Risk of heart disease in wives raised by smokers
Smoking husbands can increase their wives' risk of heart disease by one and a half to almost four times depending on how long and how heavily they smoke.
This has emerged from research over the past two years by Chinese University involving more than 500 non-smoking women. The study considered only the effect of male smokers on non-smoking wives because 85 per cent of Hong Kong's smokers are men.
The Cardiovascular and Stroke Centre and the Division of Cardiology of the university's Department of Medicine and Therapeutics interviewed 239 women suffering from heart disease, and 268 non-sufferers as a control group, between 2004 and last year.
The study found that, on average, passive smoking in the home increased a wife's risk of coronary heart disease 1.6-fold but this rose to almost 3.6-fold if the husband smoked for 10 years or more and 3.9-fold if he smoked a packet or more a day.
The researchers say the effect could be worse in Hong Kong than elsewhere because most people in the city live in small, crowded flats.
The results showed that 34 per cent of coronary heart disease patients and 25 per cent of the control group were exposed by their husbands to second-hand smoking at home.
'Smoking does not expose only the smoker to higher risk of coronary heart disease, but also the spouse,' the head of the cardiology division, Yu Cheuk-man, said, citing overseas studies which showed that smoking increased the risk of coronary disease by three fold.
'Of course, it is best if the smokers quit. Otherwise, when their husbands puff at home, wives should open more windows and avoid staying in the same room.'
Under a ban that came into force on January 1, smoking is prohibited in all indoor workplaces, restaurants and karaoke lounges.
But Dr Yu was worried that more smokers might light up at home, at the expense of their families' health. 'Smoking at home, making it like a smoking room, can affect the whole family easily, especially in the summer when air-conditioners are usually on.'