Toxic pollutants emitted by cars, trucks, and buses include
benzene, formaldehyde, 1,3-butadiene, acetaldehyde, and diesel
exhaust, all of which are known or probable carcinogens. These
pollutants are also associated with devastating health effects
including miscarriage, reproductive and developmental disorders,
asthma and other respiratory problems. The Clean Air Act
required EPA to complete emission standards for all of the toxic
pollutants - including "at a minimum" benzene and formaldehyde -
by May 1995. The Act further requires that EPA's standards
reflect the "greatest degree of emission reduction achievable,"
considering the agency's other mobile source standards, cost,
safety, energy, and lead-time. But in March 2001, almost six
years after the statutory deadline expired, EPA issued new
standards that require no reductions in any pollutants, and
actually allow emissions of benzene and formaldehyde to
increase. In May 2001, Earthjustice sued the EPA on behalf of
Sierra Club, United States Public Intere