Here’s an interesting suggestion for saving gasoline, your bank account and the environment: Forget about how many miles per gallon your car gets.

A couple of professors at Duke University have been promoting the idea this month after determining that the math-challenged American public is fairly confused about fuel efficiency because of our fixation with mpg.

And it’s not as crazy as it sounds.

Consider this example: Smith trades in a 10 mpg SUV for a slightly less inefficient 15 mpg SUV. Jones, meanwhile, almost triples his fuel efficiency by trading in a 20 mpg minivan for a 55 mpg hybrid.

Who is going to cut their gas usage more? Smith, the SUV driver.

In fact, assuming they both drive 15,000 miles a year, Smith will save $2,000 worth of gas and Jones will save $1,908. Now I, too, had understood there would be no math in this column. But times are pretty desperate with gas now rising toward $4.10 a gallon, and here is a case where a little math could change the way you look at the vehicles in your driveway and how you approach your next purchase.

The business professors at Duke started talking about fuel economy and mpg while carpooling to work in a hybrid. Then they asked college students trick questions like the one above, only not so obvious.

For example, which would save more gas: a) upgrading from 16 to 20 mpg, or b) upgrading from 34 to 50? The correct answer is a, although the college students tended to say b.

That led to an article in the journal Science, a call for a national math lesson and a lot of head scratching. “It’s been nice to get the word out,” said Jack Soll, one of the professors.

What’s basically happening here, mathematically speaking, is a case of diminishing returns.

Even a small gain in mpg for a gas-guzzler can have a huge impact on fuel consumption simply because it’s burning so much more to start with. Getting 5 mpg more out of a Ford F-150 could save $1,500 a year.

More fuel efficient vehicles, on the other hand, are already using less, so cutting their consumption by the same percentage carries a much smaller savings. Getting 5 mpg more out of a Honda Civic could save $200 a year.

Of course, trading in the F-150 for the Civic is the best deal all around, excluding cargo space, of course. The professors took pains to say that improving fuel efficiency is a good thing no matter what you’re driving.

But, if you’re looking to compare fuel efficiencies and the cost of driving one car against another, they said, forget mpg.

A much better way, they said, is to figure out “gpm” – or how many gallons it takes to drive your car 10,000 miles. Using gpm, you see that improving from 10 to 15 mpg will save 333 gallons of gas every 10,000 miles, while going from 30 to 50 will save 133 gallons.

For a more complete explanation and chart, see this Science Daily article (http://www.sciencedaily.com/releases/2008/06/080619142118.htm).

The Duke research isn’t likely to change American car ratings from mpg to gpm any time soon. But, given the cost of a tank of gas, a little math won’t hurt us.

So you’re thinking about dusting off the old bike and pedaling to work.

There are a number of good reasons, including $4 per gallon gasoline, global warming and those extra pounds you’d like to burn off.

Standing in the way, however, is an entire transportation culture that’s built around cars and trucks and is openly hostile to anything that can’t keep up.

Still, the number of people biking to work this summer is clearly way up, though no one knows by how much. And the trend, together with better safety laws, appears to be making the roadways a little more welcoming, bikers say.

Volkhard Lindner of South Portland has been riding bikes to school and work for 40 years, first in Germany where he grew up and then in American cities from Seattle to Portland.

“Biking is a lot more part of the culture” in Europe, he said. “It’s seen more as a means of transportation, where here its seen more as a form of exercise.”

Some American cities, such as Seattle and Portland, Ore., are known for their bike lanes, trails, parking facilities, safety laws and education programs, among other things.

Maine isn’t a horrible place to ride, said Lindner, who bikes year round to his job as a medical researcher in Scarborough. He and others are quick to encourage more people to make the switch, as long as they know and follow the safety rules.

But Mainers have plenty of good excuses to stay in their cars and pickups.

Sprawl has put a lot of us out of comfortable pedaling range, for one thing. The average Maine commute is nine miles, though many of the people who can least afford gasoline live 20 miles or more from work.

Our roads are designed for Ford F-150s, not Treks. In cities such as Portland, there are notorious hazard zones for bikers – try Congress Street through Stroudwater or Tukey’s Bridge, to mention a couple.

Country roads tend to be narrow with no shoulders. And during pothole season, which peaks in April but never entirely ends, the edges of those roads can resemble mountain bike courses.

Even the traffic lights are against bikers. Motion sensors don’t detect bicycles (or motorized scooters and motorcycles, for that matter), so law-abiding riders sometimes have to wait for a car to come along to trip the sensor and change the light.

But the most intimidating thing for many would-be bike commuters is the traffic. While long-time riders insist it’s possible to do it safely, they also tell stories of being beeped at, yelled at, cut off and, in some cases, knocked down.

Lindner has had drinks thrown in his face. Sometimes, he said in a faint German accent, “they show you the bird.”

“They like to scare you, so they come up from behind and scream at the top of their lungs,” he said. “You have to be a pretty good biker when people are giving you one foot as they pass you.”

But that is changing now, and many motorists are sharing the road, according to Lindner and other bikers.

A state law passed last year requires cars and trucks to give bikes at least three feet of clearance as they pass. There hasn’t exactly been a police crackdown to enforce that one, but the law has had an educational effect, bikers said.

“There are clearly some who know there’s a three-foot law now,” Lindner said. “Some are very conscientious and really watch out for you.”

Where’s that tire pump?

A wealthy Wall Street executive and his wife are facing a fine of as much as $157,500 for filling 1.5 acres of wetland when expanding the airstrip at their sprawling estate on the western shore of Moosehead Lake.

Robert Greenhill, former president of Morgan Stanley and former chairman and CEO of Smith Barney, and his wife Gayle Greenhill own more than 3,200 acres of land on the western shore of the lake. Their vacation home, which was built under a climate-controlled dome, is one of the more elaborate examples of so-called kingdom estates getting carved out the commercial forest of northern Maine.

The U.S. Environmental Protection Agency said in a news release issued today that the couple filled wetlands while expanding an airstrip for their private jet and digging a rock quarry sometime between 2001 and 2005. The damage is a violation of the federal Clean Water Act and wetland protection rules, EPA says.

The couple also got in trouble with federal regulators in 1997 when they created a trout pond on the property and disturbed about a half-acre of wetland without first seeking a Clean Water Act permit.

Wetlands serve as wildlife habitat, groundwater discharge and recharge areas, sediment and toxin removal and flood water storage. The wetlands disturbed by the Greenhills were part of larger forested complex and adjacent to two tributaries that flow into Moosehead Lake, according to the EPA.

The Greenhills are already restoring about one acre of the filled wetlands, and are creating new wetlands on another half acre, the agency said.

The final size of the fine has yet to be decided. But it may not hurt as much as the last mishap that got Robert Greenhill into the news.

Greenhill’s 604-horsepower Porsche Carrera GT – a rare auto with a $440,000 sticker price – was crumpled last November in New York City, according to this New York Post article.

Greenhill had taken the car in for some work, and the owner of an auto body shop was driving it when he swerved to avoid a truck, lost control and wrapped the silver sports car around a telephone poll. Not a pretty picture.

A rebellion against lawn pesticides may be sprouting on the Maine coast.

Four coastal communities have adopted an ordinance or a policy to ban the spraying of pesticides on town-owned parks, playing fields and other public lands. First came Brunswick in 2006, then Castine last summer, followed by Camden in April and Rockport last month.

And, if folks like Patrisha McLean have their wish, it’s just the beginning.

“Our goal is to join up all the coastal towns,” said McLean, a leader of Citizens for a Green Camden. “I think there’s an awareness (on the coast) … We’ve already had calls from people in Lincolnville and Rockland.”

The town bans effectively require their parks and recreation departments to go organic, usually with some exceptions such as roadway medians or school-owned properties.

The Camden policy, which was modeled after Castine’s and copied by Rockport, says: “All pesticides are toxic to some degree and the widespread use of pesticides is both a major environmental problem and a public health issue. … All citizens, particularly children, have a right to protection from exposure to hazardous chemicals and pesticides.”

In Castine, the pesticide policy grew out of concerns about cancer rates in the small town. In Camden, it was a more general response.

“Some people in town got together who were concerned about all the little pesticide notification signs that pop up every spring,” McLean said.

More than 20 Maine communities from all over the state have some form of local pesticide-use ordinances, said Gary Fish, manager of pesticide programs for Maine Board of Pesticides Control. Most go back many years and are aimed at protecting certain aquifers or waterways.

The more recent trend of banning lawn pesticides from parks, playgrounds and other lands is much more widespread in Canada, and still hit or miss here, Fish said.

The Maine pesticides board adopted a rule in 2004 requiring Maine school districts to spray only as a last resort. Giving up pesticides cold turkey – especially when trying to maintain athletic fields – is not easy for towns and schools and can take some re-education, according to Fish.

Some communities, such as Marblehead, Mass., have shown that it can be done, however, he said. And in Camden, the parks department is studying up on mechanical and organic methods for controlling weeds.

The backlash against pesticides on Maine’s coast also is spreading beyond municipal and school properties.

Citizens for a Green Camden took their concerns to the town’s innkeepers and hotel and bed and breakfast operators, and all of them have pledged to stop using pesticides on their green lawns and colorful gardens. Now the group is helping to spread the word about Maine’s “safe-lawn lodging town” and its lush, organic gardens.

A sheet posted at Camden’s town office quickly filled with the signatures of 50 residents and business owners who pledged not to use lawn pesticides, McLean said. And she and other leaders of the group continue to appeal directly to business owners, including commercial landlords.

“Whenever we see the pesticide notification flag anywhere, we make a note of it,” she said.

And, on the Maine coast at least, such sightings are becoming a little less common.

It was surprising enough in March when a Maine researcher found traces of industrial chemicals in bird eggs collected from all corners of the state.

Whatever the species of bird, its diet or its habitat, the eggs contained a soup of chemicals, including pesticides, solvents and carpet-stain repellents. Some of the same chemicals have also been found in humans, including some raised in relatively pristine parts of Maine, harbor seals that swim along the New England coast and even Arctic polar bears.

Now comes perhaps the most surprising evidence yet to support the “if-you-look-for-it-you’ll-find-it” theory of environmental toxicology.

The Northeast Fisheries Science Center in Woods Hole, Mass., a branch of the National Oceanic and Atmospheric Administration, reported this week that it found chemical contaminants in deep-sea squids and octopods, including the “vampire squid.”

These species, which are eaten by deep-diving whales, live 3,300 to 6,600 feet beneath the ocean’s surface. How they got exposed to industrial chemicals like flame retardants and the pesticide DDT is a mystery.

“It was surprising to find measurable and sometimes high amounts of toxic pollutants in such a deep and remote environment,” said Michael Vecchione, a lead researcher at the center. Here is a news release about the study, which is being published in the journal Marine Pollution Bulletin.

Part of the reason that we’re seeing more findings like this is that scientists are now able to detect the chemicals at low levels. In other words, it’s simply because we’re looking.

It’s not clear what affect, if any, the chemicals are having on the birds, the vampire squids or us, for that matter. But now that the chemicals seem to be showing up everywhere we look, it is, as Vecchione says, “a real concern.”

The future of New England’s only national marine sanctuary is up in the air, and Mainers will have their chance to weigh in during a meeting in Portland Thursday.

The Stellwagen Bank National Marine Sanctuary, a shallow plateau just north from the tip of Cape Cod, includes some of the most productive waters in the Gulf of Maine and is a gathering place for everything from tiny invertebrates to huge whales. It’s also a busy place for whale-watching cruises, cargo ships and fishing trawlers that operate inside the sanctuary just as they do outside the sanctuary.

Stellwagen managers are now updating its management plan for the first time since Congress created it in 1992. The draft plan doesn’t include immediate restrictions on uses, but could eventually lead to more protections for wildlife, it says.

Conservation groups, including the Conservation Law Foundation, are pushing for more aggressive protections and want Stellwagen to become more of a true sanctuary for wildlife.

Sanctuary managers will hold a public meeting to present the draft plan and gather oral and written comments Thursday from 6:30 p.m. to 9:30 p.m. at the University of Southern Maine’s Talbot Lecture Hall in Portland. Public comments will be accepted through the summer and the final plan is scheduled to be done next year.

For locations of other public meetings around New England, or to obtain a copy of the draft management plan, look here.

And look here for the Conservation Law Foundation’s take.