California Air Resources Board 2006 Almanac (web)			
Chapter 5	Table 5-7		Statewide
"1,3-Butadiene"			
County	Air Basin	tons/year	Percent
Los Angeles	South Coast	410	15%
San Diego	San Diego	190	7%
Orange	South Coast	139	5%
Tulare	San Joaquin Valley	109	4%
Santa Clara	San Francisco Bay Area	93	3%
San Bernardino	South Coast	78	3%
Alameda	San Francisco Bay Area	77	3%
Fresno	San Joaquin Valley	76	3%
Riverside	South Coast	69	2%
Sacramento	Sacramento Valley	66	2%