Persistent free radicals (PFRs), a newly discovered air pollutant, could be as harmful as cigarette smoke, say researchers of Louisiana University in Baton Rouge. These atoms, molecules, and fragments of molecules are highly reactive and damage cells. This could help explain why non-smokers develop tobacco-related diseases like lung cancer. Free radicals are formed during the burning of fuels or in photochemical processes like those that form ozone. Most of the previously identified atmospheric free radicals form gases, exist for less than a second. In contrast, PFRs form on airborne nanoparticles and other fine particle residues as gases cool in smokestacks, automotive exhaust pipes and household chimneys. These can linger in air and travel distances. Smokers get a double dose of PFRs every time they light up since tobacco smoke also contains these molecules.

Source: Down To Earth, September 2008