The use of charcoal in modified cigarette filters for mainstream smoke carbonyl reduction.

Carbonyls are harmful and potentially harmful constituents (HPHCs) in mainstream cigarette smoke (MSS). Carbonyls, including formaldehyde and acrolein, are carcinogenic or mutagenic in a dose-dependent manner. Past studies demonstrate significant reduction of HPHCs by charcoal filtration. However, limits of charcoal filtration and cigarette design have not yet been investigated in a systematic manner. Objective data is needed concerning the feasibility of HPHC reduction in combustible filtered cigarettes. This systematic study evaluates the effect of charcoal filtration on carbonyl reduction in MSS. We modified filters of ten popular cigarette products with predetermined quantities (100-400 mg) of charcoal in a plug-space-plug configuration. MSS carbonyls, as well as total particulate matter, tar, nicotine, carbon monoxide (TNCO), and draw resistance were quantified. Significant carbonyl reductions were observed across all cigarette products as charcoal loading increased. At the highest charcoal loadings, carbonyls were reduced by nearly 99%. Tar and nicotine decreased modestly (<20%) compared to reductions in carbonyls. Increased draw resistance was significant at only the highest charcoal loadings. This work addresses information gaps in the science base that can inform the evaluation of charcoal filtration as an available technological adaptation to cigarette design which reduces levels of carbonyls in MSS.

Stabilities of hemoglobins A and S in dried blood spots stored under controlled conditions.

OBJECTIVE: We aimed to measure separately the contributions of heat and humidity to changes in levels of hemoglobins A and S in dried-blood-spot (DBS) samples. DESIGN AND METHODS: We stored paired sets of DBSs at 37°C for predetermined intervals in low-humidity and high-humidity environments. Hemoglobin A and S levels of all samples in each complete set were measured in a single high performance liquid chromatography run. RESULTS: During the one-month storage intervals, both hemoglobin species lost about 35% of initial levels in low-humidity storage and almost all of initial levels in high-humidity storage. CONCLUSIONS: Minimizing both humidity and temperature in the transportation and storage environments of DBS samples is essential to maintaining the integrity of the hemoglobin tetramer molecules.