Effect of Charcoal in Cigarette Filters on Free Radicals in Mainstream Smoke

Abstract

The addition of charcoal in cigarette filters may be an effective means of reducing many toxicants from tobacco smoke. Free radicals are a highly reactive class of oxidants abundant in cigarette smoke, and here we evaluated the effectiveness of charcoal to reduce free radical delivery by comparing radical yields from commercially available cigarettes with charcoal-infused filters to those without and by examining the effects of incorporating charcoal into conventional cigarette filters on radical production. Commercial cigarettes containing charcoal filters produced 40% fewer gas-phase radicals than did regular cellulose acetate filter cigarettes when smoked using the International Organization of Standardization (ISO, p = 0.07) and Canadian Intense (CI, p < 0.01) smoking protocols. While mean-particulate-phase radicals were 25-27% lower in charcoal cigarettes, differences from noncharcoal products were not significant ( p = 0.06-0.22). When cellulose acetate cigarette filters were modified to incorporate different types and amounts of activated charcoal, reductions in gas-phase (>70%), but not particulate-phase, radicals were observed. The reductions in gas-phase radicals were similar for the three types of charcoal. Decreases in radical production were dose-responsive with increasing amounts of charcoal (25-300 mg) with as little as 25 mg of activated charcoal reducing gas-phase radicals by 41%. In all studies, charcoal had less of an effect on nicotine delivery, which was decreased 33% at the maximal amount of charcoal tested (300 mg). Overall, these results support the potential consideration of charcoal in cigarette filters as a means to reduce exposure to toxic free radicals from cigarettes and other combustible tobacco products.

Mainstream smoke constituents and in vitro toxicity comparative analysis of 3R4F and 1R6F reference cigarettes

“…The 1R6F Kentucky reference cigarette has been used as a monitor or a comparator cigarette until now only in a limited number of cases, such as a comparator to heated tobacco products and e-cigarettes in in vitro or aerosol composition studies [19,48,49], in a smoking topography study [50], or for small cigar and cigarette studies [51,52]. It has also been used as a reference in a recently published recommended method of CORESTA [53].…”

Preparation of Electrospun Active Molecules Membrane Application to Atmospheric Free Radicals

“…Cigarette smoke contains large amounts of oxidizing radicals [ 28 ]; its free radicals are mainly divided into two parts.One part is the solid phase free radicals present in cigarette tar, which has a long lifetime and mainly contains quinone and PAH free radicals. The other part is the gas-phase radicals present in cigarette smoke, which have a shorter lifetime and mainly include alkoxyl radicals (RO), carbon-nuclear alkyl radicals (R’), and nitrogen oxide radicals, which are primarily present in the gas phase in cigarette smoke.…”

Free Radical and Nicotine Yields in Mainstream Smoke of Chinese Marketed Cigarettes: Variation with Smoking Regimens and Cigarette Brands

“…The 3R4F Kentucky reference cigarette has been widely used as a comparator cigarette for the analysis of mainstream smoke constituents . 1R6F, a replacement cigarette for 3R4F, has also been used as a reference in a limited number of studies. , 3R4F and 1R6F were obtained from the University of Kentucky (Lexington, Kentucky, USA). Five Chinese commercial brands (“BS”, “SX”, “YY”, “LL”, and “ZH”) were selected based on their popularity and combined share of the Chinese cigarette market (Figure and Table ).…”