Appendix C	Butte County: Chico - Salem Street Air Quality and Health Risk													Table C-46			

Annual Average Concentrations and Health Risks																	
TAC	Conc.1/Risk2	1990	1991	1992	1993	1994	1995	1996	1997	1998	1999	2000	2001	2002	2003	2004	2005
Acetaldehyde	Annual Avg	1.27	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 
	Health Risk	6	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 
Benzene	Annual Avg	1.96	1.91	 	 	 	 	 	 	 	 	 	 	 	 	 	 
	Health Risk	182	177	 	 	 	 	 	 	 	 	 	 	 	 	 	 
"1,3-Butadiene"	Annual Avg	0.403	0.361	 	 	 	 	 	 	 	 	 	 	 	 	 	 
	Health Risk	151	136	 	 	 	 	 	 	 	 	 	 	 	 	 	 
Carbon Tetrachloride	Annual Avg	0.123	0.123	 	 	 	 	 	 	 	 	 	 	 	 	 	 
	Health Risk	32	33	 	 	 	 	 	 	 	 	 	 	 	 	 	 
"Chromium, Hexavalent"	Annual Avg	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 
	Health Risk	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 
para-Dichlorobenzene	Annual Avg	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 
	Health Risk	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 
Formaldehyde	Annual Avg	1.49	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 
	Health Risk	11	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 
Methylene Chloride	Annual Avg	0.53	0.57	 	 	 	 	 	 	 	 	 	 	 	 	 	 
	Health Risk	2	2	 	 	 	 	 	 	 	 	 	 	 	 	 	 
Perchloroethylene	Annual Avg	0.047	0.054	 	 	 	 	 	 	 	 	 	 	 	 	 	 
	Health Risk	2	2	 	 	 	 	 	 	 	 	 	 	 	 	 	 
Diesel PM	Annual Avg	No Monitoring Data Available															
	Health Risk																
Total Health Risk		386	350	 	 	 	 	 	 	 	 	 	 	 	 	 	 
																	
"1  Concentrations for Hexavalent Chromium are expressed as ng/m3, and concentrations for Diesel PM are expressed as ug/m3.  Concentrations for all other TACs are expressed as ppb."																	
2  Health Risk represents the number of excess cancer cases per million people based on a lifetime (70-year) exposure to the annual average concentration.  Total Health Risk represents only those compounds listed in																	
this table and only those with data for that year.  There may be other significant compounds for which monitoring and/or health risk information are not available.