The effects of household and workplace smoking restrictions on quitting behaviours

OBJECTIVE: To assess the association of household and workplace smoking restrictions with quit attempts, six month cessation, and light smoking. DESIGN: Logistic regressions identified the association of household and workplace smoking restrictions with attempts to quit, six month cessation, and light smoking. SETTING: Large population surveys, United States. SUBJECTS: Respondents (n = 48,584) smoked during the year before interview in 1992-1993, lived with at least one other person, and were either current daily smokers or were former smokers when interviewed. MAIN OUTCOME MEASURES: The outcome measures were an attempt to quit during the last 12 months, cessation for at least six months among those who made an attempt to quit, and light smoking (< 15 cigarettes a day). RESULTS: Smokers who lived (odds ratio (OR) = 3.86; 95% confidence interval (CI) = 3.57 to 4.18) or worked (OR = 1.14; 95% CI = 1.05 to 1.24) under a total smoking ban were more likely to report a quit attempt in the previous year. Among those who made an attempt, those who lived (OR = 1.65, 95% CI = 1.43 to 1.91) or worked (OR = 1.21, 95% CI = 1.003 to 1.45) under a total smoking ban were more likely to be in cessation for at least six months. Current daily smokers who lived (OR = 2.73, 95% CI = 2.46 to 3.04) or worked (OR = 1.53, 95% CI = 1.38 to 1.70) under a total smoking ban were more likely to be light smokers. CONCLUSIONS: Both workplace and household smoking restrictions were associated with higher rates of cessation attempts, lower rates of relapse in smokers who attempt to quit, and higher rates of light smoking among current daily smokers.     

Non-smoking policies, tobacco education, and smoking cessation programmes in facilities serving the elderly in Michigan, United States

OBJECTIVE: To determine the extent of and impetus for smoke-free policies in facilities serving Michigan's elderly, and the extent of tobacco education and smoking cessation programmes for elders and staff of these facilities. DESIGN: Telephone survey in February 1997 of three types of facilities serving Michigan's elderly population. SUBJECTS: Area Agencies on Aging (n = 12), Councils and Commissions on Aging (n = 31), and senior centres (n = 98) located in Michigan, USA. MAIN OUTCOME MEASURES: Prevalence of smoke-free policies, tobacco education, and smoking cessation programmes in facilities serving the elderly. RESULTS: 99% (95% confidence interval (CI) = 97% to 100%) of 141 facilities surveyed have an indoor smoke-free policy. Eighty-five per cent (95% CI = 79% to 91%) of these policies prohibit all smoking inside the facility. Forty-five per cent (95% CI = 37% to 54%) cited a law as requiring the smoke-free policy, whereas 38% (95% CI = 30% to 46%) indicated the policy was adopted voluntarily for health reasons. Forty-two per cent (95% CI = 34% to 50%) of the facilities provided some education on the dangers of tobacco, while 11% (95% CI = 6% to 16%) arranged smoking cessation programmes for staff or elders. CONCLUSIONS: In Michigan, a very high percentage of non-institutional facilities serving the elderly have smoke-free policies, which appear to increase participation at these facilities. Tobacco education programmes are provided in less than half the facilities, and very few arrange smoking cessation programmes for elders or staff.




     

Is concern about post-cessation weight gain a barrier to smoking cessation among pregnant women?

Women who quit smoking during pregnancy gain more weight than women who continue to smoke. Concern about weight gain is a barrier to smoking cessation in the general population, but whether attitudes about weight are associated with failure to stop smoking during pregnancy or to maintain abstinence postpartum is unknown. Thus, attitudes about weight were assessed in 412 pregnant smokers recruited from obstetric practices in Massachusetts for a smoking cessation intervention trial. Smoking cessation outcomes (7-day point-prevalence abstinence by self-report and by cotinine-validation) were assessed at end-of-pregnancy and 3 months postpartum. Bivariate and multivariable analyses assessed the relationship between attitudes about weight and smoking cessation. In bivariate analyses, a high level of concern about post-cessation weight gain was associated with older age (p = .01), smoking more cigarettes/day (p<.001), not making a quit attempt in pregnancy (p = .02), being less likely to self-report tobacco abstinence at end of pregnancy (p = .01) and postpartum (p = .02), and having less cotinine-validated abstinence at 3 months postpartum (p = .05). In multivariable analyses that adjusted for cigarettes/day, a low level of concern about post-cessation weight gain was associated with more self-reported abstinence at end-of-pregnancy (OR = 1.77, 95% CI 1.01-3.09) and postpartum (OR = 2.09, 95% CI 1.05-4.14), but not with cotinine-validated abstinence at end-of-pregnancy (OR = 1.30, 95% CI 0.63-2.68) or postpartum (OR = 2.18, 95% CI 0.93-5.10). In conclusion, women who are more concerned about post-cessation weight gain may be less likely to quit smoking during pregnancy or remain abstinent in the postpartum period.     

Smoking cessation by socioeconomic status and marital status: the contribution of smoking behavior and family background.

We studied socioeconomic status and marital status as predictors of smoking cessation, adjusting for previous smoking behavior and family background by using a large Finnish prospective twin dataset unselected for smoking behavior. The data were collected by postal surveys in 1981 and 1990, and the sample comprised 3,069 current smokers, of whom 20% had quit smoking by 1990. Logistic regression analyses of all twin individuals and conditional logistic regression analysis of discordant pairs were used to predict smoking cessation. High education predicted smoking cessation among both men (OR=2.32, 95% CI=1.31-4.10) and women (OR=3.98, 95% CI=1.85-8.51) as did high social class among women. Additionally, starting at a late age, smoking a small number of cigarettes per day, and a low level of nicotine per cigarette predicted cessation. Socioeconomic differences in cessation diminished only slightly when we adjusted for smoking behavior factors. Among the twin pairs who were discordant in terms of smoking cessation, the twin who continued smoking also smoked more on average at baseline (men: OR=.94, 95% CI=.89-.99; women: OR=.82, 95% CI=.71-.94). The male twins who continued smoking had a smaller probability of getting married during the follow-up than had the cotwin who had quit smoking (OR=3.91, 95% CI=1.02-15.02). Indicators of socioeconomic status were important predictors of smoking cessation even when we adjusted for previous smoking behavior. For men, marriage was associated with an increased probability of cessation     

Can cumulative tobacco consumption, FTND score, and carbon monoxide concentration in expired air be predictors of chronic obstructive pulmonary disease?

Between 15% and 20% of smokers develop chronic obstructive pulmonary disease (COPD). The aim of the present study was to determine which characteristics of smoking, particularly the Fagerstr?m Test for Nicotine Dependence (FTND) score, were associated with the risk of developing COPD. Data from the IBERPOC epidemiological study were analyzed. IBERPOC was a multicenter epidemiological study including 4035 individuals aged 40-69 years, 1023 (25%) of whom were active smokers. We analyzed the association between smoking characteristics--such as the cumulative consumption of tobacco, FTND score, and expired-air carbon monoxide levels--and the diagnosis of COPD. Among the smokers, 153 (15%) were diagnosed with COPD. A cumulative tobacco consumption of more than 30 pack-years (OR=4.24, 95% CI=2.83-6.36) and the FTND score (OR=1.11, 95% CI=1.02-1.21, for each point increase) were significantly associated with the diagnosis of COPD in the model obtained by logistic regression analysis with the full sample of smokers. Cumulative consumption of tobacco was associated with the diagnosis of COPD. For each point increase in the FTND score, the probability of a smoker developing COPD increased by 11%.     

Variations in treatment benefits influence smoking cessation: results of a randomised controlled trial

OBJECTIVE: To assess the impact and costs of coverage for tobacco dependence treatment benefits with no patient cost sharing for smokers with employer sponsored coverage in two large independent practice association (IPA) model health maintenance organisations (HMOs) in California, USA. METHODS: A randomised experimental design was used. 1204 eligible smokers were randomly assigned either to the control group, which received a self-help kit (video and pamphlet), or to the treatment group, which received the self-help kit and fully covered benefits for over the counter (OTC) nicotine replacement therapy (NRT) gum and patch, and participation in a group behavioural cessation programme with no patient cost sharing. RESULTS: The quit rates after one year of follow up were 18% in the treatment group and 13% in the control group (adjusted odd ratio (OR) 1.6, 95% confidence interval (CI) 1.1 to 2.4), controlling for health plan, sociodemographics, baseline smoking characteristics, and use of bupropion. Rates of quit attempts (adjusted OR 1.4, 95% CI 1.1 to 1.8) and use of nicotine gum or patch (adjusted OR 2.3, 95% CI 1.6 to 3.2) were also higher in the treatment group. The annual cost of the benefit per user who quit ranged from $1495 to $965 or from $0.73 to $0.47 per HMO member per month. CONCLUSIONS: Full coverage of a tobacco dependence treatment benefit implemented in two IPA model HMOs in California has been shown to be an effective and relatively low cost strategy for significantly increasing quit rates, quit attempts, and use of nicotine gum and patch in adult smokers.     

Social class, education, and smoking cessation: Long-term follow-up of patients treated at a smoking cessation unit.

Our objective was to examine social class and educational differences in long-term smoking cessation success among a cohort of smokers attending a specialized smoking clinic. We studied sustained abstinence after cessation among 1,516 smokers (895 men and 621 women) treated for smoking cessation between 1995 and 2001 at a university teaching hospital in the metropolitan area of Barcelona, Spain. We calculated 1-year and long-term (up to 8-year) abstinence probabilities by means of Kaplan-Meier curves and the hazard ratio of relapse by means of Cox regression, after adjusting for other predictors of relapse. Overall abstinence probability was .277 (95% CI = .254-.301). Men and women in social classes IV-V had significant hazard ratios of relapse after long-term follow-up (men: 1.36, 95% CI = 1.07-1.72; women: 1.60, 95% CI = 1.24-2.06), as compared with patients in social classes I-II. The same independent effect was observed for education: Men and women with primary or less than primary studies had higher hazard ratios of relapse (men: 1.75, 95% CI = 1.35-2.25; women: 1.92, 95% CI = 1.51-2.46), as compared with patients with a university degree. Similar estimates were obtained after adjustment for stage of change, Fagerstr?m score for nicotine dependence, and type of treatment. Patients of lower socioeconomic status are at higher risk of relapse, and this association is independent of other well-known predictors of relapse. Social differences have to be taken into account in the clinical setting when tailoring specific actions to treat smoking dependence.     

Perceived risk of harm from cigarettes or smokeless tobacco among U.S. high school seniors.

This study examined perceived risk of harm from smoking or ST use in a U.S. nationally representative sample of high school seniors and examined its association with current smoking status. Data were derived from the Monitoring the Future project for 1999 through 2003 (n = 11,093). We used multiple logistic regression analysis to examine the association between comparative perceived risk of harm of smoking and ST use with current smoking status, while adjusting for sex, race, and perceived risk of harm from smoking. In 1999-2003, 74.0% of high school seniors perceived great risk of harm from smoking and 44.9% perceived great risk from using ST. Perceived risk varied by smoking intensity: 80.3% of non-smokers perceived great risk of harm from smoking, compared to 49.7% of students who smoked about one-half pack per day and 36.1% of pack-a-day smokers. Overall, 52.7% perceived equal risk of harm from using either product, 41.3% perceived greater risk from cigarettes, and 6.1% perceived a greater risk from using ST. Adjusting for sex and race, high school seniors who perceived that smoking conveyed a greater risk for harm than did using smokeless tobacco were significantly more likely to be smokers than were those who perceived equal risk from the products (odds ratio [OR] = 1.43; 95% confidence interval [CI] 1.29-1.60). Those who perceived that using smokeless tobacco was riskier than smoking were even more likely to be current smokers (OR = 2.43; 95% CI 1.96-3.01). Effective methods for communicating accurate health risks to young people are needed.     

Are there sex differences in transdermal nicotine replacement therapy patch efficacy? A meta-analysis.

Smoking-related death and disability rates for women have risen sharply recently. Despite lower smoking cessation success rates for women using behavioral therapies, data are limited on whether specific pharmacological therapies are equally efficacious in men and women. Using meta-analytic techniques, we examined whether significant differences in therapeutic efficacy of nicotine replacement therapy (NRT) for smoking cessation exist by sex. Out of the 31 randomized clinical trials of NRT that met inclusion criteria, 11 contributed to the analysis. The odds ratios for NRT vs. placebo were derived from each trial separately by sex for males and females, and these ratios were combined to give a pooled estimate of the effect of sex in response to NRT. NRT was effective at all time points in men (< 6 months: OR = 2.05, 95% CI= 1.61-2.60; 6 months: OR = 1.98, 95% CI = 1.51-2.60; 12 months: OR = 1.86, 95% CI = 1.39-2.50) and women (< 6 months: OR = 2.09, 95% CI = 1.65-2.65; 6 months, OR = 1.52, 95% CI = 1.17-1.98; 12 months: OR = 1.63, 95% CI = 1.22-2.18). At all time points, no significant difference was observed between sexes (< 6 months: OR = .97, 95% CI = .69-1.36; 6 months: OR = 1.33, 95% CI = .91-1.95; 12 months: OR = 1.21, 95% CI = .79-1.84). The results of this meta-analysis do not support the hypothesis that NRT has higher therapeutic efficacy for men than women.     

The development of tobacco use in adolescence among "snus starters" and "cigarette starters": an analysis of the Swedish "BROMS" cohort

Whether the use of smokeless tobacco can facilitate the transition to cigarette smoking and/or to prolonged tobacco use in adolescence is unclear. We analyzed data from a cohort of 2,938 Swedish adolescents, with six follow-up assessments of tobacco use between the ages of 11 and 18 years. The majority of tobacco users (70%) started by smoking cigarettes, 11% took up snus before smoking, and 19% used both tobacco types close in time. Ever users of tobacco at baseline had a higher risk of being current smokers and/or smokeless tobacco users at the end of follow-up compared with never users, with the highest excess relative risk for "mixed users." Adolescents who initiated tobacco use with cigarettes had a non-significantly increased probability to end up as current smokers compared with snus starters (adjusted OR=1.42; 95% CI 0.98-2.10) The OR of smoking for "mixed starters" was 2.54 (95% CI 1.68-3.91). The risk of becoming current user of any tobacco was also significantly enhanced for "mixed starters." Marked sex differences were observed in these associations, as initiation with cigarettes rather than with snus predicted current smoking or tobacco use only among females. Progression of tobacco use in adolescence is not predicted by onset with snus or cigarettes, but rather by initiation with both tobacco types close in time and/or at young age. The proportion of adolescent smoking prevalence attributable to a potential induction effect of snus is likely small.     

Impact of the graphic Canadian warning labels on adult smoking behaviour

Objective: To assess the impact of graphic Canadian cigarette warning labels on current adult smokers.

Design: A random-digit-dial telephone survey was conducted with 616 adult smokers in south western Ontario, Canada in October/November 2001, with three month follow up.

Main outcome measures: Smoking behaviour (quitting, quit attempts, and reduced smoking), intentions to quit, and salience of the warning labels.

Results: Virtually all smokers (91%) reported having read the warning labels and smokers demonstrated a thorough knowledge of their content. A strong positive relation was observed between a measure of cognitive processing—the extent to which smokers reported reading, thinking about, and discussing the new labels—and smokers' intentions to quit (odds ratio (OR) 1.11, 95% confidence interval (CI) 1.07 to 1.16; p < 0.001). Most important, cognitive processing predicted cessation behaviour at follow up. Smokers who had read, thought about, and discussed the new labels at baseline were more likely to have quit, made a quit attempt, or reduced their smoking three months later, after adjusting for intentions to quit and smoking status at baseline (OR 1.07, 95% CI 1.03 to 1.12; p < 0.001).

Conclusions: Graphic cigarette warning labels serve as an effective population based smoking cessation intervention. The findings add to the growing literature on health warnings and provide strong support for the effectiveness of Canada's tobacco labelling policy.

     

Bupropion efficacy for smoking cessation is influenced by the DRD2 Taq1A polymorphism: analysis of pooled data from two clinical trials.

We analyzed pooled data from two comparable randomized placebo-controlled clinical trials of bupropion pharmacotherapy for smoking cessation for which data on DRD2 Taq1A genotype were available. A total of 722 smokers across the two trials were randomized to 10 weeks of sustained-release bupropion hydrochloride or placebo. General estimating equation analysis demonstrated a significant gene x drug interaction (B = 0.87, SE = 0.34, p = .009). Smokers with the A2/A2 genotype using bupropion were more than three times as likely, relative to placebo, to be abstinent at end of treatment (35.2% vs. 15.1%; OR = 3.25, 95% CI 2.00-5.28) and at 6 months of follow-up (26.7% vs. 12.2%; OR = 2.81, 95% CI 1.66-4.77), which was attenuated by 12 months (16.3% vs. 10.7%; OR = 1.70, 95% CI 0.95-3.05). We found no significant benefit of bupropion relative to placebo on smoking cessation outcomes at any time point in participants with A1/A1 or A1/A2 genotypes. These data suggest that bupropion may be effective for smoking cessation only in a subgroup of smokers with the DRD2 Taq1 A2/A2 genotype.     

A prospective study of household smoking bans and subsequent cessation related behaviour: the role of stage of change

Objective: To assess the degree to which smokers living with a full household ban on smoking change their cessation related behaviour.

Design, setting, and participants: Prospective cohort study; follow up of a population based cohort of 1133 smokers, identified from a 1997 telephone survey of adult Oregonians. After a median of 21 months, 565 were located and reinterviewed.

Main outcome measures: Quit attempts, time until relapse, and smoking cessation, defined as seven day and 90 day sustained abstinence at follow up.

Results: A full ban at baseline was associated with a doubling of the odds of a subsequent quit attempt (odds ratio (OR) = 2.0, 95% confidence interval (CI), 1.0 to 3.9). Among respondents in the preparation stage at baseline (intention to quit in the next month with a quit attempt in the previous year), a full ban was associated with a lower relapse rate (hazard ratio = 0.5 (95% CI, 0.2 to 0.9)), while for those in precontemplation/contemplation (no intention to quit or intention to quit within the next six months, respectively), there was no significant association between full ban and relapse rate. For respondents in preparation, those with a full ban had over four times the odds of being in cessation for seven or more days before the follow up call (OR = 4.4 (1.1 to 18.7)), but for those in precontemplation/contemplation, full bans were unrelated to cessation.

Conclusions: Full household bans may facilitate cessation among smokers who are preparing to quit by increasing quit attempts. They may also prolong time to relapse among those smokers.

     

Tobacco attributable deaths in South Africa

Background: In mid 1998, a question "Was the deceased a smoker five years ago?" was introduced on the newly revised South African death notification form. Design: A total of 16 230 new death notification forms from 1998 have been coded, and comparison of the prevalence of smoking among those who died of different causes was used to estimate, by case–control comparisons, tobacco attributed mortality in South Africa. Cases comprised deaths from causes known (from other studies) to be causally associated with smoking, and controls comprised deaths from medical conditions expected to be unrelated to smoking. Those who died from external causes, and from diseases strongly related to alcohol consumption, were excluded. Subjects: Reports were available from 5340 deceased adults (age 25+), whose smoking status was given by a family member. Results: Significantly increased risks were found for deaths from tuberculosis (odds ratio (OR) 1.61, 95% confidence interval (CI) 1.23 to 2.11), chronic obstructive pulmonary disease (COPD) (OR 2.5, 95% CI 1.9 to 3.4), lung cancer (OR 4.8, 95% CI 2.9 to 8.0), other upper aerodigestive cancer (OR 3.0, 95% CI 1.9 to 4.9) and ischaemic heart disease (OR 1.7, 95% CI 1.2 to 2.3). Conclusion: If smokers had the same death rate as non-smokers, 58% of lung cancer deaths, 37% of COPD deaths, 20% of tuberculosis deaths, and 23% of vascular deaths would have been avoided. About 8% of all adult deaths in South Africa (more than 20 000 deaths a year) were caused by smoking.     

Influence of physician and patient gender on provision of smoking cessation advice in general practice

OBJECTIVE: To examine the association between physician and patient gender and physicians' self-reported likelihood of providing smoking cessation advice to smokers using hypothetical case scenarios in primary care. DESIGN: Cross-sectional analysis of a self-administered questionnaire. SUBJECTS: National random sample of Australian general practitioners (GPs). MAIN OUTCOME MEASURES: Self-reported likelihood of advising hypothetical male and female smokers to stop smoking during a consultation for ear-syringing ("opportunistic" approach) or a dedicated preventive health "check up". RESULTS: 855 GPs returned questionnaires (67% response rate). Significantly more respondents indicated they would be "highly likely" to initiate an opportunistic discussion about smoking with a male smoker (47.8% (95% confidence intervals (CI) = 44.5 to 51.2)) than a female smoker (36.3% (95% CI = 33.1 to 39.5]). Older, male GPs were less likely to adopt an opportunistic approach to smoking cessation for patients of either sex. Respondents were more likely to recommend that a male patient return for a specific preventive health check up. Furthermore, in the context of a health check up, a greater proportion in total of respondents indicated they would be "highly likely" to discuss smoking with a man (86.9%, 95% CI = 84.5 to 89.0) than a female smoker (82.5%, 95% CI = 79.8 to 84.9). CONCLUSIONS: As measured by physician self-report, the likelihood of advising smokers to quit during primary care consultations in Australia appears to be influenced by gender bias. Gender-sensitive strategies to support cessation activities are recommended.     

Relationship between smokeless tobacco use and body weight in young adult military recruits.

Long-time cigarette smokers tend to weigh less than nonsmokers, and those who quit smoking typically gain weight. Little is known, however, about the relationship between smokeless tobacco and body weight. The present study investigated the association between smokeless tobacco use and body weight among 22,974 Air Force recruits (27.4% female, mean age=20.2 years, body mass index=22.7) undergoing basic military training. Current, former, and experimental smokeless tobacco users weighed significantly more than recruits who had never tried smokeless tobacco (p values <.05). Logistic regression analysis also indicated that the likelihood of being classified as overweight was significantly greater for daily (OR=1.29, 95% CI=1.07-1.54), occasional (OR=1.50, 95% CI=1.17-1.93), former (OR=1.33, 95% CI=1.05-1.67), and experimental (OR=1.13, 95% CI=1.02-1.24) smokeless tobacco users relative to never-users (p values <.05). These results suggest that smokeless tobacco use does not have significant weight-attenuating effects, at least in the short term. Furthermore, using chewing tobacco or snuff may be associated with a greater body weight among young adults.     

Tobacco smoking in Tanzania,East Africa: population based smoking prevalence using expired alveolar carbon monoxide as a validation tool

OBJECTIVES: To describe the prevalence of tobacco smoking in an urban East African population while using a simple validation procedure to examine the degree of under reporting in men and women. DESIGN: A cross sectional population based study in adults (15 years and over) with sampling from a well maintained census register. SETTING: Ilala Ilala, a middle income district of Dar es Salaam, Tanzania. SUBJECTS: An age and sex stratified random sample of 973 men and women. MAIN OUTCOME MEASURES: Self reported smoking status with correction by exhaled alveolar carbon monoxide (EACO). RESULTS: From the 605 participants (response rate 67.9%) age standardised (new world population) smoking prevalence, based on questionnaire and EACO, was 27.0% (95% confidence interval (CI) 20.8% to 33.2%) in males and 5.0% (95% CI 2.8% to 7.2%) in females. The age specific prevalence of smoking was highest in the age group 35-54 years (34.3%) for men and in the over 54 years group (16%) for women. Of those classified as smokers, 7.3% of men and 27.3% of women were reclassified as current smokers based on EACO (> or = 9 parts per million), after they had reported themselves to be an ex- or non-smoker in the questionnaire. CONCLUSIONS: The data suggest: (1) high rates of smoking among men in an urban area of East Africa; and (2) the importance of validating self reports of smoking status, particularly among women.     

Lung cancer, tobacco, and environmental factors in the African population of the Northern Province, South Africa

DESIGN: Case-control study among incident African patients with cancer. Questionnaire assessment of exposure to tobacco, occupation, and place of birth. SETTING: Northern Province, South Africa. SUBJECTS: Between 1993 and 1995, 288 men and 60 women with lung cancer and 183 male and 197 female controls (consisting of patients newly diagnosed with cancers other than those known to be associated with smoking) were interviewed. Unmatched, unconditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs) of developing lung cancer in relation to a number of variables. MAIN OUTCOME MEASURE: Risk of developing lung cancer related to exposure to tobacco, indoor pollution, dusty work environment, and residential exposure to asbestos. RESULTS: There was a significant increase in the risk of developing lung cancer through smoking. In men, the ORs were 2.2 (95% CI = 1.0 to 4. 6) in ex-smokers, 9.8 (95% CI = 5.9 to 16.4) in light smokers (0-14 g/day), and 12.0 (95% CI = 6.5 to 22.3) in heavy smokers. In women, the ORs were 5.8 (95% CI = 1.3 to 25.8) in ex-smokers and 5.5 (95% CI = 2.6 to 11.3) in current smokers. Work in a dusty industry showed an elevated risk (OR = 3.2, 95% CI = 1.8 to 5.8) for lung cancer only in men. Male residents of areas where asbestos was shipped for distribution (termed moderately polluted asbestos areas) had a 2.5-fold increase (95% CI = 1.0 to 4.4) in the risk (OR) of developing lung cancer, and residents of areas where asbestos was mined (termed heavily polluted asbestos areas) had a 2.8-fold increase in risk (95% CI = 0.7 to 10.4). Female residents of heavily polluted asbestos areas showed elevated risks of 5.4 (95% CI = 1.3 to 22.5) of developing lung cancer. CONCLUSION: The data suggest that tobacco smoking is the most important risk factor for the development of lung cancer in this setting. Risks for lung cancer are reminiscent of those observed in Western countries in the 1960s and 1970s. However, environmental exposure to asbestos, a dusty occupation (in men), and perhaps indoor air pollution may also contribute to the development of lung cancer in this province.