Who conducted the study?
Ki-Hyun Kim, a researcher in the Department of Civil and Environmental Engineering at Hanyang University in Seoul, South Korea, led a team of researchers from Hanyang University, Sonoma State University in California, and Sungkyukwan University in Suwon, South Korea.
Where did they do it?
The study was conducted through Hanyang University and carried out in a controlled smoking booth at the university’s Department of Civil and Environmental Engineering in Seoul, South Korea.
What did they want to learn?
The researchers compared the volatile organic compounds (VOCs) released by secondhand smoke and thirdhand smoke in an indoor environment. They also studied whether exposure to these compounds could pose cancer or non-cancer health risks, and whether those risks differed between secondhand and thirdhand smoke.
How did they perform the study?
The researchers conducted controlled laboratory experiments inside a smoking booth using standard reference cigarettes. They measured 32 VOCs released during active smoking (secondhand smoke) and those that remained on indoor surfaces and were later emitted into the air (thirdhand smoke). They also examined how the number of cigarettes smoked and the level of ventilation affected VOC concentrations before estimating the potential cancer and non-cancer health risks associated with inhaling these compounds.
What did they find?
The researchers found that several harmful VOCs, including 1,3-butadiene and benzene, were present in both second- and thirdhand smoke. Although secondhand smoke contained higher concentrations of these chemicals immediately after smoking, thirdhand smoke was associated with a greater estimated lifetime cancer risk under the study’s exposure assumptions. Both benzene and 1,3-butadiene continued to be released from contaminated indoor surfaces over time, resulting in estimated cancer risks that exceeded the U.S. Environmental Protection Agency’s commonly accepted risk threshold. In contrast, the estimated cancer risk associated with secondhand smoke remained below that threshold under the experimental conditions used in this study.
Why is this study important?
This study shows that the potential health risks of tobacco smoke may extend beyond active smoking and secondhand smoke exposure. Under the controlled laboratory conditions, the researchers estimated that thirdhand smoke was associated with higher lifetime cancer risks from VOCs than secondhand smoke because certain chemicals persisted on indoor surfaces and
continued to be released into the air over time. Overall, the findings highlight the potential long-term cancer risks associated with exposure to thirdhand smoke re-emissions. Thirdhand smoke exposure should be considered when evaluating indoor air quality and strategies to reduce tobacco smoke exposure.
SOURCES:
Click here to read the research study.
