Tobacco use is a leading preventable cause of death in India, where smoking of cigarettes and bidis and the use of smokeless tobacco are widespread [1,2]. Surveys of school students in India found high rates of exposure to second-hand smoke both at home and in public places [3], a pattern seen in many countries [4]. Second-hand smoke is a cause of lung cancer [5] and ischaemic heart disease in non-smokers [6,7], and its effects on the cardiovascular system are rapid [8]. Indian studies have linked exposure to environmental tobacco smoke with chronic obstructive pulmonary disease, respiratory symptoms and poor control of asthma in non-smokers [9-11]. There is no safe level of exposure, and workers in places where smoking is allowed are at high risk [12].

Smoke-free legislation is the only effective way to protect non-smokers from second-hand smoke. Laws that banned smoking in workplaces and public places improved the respiratory health of bar and hospitality workers [13-16] and were followed by reductions in hospital admissions for acute myocardial infarction and acute coronary syndrome [17-22]. Measurements of air quality showed high levels of tobacco smoke in public places where smoking was allowed [23-25] and large reductions after comprehensive laws were implemented [26-29]. Smoke-free laws also gained public support and encouraged smokers to quit [26,30].

In India, the Cigarettes and Other Tobacco Products Act prohibits smoking in public places, and the revised rules on prohibition of smoking in public places, which came into force in October 2008, made the owner or manager of each public place responsible for compliance. The rules require the display of a prescribed "No Smoking" board, prohibit ashtrays and other smoking aids, and allow smoking only in designated areas of large hotels, restaurants and airports; the Act also prohibits the sale of tobacco products within 100 yards of educational institutions. The impact of a smoke-free law depends on how well it is enforced, and there is little information on compliance in Indian cities. The objectives of this study were to assess compliance with the smoke-free public places rules in an urban area, to estimate the exposure of adults to second-hand smoke in public places, and to assess public awareness of the law.

Study design and setting This cross-sectional study was conducted in Nashik city, Maharashtra, by the Department of Community Medicine, Dr. Vasantrao Pawar Medical College, Hospital & Research Centre, Nashik. The study had two components: observation of public places and interviews with adults visiting them. Verbal informed consent was obtained from each respondent and from the person in charge of each public place where required. Selection of public places Public places were listed in six categories as defined under the rules: hospitals and health facilities, educational institutions, government and private offices, transport hubs (bus stands and railway stations), restaurants and eateries, and other places such as cinema halls, shopping areas and markets. A total of 120 public places were selected by stratified random sampling, with 20 places from each category. The 20 educational institutions were also used to assess the sale of tobacco products within a radius of 100 yards, and the 20 restaurants were assessed for the presence of a designated smoking area. Observation of compliance Trained observers visited each public place unannounced and spent at least 30 minutes observing it, using a structured checklist adapted from compliance assessment tools used in smoke-free law evaluations. The indicators were: active smoking by any person; the smell of tobacco smoke; the presence of cigarette or bidi butts; the presence of ashtrays or other smoking aids; display of at least one "No Smoking" board of the prescribed size and content at the entrance and in prominent places; the presence of a designated smoking area where applicable; and the sale of tobacco products within the premises or within 100 yards of educational institutions. A public place was considered fully compliant if no active smoking, smoking aids or butts were observed and the prescribed signage was displayed. Interviews on second-hand smoke exposure Adults aged 18 years or more visiting the selected public places were interviewed with a pre-tested questionnaire. The sample size was calculated from an expected prevalence of exposure to second-hand smoke in public places of 50%, which gives the largest sample size; with an absolute precision of 5% and a 95% confidence level, the formula n = Z² p (1 - p) / d² gave a minimum of 384 respondents, and 400 were interviewed. Three or four consenting adults were selected conveniently at each of the 120 public places. Information was collected on socio-demographic characteristics, current smoking, exposure to second-hand smoke in public places, at the workplace and at home during the previous 7 days, awareness of the ban on smoking in public places and the penalty for violation, and attitudes towards the law. Exposure to second-hand smoke was analysed among non-smokers. Statistical analysis Data were entered in Microsoft Excel and analysed with Python version 3.13 using the SciPy and statsmodels libraries. Compliance indicators were expressed as numbers and percentages of public places with exact 95% confidence intervals and compared between categories with the chi-square test, or the Fisher exact test when expected cell counts were less than five. Exposure to second-hand smoke and awareness of the law were expressed as percentages of respondents, and their association with smoking status, sex, age and education was tested with the chi-square test. A p-value below 0.05 was considered significant.

Compliance in public places

A total of 120 public places, 20 in each category, were observed. Active smoking was observed in 30 places (25.0%, 95% CI 17.5 to 33.7), the smell of tobacco smoke in 46.7%, cigarette or bidi butts in 42.5% and ashtrays in 14.2%. "No Smoking" signage was displayed in 76.7% of places. Overall, 43 places (35.8%, 95% CI 27.3 to 45.1) were fully compliant (Table 1).

Table 1. Compliance indicators by category of public place

Fully compliant: no active smoking, no butts or ashtrays, and "No Smoking" signage displayed. Chi-square or Fisher exact test across categories.

Full compliance was highest in hospitals (65.0%) and educational institutions (60.0%) and lowest in bus and railway stations and restaurants (10.0% each) (p < 0.001). Active smoking was seen in 9 of 20 bus and railway stations and 9 of 20 restaurants, compared with 1 hospital and 2 educational institutions (p = 0.009), and signage was least often displayed in these two categories (p = 0.009). A "No Smoking" sign was displayed in 16 of the 30 places where active smoking was observed. Tobacco products were sold within 100 yards of 4 of the 20 educational institutions (20.0%). Only 1 of the 20 restaurants had a designated smoking area meeting the specifications, and the name of the officer to whom a complaint could be made was displayed in 35.0% of places (Table 2).

Table 2. Other compliance indicators

Exposure to second-hand smoke and awareness

A total of 400 adults were interviewed; 52.2% were men, the mean age was 44.5 ± 16.6 years and 100 (25.0%) were current smokers. Of the 300 non-smokers, 115 (38.3%, 95% CI 32.8 to 44.1) reported exposure to second-hand smoke in a public place in the previous 7 days, 27.3% at the workplace and 22.0% at home. Among public places, exposure was most often reported in markets (21.3%), restaurants and eateries (14.7%) and bus and railway stations (11.7%), and least often in hospitals (2.0%) (Table 3). Non-smokers interviewed at bus and railway stations and restaurants reported exposure more often than those interviewed at other places (50.5% versus 32.0%, p = 0.002). Exposure in public places was not significantly associated with sex (p = 0.162), age below 40 years (p = 0.080) or education (p = 0.364).

Table 3. Self-reported exposure to second-hand smoke in the previous 7 days among non-smokers (n = 300)

Respondents could report more than one place.

Overall, 69.5% of respondents knew that smoking in public places is prohibited, but only 23.5% knew the penalty for violation and 16.2% had ever seen action being taken against a violator. Only 23.0% had ever asked someone not to smoke in a public place. Awareness did not differ between smokers and non-smokers. The ban was supported by 81.5% of respondents, including 69.0% of smokers, although support was higher among non-smokers (85.7%, p < 0.001) (Table 4).

Table 4. Awareness of and attitudes towards the smoke-free law by smoking status

Chi-square test, non-smokers versus smokers.

Awareness of the law was significantly higher among respondents with secondary or graduate education than among those with primary education or no education (77.0% versus 51.3%, p < 0.001), being highest among graduates (81.0%). It was not associated with sex, age or smoking status (Table 5).

Table 5. Factors associated with awareness of the ban on smoking in public places

Chi-square test.

This study found that compliance with the smoke-free public places rules in an urban area was poor. Only about one third of public places were fully compliant, active smoking was observed in one in four places and cigarette or bidi butts in 42.5%, and 38.3% of non-smokers had been exposed to second-hand smoke in a public place in the previous week. Awareness of the ban was fairly high, but knowledge of the penalty and experience of enforcement were low. Compliance varied widely between categories of public places. It was highest in hospitals and educational institutions, where institutional rules and the presence of staff discourage smoking, and lowest in bus and railway stations and restaurants, where only 2 of 20 places in each category were fully compliant. These places have large numbers of visitors, open or semi-open spaces and nearby tobacco vendors. Non-smokers interviewed at these places also reported exposure more often, which supports the observational findings. Studies of air quality in Europe and in 32 countries found the highest levels of tobacco smoke in bars, restaurants and transport venues where smoking was permitted [23-25]. The sale of tobacco near 4 of the 20 educational institutions shows that the provisions of the Act intended to protect children were also not fully followed, which is of concern given the high exposure of Indian students to second-hand smoke [3]. An important finding was that "No Smoking" signage was displayed in 76.7% of places, yet more than half of the places where active smoking was observed had a sign on display, and the name of the officer to whom a complaint could be made was displayed in only about a third. Signage is necessary but does not by itself ensure compliance. Experience from other countries shows that smoke-free laws achieve high compliance when they are comprehensive and actively enforced. In Ireland, Spain and New Zealand, comprehensive laws led to large reductions in tobacco smoke in public places and in the exposure of non-smokers [26-29], and to improvements in the respiratory health of workers [13-16]. Smoke-free laws were also followed by fewer admissions for acute myocardial infarction and acute coronary syndrome [17-20], and pooled analyses estimated that the risk of myocardial infarction fell substantially after such laws [21,22]. These benefits depend on high compliance, which requires visible enforcement as well as signage and public support. About 69.5% of respondents knew of the ban, but fewer than one in four knew the penalty and only 16.2% had seen action against a violator. Awareness was lower among those with little or no education, who should be reached through mass media and community-level communication. The ban was supported by 81.5% of respondents and by more than two thirds of smokers, as in Ireland, where support for smoke-free places increased after the law was implemented [26]. Few respondents had ever asked a smoker to stop, which shows that this support has not translated into social enforcement. The gap between awareness and compliance suggests that the main problem is lack of enforcement rather than lack of knowledge. Owners and managers of public places, who are responsible for compliance under the rules, need to be made aware of their duties, and the authorised officers need to carry out regular inspections and impose fines. Smoke-free laws can also encourage smokers to quit [30], and cessation services should be offered alongside enforcement. The health effects of second-hand smoke make this an important public health issue. Exposure causes lung cancer and ischaemic heart disease [5-7], its cardiovascular effects occur even after brief exposure [8], and in India it has been associated with respiratory symptoms, asthma and chronic obstructive pulmonary disease in non-smokers [9-11]. Workers in public places where smoking continues, such as staff of eateries and transport hubs, are at particular risk [12]. Strengths and limitations The strengths of this study are the direct, unannounced observation of public places with a standard checklist, the inclusion of all major categories of public places, and the combination of observation with interviews on exposure and awareness. It has limitations. Observation was limited to a fixed period and may have missed smoking at other times of the day. Exposure to second-hand smoke was self-reported and was not confirmed by measurement of air quality or biomarkers such as cotinine. Respondents were selected by convenience at public places and may not represent the general population. The study was conducted in one city.

Compliance with the smoke-free public places rules in this urban area was poor, with only 35.8% of public places fully compliant, and was lowest in bus and railway stations and restaurants. More than one third of non-smokers had been exposed to second-hand smoke in a public place in the previous week. Although most people knew of the ban and supported it, few knew the penalty or had seen it enforced. Regular inspections, imposition of fines, display of the name of the responsible officer, a ban on tobacco sale near educational institutions and awareness campaigns targeting less educated groups are needed to make public places smoke-free.

DECLARATIONS

Acknowledgement: The author thanks the faculty, interns and staff of the Department of Community Medicine, Dr. Vasantrao Pawar Medical College, Hospital & Research Centre, Nashik, and all the respondents who took part in the study.

Funding: None.

Conflict of interest: The author declares no conflict of interest.

Author contribution: Dr. Surjuse Bhooshan Ganpatrao designed the study, supervised data collection, analysed the data, wrote the manuscript and approved the final version.

Data availability: The data supporting the findings of this study are available from the corresponding author on reasonable request.