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re:air pollutants wording

"The Clean Air Act gives EPA authority to set national standards to protect 
human health and the environment from emissions that pollute ambient 
(outdoor) air.  The act assigns primary responsibility for ensuring adequate 
air quality to the states.  The pollutants regulated under the act can be 
grouped into two categories--"criteria" pollutants and "hazardous air" 
pollutants.  While small in number, criteria pollutants are discharged in 
relatively large quantities by a variety of sources across broad regions of 
the country. Because of their widespread dispersion, the act requires EPA to 
determine national standards for these pollutants.  These national standards 
are commonly referred to as the National Ambient Air Quality Standards 
(NAAQS).  The NAAQS specify acceptable air pollution concentrations that 
should not be exceeded within a geographic area. States are required to meet 
these standards to control pollution and to ensure that all Americans have 
the same basic health and environmental protection.  NAAQS are currently in 
place for six air pollutants:  ozone, carbon monoxide, sulfur dioxide, 
nitrogen dioxide, lead, and particulate matter.  The second category, 
referred to as "hazardous air pollutants" or "air toxics," includes 
chemicals that cause serious health and environmental hazards.  For the most 
part, these pollutants emanate from specific sources, such as auto paint 
shops, chemical factories, or incinerators.  Prior to its amendment in 1990, 
the act required EPA to list each hazardous air pollutant that was likely to 
cause an increase in deaths or in serious illnesses and establish emission 
standards applicable to sources of the listed pollutant.  By 1990, EPA had 
listed seven pollutants as hazardous:  asbestos, beryllium, mercury, vinyl 
chloride, arsenic, radionuclides, and benzene.  However, the agency was not 
able to establish emissions standards for other pollutants because EPA, 
industry, and environmental groups disagreed widely on the safe level of 
exposure to these substances."

this document doesn't list the 189 "hazardous air pollutants" tim refers to 
in an earlier post, but does note that the clean air act "Creates a program 
to monitor and control the 189 hazardous air pollutants."  has anyone found 
a more specific and limiting term than "criteria air pollutants?"
david
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