Even transient, short term exposure to environmental smoke significantly reduces coronary blood flow in healthy, young non-smokers, a new study has reported.

The research supports arguments that passive smoke is dangerous and a risk factor for ischaemic heart disease; on the basis of epidemiological studies, the American Lung Association has already estimated that passive smoking is responsible for 35 000 to 50 000 cardiovascular deaths a year.

Dr Hiroyuki …