The nicotine in tobacco has toxicity effects over the central nervous system, it makes the pilot suffer from systemic vasoconstriction resulting in decreased vision, as well as air pollution, and even leads to possible fire accidents. In 1983, the General Administration of Civil Aviation of China issued regulations to prohibit smoking on domestic airline passenger flight. In view of the dangers of smoking, the ICAO 153 member states in October of 1992 in Montreal, Canada passed a resolution requiring national airlines to prohibit passengers from smoking prior to July 1, 1996 on international flights. In June 1993, the General Administration of Civil Aviation of China decided that, with effect from July 1 of that year, the progressive introduction of non-smoking international airline passenger flight will be started in order to protect the health of travelers.
Source: Civil Aviation Administration of China (CAAC, 中国民用航空局)