Anyone who has ever stepped onto a school bus-or even walked past one-knows the smell of diesel exhaust. Kids are exposed to the fumes every day at school and, according to a new report, we could be doing more to reduce their exposure.
Illinois received a C in the School Bus Pollution Report Card 2006 issued by the American Lung Association and the Union of Concerned Scientists, a nonprofit environmental organization based in Cambridge, Mass. The state's main problem, according to the analysis, is that about 40 percent of its 19,000 school buses are more than a decade old. As a result, each Illinois school bus produces far more soot than it should-an average of about 15 pounds a year, more than twice the amount of a semi-trailer truck.
Diesel exhaust is made up of dozens of toxic substances that can cause headaches, breathing trouble, nausea and cancer. Of greatest concern are microscopic pieces of soot, no bigger than a hundredth of a child's freckle, known as particulate matter. When inhaled, particulates can lodge in the lungs and get absorbed into the bloodstream. Children are especially vulnerable to particulates, doctors say, because their lungs are still developing and they breathe faster than adults.
Yet over the last several years ambitious state and federal programs designed to cut diesel exhaust have failed to prevent thousands of Illinois children from intense doses from old school buses, according to the report. And local school districts don't have the money for necessary equipment upgrades.
Turn off the engine
Diesel exhaust is commonly associated with idling buses. Education officials say the buses have to idle at times so they're ready for kids when they leave school.
But Julie Magee, an environmental protection specialist for the U.S. Environmental Protection Agency, believes that should be a rare occurrence, such as when it's cold outside. Diesel engines don't need to be warmed up longer than five minutes, says Magee, who also coordinates the Midwest Clean Diesel Initiative, a joint public-private effort to curb diesel emissions through voluntary action.
"There's a behavioral option for reducing exhaust-getting the school buses to turn their engines off," Magee says. "A lot of school bus drivers idle because that's what they've done for a long time."
The idea has gained wide support. Some districts have created no-idling policies, and a state bill awaiting the signature of Gov. Rod Blagojevich would prohibit diesel-powered vehicles from idling longer than 10 minutes at a time, except in the event of freezing weather or other exceptional situations.
In older vehicles, though, exhaust may be just as bad inside the cabin when the buses are moving. According to studies cited in the report card, children who ride the bus daily may inhale particulate concentrations that exceed federal standards, and longtime riders may face a greater risk for cancer later in life.
"There are a lot of toxic components in diesel exhaust that make breathing it unhealthy for anybody," says Renate Anderson, an environmental health associate for the American Lung Association of Metropolitan Chicago. "Whether [short exposure to it] causes cancer or anything else, well, we don't know for sure, but it's certainly not a healthy thing."
It's well established that diesel exhaust can trigger asthma attacks and other "severe symptoms" among people with serious allergies, says Dr. Aaron Donnell of Associated Allergists and Asthma Specialists, which has offices across the Chicago area. But researchers also suspect diesel soot may actually cause allergies. According to this theory, particulates weaken the immune system in the lungs to the point that they become more vulnerable to irritants and turn asthmatic.
"It can definitely make things worse, and it might even start them," says Donnell.
Ideally, all old buses should be replaced. Newer models spew 95 percent less exhaust than older ones. Federal regulations now require that newly built diesel-fueled trucks and buses burn cleaner fuel and emit drastically lower levels of fumes.
"You have this new rule that's going to clean up the future fleet," Magee notes. "But obviously you have all these older engines out there that are going to continue to pollute."
Most districts have no choice but to stick with the old buses. New ones cost at least $50,000 apiece, Anderson says, and districts don't have the money.
"Retrofitting" older buses with emissions-reduction equipment is a less costly option. Tailpipe filters can cut the release of particulates between 60 and 90 percent. Other engine filtration systems and fuel-processing upgrades can reduce the exhaust that seeps into the bus cabin by half.
But this equipment isn't cheap, either. The tailpipe filter, for example, costs up to $10,000 for each bus. Cheaper but less effective are oxidation catalysts, installed in the exhaust system to help eliminate toxins, which run $800 to $1,000. EPA officials note that while oxidation catalysts only cut particulate emissions by half as much as tailpipe filters, they achieve greater reductions per dollar.
Over the last few years, the U.S. and Illinois EPAs have both launched initiatives to help local districts pay for retrofits. Yet funding hasn't kept pace.
In April, the U.S. EPA office in Chicago announced it would hand out $464,320 for diesel emissions control this year-for the entire region of Illinois, Indiana, Wisconsin, Minnesota, Michigan and Ohio. In other words, the money could pay for tailpipe filters for about 66 buses, or oxidation catalysts for 580. Altogether the six states have about 92,000 school buses in service.
Competition for these funds has been intense. In 2003, the U.S. EPA received $50 million in grant requests for $5 million in funds. The funding level rose to $7.5 million in 2005 before dipping to $7 million this year. The 2007 budget hasn't been finalized.
"The problem is there's never going to be enough funding to address this issue," Magee says. Still, she emphasizes that the U.S. EPA has found ways to put money into the program during an era when Washington has repeatedly tightened environmental budgets, and states are adding their own programs.
Jill Watson, spokeswoman for the Illinois EPA, notes that at least 1,296 school buses in 24 districts statewide are now equipped with clean-fuel technology-and some of the $2.9 million in funding since 2003 has been provided by the American Lung Association.
"The voluntary Illinois Clean School Bus Program is resulting in cleaner air for thousands of Illinois school children as a result of grants for retrofitting diesel buses with control equipment and use of cleaner fuels, as well as investments made by private school bus operators, state and federal agencies, and the American Lung Association," she wrote in an e-mail. "It is our hope that more school bus companies enroll in this voluntary program."
State Rep. Elaine Nekritz, a Des Plaines Democrat who was the chief sponsor of the anti-idling bill, says she hasn't heard any discussions about boosting funding for clean bus programs. "I do think there's quite a bit of interest from our state EPA on doing this," she says. "But I've tried really hard not to work on things that cost a lot of money because we just don't have a lot of it."
The Chicago Public Schools stand as a partial success story. In 2004, the system received $465,000 in state and federal grants to fund upgrades on 620 buses; these vehicles are on the road for 1.1 million hours a year, the district estimates. "You have school buses sitting outside schools idling sometimes, and children and families in the area," says Michael Vaughn, press secretary for CPS. "Obviously, we want to reduce the idling time, but buses do have to run, so we're going to have some diesel exhaust and we want to cut it down."
But more needs to be done. These upgraded buses make up less than a third of the CPS fleet.
Both clean air advocates and state officials emphasize that buses are still the safest way to get kids to school. But Anderson urges parents to approach their principal or administrators and find out if they have plans to cut diesel exhaust. "And if they don't, say, 'Hey, it would improve the health of the students.' "
For starters, parents should make sure buses aren't left idling when they're not being used. "We have a very big challenge ahead of us in terms of enforcement of the legislation we've passed," Nekritz says. "We have to get the word out there that it's still better for buses not to run needlessly than even to run with some of the retrofits."
Mick Dumke is a Chicago writer, an uncle and a teacher in the journalism department at Columbia College Chicago. School bus fumes can trigger asthma attacks and increase the risk of cancer, studies say.