restaurants, karaoke rooms, buildings, and public parks (bars which do not admit minors were exempt until 2009). In Romania smoking is illegal in trains, metro stations, public institutions (except where designated, usually outside) and public transport. In Germany, in addition to smoking bans in public buildings and transport, an anti-smoking ordinance for bars and restaurants was implemented in late 2007. A study by the University of Hamburg (Ahlfeldt and Maennig 2010) demonstrates, that the smoking ban had, if any, only short run effects on bar and restaurant revenues. In the medium and long run no negative effect was measurable. The results suggest either, that the consumption in bars and restaurants is not affected by smoking bans in the long run, or, that negative revenue effects by smokers are compensated by increasing revenues through non-smokers. Ignition safety An indirect public health problem posed by cigarettes is that of accidental fires, usually linked with consumption of alcohol. Enhanced combustion using nitrates was traditionally used but cigarette manufacturers have been silent on this subject claiming at first that a safe cigarette was technically impossible, then that it could only be achieved by modifying the paper. Roll your own cigarettes contain no additives and are fire safe. Numerous fire safe cigarette designs have been proposed, some by tobacco companies themselves, which would extinguish a cigarette left unattended for more than a minute or two, thereby reducing the risk of fire. Among American tobacco companies, some have resisted this idea, while others have embraced it. RJ Reynolds was a leader in making prototypes of these cigarettes in 1983 and will make all of their U.S. market cigarettes to be fire-safe by 2010. Phillip Morris is not in active support of it. Lorillard (purchased by RJ Reynolds), the US' 3rd-largest tobacco company, seems to be ambivalent. Gateway drug theory The relationship between tobacco and other drug use has been well-established, however the nature of this association remains unclear. The two main theories are the phenotypic causation (gateway) model and the correlated liabilities model. The causation model argues that smoking is a primary influence on future drug use, while the correlated liabilities model argues that smoking and other drug use are predicated on genetic or environmental factors. One study published by the NIH found that tobacco use may be linked to cocaine addiction and marijuana use. The study stated that 90% of adults who used cocaine had