BMJ - Mortality associated with passive smoking in Hong Kong (McGhee et al 2005)

There's plenty of evidence for the association between cigarette smoke on one hand and lung cancer, coronary heart disease, and stroke on the other. This study, based on retrospective study of Hong Kongese patients, confirmed again the association of passive smoking with stroke, COPD, and lung cancer. The does-response curve is that much more dramatic in this particular study perhaps due to the crowded living conditions not atypical for urban cities in Asia.

We note that China, with 20% of the world's population, smokes 30% of the world's cigarettes! (sorry can't locate original source)

This is a follow-up to their 2001 case-control study:

In the general population of Hong Kong in 1998 tobacco caused about 33% of all male deaths at ages 35�69 plus 5% of all female deaths, and hence 25% of all deaths at these ages.

In the male smokers tobacco caused about half of all deaths at ages 35 to 69