This cross-sectional study provides information on the opinions and attitudes about smoking in a sample of parents and teachers of adolescents aged between 12 and 17 years who were students of first, second, and third ESO grades in a public high school center in Sueca, Valencia, Spain. At the time of the study, these grades included 14 classes with about 25 students per class, so it may be expected that approximately the parents of 350 adolescents would attend the informative sessions at the beginning of each academic course. Therefore, the sample of 304 parents who completed the questionnaire may be considered representative of the target population, but the number of 41 participating teachers was relatively small, probably because they were approached through the tutors of the different classes instead of organizing a joint meeting for their recruitment.

Interestingly, there was a high prevalence rate of smoking of 36.2% among parents surveyed, although occasional smokers accounted for 75.4% of all smokers. This prevalence of 19.5% was notably lower in the teachers’ population, in which 62.5% were also occasional smokers. In a sample of 406 parents of adolescents aged 12–17 years included in the New England Family Study (NEFS), the prevalence of smokers was 26.3% with criteria of nicotine dependence in 14.8% [15]. This study also showed that among adolescents with parents who were nicotine dependent, each previous year of exposure to parental smoking increased the likelihood that adolescents will be in a higher-risk smoking trajectory and progress to regular smoking, supporting the need to address parental smoking cessation as an important strategy to reduce youth smoking risk. However, counseling interventions encouraging parents to quit smoking for their children’s benefit have shown a modest impact on smoking cessation rates [16]. We have also found that the behavior of parents who were non-smokers or did not smoke in front of their children was a significant independent factor in the likelihood of offspring smoking. This finding further confirms the influence of parental smoking on adolescent smoking behaviors consistently reported in the literature [3,8,9,15,16]. It should be noted, however, that the lack of data on actual teen tobacco-use behavior and parental use of other nicotine delivery products is a weakness of the study. Moreover, a potential correlation between teachers’ behavior and the smoking status of students was not evaluated. It would be interesting to repeat a similar survey assessing the correlation between parental and teacher smoking behavior and actual tobacco use by adolescents. Since the majority of smokers start smoking at the adolescent age, the influence of the teachers’ behavior could be crucial for adolescents’ future lifestyle. None of the teachers smoked at school and on all school premises (regulated by a comprehensive Spanish governmental ban) and 90.2% had provided recommendations to their students to quit smoking. However, the prevalence of smokers was 19.5% higher than the 7.8% reported in a study among 495 secondary school teachers in Malaysia [17]. Also, in two French surveys before and following anti-smoking policies, including 2931 teachers in 1999 and 3702 in 2005 aged 20–59 years, the prevalence decreased significantly from 25.7% to 18.2% [18]; this last figure is consistent with our findings. Data reported in 2014 from the Control of Adolescent Smoking (the CAS study) in seven European countries with marked differences in terms of smoke-free schools, ranging from as little as 1% of schools in Denmark to 65% in Norway, clearly showed that restrictive smoking control policies at national and local levels seem to be effective in reducing non-smokers’ exposure to environmental tobacco smoke in school [19].

E-cigarettes are perceived as less harmful than regular cigarettes, but aerosol can contain harmful and potentially harmful substances, including nicotine, heavy metals like lead, volatile organic compounds, and cancer-causing agents [20]. In our study, a high percentage of parents (71%) and teachers also (69.7%) believed that the use of e-cigarettes was harmful to health and agreed on the influence of e-cigarettes to start smoking. Data from the 2023 Annual National Youth Tobacco Survey showed that among U.S. middle and high school students, e-cigarette products were the most used tobacco product (7.7%; 2.13 million) with close to 40% of high school students using e-cigarettes reported frequent use and 29.9% daily use [21]. Availability of flavored products, marketing, and misperceptions regarding harm continue to influence tobacco product use, particularly e-cigarettes, among adolescent students.

Parents also recognized the influence of friends as a highly influential factor for adolescent smoking. Peers and the popularity of peers have been identified as drivers of smoking adoption among youth and the desire for social status as an important motivation [22]. Teachers and parents reported that cigarette smoking may favor the consumption of cannabis. A growing literature has documented the substantial prevalence of and putative mechanisms underlying co-occurring cannabis and tobacco use. In a systematic review of 28 studies, cannabis users who also smoke tobacco were more dependent on cannabis and had more psychosocial problems and poorer cessation outcomes than those who use cannabis but not tobacco [23]. In the present survey, more than 85% of parents believed that tobacco and cannabis were consumed together, but both cannabis and tobacco were considered harmful to health to the same extent by more than 70% of parents. A high percentage of teachers also believed that tobacco is a risk factor for e-cigarette consumption. Co-users and exclusive cigarette smokers have demonstrated comparable levels of biomarkers of exposure to harmful chemicals and toxicants [24]. Therefore, it is critical to consider how concurrent cannabis use may influence health-related outcomes among adolescent smokers [25]. Co-use of e-cigarettes and cannabis is common among youth. Indeed, using tobacco and cannabis together has been associated with greater nicotine addiction, making it more difficult to quit. In a survey of high school students carried out in California in 2020/2021, co-use of tobacco and cannabis was most likely associated with absenteeism and lower grades, so educational outcomes could be improved by comprehensive efforts to prevent or reduce youth substance co-use [26].

More than half of parents reported good relationships with their offspring. The influence of the family environment has been identified as an important etiology for adolescent smoking, and family-based programs may be considered when targeting adolescent anti-smoking interventions. Family dynamics characterized by openness and clarity of communication may have a preventive function for adolescent smoking behavior [27].

The present findings should be interpreted considering the limitations of the study, including a convenience sample of parents and teachers selected from a single high school. Expanding the sample size with more schools and regions would contribute to increasing the representativeness and generalizability of the findings. As the number of participating teachers was relatively small, organizing joint meetings for recruitment to increase participation would be necessary in the design of future studies. Also, the fact that differences in responses between smoking and non-smoking parents and teachers were not evaluated nor between male and female participants should be considered a limitation of the present study. However, strengths of the study include the large size of the parents’ sample as well as there is relatively little information based on cross-sectional survey studies on the perspectives of parents and teachers regarding different aspects related to smoking in adolescents.