BERKELEY, Calif., Aug. 17 (UPI) -- Ozone can react with secondhand tobacco smoke to form ultrafine particles that may pose a bigger threat to asthma sufferers than nicotine, U.S. researchers say.
Study leader Mohamad Suleiman, a chemist with the Lawrence Berkeley National Laboratory's environmental energy technologies division, and colleagues say the ultrafine particles become major components of thirdhand smoke -- the residue from tobacco smoke that clings on surfaces, long after a cigarette or cigar has been extinguished.
The study, published in the journal Atmospheric Environment, finds nicotine can react with ozone to form secondary organic aerosols that are less than 100 nanometers in diameter and become a source of thirdhand smoke.
"Because of their size and high surface area to volume ratio, ultrafine particles have the capacity to carry and deposit potentially harmful organic chemicals deep into the lower respiratory tract where they promote oxidative stress," Suleiman says in a statement. "It's been well established by others that the elderly and the very young are at greatest risk."