WHO Panel: Diesel Exhaust Causes Cancer Agency labels it a carcinogen By John Johnson, Newser Staff Posted Jun 12, 2012 6:19 PM CDT 16 comments Comments Trucks make their way on eastbound in Livermore, Calif. (AP Photo/Ben Margot) (Newser) – Steer clear of diesel engine exhaust or raise your risk of cancer, a WHO health panel declared today. The International Agency for Research on Cancer labeled the exhaust a carcinogen, putting it on par with asbestos and tobacco, reports Reuters. It specifically cited a link to lung and bladder cancer. How big of an effect the ruling has in the US will depend on whether the EPA or individual states follow suit, a UCLA professor tells the Los Angeles Times. But it's significant no matter what, he adds. “The implications of this decision are immense" because the IARC is so widely respected and is careful not to sound false alarms. "If it says diesel is a human lung carcinogen, you can be sure they are undoubtedly correct." Diesel fuel already is facing a potential threat from natural gas.