Appendix C	South Coast Air Quality and Health Risk										Table C-23			

Annual Average Concentrations and Health Risks														
TAC	Conc.*/Risk**	1990	1991	1992	1993	1994	1995	1996	1997	1998	1999	2000	2001	2002
Acetaldehyde	Annual Avg	2.46	3.00	2.46	2.67	2.30	0.97	2.08	1.77	1.54	1.63	1.26	1.47	1.41
	Health Risk	12	15	12	13	11	5	10	9	7	8	6	7	7
Benzene	Annual Avg	3.42	2.91	2.61	2.17	2.40	1.89	1.45	1.34	1.25	1.20	0.97	0.86	0.77
	Health Risk	317	269	242	201	222	175	134	124	116	111	90	80	71
"1,3-Butadiene"	Annual Avg	0.53	0.45	0.50	0.57	0.50	0.46	0.39	0.38	0.35	0.33	0.25	0.25	0.21
	Health Risk	200	170	187	212	187	173	146	142	133	123	94	94	79
Carbon Tetrachloride	Annual Avg	0.14	0.13		0.11		0.10	0.08		0.11		0.10	0.09	0.09
	Health Risk	36	35		28		27	21		30		25	23	24
Chromium (Hexavalent)	Annual Avg			0.39	0.29	0.29	0.46	0.18	0.17	0.15	0.14	0.18		
	Health Risk			59	43	43	69	27	25	22	22	27		
para-Dichlorobenzene	Annual Avg		0.17	0.19	0.17	0.13	0.17	0.11	0.13			0.13	0.15	0.16
	Health Risk		11	13	11	8	11	7	9			9	10	11
Formaldehyde	Annual Avg	2.92	3.08	2.22	3.22	3.14	3.57	5.06	4.47	3.79	4.06	3.13	4.13	4.16
	Health Risk	22	23	16	24	23	26	37	33	28	30	23	30	31
Methylene Chloride	Annual Avg	1.86	1.51	0.90	1.23	1.10	1.28	0.95	1.14	0.85	0.92	0.83	0.63	0.57
	Health Risk	6	5	3	4	4	4	3	4	3	3	3	2	2
Perchloroethylene	Annual Avg	0.58	0.55	0.41	0.45	0.39	0.36	0.32	0.27	0.26		0.21	0.18	0.15
	Health Risk	23	22	16	18	16	15	13	11	10		8	7	6
Diesel PM***	Annual Avg	(3.6)					(2.7)					(2.4)		
	Health Risk	(1080)					(810)					(720)		
Average Basin Health Risk		616	550	548	554	514	505	398	357	349	297	285	253	258

"*    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.														
"*** The Diesel PM concentrations are estimates based on receptor modeling.  Because data are not available for all years, Diesel PM is not included in the Average Basin Health Risk number."