China's rising income levels could literally go tip in smoke. A recent article in the Journal of the American Medical Association maintains that lung cancer rates for the Chinese population was increasing by 4.5 per cent per annum and that 900,000 people a year could be killed by lung cancer by the year 2025. Even modest incomes do not seem to dissuade the hardened smoker. The report points out that the Chinese were open to spending an average of 60 per cent of personal income and 17 per cent of household income to buy cigarettes. The study also causes alarm for another reason. Cigarettes sold in China pose a greater health risk because they have a higher tar content and are more likely to be unfiltered than those sotd in the us. "Future prospects could be even grimmer," says the study.