Researchers found that chronic cases of indoor tobacco cigarette smoking can expose nonsmokers to long-term health risks, as reported in a study published July 28.
Specifically, according to Hugo Destaillats, senior scientist for the Indoor Environment Group at Lawrence Berkeley National Lab, or Berkeley Lab, such exposure is caused by living in spaces contaminated with carcinogenic chemicals from smoking that has occurred over a long period of time.
The group, California Consortium on Thirdhand Smoke, funded by the Tobacco-Related Disease Research Program, or TRDRP, has committed over a decade of research to thirdhand smoke and its effects. The research started when the group first identified the impacts of tobacco-specific nitrosamines, or TSNAs, that are emitted into the air and linger on surfaces indoors, according to TRDRP Program Officer Deborah Colosi.
According to Colosi, TRDRP has supported researchers investigating thirdhand smoke in indoor environments for commercial buildings and homes, as well as its impact on children’s health. Findings funded by TRDRP have led to bans on indoor smoking for home day care centers, even once children have left.
“We are exposed to many, many chemicals, but the question we’re trying to answer in this particular case is — would this exposure have a health impact?” Destaillats said. “In some cases, yes, and in some cases, not. But there are some situations in which it could have an impact.”
Destaillats, who is also the principal investigator of the paper, said the consortium made up of researchers from various university campuses and research disciplines set out to study one of three TSNAs: NNK, a known carcinogen. The researchers observed how NNK penetrates mice skin and analyzed quantitative data from the past decade of research to quantify the daily dose a non-smoker takes through contact with skin and through inhaling and ingesting dust.
According to a Berkeley Lab press release, researchers found the daily dose of NNK exceeds health guidelines issued by the state of California and the Office of Environmental Health Hazard Assessment that determine the warning labels for products as part of Proposition 65. Destaillats said this is an ongoing study and added that the researchers plan to continue researching various chemicals of tobacco, and possibly contaminants of e-cigarettes and smoking cannabis.
“To say a chemical is toxic is irrelevant if you don’t specify the amount that is consumed over which period of time, because in principle, everything is toxic,” Destaillats said. “That’s why we’re trying to clarify it further. The same applies to every other environmental exposure.”
The main collaborators of the paper include researchers from UCSF, UC Riverside and San Diego State University, in addition to Berkeley Lab scientists, according to the press release.