Changes in concentrations of Tobacco Specific Nitrosamines in saliva in the general population of Barcelona before and after implementation of tobacco control legislation

This study evaluated changes in salivary tobacco-specific nitrosamines (TSNAs) in smokers and non-smokers before and after Spain’s smoke-free legislation.
We conducted a longitudinal study of 272 adults in Barcelona, surveyed in 2004–2005 and 2013–2014, spanning the 2006 legislation and its 2011 extension. Saliva samples were analyzed for NNN, NNK, and NNAL, and geometric means with 95% confidence intervals were calculated. Data were stratified by sociodemographics, smoking status, smoking behavior, and anthropometrics. Linear mixed-effects models assessed adjusted percentage changes in TSNA concentrations.
At baseline, overall TSNA concentrations were 1.5 [1.2–1.8] pg/mL for NNN, 1.4 [1.3–1.5] pg/mL for NNK, and 0.5 [0.5–0.6] pg/mL for NNAL. Among baseline smokers who quit, TSNAs decreased by −90.5% (NNN), −48.7% (NNK), and −86.2% (NNAL). Continuing smokers showed a 149.8% increase in NNN, while non-smokers showed no significant change.
Concentrations of salivary TSNAs declined in those who quit smoking but increased for continuing smokers. Monitoring TSNAs in saliva is useful for assessing legislative impact.
Tobacco-specific nitrosamines are potent carcinogens directly linked to DNA damage and tobacco-related disease risk. Evaluating their variation before and after the implementation of tobacco control laws is clinically essential to determine real-world biological impact beyond self-reported smoking behavior. In this cohort of adults from Barcelona, substantial reductions in TSNA concentrations were found among baseline smokers, suggesting a positive effect of legislation, likely linked to reduced consumption of tobacco products. Conversely, increases among continuing smokers may indicate compensatory smoking behaviors. Assessing TSNAs in saliva (an accessible, minimally invasive matrix) offers an effective approach for monitoring population-level exposure and guiding future public health tobacco policies.