 95 percent in the last 30 years," says Bev Holland, public affairs manager of the Simpson Tacoma Kraft Mill--which is the main reason why the "Tacoma aroma" is something only old-timers along Puget Sound still remember.

The simplest solution for getting rid of industrial odor may be for the offender to shut down, but that's rarely the best way. Residents of St. Marys, Georgia, used to complain about the local Durango- Georgia Co. paper mill's rotten egg smell, but they miss it now that the mill--and its 900 jobs--are gone for economic reasons. The mill was the largest employer and biggest taxpayer in the coastal town of 15,000 people. "It smelled like money to me," says Mayor Deborah Hase.

But there's a silver lining to its closure: Unlike the typical shuttered mill town of the Northeast, St. Marys is starting a second life as a tourist destination and home to retirees and commuters driving to jobs in Brunswick and Jacksonville, Florida. The city was chosen as the site for a "Dream House" program on the cable Home & Garden Television network. Without the mill and its smells, Hase declares, St. Marys "absolutely" can attract more upscale property owners.