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J Clin Epidemiol Vol. 52, No. 11, pp. 1055-1062, 1999 i 0395-4356j99/$-see front matter Copyright ©1999 ELsevier Science Ine. All rights reserved. Pll S0895-4356(99)00089-X ELSEViER Relation of Environmental Tobacco Smoke to Diet and Health Habits: Variations According to the Site of Exposure F. Curtin, A. Marabia,* and M. S. Berrutein DIVISION OF CLINICAL EPIDEMIOLOGY, GENEVA UNIVERSITY HOSPITAL, GENEVA, SWITZERLAND ABSTRACT. It has been postulated that the relationship of environmental tobacco smoke (ETS) exposure to cancer or cardiovascular diseases may be confounded by social class or diet because women exposed to ETS by their smokerspouse belong to lowersocial classes and have an unhealthy diet. In a population survey in Geneva, Switzerland, 914 female never-'smokers were interviewed about.sociodemographic factors, health habits including a semiquantitative food frequency questionnaire, and exposure to ETS according to the site (home, work, leisure). Compared to women unexposed to ETS, those exposed to ETS at work ate fess fibers, cereals, vegetables, lean meat, had a lower intake of iron and beta-carotene, and had a lower total energy intake; women exposed during leisure cime ate less cereals, drank less skim milk, and had a lower intake of complex carbohydrates. But the diet of women exposed at home did not differ from the diet of those unexposed to ETS. Thus, "living with a smoker" in Geneva does not necessarily imply adopting his health and dietary habits. We conclude that confounding factors of the association of ETS and disease vary according to site and populations and therefore should not be invoked as a systematic source of bias in all studies. l cuN snnEMiot 52;11:I055-1062, 1999. © 1999, Elsevier Science Inc. All rights reserved. KEY WORDS. Environmental tobacco smoke, site of exposure, diet, health habits, sociodemographic factors, women INTRODUCTION Exposure to environmental tobacco smoke (ETS) has been associated with increased risks of cancer, particularly of the lungs [1-9], heart disease [10-14], or respiratory functional disorders [15-17]. These associations are relatively weak. For example, the excess relative risk of lung cancer due to ETS has been estimated around 20% by two meta-analyses :i [18,19]. The role played by ETS exposure in carcinogenesis or in cardiovascular diseases has, therefore, been challenged [20-23]. Relying on studies showing that subjects living with a smoker share some of the smoker's unhealthy life- style [24-26], it has been argued that the association be- tween exposure to ETS and cancer incidence could be due to the confounding effect of socioeconomic and lifestyle factors [25,27]. Incriminated confounding factors include para-occuparional exposure to carcinogens, other toxic agents from the workplace [27,28], and diet [24,29,30j. ETS exposure may occur at home, at work, in public places, and during leisure time. The workplace, for exam- ple, is a source of exposure as important as home (31,32). 'Address for correspondencc Dr. A- Morabia, Division of Clinical Epide- miology, Geneva University Hospiml, CH-1211 Geneva 14, Swirzerland. E-mail: <Alfredo.Morabia®hcugech>. Accepted kr publication on 15 April 1999. People exposed to ETS at work appear to be at increased risk of lung cancer and cardiovascular disease [9,33]. Thus, in order for diet to be a confounder of the association be- rween ETS and disease (assuming that diet is related to dis- ease), we should observe that the diet of passive smokers al- ways resemble that of smokers, independently of whether the primary source of exposure is home, work or leisure time. However, differences in diet between passive smokers, sub- jects unexposed to ETS or active smokers have not been described yet according to site of exposure to ETS. The present study evaluated whether the association be- tween ETS exposure and other health risks differed accord- ing to the sites (home, work, leisure) of exposure to ETS in a representative sample of urban Swiss women who never smoked. METHODS Subjects Between January 1993 and December 1996, a random sam- ple of the adult female population of Geneva was selected to represent the 98,000 female noninsritutionalized resi- dents of Canton Geneva aged 35 to 74 years [341. Subjects were identified from an official list of all residents that in- cluded names, date of birth, address, and nationality. Ran- dom sampling in age-nationality strata was proportional to

1056 the corresponding distributions in the Geneva population. Subjects were asked by mail co participate in a population survey about "women's health." In the case of nonresponse after 15 days, they were called by telephone up to seven times on different days of the week and at different hours of the day and, if necessary, sent a second and third letter. The subjects who could not be reached represented 13% of the original sample. A systematic check in the following edition of the list has shown that over 90% of the subjects that had not been reached did not reside in Geneva any- more. On the other hand, subjects who were reached but refused to participate were not replaced. The overall re- cruitmenr procedure of a subject took up to 2 months. The participation rate represented 70% of the eligible sample. All participants were invited to visit a mobile epidemiol- ogy clinic and to bring back the completed standardized questionnaire covering lifestyle factors, reproductive his- tory, classic CVD risk factors, occupational history, smok- ing behavior, and ETS exposure. Both questionnaires were checked by trained technicians. No questionnaire was ac- cepted if it could not be checked and completed in-person on the mobile clinic. Weight and height were measured. The smoking history section of the questionnaire was structured as a calendar dedicated to active smoking, where the subjects reported the amount of cigarettes smoked year by year, between age 10 and the date of interview. There were three additional, separated calendars dedicated to ETS exposures on three different sites: home, work, and leisure time. Each site-specific calendar was filled by the interviewer only if the interviewee reported having been exposed to ETS at least 1 hr per week during a full year on that site. Of the four questions about health habits analyzed in this study ("Have you ever attempted to lose weighrl," "Do you consume light food?," "When eating meat, do you remove the fat?"), the last two were added to the questionnaire in 1995 and this information was not available for the women interviewed before this date. All participants also completed at home a self-adminis- tered, semiquantirative food frequency questionnaire. This food frequency questionnaire had been developed and tested in the study target population during 1992 [35-371. It comprised a[ist of 97 food items and serving sizes that could be converted into daily energy, nutrients, and alcohol in- takes [37]. All women interviewed since 1993 brought back the food frequency questionnaire on the day of the visit to the mobile unit, where it was checked by the interviewer. The questionnaire has been published [37]. Its food items are numbered vl to v97. Food groups were defined on the basis of the variables defined in the semiquantitative food frequency questionnaire (see Appendix 1). Data Analyses and Statistics We defined as never-smokers women who had smoked less than 100 cigarettes in their lifetime. Exposure to ETS was F. Curtin et a!. defined as an exposure of at least 1 hr per day for at least 1 year exclusively either at home, at work, or during leisure time that was still on-going during the year preceding the interview. To investigate differences in health habits by in- tensity of exposure to ETS, the median duration of ETS ex- posure from all sources (i.e., 11 hr per week) was used as a cutoff for low or high exposure at home or at work. This cutoff was not applied to leisure time exposure because 93% of the women had been exposed less than 11 hr per week. Education was divided into primary school education (s8 years of schooling), secondary school up to but not in- cluding the Swiss baccalaureate or equivalent (9-12 years of schooling), and a tertiary level comprising women with at least the Swiss baccalaureate (?13 years of schooling). Participants were interviewed about the current occupation and the two previous occupations held for the longest time, with description of the exact occupation performed, its du- ration, and characteristics of the enterprise. Social class w defined by the longest occupied job coded according to-rV Swiss adaptation of the criteria of the British Registrar General's Classification of Occupations [38]. Class I in- cludes: academics and professionals; class II: highly quali- fied workers or managers; class IIINM: nonmanual qualified workers; class IIIM: manual qualified workers; and classes IV+V: unqualified workers. Overweight was defined as a BMI equal or superior to 25 hg/mz. For categorical data, differences in proportions across groups of exposure to ETS (unexposed, exposed at home, at work, during leisure time) were evaluated by chi-square test. For dietary variables, comparisons between groups were done using analysis of covariance (ANCOVA) with age and BMI as continuous covariates and social class as an ordered categorical covariate [39,40]. With the exception of total carbohydrates (°.6), total fat (%), and saturated fat (%), all dietary variables were ana- lyzed after logarithmic transformation but presented as geo- metrical means adjusted for other covariates. Post hoc te were done according to Dunett's method for multiple com~' parisons [41]. RESULTS There were 14 women who had been simultaneously ex- posed at several sites for at least 1 hr per day during at least 1 year in each site. They were not kept in the present anal- ysis. Of the 1674 studied women, 375 (22.4%) were current smokers and 385 (23%) were ex-smokers. Of the 914 (54.6%) never-smokers, 698 (76.3%) were currently not exposed to ETS. Among the 216 never-smokers exposed to ETS, 81 had only been exposed at home, 83 only at work, and 52 only during leisure time. Table I presents the sociodemographic characteristics and health habits according to the site of ETS exposure. The only statistically significant difference was that women exposed to ETS at work were younger (mean age: 48 years) 2505586073

Diet, Health Habits, and Environmental Tobacco Smoke than the other women (mean age: 52-54, years), because most Swiss women stop working at 65 or before. A majority of women in all subgroups (49-69%) had a secondary level of education while 2-17% of them had only a primary level of education. Between 56% and 69% of the women were cate- gorized as manual or nonmanual qualified workers (class IIINM+M). Social classes I and II tended to be more fre- quent in women unexposed to ETS (27%) than among women exposed to ETS (18-20%). About half of the women not exposed to ETS or exposed at home were un- employed, but this percentage was 42% for women exposed to ETS during leisure time. All subgroups had similar average BMI. More than half of all women had ever attempted to lose weight, more than 70% removed the fat when eating meat, and 30-11 % con- sumed °light" food. .. Table 2 presents the adjusted, daily intakes of energy :oucces and nutrients according to the site of exposure to ~ETS. Women not exposed had on average a higher daily energy intake (1819 kcal) and women exposed at work had the lowest energy intake (1636 kcal, P= 0.07). In all sub- groups, total proteins represented about 16.0% of the daily energy intake, of which about a third was from vegetable origin; another 46% of the energy came from carbohy- drates, 36% from total fat, and 2% from alcohol. Complex carbohydrates were less consumed (20%) among women exposed to ETS during leisure time than among women un- 1057 exposed to ETS(22,:9%). The fiber intake was lower (13 g/ day) in women exposed to ETS at work compared to women of the other groups (14.5-15 g). The iron intake (8.4 mg) as well as the beta-carotene intake (2446 µg) were significantly lower among women exposed to ETS at work. There was no statistically significant difference in the in- take of calcium, retinol, or vitamin D. Table 3 shows that, with respect to specific food items or food groups and compared to unexposed women, women exposed at work ate less cereals (131 g), less vegetables (186 g), and less lean meat (31 g). Women exposed during lei- sure time ate less cereals and less skim milk than women unexposed to ETS. No statistically signficiant differences were observed for fried food, fruits, eggs/tofu, fish, fat meat, coffee, or whole milk between groups. Because the differences between women exposed at work (n = 83) and women unexposed to ETS (n = 698) may have been confounded by social class, we repeated the anal- yses for the intake of energy sources, micronutrients, and food items that were statistically different in Tables 2 and 3, but this time the comparison was made among working women, between those exposed (n = 83) and those not ex- posed to ETS (n = 353). Table 4 shows that the two types of analyses yielded the same results, that is, women exposed at work had a lower daily energy intake, ate less fibers, iron, beta-carotene, cereals, vegetables, and lean meat than women unexposed to ETS. TABLEI. Sociodemographic characteristics and life habits (%) by sites of environmental tobacco smoke (ETS) exposure at least until the year preceding interview: Nonsmoking women aged 35-74, Geneva, Switzerland, 1993-1996 Exposed to ETS Unexposed to ETS (n = 698) % Athome (n = 81) % Atwork (n = 83) % Dtrrin g leisure (n = 52) % valuea Age (average, year) 54.1 52.5 47.8 51.7 0.0001 Education (%) Tertiary 33.1 33.3 34.9 28.9 Secondary 54.6 49.4 51.8 69.2 Primary 12.3 17.3 13.3 1.9 0.16 Social class (%) I 3.7 0.0 2.5 1.9 I1 23.5 19.7 16.0 17.3 IIINM+M 55.7 59.3 69.1 69.2 IV+V 11.5 13.6 12.4 7.7 0.356 Never worked 5.6 7.4 0.0 3.9 Currently unemployed (%) 49.4 49.4 0.0 42.3 0.0& Body mass index (average, kg/mr) 25.1 25.4 24.1 24.2 0.88 Overweight (%) 34.5 39.5 28.9 28.9 0.43 Ever attempted to lose weight (%) 59.3 64.2 55.4 69.2 0.35 Remove the fat from meatd (%) 78.7 78.6 71.4 88.9 0.39 Consume light foodd (%) 40.8 37.2 38.1 29.6 0.68 ^Chi-square test for categorical variables and ANOVA for continuous variables (age, BMI). ^Not including women having never worked. cNot including women exposed at work. aData from a sample size n= 492.

1058 TABLE 2. Daily energy sources and nutrient intakes by sites of exposure to environmental tobacco smoke (ETS) at least unW the year preceding interview: Nonsmoking women aged 35-74, Geneva, Switzerland, 1993-1996 Unexposed Exposed to ETS Daily nutrient intake to ETS (n = 698) At home (n = 81) At work (n = 83) During leisure (n = 52) ANCOVA Pa Tocalenergy(kcal) L,819 1,745 1,636 1,744 0.07 Total proteins (%)b 15.4 15.7 15.5 15.9 0.66 Vegetable proteins (%)b 4.7 4.8 4.6 4.8 0.69 Animal proteins (%)6 10.2 10.5 10:5 10.7 0.76 Total carbohydrates (%)b 46.3 46.3 45.7 43.9 0.36 Saccharose (%)6 20.9 20.2 22.0 20.6 0.52 Complex carbohydrates (%)6 22.9 22.3 21.0 20.1* 0.05 Total far (%)6 35.1 -34-5 35.3 35.7 0.82_ Saturated fat (%)b 12.9 12.2 13.0 13.2 0.46 Monounsaeurated fat (%)b 13.1 12.9 13.0 - 13.2 0.98 Polyunsaturated fat (%)6 5.4 5.7 5.3 5.2 0.43 Alcohol (%)b - 1.9 2.2 2.0 2.5 0.47 Fibers (g) 15.0 14.5 13.0* 14.8 0.05 Cholesterol (mg) 300 278 271 289 0.33 Calcium (mg) 956 888 852 857 0.12 Iron (mg) 9.7 9.5 8.4* 9.7 0.02 Beta-carotene (µg) 3,236 2,993 2,446* 3,035 0.005 Retinol (µg) ",49 431 390 391- 0.40 Vitamin D (µg) 2.2 2.0 1.9 2.5 0.19 °Adjuseed for body mass index, social class, and age. ... sPement of the mcal energy from proteins, lipids, carbohydrates, and alcohol. *Scacistically different from unexposed to ETS at P 5 0-05- -- - We also investigated whether the differences observed in Tables 2 and 3 could be dose related to the intensity of ex- posure to ETS at home or at work. Table 5 shows a decrease in the daily intake of energy with the increase of ETS expo- sure, especially at home. There was similar or decreased consumption of complex carbohydrates, fibers, iron, vegeta- bles, and lean meat for more intense exposures. Cereals were consumed in smaller quantity by women intensely ex- F. Curtin et al. posed at work, while beta-carotene was consumed in smaller quantity by women exposed at work and intensely exposed at home. The differences for lean meat and fibers were no longer statistically significant, probably because of the smaller size. For the items not differing in a statistically significant way in Tables 2 and 3, there was no clear trend of consumption along the exposure intensity gradient (data not shown). --- TABLE 3. Daily food group intakes by sites of exposure to environmental-tobacco smoke (ETS) at least until the year preceding rnterview: Nonsmoking women aged 35-74, Gene- va, Switzerland, 1993-1996 Daily intake of Unexposed Exposed to-ETS food items or to ETS food groups (n = 698) At home (n = 81) At work (n = 83) During leisure (n = 52) - ANCOVA P^ Cereals (g) 170 167 131* 133* 0.0006 Fried food (g) 14-1 13.8 - 16.1 15.4 0.72 Fruits (g) 182 171 184 188 0.95 Vegetables (g) 225 221 186" -236 0.04 Eggs/tofu (g) 12.9 10.5 13.1 12.6 0.34 Fish (g) 22.0 20.8 22.4 29-7 0.13 Fat meat (g) 17.5 16.7 15.8 17.2 0.76 Lean meat (g) 39.4 41.1 31.3* 43.8 0.05 Coffee(mt) 154 130 200 125 0.28 Whole milk (ml) 479 39.4 37.4 . 33.8 0.23 Skim milk (ml) 91.3 97.9 92.8 53.9* 0.02 "Adjusted for body mass index, social class, and age. *Statisrical4y differenr from nonsmokers nor exposed to ETS at P~ 0.05.

Diet, Health Habits, and Environmental Tobacco Smoke TABLE 4. Daily energy sources, food and nutrient intakes differing between working women unexposed and exposed to environmental tobacco smoke (ETS) at work at least un- til the year preceeding interview: Nonsmoking women aged 35-74, Geneva, Switzerland, 1993-1996 Daily intake Unexposed to ETS (n = 353) Exposed.to ETS at work (n = 83) ANCOVA P value° Total energy (kcal) 1,822 1,636 0.045 Complex carbohydrates (%)s 22.3 21.0 0.07 Fibers (g) 15.0 13.0 0.05 Iron (mg) 9.7 8.4 0.01 Beta-carotene (µg) 3,295 2,446 0.002 Cereals (g) - 169 131 0.003 Vegetables (g) 230 186 0.009 Lean meat (g) 40.9 31.3 0.02 ^Adjusted for body mass index, social ciass and age, sPercent of the total energy from pmmins, lipids, carbohydrates, and al- : ohol. DISCUSSION By using an accurate definition of ETS exposure, with mu- tual.ly exclusive sites of exposure, we found that the diet and health habits of women exposed to ETS at home was simi- lar to that of women unexposed to ETS, but different from that of women exposed to ETS at work or during leisuree time. Sociodemagraphic Factors and Attitude Toward Health In contrast to other reports [25-27,42,43], we did not find that ETS exposure was-more common among low social classes, among unemployed, or among women with low ed- 1059 ucation level. Though women unexposed to ETS belonged more often to classes I and II than women exposed to ETS, , the differences were not statistically significant. British adults exposed to ETS have been found more likely to live a less healthy life, to cut down on fatty food less often, or to practice sport less often [25]. These findings were not observed in Geneva. Similarly, women exposed to ETS in the United States, the United Kingdom, Japan, or Hong Kong [24,25,43] tended to be more obese. In Geneva, the percentage of overweight women was higher among women not exposed or exposed to ETS at home than among those exposed at work or during leisure time. Diet and Site of Exposure to ETS It has been reported that women exposed at home are less fibers, less cereals, and less vegetables in Westera or Asiatic countries [25,30,42-44] or had a deficit in dietary beta-car- otene [29,30]. In contrast to these studies, the diet of Geneva women exposed at home was similar to that of un- exposed women. It is of note that, in the present study, ex- posure at home could mean that the spouse and/or anybody else in the household smoked. We failed to confirm that a woman living with a smoker adopts his/her health habits. Swiss smokers have as their Western counterparts a less healthy diet than nonsmokers [45-47), but on average living with a smoker in Geneva was not associated with unhealthy diet or lifestyle. To our knowledge, there is scarce information on the dietary differ- ences between women exposed to ETS at home and those not exposed has not been previously reported [48]. It can- not be ruled out that this is due to publication bias [49]. TABLE 5. Daily energy sources, food and nutrient intakes stratified by intensity of environmental tobacco smoke (ETS ) expo- sure at home and at work at least un8ll the year preceding intervieav: Nonsmoking women aged 35-74, Geneva, Switzerland, 1993-1996 ~ Exposed to ETS At home At work Unexposed to ETS Daily intake (n = 698) Low intensityb (n = 43) Hig intens (n = h Low ity° intensitys 38) (n = 41) High Intensity= (n = 42) ANCOVA P^ Total energy (kcal) 1818.6 1,823 1,65 6 1,639 1,601 0.14 Complex carbohydrates (%) 22.9 22.3 22 .3 22.0 19.0* 0.02 Fibers (g) 15.0 15.0 13 .9 13.1 12.8 0.15 Iron (mg) 9.7 10.0 8 .9 8.4* 8.4• 0.05 Beca-carotene (mg) 3,236 3,463 2,515 2,276* 2,644* 0.003 Cereals (g) 170 159 176 147 114* 0.0007 Vegetables (g) 225 245 194 191 181* 0.05 N Lean meat (g) 39.4 42.9 38 .9 32.1 30.6 0.14 O •Adjusted for body mass index, social class, and age. 'ETS exposure -=11 hr/week. Ul Ul ~ =ETS exposure > I I hr/week. ~ dPercene of the total energy from proteins, lipids, carbohydrares, and alcohol. *Statistically different from nonsmokers not exposed to ETS at P ~ 0.05. O V M

1060 As previously observed [50], compared to unexposed women, women exposed at work ate smaller amounts of fi- bers, cereals, vegetables, or lean meat and had a lower in- take of iron and beta-carotene. The differences remained when the comparison was limited to working women (Ta- ble 4). The two groups of working women were very similar in terms of age and social class. Women exposed during lei- sure time ate less cereals and drank less skim milk than those unexposed, but had a similar diet otherwise. Limitations and Strengths Women in this study were similar to the general population in terms of sociodemographic characteristics and diet [36,51]. Although misreporting bias can appear in nutri- tional studies [52], the diet questionnaire used in this study has been previously validated in that same population [36,371. We did not use biological markers such as cotinine, carbon monoxide, or thiocyanate to assess ETS exposure, but the validity of questionnaires on current ETS exposure status is generally good [531. Questions on passive smoking exposure were asked by trained interviewers with a detailed questionnaire. The women defined as exposed to ETS were likely to have been substantially exposed because, accord- ing to our definition, a passive smoker had to have been ex- posed to ETS at least 1 hr per day during at least 1 year. The definition applied to each site exclusively. The definition "living with a smoker" is commonly used to categorize women exposed to ETS at home, notably in studies relating ETS exposure and lung cancer [19].Our def- inition was more restrictive since it eliminated intermittent exposures to ETS. It is then possible that some women who were categorized as unexposed in our study were yet ex- posed to a small amount of ETS at home. It may be argued that this has reduced the dietary differences between ex- posed and unexposed. However, it seems implausible that intermittent contacts with smokers have major impact on lifestyle. On the other hand, the definition "living with a smoker" does not take into account exposure to ETS out- side of the home and therefore misclassifies as unexposed women who are exposed, for example, at work but whose spouse does not smoke. In the present study, exposure to occupational ETS appeared as the most influential expo- sure site on dietary habits. Overreporting ETS exposure was likely to be limited due to the moderate concerns in the Swiss public opinion about the risk associated with ETS [16]. These data were collected during a general survey on health habits without specific interest on ETS or diet. CONCLUSION This study did not find that living for a substantial period of time with one or multiple smokers is a major determinant of a woman's diet in Geneva. Therefore, we caution against R Curcin et ut. the generalization of results from studies in specific popula- tions associating ETS exposure at home to a conjunction of risk factors for cancer and cardiovascular disease like poor health habits, low socioeconomic status, and diet of poor quality. The relationships between ETS, socioeconomic status, and health habits appear to be considerably influ- enced by sociological context. They may differ in the United States, and across Europe. As unhealthy lifestyle and diets are not universally associated with living with a smoker, confounding by these factors cannot explain the results of all studies associating ETS with an excess risk of cancer or cardiovascular disease. APPENDIX 1 Food groups were defined on the basis of the variables de- fined in the semiquantitative food frequency questionnaire [36] as follows. Cereals were the sum of variables v9 to v1" (white and whole-meal bread, cereals, crackers, etc.) anm v42 to v47 (pastas, raviolis, rice, pizza, couscous, etc.). Fried food was the sum of variables v26 (fried fish), v27 (tuna in oil), and v41 (french fries). Fruits were the sum of variables v55 to v60 (bananas, apple, pears, citrus fruits, peach, apri- cot, berries, kiwi, canned fruits, etc.). Vegetable was the sum of variables v30 to v34 (spinach, cabbage, green beans, tomatoes, carrots, salad, etc.), v36 to v40 (peas, corn, vege- table soup, cream of vegetable, potatoes, etc.), and v45 (to- mato sauce). Eggs/tofu were the sum of variables v49 and v50 (eggs, tofu). Fish was the sum of variables v25 (salmon), v28 (trout, cod, etc.), and v29 (sea food). Fat meat was the sum of variables v18 to v22 (ham, pork, sau- sages, pat6, etc.). Lean meat was the sum of v14 to v17 (steak, chicken, roasted beef, etc.). Skim milk was the sum of variables vl to v6 (yogurt, quark, cottage cheese, feta, mozzarella, etc.), v82 (skim milk in coffee), and v85 (skim milk). Whole milk was the sum of variables v7 (Gruyere- like cheese), v8 (cheese fondue), v83 (fat milk in coffee v84 (coffee cream), and v86 (fat milk). Coffee was the van able v81. Alcohol was the sum of the variables v94 to v97 (beer, wine, aperitives, liquors). References 1. Trichopoulos D, Kalandidi A, Sparros L, MacMahon B. Lung cancer and passive smoking. Int J Cancer 1981; 27: 1-4. 2. Hirayama T. Non-smoking wives of heavy smokers have a higher risk of lung cancer: a study from Japan. BMJ 1981; 282: 183-185. 3. Correa P, Pickle LW, Fontham E, Lin Y, Haenszel W. Passive smoking and lung cancer. Lancet 1983; 2: 595-597. 4. Kabat GC, Wynder EL. Lung cancer in non-smokers. Cancer 1984; 53: 1214-1221. 5. Sandler DP, Wilcox AJ, Everson RB. Cumulative effects of lifetime passive smoking on cancer risk. Lancet 1985; 1: 312- 314. 6. 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