Acetaldehyde | Acrolein | Acrylonitrile | Benzene |1,3 Butadiene |Carbon Tetrachloride | Chloroform | Ethylene Dichloride | Formaldehyde | Tetrachloroethylene
Acetaldehyde
Primary sources: 
Acrolein
Primary source: 
* Data for 2010-2013 invalidated by AQCD
Acrylonitrile
Primary source: 
* Data for 2010-2013 invalidated by AQCD
Benzene
Primary source:
1, 3 Butadiene
Primary Source: 
Carbon Tetrachloride
Primary source: 
Note due to it's long history of use and extended half-life in the atmosphere, carbon tetrachloride is present world-wide at a concentration of 0.5 ug.m3 (2014)
Chloroform
Primary source:
Ethylene Dichloride
Primary source: 
Formaldehyde
Primary source:
Tetrachloroethylene
Primary source:
