Second-hand smoke can increase the chance of developing cardiovascular disease, it has been suggested.
According to a recent study published in the Journal of the American College of Cardiology, exposure to other people's smoke results in inflammation.
Elevated levels of this low-grade inflammation were concluded to be the cause of death in otherwise healthy British adults who had been exposed to second-hand smoke.
June Davison, senior cardiac nurse at the British heart Foundation, commented: "There is clear evidence that passive smoking increases the risk of developing heart disease."
She added: "One study has even shown that non-smokers living with smokers have a 30 per cent increased risk of developing the disease."
Earlier this year the American Heart Association revealed that air pollution is also contributing to cases of heart disease.
A "small yet consistent" connection was drawn between short-term exposure to air pollution and premature death.