Appendix C	Santa Clara County: San Jose - Jackson Street Air Quality and Health Risk													Table C-33		

Annual Average Concentrations and Health Risks																
TAC	Conc.*/Risk**	1990	1991	1992	1993	1994	1995	1996	1997	1998	1999	2000	2001	2002	2003	2004
Acetaldehyde	Annual Avg														0.84	0.82
	Health Risk														4	4
Benzene	Annual Avg														0.577	0.502
	Health Risk														53	46
"1,3-Butadiene"	Annual Avg														0.131	0.137
	Health Risk														49	51
Carbon Tetrachloride	Annual Avg														0.096	
	Health Risk														25	
"Chromium, Hexavalent"	Annual Avg														0.098	0.1
	Health Risk														15	15
para-Dichlorobenzene	Annual Avg														0.15	0.15
	Health Risk														10	10
Formaldehyde	Annual Avg														2.79	2.13
	Health Risk														21	16
Methylene Chloride	Annual Avg														0.19	0.16
	Health Risk														<1	<1
Perchloroethylene	Annual Avg														0.04	0.037
	Health Risk														2	1
Diesel PM	Annual Avg	No Monitoring Data Available														
	Health Risk															
Total Health Risk 															179	143

"*    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."																
**  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.