Third-hand smoke

What is Third-hand Smoke (THS)?

While people nowadays are familiar with first-hand and secondhand smoke, they may not have a thorough understanding of THS. THS refers to the chemical residuals of tobacco smoke that clings to places such as various surfaces, clothes, hair and skin after the cigarette is extinguished.

The harmful effects of THS

A large amount of toxic substances can be found in THS, such as hydrogen cyanide, butane, toluene, arsenic, lead, carbon monoxide and even polonium-210 (a highly radioactive carcinogen).

These toxic chemical substances can remain on the surface of household utensils and furniture of the indoor area, carpets, floors, walls, ceilings, etc. Nicotine, one of these toxic substances, could react with nitrous acid (a common pollutant found indoor) to produce carcinogenic tobacco-specific nitrosamines (TSNAs).

TSNAs enter the human body mainly through dust inhalation or direct contact of skin. Infants and toddlers are full of curiousity. They love crawling on the floor, touching everything in sight and even putting objects into their mouths. Thus TSNAs pose especially serious hazard to children.

How to Protect Infants, Toddlers and Children from THS

Do not smoke in front of your children and at places they stay (e.g. at home and inside vehicle). Keep your infants, toddlers and children away from belongings of smokers.

Most alkaline cleaners available in the market cannot remove these substances. Therefore, not smoking at all is the best way to protect your loved ones. Research suggests that children are more likely to develop tobacco addiction if their parents smoke, so please quit immediately.

Smoking Cessation Services

At present, there are a number of smoking cessation services provided by the Department of Health (DH), the Tung Wah Group of Hospitals, the United Christian Nethersole Community Health Service, the Pok Oi Hospital, the Hospital Authority and various organisations. Some family doctors and private hospitals also provide smoking cessation services. Members of the public can call the DH's Integrated Smoking Cessation Hotline at 1833 183 or click here for more information.

Smoking is the major preventable cause of death. For yourself and your family’s health, quit smoking now.

1. Winickoff JP, Friebely J, Tanski SE, et al. Beliefs about the health effects of "thirdhand" smoke and home smoking bans. Pediatrics. 2009;123(1):e74–e79. doi:10.1542/peds.2008-2184

2. Kuschner WG, Reddy S, Mehrotra N, Paintal HS. Electronic cigarettes and thirdhand tobacco smoke: two emerging health care challenges for the primary care provider. Int J Gen Med. 2011;4:115–120. Published 2011 Feb 1. doi:10.2147/IJGM.S16908

13 Sept 2021