Toxic chemicals from cigarettes remain toxic in second-hand smoke

Dear Mayo Clinic: Is second-hand cigarette smoke dangerous to my health?

A: The short answer to your question is yes, second-hand smoke is dangerous. Secondhand smoke — also known as environmental tobacco smoke — is a combination of the smoke coming from a burning cigarette and the smoke exhaled by the smoker, which spreads out to the surrounding space. Second-hand smoke contains the same toxic chemicals that are inhaled by smokers, including nicotine, carbon monoxide, benzene, formaldehyde, cyanide and a variety of cancer-causing substances. The effects of these chemicals are greater when inhaled directly from a cigarette; nonetheless, the effects are still toxic second-hand.

Particles in second-hand smoke can remain in the air for hours, and the residue that clings to a smoker’s hair, clothing and other items also may pose health risks, especially for children. This residue is sometimes referred to as third-hand smoke.

Evidence indicates that the second-hand smoke exposure that comes from living with a smoker can increase your risk of lung cancer by 20 to 30 per cent. Second-hand smoke also increases your risk of coronary heart disease by 25 to 30 per cent and can lead to a variety of health risks for children, as well as for pregnant women and their unborn babies.

As with active smoking, the greater the exposure — and the longer the duration of exposure — the greater the risk of harm, especially for diseases such as lung cancer. However, even short-term exposure can worsen symptoms of asthma and coronary heart disease.

Unfortunately, air cleaning devices or filters don’t effectively clear the air of secondhand smoke.

The only way to eliminate the risks of exposure is to eliminate smoking.