Filters and harm

Despite being labelled the “deadliest fraud in the history of human civilisation”,1 filter tips now feature on almost every mass-produced cigarette smoked across the globe.2 After filters first appeared in the 1860s as an attempt to protect against tobacco flakes entering the mouth,3 the tobacco industry introduced modern cellulose acetate cigarette filters in the 1950s to alleviate public concerns about smoking-related lung cancer.4 Filters and innovations to filters have been consistently marketed as a means to reduce smoking-related health risks,5 with the very name ‘filter’ suggesting reduced harm.6 For instance, filter perforations introduced in the 1970s and 1980s to create ‘light’ and ‘mild’ cigarettes produced lower machine-tested yields of tar and nicotine. When smoking, however, the perforations are blocked by smokers’ fingers,7 8 serving to increase rather than decrease harm as smokers take more frequent and deeper puffs to satisfy nicotine cravings.9 The overwhelming majority of independent research shows that filters do not reduce the harms associated with smoking7–9—a fact understood by tobacco industry scientists in the 1960s.4 In fact, filters may increase the harms caused by smoking by enabling smokers to inhale smoke more deeply into their lungs.8 Furthermore, toxic fibres shed from the cut end of the filter are inhaled and ingested by smokers.3 A recent research letter reporting a study with contradictory findings10 has been criticised for a non-representative sample11 and failing to take into account confounding factors such …