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	2006	2007
Acetaldehyde	Annual Avg	1.3	1.4	1.03	1.31	1.17	0.42	0.83	0.73	0.65	0.76	0.68	0.73	0.63	0.74	0.74	0.71	0.66	0.56
	Health Risk	6	7	5	6	6	2	4	4	3	4	3	4	3	4	4	3	3	3
Benzene	Annual Avg	2.18	1.82	1.49	1.49	1.4	1.26	0.71	0.61	0.71	0.6	0.56	0.425	0.454	0.439	0.372	0.314	0.326	0.274
	Health Risk	202	169	138	138	129	116	66	56	66	55	52	39	42	41	34	29	30	25
"1,3-Butadiene"	Annual Avg	0.359	0.287	0.275	0.367	0.287	0.277	0.218	0.187	0.217	0.17	0.149	0.133	0.137	0.098	0.09	0.075	0.069	0.06
	Health Risk	135	108	103	138	108	104	82	70	82	64	56	50	51	37	34	28	26	23
Carbon Tetrachloride	Annual Avg	0.128	0.125		0.108		0.1	0.078				0.094	0.087	0.089	0.095				
	Health Risk	34	33		29		26	21				25	23	24	25				
"Chromium, Hexavalent"	Annual Avg			0.23	0.2	0.19	0.25	0.13	0.12	0.1	0.1	0.12		0.074	0.096	0.094	0.08	0.063	0.053
	Health Risk			34	29	29	37	19	17	15	15	18		11	14	14	12	9	8
para-Dichlorobenzene	Annual Avg		0.12	0.12	0.12	0.11	0.13	0.14	0.12			0.11	0.14	0.15	0.15	0.17	0.15	0.15	
	Health Risk		8	8	8	7	8	9	8			7	9	10	10	11	10	10	
Formaldehyde	Annual Avg	1.87	1.73	1.43	1.56	1.66	2.06	2.62	1.85	1.76	2.09	1.77	2.32	2.57	2.22	1.71	1.32	1.59	1.45
	Health Risk	14	13	11	11	12	15	19	14	13	15	13	17	19	16	13	10	12	11
Methylene Chloride	Annual Avg	1.04	2.32	0.65	0.72	0.59	0.6	0.58	0.55			0.53	0.27	0.22	0.22	0.14	0.13	0.16	0.13
	Health Risk	4	8	2	2	2	2	2	2			2	<1	<1	<1	<1	<1	<1	<1
Perchloroethylene	Annual Avg	0.204	0.232	0.169	0.128	0.082	0.094	0.067	0.071			0.078	0.059	0.052	0.039	0.035	0.029	0.027	0.031
	Health Risk	8	9	7	5	3	4	3	3			3	2	2	2	1	1	1	1
Diesel PM3	Annual Avg	(2.5)					(1.9)					(1.6)							
	Health Risk	(750)					(570)					(480)							
Average Basin Risk	w/o Diesel PM	403	355	308	366	296	314	225	174	179	153	179	144	162	149	111	93	91	71
	w/ Diesel PM	(1153)					(884)					(659)							





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