California Air Resources Board 2009 Almanac (web)			
Chapter 5	San Diego		Table 5-58
"San Diego - 1,3-Butadiene"			
Emissions Source	tons/year	Percent Air Basin	Percent State
Stationary Sources	1	1%	0%
Area-wide Sources	13	6%	0%
On-Road Mobile	85	36%	2%
   Gasoline Vehicles	83	35%	2%
   Diesel Vehicles	2	1%	0%
Other Mobile	82	35%	2%
   Gasoline Fuel	52	22%	1%
   Diesel Fuel	5	2%	0%
   Other Fuel	25	11%	1%
Natural Sources	52	22%	1%
Total	233	100%	6%
Total Statewide	3754