Chapter 5	"Toxic Air Contaminant Emissions, Air Quality, and Health Risk"					Table 5-1

Toxic Air Contaminant Unit Risk Factors						
Toxic Air Contaminant	Unit Risk/Million People*					
Acetaldehyde	2.7					
Benzene	29					
"1,3-Butadiene"	170					
Carbon Tetrachloride	42					
Chromium (Hexavalent)	"150,000"					
para-Dichlorobenzene	11					
Formaldehyde	6					
Methylene Chloride	1					
Perchloroethylene	5.9					
Diesel Particulate Matter	300**					

*    The Unit Risk represents the number of excess cancers per million people						
"per microgram per cubic meter TAC concentration over a 70-year, lifetime exposure."
**   A diesel particulate matter unit risk value of 300 is used as a reasonable estimate
in the “Risk Reduction Plan to Reduce Particulate Matter Emissions from
"Diesel-Fueled Engines and Vehicles” (ARB, October 2000)."