Annual Average Concentration*										Health Risk**									
COUNTY	SITE NAME	TAC	1990	1991	1992	1993	1994	1995	1996	1997	1998	1999	1990	1991	1992	1993	1994	1995	1996	1997	1998	1999
Los Angeles	Burbank-West Palm Avenue	Acetaldehyde	3.16	3.89		3.06	2.46	0.79			1.94	2.7	15	19		15	12	4			10	13
		Benzene	4.79	3.91	3.44	2.63	3.33	2.45	1.91	1.48	1.66	1.64	444	362	319	244	308	227	177	137	154	151
		"1,3-Butadiene"	0.78	0.62	0.73	0.75	0.75	0.61	0.51	0.42	0.48	0.48	294	234	272	282	283	227	192	158	182	181
		Carbon Tetrachloride	0.14	0.13				0.1	0.08		0.11		37	35				28	22		30	
		Chromium (Hexavalent)			0.65	0.37	0.43	1.24			0.23				97	55	64	186			34	
		para-Dichlorobenzene		0.23	0.22	0.19	0.14	0.2	0.1	0.11				15	15	13	9	13	7	7		
		Formaldehyde	4.05	3.59		3.66	3.92	4.58			4.72	6.07	30	27		27	29	34			35	45
		Methylene Chloride	3.25	1.69	1.42	2.01	1.94	1.82	1.41	1.11	1.07		11	6	5	7	7	6	5	4	4	
		Perchloroethylene	1.19	0.79	0.61	0.62	0.66	0.49	0.44	0.37	0.5		48	31	24	25	27	20	18	15	20	
		Diesel PM	No Monitoring Data Available																			
	Total Health Risk												879	729	732	667	738	744	420	321	468	390

	Los Angeles-North Main Street	Acetaldehyde	2.68	2.78	2.5	2.89	2.35	1.28	2.33			1.43	13	14	12	14	11	6	11			7
		Benzene	3.5	3.25	2.97	2.54	2.45	2.24	1.86		1.36	1.5	324	301	275	235	227	207	173		126	139
		"1,3-Butadiene"	0.6	0.55	0.64	0.73	0.59	0.6	0.54		0.42	0.43	226	206	242	276	221	225	204		158	162
		Carbon Tetrachloride	0.14	0.13				0.1	0.08		0.11		37	35				27	21		30	
		Chromium (Hexavalent)				0.24	0.27	0.23	0.17							36	40	35	25			
		para-Dichlorobenzene		0.19	0.22	0.19	0.16	0.19	0.12					13	14	12	11	13	8			
		Formaldehyde	3.5	3	2.3	3.23	3.54	4.13	5.87			3.88	26	22	17	24	26	30	43			29
		Methylene Chloride	1.28	2.72	0.68	1.05	1.06	1.51	1.1		0.8	1.2	4	9	2	4	4	5	4		3	4
		Perchloroethylene	0.55	0.6	0.54	0.59	0.5	0.57	0.5		0.23		22	24	21	24	20	23	20		9	
		Diesel PM	No Monitoring Data Available																			
	Total Health Risk												652	624	584	624	560	572	510		326	341

	North Long Beach	Acetaldehyde	2.49	2.52		2.36	2.18	0.81		1.43			12	12		12	11	4		7		
		Benzene	3.53	2.45	2.6	1.99	2.04	1.69		1.24	1.16	1.11	327	227	241	185	188	157		115	108	103
		"1,3-Butadiene"	0.59	0.44	0.52	0.58	0.45	0.45		0.36	0.34	0.32	223	165	197	216	168	169		137	127	121
		Carbon Tetrachloride	0.14	0.13				0.1			0.12		37	34				26			31	
		Chromium (Hexavalent)			0.44	0.34	0.22	0.25		0.15	0.11				66	51	33	38		22	16	
		para-Dichlorobenzene		0.17	0.26	0.19	0.12	0.17		0.16				11	17	13	8	11		10		
		Formaldehyde	2.97	2.76		3.22	3.06	3.29		3.68			22	20		24	23	24		27		
		Methylene Chloride	2.05	0.88	1	1.15	0.84	0.98		0.74	0.6		7	3	4	4	3	3		3	2	
		Perchloroethylene	0.48	0.36	0.35	0.43	0.32	0.32		0.23	0.19		19	14	14	17	13	13		9	8	
		Diesel PM	No Monitoring Data Available																			
	Total Health Risk												647	487	539	521	446	445		330	292	224

			Annual Average Concentration*										Health Risk**									
COUNTY	SITE NAME	COMPOUND	1990	1991	1992	1993	1994	1995	1996	1997	1998	1999	1990	1991	1992	1993	1994	1995	1996	1997	1998	1999
Riverside	Riverside-Rubidoux	Acetaldehyde	1.87	2.54	1.86	2.19	2.08	0.89	1.84			1.36	9	12	9	11	10	4	9			7
		Benzene	2.55	2.22	1.9	1.77	2.01	1.45	1.03			0.87	236	206	176	164	186	134	95			80
		"1,3-Butadiene"	0.34	0.31	0.29	0.38	0.36	0.33	0.27			0.21	128	117	110	143	136	125	100			78
		Carbon Tetrachloride	0.13	0.14				0.1	0.08				35	36				27	21			
		Chromium (Hexavalent)			0.33	0.33	0.36	0.38	0.22						50	50	55	56	33			
		para-Dichlorobenzene		0.13	0.13	0.16	0.12	0.17	0.11					9	8	10	8	11	7			
		Formaldehyde	1.75	2.7	1.53	2.73	2.5	2.65	4.15			3.55	13	20	11	20	18	20	31			26
		Methylene Chloride		0.69	0.6	1.1	0.93	0.98	0.83			0.58		2	2	4	3	3	3			2
		Perchloroethylene	0.24	0.28	0.2	0.2	0.19	0.18	0.18				10	11	8	8	8	7	7			
		Diesel PM	No Monitoring Data Available																			
	Total Health Risk												430	413	375	410	424	388	306			193

San Bernardino	Upland-San Bernardino Road	Acetaldehyde	2.12	3.28	2.36	2.84	2.42	1.09	2.13				10	16	12	14	12	5	10			
		Benzene	2.73	2.7	2.14	1.92	2.15	1.62	1.11	1.11			253	250	198	178	199	150	103	103		
		"1,3-Butadiene"	0.35	0.34	0.31	0.39	0.34	0.31	0.26	0.25			131	128	116	147	126	117	97	95		
		Carbon Tetrachloride	0.13	0.14		0.1		0.1	0.08				35	36		27		26	20			
		Chromium (Hexavalent)			0.22	0.16	0.16	0.2	0.12						33	24	24	30	17			
		para-Dichlorobenzene		0.13	0.14	0.14	0.1	0.13	0.1	0.14				9	9	9	7	9	7	9		
		Formaldehyde	2.35	3.34	1.98	3.25	2.67	3.21	5.2				17	25	15	24	20	24	38			
		Methylene Chloride	1.41	1.59	0.82	0.87	0.72	1.13	0.66	1.7			5	6	3	3	3	4	2	6		
		Perchloroethylene	0.42	0.72	0.36	0.4	0.29	0.26	0.2	0.21			17	29	15	16	11	11	8	8		
		Diesel PM	No Monitoring Data Available																			
	Total Health Risk												469	498	400	442	401	375	302	222		

	Fontana-Arrow Highway	Acetaldehyde																				
		Benzene									0.98										91	
		"1,3-Butadiene"									0.24										92	
		Carbon Tetrachloride									0.11										30	
		Chromium (Hexavalent)																				
		para-Dichlorobenzene																				
		Formaldehyde																				
		Methylene Chloride									0.59										2	
		Perchloroethylene									0.18										7	
		Diesel PM	No Monitoring Data Available																			
	Total Health Risk																				222	
			Annual Average Concentration*										Health Risk**									
COUNTY	SITE NAME	COMPOUND	1990	1991	1992	1993	1994	1995	1996	1997	1998	1999	1990	1991	1992	1993	1994	1995	1996	1997	1998	1999
All Counties	BASIN SUMMARY	Acetaldehyde	2.46	3	2.46	2.67	2.3	0.97	2.08	1.77	1.54	1.63	12	15	12	13	11	5	10	9	8	8
		Benzene	3.42	2.91	2.61	2.17	2.4	1.89	1.45	1.34	1.25	1.2	317	269	242	201	222	175	134	124	116	111
		"1,3-Butadiene"	0.53	0.45	0.5	0.57	0.5	0.46	0.39	0.38	0.35	0.33	200	170	187	212	187	173	146	142	133	123
		Carbon Tetrachloride	0.14	0.13		0.11		0.1	0.08		0.11		36	35		28		27	21		30	
		Chromium (Hexavalent)			0.39	0.29	0.29	0.46	0.18	0.17	0.15				59	43	43	69	27	25	22	
		para-Dichlorobenzene		0.17	0.19	0.17	0.13	0.17	0.11	0.13				11	13	12	8	11	7	9		
		Formaldehyde	2.92	3.08	2.22	3.22	3.14	3.57	5.06	4.47	3.79	4.06	22	23	16	24	23	26	37	33	28	30
		Methylene Chloride	1.86	1.51	0.9	1.23	1.1	1.28	0.95	1.14	0.85	0.92	7	5	3	4	4	5	3	4	3	3
		Perchloroethylene	0.58	0.55	0.41	0.45	0.39	0.36	0.32	0.27	0.26		23	22	17	18	16	15	13	11	10	
		Diesel PM***	-3.6					-2.7				-2.4	-1080					-810				-720
	Average Basin Health Risk												616	550	548	554	514	505	398	356	350	275

"*      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 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 the year.  There may be other significant compounds for which monitoring and/or health risk information are not available.  																						
"***   The Diesel PM concentrations are estimates based on receptor modeling.  The 1999 concentrations reflect an estimate for the year 2000.  Because data are not available for all years, Diesel PM is not included in the "																						
         Average Basin Health Risk number.