California Air Resources Board 2007 Almanac (web)			
Chapter 5	Table 5-8		Statewide
"1,3-Butadiene"			
County	Air Basin	tons/year	Percent
Los Angeles	South Coast	437	12%
San Diego	San Diego	241	7%
Tulare	San Joaquin Valley	156	4%
Orange	South Coast	135	4%
San Bernardino	South Coast	110	3%
San Bernardino	Mojave Desert	109	3%
Fresno	San Joaquin Valley	108	3%
Tuolumne	Mountain Counties	99	3%
Siskiyou	Northeast Plateau	98	3%
Trinity	North Coast	87	2%