Appendix C	Los Angeles County: North Main Street Air Quality and Health Risk													Table C-21			

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
Acetaldehyde	Annual Avg	2.68	2.78	2.5	2.89	2.35	1.28	2.33	 	 	1.43	0.84	1.45	1.3	1.39	1.24	1.84
	Health Risk	13	13	12	14	11	6	11	 	 	7	4	7	6	7	6	9
Benzene	Annual Avg	3.5	3.25	2.97	2.54	2.45	2.24	1.86	 	1.36	1.5	1.04	1.03	 	0.853	0.677	0.722
	Health Risk	324	301	275	235	227	207	173	 	126	139	97	95	 	79	63	67
"1,3-Butadiene"	Annual Avg	0.6	0.547	0.643	0.733	0.588	0.599	0.542	 	0.421	0.432	0.296	0.313	 	0.186	0.195	0.164
	Health Risk	226	206	242	276	221	225	204	 	158	162	111	118	 	70	73	62
Carbon Tetrachloride	Annual Avg	0.138	0.134	 	 	 	0.103	0.079	 	0.112	 	0.098	0.086	 	0.095	 	
	Health Risk	36	35	 	 	 	27	21	 	30	 	26	23	 	25	 	
"Chromium, Hexavalent"	Annual Avg	 	 	 	0.24	0.27	0.23	0.17	 	 	0.11	0.13	 	0.133	0.07	 	0.125
	Health Risk	 	 	 	36	40	35	25	 	 	16	19	 	20	11	 	19
para-Dichlorobenzene	Annual Avg	 	0.19	0.22	0.19	0.16	0.19	0.12	 	 	 	0.16	0.17	 	0.16	0.17	0.15
	Health Risk	 	13	14	12	10	13	8	 	 	 	11	11	 	10	11	10
Formaldehyde	Annual Avg	3.5	3	2.3	3.23	3.54	4.13	5.87	 	 	3.88	2.42	4.3	4.32	3.79	5.69	6.64
	Health Risk	26	22	17	24	26	30	43	 	 	29	18	32	32	28	42	49
Methylene Chloride	Annual Avg	1.28	2.72	0.68	1.05	1.06	1.51	1.1	 	0.8	1.2	0.68	0.74	 	0.59	0.5	0.44
	Health Risk	4	9	2	4	4	5	4	 	3	4	2	3	 	2	2	2
Perchloroethylene	Annual Avg	0.551	0.603	0.536	0.588	0.503	0.574	0.502	 	0.232	 	0.187	0.177	 	0.109	0.088	0.087
	Health Risk	22	24	21	24	20	23	20	 	9	 	7	7	 	4	4	3
Diesel PM	Annual Avg	No Monitoring Data Available															
	Health Risk																
Total Health Risk		651	623	583	625	559	571	509	 	326	357	295	296	58	236	201	221
																	
"1  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."																	
2  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.