Appendix C	Air Quality and Health Risk		Table C-29										

SANTA CLARA - San Jose - 4th Street - Annual Average Concentrations and Health Risks													
TAC	Conc.*/ Risk**	1990	1991	1992	1993	1994	1995	1996	1997	1998	1999	2000	2001
Acetaldehyde	Annual Avg	1.53	1.55	1.41	1.58	1.27	0.35	1.04	0.97	0.77	0.93	0.79	0.76
	Health Risk	7	8	7	8	6	2	5	5	4	4	4	4
Benzene	Annual Avg	3.02	2.44	2.03	1.89	1.88	1.55	0.97	0.93	1.04	0.73	0.7	
	Health Risk	280	226	188	175	174	144	89	86	97	68	65	
"1,3-Butadiene"	Annual Avg	0.549	0.385	0.436	0.485	0.385	0.348	0.311	0.287	0.293	0.227	0.193	
	Health Risk	207	145	164	182	145	131	117	108	110	85	72	
Carbon Tetrachloride	Annual Avg	0.127	0.128		0.107		0.102	0.077				0.095	
	Health Risk	33	34		28		27	20				25	
Chromium (Hexavalent)	Annual Avg			0.29	0.25	0.25	0.33	0.17	0.13	0.11	0.1	0.13	
	Health Risk			43	37	38	49	25	20	17	15	19	
para-Dichlorobenzene	Annual Avg			0.12	0.12	0.1	0.12	0.14	0.12			0.12	
	Health Risk			8	8	7	8	10	8			8	
Formaldehyde	Annual Avg	2.27	2	2.09	1.83	2.16	2.28	2.7	2.56	2.24	2.69	2.24	2.27
	Health Risk	17	15	15	13	16	17	20	19	16	20	16	17
Methylene Chloride	Annual Avg	0.83	6.65	0.66	0.58	0.8	0.69	0.55	0.75			0.5	
	Health Risk	3	23	2	2	3	2	2	3			2	
Perchloroethylene	Annual Avg	0.161	0.153	0.1	0.094	0.064	0.069	0.068	0.096			0.088	
	Health Risk	6	6	4	4	3	3	3	4			4	
Diesel PM	Annual Avg	No Monitoring Data Available											
	Health Risk												
Total Health Risk		553	457	431	457	392	383	291	253	244	192	215	21

*    Concentrations for Chromium (Hexavalent) are expressed as ng/m3 and concentrations for Diesel PM are expressed as ug/m3.  Concentrations for all other TACs are expressed as parts per billion.													
**   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.