Exposure to residual or third-hand smoke is also a health risk, especially among children, according to Dr José M. Martinez-Sanchez, head of the Health Determinants and Health Policies Assessment Group at UIC Barcelona. As the researcher explains, tobacco smoke is a combination of gases and particles that remain on surfaces after smoking in dust and even in hair, skin and clothing, and can be inhaled, ingested or absorbed through the skin. This can pose a problem for the health of non-smokers, especially children, as scientific evidence shows.

Accordingly, Martínez-Sánchez stresses that children, especially infants, are at increased risk due to specific behaviours such as crawling or carrying objects in their mouths. They also have an immune system that is still developing, a higher respiratory rate, and thinner skin, all of which increase the risk.

As studies show, children's contact with family members or educators that smoke increases the risk of exposure to residual tobacco smoke, so smokers should pay special attention to body and clothing hygiene when in contact with children after smoking. Cleaning the home or vehicle is also recommended if they have been smoking indoors, to reduce exposure of children to residual tobacco smoke.

In the context of World No Tobacco Day, Martínez-Sánchez welcomed the measures planned by the Ministry of Health to deal with smoking, which would include banning smoking on beaches and terraces, as well as in vehicles where minors and pregnant women are present.