Marlboro UltraSmooth: a potentially reduced exposure cigarette?

AIM: To compare relative toxic emissions scores (RTE) of the carbon filter cigarette Marlboro UltraSmooth (MUS), against regular Marlboro, Holiday, and British Columbian brands.
METHOD: MUS cigarettes were purchased in Tampa, Florida; Marlboro regular and Holiday were purchased in Auckland, New Zealand, and all emissions tested by Labstat International Inc, Kitchener, Ontario under Health Canada Intensive (HCI) machine-smoking conditions (55 ml puff per 30 seconds, filter ventilation holes blocked) against: (1) previous same brand emissions tested under ISO (International Organization for Standardization) conditions; (2) ISO and HCI average emissions for 16 regular brands sold in British Columbia (BC), the reference standard. Toxicants, selected by toxicological risk assessment, enabled estimation of an RTE per brand, and RTE per mg of nicotine.
RESULTS: The BC standard for RTE in both ISO and HCI test modes, including metals and nitrosamines, was set at 100. Hereafter excluding them, RTE in ISO mode for BC was 97, MUS 4, Marlboro 102, and Holiday regular 99; and in HCI test mode BC was 97, MUS 42, Marlboro regular 107, and Holiday 95. From ISO to HCI, MUS total puff volume increased 50%, from 252 ml to 380 ml; nicotine yield increased 2.6 fold. Normalising for nicotine (RTE per mg nicotine), in ISO test mode, the BC standard was 97, MUS 10, Marlboro regular 124, and Holiday regular 107. In HCI mode, however, MUS/nicotine at 104 exceeded the average BC standard of 97; Marlboro regular was 137, and Holiday regular 97; MUS ranked sixth highest among 18 regular brands. MUS contained 103 mg of carbon in its 304 mg filter, which was 55% ventilated.
CONCLUSION: The combined acetate-carbon filter of MUS performed best at low smoke volumes on ISO testing. Under more smoker-realistic intensive machine testing, and correcting for relative nicotine concentration and compensatory smoking, MUS increased the RTE, for all toxicants combined, for carcinogens, and for cardiovascular toxicants, compared with most regular brands. MUS was not a potentially reduced-exposure product (PREP) under smoker-realistic test conditions, and thus would not be expected to reduce overall harm. It is unrealistic to expect that even major design changes, as seen in MUS, or a regulatory framework to enforce such changes, could reduce cigarette smoking mortality risks to acceptable levels.