Carcinogenicity of PAHs in smoke
Smoke contains large volumes of particlate matter air pollution and is highly toxic and carcinogenic due primarily to the presence of Polycyclic Aromatic Hydrocarbons (PAHs).

Polycyclic Aromatic Hydrocarbons (PAHs) are a group of chemicals that are formed during the incomplete burning of coal, oil, gas, wood, garbage, or other substances. There are more than 100 different PAHs.  In the environment, you are most likely to be exposed to PAH vapors or PAHs that are attached to dust and other particles in the air. Sources include cigarette smoke, vehicle exhausts, asphalt roads, coal, coal tar, wildfires, agricultural burning, residential wood burning, municipal and industrial waste incineration, and hazardous waste sites. EPA and others have determined that Dibenz[a]anthracene is the most toxic PAH, with a Toxicity Equivalency Factor (TEF) of 5; and Benzo[a]pyrene, the next most toxicwith a TEF of 1.  Particle-bound PAHs can be transported long distances and removed from the atmosphere through precipitation and dry deposition.

Examples of PAHs include:

CAS
No.               
Chemical                Carcinogenic
status
56-55-3

Benz[a]anthracene      Reasonably 

Anticipated Carcinogen, Known to cause
cancer
205-99-2        

Benzo[b]fluoranthene    Reasonably
Anticipated Carcinogen, Known to cause cancer
205-82-3       

Benzo[j]fluoranthene    Reasonably
Anticipated Carcinogen, Known to cause cancer
207-08-9      

 
Benzo[k]fluoranthene    Reasonably
Anticipated Carcinogen, Known to cause cancer
50-32-8

Benzo[a]pyrene  Reasonably Anticipated
Carcinogen,  Known to cause cancer
218-01-9      

 
Chrysene         Known to cause cancer
226-36-8       

Dibenz[a,h]acridine    
Reasonably Anticipated Carcinogen, Known to cause
cancer
224-42-0     

Dibenz[a,j]acridine    
Reasonably Anticipated Carcinogen, Known to cause
cancer
53-70-3

Dibenz[a,h]anthracene    
Reasonably Anticipated Carcinogen, Known to cause cancer
194-59-2       

7H-Dibenzo[c,g]carbazole  Reasonably Anticipated
Carcinogen,  Known to cause cancer
192-65-4       

Dibenzo[a,e]pyrene     
Reasonably Anticipated Carcinogen, Known to cause
cancer
189-64-0       

Dibenzo[a,h]pyrene     
Reasonably Anticipated
Carcinogen        Known
to cause cancer
189-55-9 

Dibenzo[a,i]pyrene     
Reasonably Anticipated
Carcinogen       Known to
cause cancer
191-30-0 

Dibenzo[a,l]pyrene     
Reasonably Anticipated
Carcinogen        Known
to cause cancer
57-97-6 

7,12-Dimethylbenz(a)anthracene Known to cause
cancer
193-39-5      

 
Indeno [1,2,3-cd]pyrene Reasonably Anticipated
Carcinogen        Known
to cause cancer
3697-24-3

5-Methylchrysene       
Reasonably Anticipated
Carcinogen        Known
to cause cancer