Smoking is known to be a major and the most preventable cause of a large variety of cancers, heart diseases, apoplexy, pregnancy complications, chronic obstructive pulmonary diseases and early death. Due to the high smoking rate in adult men and the increasing smoking rate among adolescents, smoking cessation has become an immediate concern for raising Korean people’s health level. In this situation, many associations and organizations are conducting smoking cessation education and anti-smoking campaigns and there are active movements for creating anti-smoking environment such as regulations on cigarette advertisements, warning signs against smoking, designation of non-smoking areas in public places, and prohibition of cigarette sale to adolescents [1].

On the other hand, the reason for failure of smoking cessation in smokers is their dependence on nicotine contained in cigarette. When they inhale cigarette smoke, nicotine is transmitted deep into the lungs and absorbed rapidly into the blood vessels. Nicotine absorbed into the body has an arousal effect, increases attention, and makes the person feel pleasant. These effects last only temporarily and smokers have to keep smoking in order to maintain such effects continuously. What is more, if nicotine is absorbed into the body continuously the body comes to have tolerance to such effects and the smoking quantity increases in order to attain effects of the same intensity. Therefore, continuous smoking results in increased nicotine dependence, and such dependence is manifested in two types, namely, physical dependence and psychological dependence. First, physical dependence means that smokers have tolerance and experience withdrawal symptoms caused by nicotine deficiency whenever they try to stop smoking and such symptoms include depression, insomnia, anxiety, low attention, headache, and fatigue [2]. In addition, psychological dependence occurs when the smoker begins to associate a feeling, situation or environmental stimulus with the compensation effect of nicotine. That is, if one associates smoking with relief from anxiety or stress, he/she is simulated to smoke whenever he/she feels anxiety or stress, and if one associates smoking with increased pleasure, he/she has a strong desire to smoke during social activities, after a meal, or while drinking. In other words, smoking is involved deeply in the individual’s life and smoking behavior is automated in daily life [3]. Moreover, nicotine dependence and its severity are often determined by individuals’ psychosocial factors [4]. In particular, job stress is known to be a psychosocial factor having a considerable effect on the start and extent of smoking [5, 6]. Nicotine dependence can be tested by various methods but the most common method is Fagerström’s Test for Nicotine Dependence (FTND) consisting of 6 questions. This test is also used to predict success in smoking cessation or to determine the replacement dose of nicotine. In addition, FTND is a statistically proven instrument for evaluating the severity of nicotine dependence, and because it has been used in many other studies the results of evaluation can be compared with previous reports.

Job stress has been reported to cause not only physical diseases but also behavioral changes and psychological problems. That is, it is reported to induce physical and mental diseases as well as changes in individuals’ behavioral pattern such as increased smoking, drug dependence, caffeine intake, and alcohol intake [7–9]. Employment insecurity and the flexibility of the labor market resulting from recent economic changes are expected to aggravate wage workers’ job stress and its adverse effects on health.

Thus, this study purposed to analyze how Korean workers’ job stress is related with nicotine dependence according to demographic and occupational characteristics in order to reduce smoking related to job stress and to establish objective indicators to be used in developing adequate smoking cessation strategies.

This study analyzed relationship between job stress and nicotine dependence, and is meaningful in that it demonstrated that job stress can be a problem in reducing smoking based on the finding that the smoking group showed high job stress and those with high job stress and subjective stress showed high nicotine dependence and, consequently, job stress was in a relationship with nicotine dependence.

In Korea, the smoking rate in 20-year-old or older adult men was 79.3 % in 1980 but decreased continuously down to 64.9 % until 1999. Then it maintained the level without a notable change but decreased sharply to 60.5 % in 2002, 50.3 % in 2005, and 20.7 % in 2010. Among 20-year-old or older adult women, on the contrary, the rate was 12.6 % in 1980 and decreased steadily down to 3.0 % until 2000, and then showed inconsistent up and down to 6.0 % in 2002, 4.0 % in 2004, and 3.1 % in 2005 [12]. After that, it showed a continuous decrease and reached 2.2 % in 2010. In our results, the overall smoking rate was 42.0 %, similar to 41.4 % reported as workers’ smoking rate by Kim et al. [13]. The age group of 30–39 showed the highest smoking rate as 47.3 %, suggesting that the smoking rate is relatively higher among young adults. In addition, men’s smoking rate was 54.1 %, somewhat higher than the report of Korean Institute for Health and Social Affairs, while women’s was 2.5 %, somewhat lower. According to smoking cessation attempt rate of Korean adults, on the other hand, 48.3 % of male smokers and 38.9 % of female ones had tried to stop smoking within the previous one year. In addition, the rate was higher in young smokers [14]. In our study, however, the percentage of ex-smokers among those who experienced smoking at least once in the past was 24.4 % (621/2542) of male smokers and 25 % (9/36) of female ones, showing a far lower smoking cessation attempt rate than before. This result was somewhat different from previous data in Korea.

And this study divided the subjects into the quartiles of job stress score and examined the groups according to demographic characteristics. The job stress level was higher in the young age groups than in the old age groups, in men than in women, in the lowly educated groups than in the highly educated groups, and in the divorced/separated group. Also in terms of occupational characteristics, job stress was higher in those working longer, in blue-collar workers than in white-collar workers, in the low position groups than in the high position groups, in the group without breaks than in the group having breaks during office hours. With regard to these relationships between occupational characteristics and stress, there was a report that the stress recognition rate was higher in manufacturing industry according to industry type, in temporary workers according to employment type, in white-collar workers according to job type, and in those working over 56 hours according to working hour [15].

Broms et al. [16] stated that marriage can reduce smoking through protective caring among the family members against nicotine dependence. In this study, however, nicotine dependence was not significantly different according to marital status. Schmidt et al. [17] reported that marital status did not affect nicotine dependence as found in this study but low education was a decisive risk factor for nicotine dependence. In addition, Finney et al. [18] argued that high-level education can reduce the risk factors of smoking by working as a protective factor on nicotine dependence. In this study as well, nicotine dependence was higher when education level was low. Furthermore, nicotine dependence was relatively higher in older groups, confirming indirectly that nicotine dependence grows stronger with increasing smoking period. The higher nicotine dependence in low education level groups and old groups may be related to the finding that subjective stress was high in these groups.

John et al. [19] investigated the correlation between nicotine dependence and job stress factors using FTND, and found that smoking was not associated with job stress. According to the report of Kouvonen et al. [20], however, imbalance between effort and reward can be a risk factor increasing smoking. In our study as well, nicotine dependence was higher in blue-collar workers according to job type, and in managers or higher-position workers according to position. What is more, Schmidt et al. [17] reported that excessive workload is rather related with low nicotine dependence. This is probably because workers having many breaks may smoke more using the breaks. In this study, working hour and whether to have breaks were not highly related with nicotine dependence, but the smoking rate was higher in those with longer working hour and those having many breaks and this suggests that the smoking rate goes down when workload is high.

This study was analyzed that the job stress factors were in a relationship with demographic and occupational characteristics. That is, nicotine dependence was higher in those whose score was high in organization system, and lack of reward. As the results of multivariate logistic analysis, high job control score effected nicotine dependence. Organization system and lack of reward score effected too negatively. Those stress factors were more effected Korean worker. This result may suggest that smokers keep smoking as a relief from job stress even if they recognize smoking to be a serious problem to their health. Therefore, job stress is believed to have an adverse effect on individuals and organizations as a risk factor inducing smoking or checking the fall of the smoking rate.

On the other hand, health promotion through smoking cessation in workplace can be efficient because the targets are specific and limited. Moreover, the consequent low turnover rate can bring not only health-related benefits to participating workers but also diverse benefits to the company including low absence rate, saving of medical expenses, high morale, low morbidity, and improved welfare as well as company image. Anti-smoking policies in workplace can reduce workers’ smoking quantity by inhibiting smoking during working hours and such efforts can be extended outside the workplace and reduce the number of regular smokers. In addition, the number of workers deciding to stop smoking is increasing as individual workers are increasingly aware of the harms of smoking and various studies have reported that smoking cessation can reduce damage to health. Nevertheless, it is hard to succeed in smoking cessation and therefore appropriate management is required for raising the smoking cessation success rate. Thus, the result of this study showing the correlation between job stress and smoking status and nicotine dependence can be used as an objective indicator for preventing smoking induced by job stress and for developing adequate smoking cessation strategies. Based on the results of this study, we may need to invent ways to enhance workers’ welfare for health promotion in workplace through improving working environment in order to reduce job stress and consequently to decrease smoking. What is more, because job stress is related not only to individuals’ health problems but also to industrial and social problems, it is urgently demanded to establish means and systems to control and reduce job stress. Moreover, as it was reported recently that stressful situations in workplace are related directly to the morbidity of various diseases and in particular chronic diseases [11, 21], the importance of job stress is expected to grow higher not only for workers but also for people’s practice of healthy life, chronic disease control and disease prevention, and therefore, it is considered essential to introduce ways for lowering the smoking rate through decreasing job stress.

Job stress was found to be related with smoking status and nicotine dependence. Based on this result, it is suggested to enhance workers’ welfare for health promotion in workplace by improving their working environment in order to reduce job stress and consequently to decrease the smoking rate.