Researchers from universities in China and the United Kingdom studied the association between thirdhand smoke exposure and cervical cancer. This is the first large-scale epidemiologic study examining the negative health consequences of thirdhand smoke exposure compared to secondhand smoke.
June 29, 2022
Cervical cancer is the fourth leading cause of cancer death among women and a known health risk of tobacco use and secondhand smoke exposure. Dr. Qiaorui and colleagues from Peking University Health Science Center, China, and the University of Oxford, United Kingdom, investigated a large sample of Chinese women to study the association between cervical cancer and exposure to thirdhand smoke—the toxic residue left behind on surfaces and dust after smoking.
The study reviewed data collected from 300,000 individuals in urban and rural regions across China over a 10-year period. The nonsmoking participants were asked questions about their frequency of exposure to second- and thirdhand smoke at home, their workplace, and public places. The researchers defined secondhand smoke exposure as being exposed to other people’s tobacco smoke directly, and defined thirdhand smoke as living with a smoker (for over six months) who smoked nearly every day outside the home. Thirdhand smoke exposure occurs when someone dermally absorbs, inhales, or ingests the toxic residue left behind from tobacco smoke. The participants also provided information about their dietary habits, reproductive history, living environment, and medical history.
The scientists reported that both second- and thirdhand smoke exposure were associated with higher risks of cervical cancer. The authors found that participants exposed to secondhand smoke had a 22% higher risk of cervical cancer compared to those not exposed to second- or thirdhand smoke. Participants exposed to thirdhand smoke were found to have a 24% greater risk of cervical cancer than those not exposed to either second- or thirdhand smoke. This finding suggests that women only exposed to thirdhand smoke are at equivalent risk of contracting cervical cancer compared to those exposed to only secondhand smoke. This study suggests that thirdhand smoke exposure may be as consequential to health as secondhand smoke exposure. The association between thirdhand smoke and cervical cancer was greater in rural populations than in urban populations, which may be the result of limited accessibility to healthcare in rural regions. The results also indicate that women exposed to both second- and thirdhand smoke have a 29% greater chance of cervical cancer compared to non-exposed individuals.
This study is the first large-scale epidemiologic study of the association between thirdhand smoke exposure and cervical cancer in women. Thirdhand smoke results from permissive indoor smoking policies that leave behind a toxic legacy that can cause that can cause harm long after smoking bans have been introduced. This study reinforces the need for greater tobacco control advocacy to impose comprehensive indoor smoking bans to prevent thirdhand smoke pollution. In addition, efforts are needed to identify and clean up thirdhand smoke polluted homes to protect the public from the harmful consequences of exposure to toxic thirdhand smoke residue.
Click here to read the research study.