Passive smoking is when someone breathes in the chemicals from “second-hand” tobacco smoke – i.e., the smoke that smokers breathe out combined with “sidestream smoke” from the lit end of cigarettes.

Passive smoking can occur even when there are no smokers present. The chemicals in second-hand smoke can stay in the air for hours, and can stay on walls, furniture, clothes and other objects for months or even years. This residue is known as “third-hand smoke”. It is difficult to get rid of third-hand smoke through ventilation or cleaning.

Passive smoking is harmful even at low levels of exposure. It can cause or worsen a range of conditions including:

• Cancer
• Heart attacks
• Heart disease
• Respiratory infections such as pneumonia and chronic bronchitis
• Asthma
• Diabetes.

Passive smoking is especially risky for:

• Unborn babies
• Children and young people
• People with breathing problems.