Researchers at the University of California, Davis, have found that hydrogen peroxide (or similar oxidants) is to blame for lung cancer caused by cigarettes.

The study, printed in the March 2008 edition of the  FASEB Journal, exposed different sets of human lung airway cells (in the laboratory) to cigarette smoke and hydrogen peroxide. After an incubation period, these lung airway cells were compared with unexposed cells for signs of cancer development. The cells exposed to cigarette smoke and hydrogen peroxide had similar signs of cancer development. The unexposed cells did not.

“We hope this study will provide better insight into the identification of new therapeutic targets,” said Tzipora Goldkorn, senior author of the report.

Cigarette smoking is the single most preventable cause of death in the United States, according to the CDC. Smoking causes more than 400,000 deaths per year, and accounts for 90% of lung cancer deaths in men, and 80% of lung cancer deaths in women.

The study’s findings could be the link to developing “safer” cigarettes in addition to pinpointing new targets for lung cancer treatment.