The wonderfully named author Jerry Mander tells an anecdote about the environmental effects of air travel. A Boeing Corp. physicist told him that "the pollution from the take-off of a single 747" is like "setting the local gas station on fire and flying it over your neighborhood.'" A sobering image, especially when you consider there were 8.8 million US commercial airline flights last year.

            But some news about ground-based vehicles is disturbing, too.

            For example, a February 2002 report from the Union of Concerned Scientists looked at the ordinary school bus. "The exhaust from diesel fuel --- which powers nearly 90 percent of the 454,000 school buses on the road today --- has been shown to cause or exacerbate a host of health problems, including asthma and other respiratory ailments, and has been linked to cancer and premature deaths," said the report. Children, said the report, get unhealthy doses of exhaust as they stand on the curb near idling buses and even while they're aboard. Soot is of special concern, because the solid particles of which its formed are havens for cancer-causing combustion products.

The UCS report gave New York State a "C" grade overall, mostly because of bad "fuel choice." The relevant data: Statewide, 95 percent of our 45,000 school buses run on diesel fuel, five percent run on gasoline, and just 0.09 percent use other fuels like natural gas. The statewide fleet pours out 9,500 tons of smog-related substances and 375 tons of particulate matter (read: soot). The soot emissions, the highest of any state, account for more than a tenth of the US total.

            Surprisingly, New York has by far the biggest school bus fleet in the country. Number two is Texas, with 33,000; Pennsylvania and California are next, with 26,000 and 25,000 respectively. Total school-bus route mileage is a different matter, though: New York, with 205 million route miles, is well behind other leading states. In any case, it all adds up to a disproportionate dose of pollution.

            "All states rely to some extent upon high-polluting school buses, primarily those powered by diesel," says the UCS report. To some extent, the problem is one of age. Older school buses tend to have older-version, dirtier engines. (How old is old? The Natural Resources Defense Council surveyed the country and found that many buses more than 20 years old are on the road, even in air-quality-conscious states like California.) And there's incentive to hang on to the old ones, since new buses can cost $100,000 or more.

            Change is coming nationally and locally, though perhaps too slowly.

            In May, a federal court of appeals upheld the Environmental Protection Agency's new diesel-emissions rule against a challenge from the National Petroleum and Refiners Association. Issued in January 2001, the EPA rule mandates that by 2007, soot, nitrogen oxides, and other substances in diesel exhaust must be reduced 90 to 95 percent. The rule also mandates a 97 percent reduction in sulfur, which can damage pollution-control equipment and therefore must be minimized.

            The American Lung Association was just one group to applaud the court's decision. In a news release, the group cited EPA findings that the rule will prevent 8,300 premature deaths and 9,500 hospitalizations every year. Children will benefit most of all, said the group, citing EPA data --- 17,600 fewer cases of acute bronchitis and much less exposure to "likely" carcinogens.

            But an individual child's fate may be linked with the type of bus he or she must ride or stand next to --- and reports from environmental groups have found wide disparities.

And what about our corner of New York State? Consider what's happening with one massive local fleet.

            Brian Habkirk, district manager for Laidlaw Transit, sees much improvement ahead. Laidlaw, a private company, operates school buses for the Rochester City School District and for the suburban districts of Brighton, East and West Irondequoit, East Rochester, and (in part) Greece.

            Laidlaw's 600 buses meet current federal standards, Habkirk says. All 600 do have diesel engines, he says, but they're running on low-sulfur fuel. And, he says, as buses are upgraded or replaced, more and more of them are equipped with the International Truck and Engine Corporation's T444E, a state-of-the-art diesel engine that's a key component of the company's "Green Diesel" initiative. (Green Diesel is focused on California and other states "where diesel fuel with sufficiently reduced sulfur content is available," says a company fact sheet.)

            When it comes to political action on this issue, Rochester is no California. US Representative Sherwood Boehlert, a Republican whose district is just to the east of us, has been a Congressional leader in this regard, however.

            Judy Wadsworth, deputy director of the Monroe County School Boards Association, can't recall any citizens' groups or school districts taking up the banner. "I think in other parts of the country, smog is a bigger issue," she says. "Our air seems to be cleaner," she says, "and right now, the schools are overwhelmed by a whole lot of things that are happening to them." Budget woes, for example.

            On the national scene, though, there's a debate going that could filter down to our neighborhoods. As usual, the environmental movement is pitted against industry. And as in other recent cases, both sides lay claim to the green label.

            In February 2001, the Natural Resources Defense Council and the national Coalition for Clean Air released a study, No Breathing in the Aisles, that looked at some California buses built in the 1980s. The study found that 30 percent of California school buses were built before 1987. The passage of years made another point: "Cancer risks from diesel exhaust are related to the number of years the child rides the bus," the study said.

            "School children are being transported on buses that are older than the typical transit bus, which is 12 years old," says San Francisco-based NRDC staff scientist Diane Bailey, a Binghamton native.

            The NRDC study didn't sound too hopeful about "Green Diesel," moreover. That approach, said the study, "is an improvement over existing diesel technology but still remains dirtier than alternative-fuel technologies." The latter, including natural gas, "use inherently cleaner-burning, lower-carbon fuels and will therefore continue to hold their low emissions advantage over diesel technologies in the future."

            Simple translation: Natural gas produces almost no soot, does not require failure-prone anti-emissions devices, and therefore will be easier to keep clean.

            The NRDC has felt the wrath of detractors. "We've been attacked on it because our findings are so damning," says Diane Bailey. One leading critic is the American Council on Science and Health, an independent group based in New York City. (ACSH also has opposed banning of DDT, maintained that dry-cleaning emissions pose little threat to health, and criticized New York City politician Mark Green for citing the hazards of lead for children.) An ACSH memo from 2001 calls the NRDC study "bogus science... replete with invalid and unsupported assertions." A key objection: the sample was too small.

            The memo also expresses regret that the NRDC study was "instrumental" in a Los Angeles agency's decision "to ban the purchase of school buses powered by clean diesel technology."

So which path will be taken?

            There have been some local stabs at really cleaning up the buses.

            For example, the Marcus Whitman Central School District (Ontario County) is ahead of the curve in using "CNG" (compressed natural gas) buses. Transportation supervisor David Adam says around one-third of the district-owned fleet is CNG-driven --- actually down from a few years ago, when 16 of the district's 25 buses ran on natural gas.

            Not that there haven't been practical problems. Adam recalls sending buses to Erie, Pennsylvania, a route with no CNG refueling stations along the way. Faced with that, Adams sent ordinary buses to Erie. Then there's money; CNG buses can cost $30,000 to $40,000 more than traditional ones, a margin that grants sometimes cover. But "the grant money has kind of dried up," says Adam.

            Some locals are looking into "bio-diesel" --- entirely soy-based or a mixture of soy and traditional diesel fuel. Paul Heaney, a retired Eastman Kodak mechanical engineer who works with Genesee Region Clean Communities, says his group has started working with the Pittsford schools to put some bio-diesel buses in place. Bio-diesel, he says, "reduces emissions dramatically." Heaney is also interested in electric buses, which are cleaner still. He recalls one, a 60-passenger model that was on display at Rochester Institute of Technology not long ago. But as with CNG, refueling (recharging) can be a challenge.

            But such considerations pale next to the big one: human health.

            Peter Iwanowicz, environmental health director with the Albany office of the American Lung Association, is deeply involved. He says his group "is somewhat fuel-neutral." He notes, however, that while 1,000 transit buses in New York State are natural-gas driven (including some owned by the Rochester transit authority), less than two percent of the state's school buses are "clean."

            Iwanowicz cuts through the data with a common-sense observation: "Diesel exhaust is as bad as it looks."