Connecticut Green LEAF Schools

ct greenSchoolLogo
The Connecticut Green LEAF Schools program is a collaborative effort of the Connecticut Departments of Construction Services, Education, Energy and Environmental Protection and Public Health, as well as many Connecticut environmental and educational organizations created to promote green and healthy schools for all.  Find Out More About It: CT Green LEAF Schools


Vehicle Exhaust

Diesel exhaust contains more than 40 chemicals that are listed as hazardous air pollutants under the Clean Air Act. These include chemicals that are known to cause cancer, respiratory illnesses and birth defects. The soot and gases emitted by diesel buses are associated with acute eye, throat and bronchial irritation, exacerbation of allergic responses and can potentially interfere with proper lung growth and development in children. Recent studies link exposure to diesel exhaust to an increase in the frequency and severity of asthma attacks. These studies also link airborne fine particulates, such as those in diesel exhaust, to increased hospital admissions for respiratory diseases, chronic obstructive lung disease, pneumonia, heart disease and up to 60,000 premature deaths annually in the US.

 According to the American Lung Association, “The health risk from diesel exposure is greatest for children, the elderly, people who have respiratory problems or who smoke, people who regularly strenuously exercise in diesel-polluted areas, and people who work or live near diesel exhaust sources. Studies have shown that the proximity of a child's residence to major roads is linked to hospital admissions for asthma, and there is a positive relationship between school proximity to freeways and asthma occurrence. Truck and traffic intensity and exhaust measured in schools were significantly associated with chronic respiratory symptoms.”

 Children are more vulnerable to the health effects of exposure to diesel exhaust than adults. Their lungs are still developing and they breathe faster than adults, taking in 50% more air per pound of body weight than adults. School children are exposed to diesel exhaust while waiting to board idling school buses and while traveling on school buses. They are also exposed while inside schools from exhaust that has entered through outdoor air intakes, doors and windows   School bus drivers are constantly exposed to the risks of inhaling diesel exhaust. Teachers and school administrators who are assigned to bus duty are also at risk. Adults with heart disease and pregnant women are especially vulnerable to the harmful effects of diesel exhaust exposure.

 Schools can minimize the exposure of students and staff to diesel exhaust fumes by:

 -          Eliminating unnecessary school bus and other vehicles idling

 -          Installing effective emission control systems on newer buses

 -          Fueling buses with cleaner fuels

 -          Replacing old buses with newer, less polluting ones

 -          Locating areas where cars and buses idle as far away as possible from outdoor air intakes, classroom windows and doors.

 Special Note:

Connecticut law now prohibits vehicles of all kinds from unnecessary idling for more than 3 minutes.  Provisions are made for weather extremes, certain service vehicles and health-related conditions.

Statute:  R.C.S.A. 22a-174-18   

- This regulation applies to ALL vehicles in Connecticut and is enforced by DEEP Field Staff.


Summary of CT LAW dealing with school bus emissions:

(CT General Statutes Section Nos. 14-164 n and o, 14-277, 22a-21k and 22a-21j)

1. Prohibits school bus drivers from idling bus engines for more than three consecutive minutes when the bus is stopped except where:

-          the bus is stopped because of traffic conditions or mechanical problems over which the driver has no control;

-          it is necessary to operate heating, cooling, or auxiliary equipment needed for the proper operation of the bus, such as the operation of safety equipment;


-          the outside temperature is below 20 degrees Fahrenheit;

-          it is necessary to maintain a safe temperature for special needs students;


-          the bus is being repaired; or

-          the driver is picking up or discharging passengers on a public highway or public road.

2.  Establishes fines for noncompliance: A first violation is an infraction, for which the total amount due is $ 102, if paid by mail. Subsequent offenses are punishable by fines of between $ 100 and $ 500. Fines are enforceable by local police.

3.  Requires certain full-sized buses to be retrofitted with emissions-reducing equipment by September 1, 2010.

4.  Requires, as an alternative, that a bus must meet US EPA 2007 emissions standards or use compressed natural gas or another alternative fuel certified by either the EPA or the California Air Resources Board in order to reduce soot emissions by at least 85% compared to ultra low sulfur diesel fuel.

 5. Establishes CT Department of Environmental Protection (DEP) grants to cover the retrofitting costs

 6. Requires CT DEP to develop an outreach plan to educate municipalities, school boards and bus companies about the law and help them with the retrofits.



Question: How has your school dealt with vehicle exhaust problems?

Answer: We have posted NO IDLING signs in all parking areas and at all student drop-off points near the building.




CT Department of Energy & Environmental Protection:

School Anti-Idling Information


CT DEP Clean Diesel Plan:



Environment and Human Health, Inc. website section on Asthma:


Environment and Human Health, Inc. website section on Vehicle Exhaust:


EPA Clean School Bus USA Program:


EPA Regulations on Diesel Exhaust in the United States:

diesel exhaust in US.pdf


EPA School Buses and Health:

EPA school bus fact sheet



EPA TfS IAQ Reference Guide Appendix I – Emissions from motor vehicles and equipment:


Fact sheet on Clean Diesel Fuel:

clean diesel fuel.pdf


Fact sheet on Clean Fuel Options:

clean fuel options.pdf


CT Tools for Schools Heroes