Smoking in the Schoolyard
Diesel School busses

Jason Mark / Nucleus Fall 2000 v.22, n.3

You are at work. The nurse at your child's school calls to tell you that your daughter is sick and needs to be taken home, or to the doctor, or even the hospital. For the parents of the more than 4 million children suffering from asthma in the United States, this is a constant fear.

Public health studies have linked higher rates of asthma attacks, emergency-room visits, and hospital admissions to air pollution. Even for kids who don't have asthma, air pollution poses an ongoing threat to their developing lungs. America's schools have made great strides in protecting our kids, but all parents need to know that diesel buses smoking in the schoolyard still threaten their health.

School Buses and Children's Health Nearly 25 million American children went back to school this fall on the famous yellow school bus. Its outward appearance hasn't changed much over the years, and neither has the technology under the hood. Most of the 400,000 buses that carry our country's next generation are running on last-generation fuel: diesel. As a result, they emit clouds of harmful soot and smog-producing pollution-fumes that can harm our children.

Children are more susceptible to air pollution than adults because their respiratory systems are still developing. Because they breathe 50 percent more air per pound of body weight than adults, their relative exposure to pollution is greater. And children spend more time outdoors, so they are exposed to more pollutants overall.

Most of the fine particles emitted by a diesel bus are tiny enough to evade the body's defenses and lodge deep in the lungs. Numerous public health studies have linked these particles to increased asthma hospitalizations, chronic bronchitis, pneumonia, heart disease, and even premature death in adults. Moreover, as particulate pollution increases, so does absenteeism among school children. Studies of childhood doctor visits indicate a link between soot pollution and increases in respiratory symptoms. Children who suffer from asthma are especially sensitive to diesel soot.

More than 40 compounds in diesel exhaust have been linked to cancer. Diesel soot, in particular, was recently singled out as the predominant cancer threat in urban air. In California, for example, officials estimate that diesel soot accounts for over two-thirds of the cancer risk from air pollution. One study estimates that at least 125,000 people out of our present national population could contract lung cancer as a result of long-term exposure to toxic diesel exhaust.

Diesel exhaust also contributes to urban ozone, or smog, which causes coughing, choking, and reduced lung capacity. Hospital admissions, especially for those with asthma, increase on smoggy days, and repeated exposure to smog may permanently injure lungs. Studies have linked smog to decreased lung function in healthy children.

Fortunately, school districts, urged on by parents and educators, now have the option to choose cleaner school buses. While the 400,000 diesel school buses currently in use can be substantially improved through cleanup technologies, the greatest opportunity for improvement lies in new buses. Although diesel engine makers are required by law to produce cleaner bus engines in the future, cleaner diesel still provides far less health protection than other alternatives.

Buses powered by natural gas offer a big step forward. Today, one in seven new school buses runs on natural gas. They emit 10 times less soot and 40 percent less smog-producing pollutants than their commercial diesel counterparts. While they cost more to buy than diesel buses, they cost less to run because fuel and maintenance expenses are lower.

Electric school buses are the best choice of all, because they provide children with zero-pollution travel. The electricity that powers the buses is stored in batteries and, in the future, will be produced on board by fuel cell engines. These buses are already finding success in the transit bus market, and it is only a matter of time before they become a common choice for schools.

But schools interested in a zero-pollution future don't have to wait. By investing in natural gas buses and a natural gas refueling infrastructure today, they are helping to prepare the way for a transition to fuel cells that run on hydrogen. Many of the facility changes needed to accommodate natural gas fuel will be directly applicable to hydrogen fuel, and natural gas and hydrogen filling stations share many common parts.

School districts that are putting clean school buses on the road today are at the head of the class when it comes to protecting their students. But boosting the transportation performance of all schools is a major priority for children's health. Since cleaner alternatives typically cost more, federal, state, and local governments must

help out with additional funding. Some states, such as California, have already created funds for cleaner buses, but the funding levels are still small.

Policymakers at all levels of government need to understand that increased spending for clean school buses is a smart investment-in the health of our children, as well as in technologies that will help clean up all buses and trucks.

Parents and teachers need to push school districts to replace their aging fleets with the cleanest options available. It's time to take our kids off of toxic school buses.