Lianda Goossens, a smoking-cessation coach at Amphia Hospital in Breda, warned during Stoptober about third-hand smoke: toxic residues left on clothing, skin, hair, furniture and other surfaces after smoking. She said these substances can reach young children even when people smoke outside, wash their hands and avoid smoking in their presence.

An American study of 80 babies in incubators and their mothers found cotinine, a breakdown product of nicotine, in the urine of more than 93% of the infants. Nicotine was also detected on almost 94% of the furniture surfaces examined, despite the hospital’s smoking ban. The findings showed exposure but did not establish that the babies had suffered health damage. The extent of the health effects of third-hand smoke in humans is still being investigated.