The U.S. Environmental Protection Agency (EPA) has
identified 21 chemicals in bus and truck exhaust that are known
or suspected to cause cancer or other serious health effects.
These include chemicals such as benzene, formaldehyde,
acetaldehyde and 1,3 butadiene.
Bus emissions also contain
other pollutants that have been linked to respiratory diseases
and other serious health effects. These pollutants include:
Particulate Matter- both black soot you can see and tiny,
invisible particles (a fraction of the width of a human hair) that
can lodge deep in your lungs. Diesel exhaust contains significant
amounts of fine particulate matter. Over 90 percent of diesel
engine particulate emissions are highly respirable and carry
toxins deep into the lung:
Adverse health symptoms have been observed
even at low levels of atmospheric pollution. For ozone and fine
particulate matter, in particular, there does not appear to be a
threshold pollution level below which one can be assured of being at
no risk. The most sensitive people will experience discomfort at low
levels of pollution and are under some degree of stress even if
symptoms are not felt or observed. The various constituents of
vehicle exhaust, and their photochemical products, are known to
either cause or exacerbate a number of ailments. Some of the health
- lung cancer
- cardiovascular disease
- asthma attacks
- chronic bronchitis
- decreased lung function
- impaired immune system function
- shortness of breath
Who is at
There are many groups of people at risk from
emissions from idling vehicles:
Children are more susceptible than
healthy adults because their respiratory system are still
developing and they breathe at a faster rate.
People with existing heart or lung disease, asthma or
other respiratory problems.
- The elderly are also at risk.
This Clean School Bus Site