PAHs are widespread environmental contaminants formed as a result of incomplete burning of wood, coal, fat in meat, and organic matter. PAHs form, for instance, during the grilling of burgers, steaks and other meat.

'The feeling of safety among some smokeless users is wrong,' said Stepanov. 'A total of 28 carcinogens were identified in smokeless tobacco even before our study,' she said, according to an UM-M release.

'Continued exposure to these over a period of time can lead to cancer. Now we have found even more carcinogens in snuff,' Stepanov added.

Besides the heightened cancer risk, she noted that chronic use of snuff leads to nicotine addiction, just as it does with cigarette smoking.

These findings were presented at the 238th National Meeting of the American Chemical Society (ACS).