And, Inhale: Scientists recently found a class of pollutants that may be a major cause of lung cancer. tskdesign (CC Licensed)

Think smoking is bad for you? Try just breathing. Louisiana scientists have discovered a group of previously undetected air pollutants that when inhaled exposes the average person to 300 times more free radicals than that of one cigarette in a day.

Scientists have long suspected that free radicals from tobacco smoke can damage human cells and accelerate the progression of cancer or cardiovascular disease among other health-related problems. These free radicals, which are highly reactive compounds that form during the burning of fuels and photochemical processes, usually last for about a second and then disappear. However, the new class of pollutants is unlike atmospheric free radicals and can linger in the air for days or longer as well as travel far distances.

Scientists, who termed the air pollutants persistent free radicals (PFRs), say they form on fine airborne particles, usually the main culprit behind air pollution alerts in a lot of cities. Even worse are the particles with metals like copper and iron, which are more likely to persist. When inhaled, the lungs and other tissues absorb the PFRs, causing health effects similar to smoking. While more research is needed to tie PFRs to certain diseases, scientists believe this could explain why 10 to 15 percent of those diagnosed with lung cancers are non-smokers.

Via PhysOrg