NRDC: No Breathing in the Aisles: Diesel Exhaust Inside School ...

CHAPTER 2
THE SERIOUS
HEALTH IMPACTS
OF DIESEL EXHAUST
12
Diesel exhaust poses a significant health hazard; children are among the
most susceptible to its deleterious effects.
illions of people are exposed on a daily basis to a significant risk from diesel
exhaust. Diesel exhaust has been demonstrated in more than 30 human epidemiological
studies to increase cancer risk. Diesel exhaust contains hundreds of
constituent chemicals, dozens of which are recognized as human toxicants, carcinogens,
reproductive hazards, or endocrine disruptors. 28 Diesel particles also contribute to premature
deaths, increase respiratory illnesses, and exacerbate asthma cases. Nitrogen oxides (NOx),
another significant component of diesel exhaust, is a major contributor to ozone production
and smog, and has recently been connected with decreased lung function growth in children. 29
Unfortunately, children are among those most susceptible to the health effects of diesel
exhaust, yet school bus fleets continue to include some of the oldest and most polluting buses
on the road today. 30
M
DIESEL EXHAUST AND THE INCREASED RISK OF CANCER
Over two dozen well-designed occupational studies have demonstrated that long-term
exposure to diesel exhaust significantly increases the human incidence of long-term lung
cancer and possibly of bladder cancers. The National Institute for Occupational Safety and
Health, the International Agency for Research on Cancer, EPA, and the National Toxicology
Program have all consistently agreed that there is a relationship between diesel exhaust
exposure and lung cancer. 31 In addition, the state of California listed diesel exhaust as a
known carcinogen in 1990 under its Safe Drinking Water and Toxic Enforcement Act
(Proposition 65), and in 1998 the California Air Resources Board (CARB) listed diesel
particulate as a Toxic Air Contaminant (TAC), also based on its carcinogenicity. Over 40
individual chemical compounds in diesel exhaust have separately been listed as TACs. 32
Many of these chemicals are also identified by EPA as compounds that cause cancer. 33
A March 2000 study by the South Coast Air Quality Management District (SCAQMD) in
Southern California estimated the average cancer risk attributed to the carcinogenic
components in the air of the South Coast to be about 1,400 in a million. 34 Significantly,