The Road to Safe School Buses

Today we have a guest blog from Anna Frostic, Esq., Environmental Health Advocate with the
Respiratory Health Association of Metropolitan Chicago

The typical back-to-school jitters for parents and kids include the fear of a new teacher, new friends, or even a new school…but what about the school bus? Buses are often heralded as the safest way to transport kids to and from school, but are they the healthiest?

The vast majority of the friendly yellow buses that transport our children to school are powered by diesel engines. The exhaust from diesel buses contains over 40 toxic air contaminants, carcinogens, ozone smog-forming compounds, and fine particulate matter (“soot”). 

Because of their small size, fine particles evade the body’s natural defenses, such as coughing and sneezing, and penetrate deep into the lungs. 

Exposure to fine particles is known to cause asthma attacks, heart attacks, lung cancer, stroke, and even premature death. Children are particularly vulnerable to this pollution, as their lungs are not yet fully developed. 

When diesel exhaust escapes out of the tailpipe untreated, it can cause immediate health impacts on those near the exterior of the bus, and contributes to our region’s poor air quality.

The federal government has recognized this public health and environmental problem, and requires that newly manufactured diesel buses be 90 percent cleaner beginning with model year 2007.  To achieve this, buses will be built standard with a diesel particulate filter, which nearly eliminates fine particle pollution from the exhaust. 

Fortunately, the same technology can and should be retrofitted [pdf] on most existing buses. Older buses that cannot be retrofitted should be replaced with newer, cleaner models. 

Not only does diesel exhaust exit through the tailpipe, but exhaust also enters the bus cabin through the crankcase, under the vehicle’s hood.

Schoolchildren experience more exposure to particulate matter pollution during their daily rides to and from school than the average person receives during an entire day. To address in-cabin pollution, buses should be retrofitted with closed crankcase filtration systems, which nearly eliminate crankcase emissions. 

To prevent unnecessary diesel pollution, anti-idling policies [pdf] must be enforced. Idling consumes a half gallon of fuel per hour, and idling for more than three minutes produces 66 percent more pollution than stopping and re-starting the engine.

The Illinois General Assembly passed a law (Public Act 094-0845) that prohibits school buses from idling more than 10 minutes in a 60 minute period (with some exceptions). Additionally, the Chicago Public Schools require that buses not idle for more than 5 minutes, and encourage schools to set up places inside for bus drivers to wait during the colder months.  Parents should talk with school officials to ensure that these rules are being adhered to on a daily basis. 

In order for a school bus to be truly child-friendly, the problem of dangerous diesel emissions must be addressed. Retrofitting, replacing, and reducing idling times are essential to eliminating dangerous diesel soot.

The Illinois Campaign to Clean up Diesel Pollution is committed to raising public awareness of this issue, and to advocating for pollution-reduction policies. You can learn more about the issue from the Respiratory Health Association of Metropolitan Chicago.