Occupational exposure of truck drivers to dust and polynuclear aromatic hydrocarbons: a pilot study in Geneva, Switzerland.

The exposure to dust and polynuclear aromatic hydrocarbons (PAH) of 15 truck drivers from Geneva, Switzerland, was measured. The drivers were divided between "long-distance" drivers and "local" drivers and between smokers and nonsmokers and were compared with a control group of 6 office workers who were also divided into smokers and nonsmokers. Dust was measured on 1 workday both by a direct-reading instrument and by sampling. The local drivers showed higher exposure to dust (0.3 mg/m3) and PAH than the long-distance drivers (0.1 mg/m3), who showed no difference with the control group. This observation may be due to the fact that the local drivers spend more time in more polluted areas, such as streets with heavy traffic and construction sites, than do the long-distance drivers. Smoking does not influence exposure to dust and PAH of professional truck drivers, as measured in this study, probably because the ventilation rate of the truck cabins is relatively high even during cold days (11-15 r/h). The distribution of dust concentrations was shown in some cases to be quite different from the expected log-normal distribution. The contribution of diesel exhaust to these exposures could not be estimated since no specific tracer was used. However, the relatively low level of dust exposure dose not support the hypothesis that present day levels of diesel exhaust particulates play a significant role in the excess occurrence of lung cancer observed in professional truck drivers.

Association of smoking and nicotine dependence with pre-diabetes in young and healthy adults.

INTRODUCTION: Several studies have shown an increased risk of type 2 diabetes among smokers. Therefore, the aim of this analysis was to assess the relationship between smoking, cumulative smoking exposure and nicotine dependence with pre-diabetes. METHODS: We performed a cross-sectional analysis of healthy adults aged 25-41 in the Principality of Liechtenstein. Individuals with known diabetes, Body Mass Index (BMI) >35 kg/m² and prevalent cardiovascular disease were excluded. Smoking behaviour was assessed by self-report. Pre-diabetes was defined as glycosylated haemoglobin between 5.7% and 6.4%. Multivariable logistic regression models were done. RESULTS: Of the 2142 participants (median age 37 years), 499 (23.3%) had pre-diabetes. There were 1,168 (55%) never smokers, 503 (23%) past smokers and 471 (22%) current smokers, with a prevalence of pre-diabetes of 21.2%, 20.9% and 31.2%, respectively (p <0.0001). In multivariable regression models, current smokers had an odds ratio (OR) of pre-diabetes of 1.82 (95% confidential interval (CI) 1.39; 2.38, p <0.0001). Individuals with a smoking exposure of <5, 5-10 and >10 pack-years had an OR (95% CI) for pre-diabetes of 1.34 (0.90; 2.00), 1.80 (1.07; 3.01) and 2.51 (1.80; 3.59) (p linear trend <0.0001) compared with never smokers. A Fagerström score of 2, 3-5 and >5 among current smokers was associated with an OR (95% CI) for pre-diabetes of 1.27 (0.89; 1.82), 2.15 (1.48; 3.13) and 3.35 (1.73; 6.48) (p linear trend <0.0001). DISCUSSION: Smoking is strongly associated with pre-diabetes in young adults with a low burden of smoking exposure. Nicotine dependence could be a potential mechanism of this relationship.

Perception of the damaging effects of smoking, and brief cessation counselling by doctors.

An open prospective study was conducted among the patients visiting an urban medical policlinic for the first time without an appointment to assess whether the immigrants (who represent more than half of our patients) are aware of the health effects of smoking, whether the level of acculturation influences knowledge, and whether doctors give similar advice to Swiss and foreign smokers. 226 smokers, 105 Swiss (46.5%), and 121 foreign-born (53.5%), participated in the study. 32.2% (95% CI [24.4%; 41.1%]) of migrants and 9.6% [5.3%; 16.8%] of Swiss patients were not aware of negative effects of smoking. After adjustment for age, the multivariate model showed that the estimated odds of "ignorance of health effects of smoking" was higher for people lacking mastery of the local language compared with those mastering it (odds ratio (OR) = 7.5 [3.6; 15.8], p < 0.001), and higher for men (OR = 4.3 [1.9; 10.0], p < 0.001). Advice to stop smoking was given with similar frequency to immigrants (31.9% [24.2%; 40.8%] and Swiss patients (29.0% [21.0%; 38.5%]). Nonintegrated patients did not appear to receive less counselling than integrated patients (OR = 1.1 [0.6; 2.1], p = 0.812). We conclude that the level of knowledge among male immigrants not integrated or unable to speak the local language is lower than among integrated foreign-born and Swiss patients. Smoking cessation counselling by a doctor was only given to a minority of patients, but such counselling seemed irrespective of nationality.

Secular trends in legal and illegal substance use among 16 to 20 year old adolescents in Switzerland.

BACKGROUND: Data targeting trends in legal and illegal substance use by adolescents are scarce. Using the data from two similar large national surveys run in 1993 and 2002, this paper assesses secular trends in rates of substance use among 16-20-year-old Swiss adolescents. METHODS: Self-reported regular use of tobacco, alcohol misuse, regular cannabis use (01 occasion over last 30 days) and lifetime use of psychoactive medication, LSD, ecstasy, cocaine and heroine were assessed through identical questions using an anonymous self-administered questionnaire. 9268 (1993) and 7428 (2002) high school students and apprentices were included in the analyses. RESULTS: There is a higher proportion of regular smokers among apprentices than among students (p <0.001). Between 1993 and 2002 the increase in regular tobacco consumption was significant among both female and male apprentices (p <0.001) but not among students. Between 1993 and 2002 alcohol misuse significantly increased in all four groups (p <0.001). It is more prevalent among males than among females (p <0.001) and higher among apprentices than among students (p <0.001). Regular use of cannabis has increased in the four groups (p <0.0001). It is higher among males than among females (p <0.001), while it is largely the same among students and apprentices. While the increase in ecstasy use is highly significant in all four groups (p <0.001), the increase in LSD and cocaine use is significant among apprentices only (p <0.001). Use of LSD, ecstasy and cocaine is more prevalent among males than among females (<0.001) and higher among apprentices than among students (p <0.001). CONCLUSION: The secular increase in psychoactive substance use among older Swiss adolescents calls for the implementation of effective strategies both from individual and public health viewpoints.

Biomedical risk assessment as an aid for smoking cessation.

BACKGROUND: A possible strategy for increasing smoking cessation rates could be to provide smokers who have contact with healthcare systems with feedback on the biomedical or potential future effects of smoking, e.g. measurement of exhaled carbon monoxide (CO), lung function, or genetic susceptibility to lung cancer. We reviewed systematically data on smoking cessation rates from controlled trials that used biomedical risk assessment and feedback. OBJECTIVES: To determine the efficacy of biomedical risk assessment provided in addition to various levels of counselling, as a contributing aid to smoking cessation. SEARCH STRATEGY: We systematically searched he Cochrane Collaboration Tobacco Addiction Group Specialized Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1966 to 2004), and EMBASE (1980 to 2004). We combined methodological terms with terms related to smoking cessation counselling and biomedical measurements. SELECTION CRITERIA: Inclusion criteria were: a randomized controlled trial design; subjects participating in smoking cessation interventions; interventions based on a biomedical test to increase motivation to quit; control groups receiving all other components of intervention; an outcome of smoking cessation rate at least six months after the start of the intervention. DATA COLLECTION AND ANALYSIS: Two assessors independently conducted data extraction on each paper, with disagreements resolved by consensus. MAIN RESULTS: From 4049 retrieved references, we selected 170 for full text assessment. We retained eight trials for data extraction and analysis. One of the eight used CO alone and CO + Genetic Susceptibility as two different intervention groups, giving rise to three possible comparisons. Three of the trials isolated the effect of exhaled CO on smoking cessation rates resulting in the following odds ratios (ORs) and 95% confidence intervals (95% CI): 0.73 (0.38 to 1.39), 0.93 (0.62 to 1.41), and 1.18 (0.84 to 1.64). Combining CO measurement with genetic susceptibility gave an OR of 0.58 (0.29 to 1.19). Exhaled CO measurement and spirometry were used together in three trials, resulting in the following ORs (95% CI): 0.6 (0.25 to 1.46), 2.45 (0.73 to 8.25), and 3.50 (0.88 to 13.92). Spirometry results alone were used in one other trial with an OR of 1.21 (0.60 to 2.42).Two trials used other motivational feedback measures, with an OR of 0.80 (0.39 to 1.65) for genetic susceptibility to lung cancer alone, and 3.15 (1.06 to 9.31) for ultrasonography of carotid and femoral arteries performed in light smokers (average 10 to 12 cigarettes a day). AUTHORS' CONCLUSIONS: Due to the scarcity of evidence of sufficient quality, we can make no definitive statements about the effectiveness of biomedical risk assessment as an aid for smoking cessation. Current evidence of lower quality does not however support the hypothesis that biomedical risk assessment increases smoking cessation in comparison with standard treatment. Only two studies were similar enough in term of recruitment, setting, and intervention to allow pooling of data and meta-analysis.

Risk factors for head and neck cancer in young adults: a pooled analysis in the INHANCE consortium.

BACKGROUND: Increasing incidence of head and neck cancer (HNC) in young adults has been reported. We aimed to compare the role of major risk factors and family history of cancer in HNC in young adults and older patients. METHODS: We pooled data from 25 case-control studies and conducted separate analyses for adults ≤45 years old ('young adults', 2010 cases and 4042 controls) and >45 years old ('older adults', 17 700 cases and 22 704 controls). Using logistic regression with studies treated as random effects, we estimated adjusted odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: The young group of cases had a higher proportion of oral tongue cancer (16.0% in women; 11.0% in men) and unspecified oral cavity / oropharynx cancer (16.2%; 11.1%) and a lower proportion of larynx cancer (12.1%; 16.6%) than older adult cases. The proportions of never smokers or never drinkers among female cases were higher than among male cases in both age groups. Positive associations with HNC and duration or pack-years of smoking and drinking were similar across age groups. However, the attributable fractions (AFs) for smoking and drinking were lower in young when compared with older adults (AFs for smoking in young women, older women, young men and older men, respectively, = 19.9% (95% CI = 9.8%, 27.9%), 48.9% (46.6%, 50.8%), 46.2% (38.5%, 52.5%), 64.3% (62.2%, 66.4%); AFs for drinking = 5.3% (-11.2%, 18.0%), 20.0% (14.5%, 25.0%), 21.5% (5.0%, 34.9%) and 50.4% (46.1%, 54.3%). A family history of early-onset cancer was associated with HNC risk in the young [OR = 2.27 (95% CI = 1.26, 4.10)], but not in the older adults [OR = 1.10 (0.91, 1.31)]. The attributable fraction for family history of early-onset cancer was 23.2% (8.60% to 31.4%) in young compared with 2.20% (-2.41%, 5.80%) in older adults. CONCLUSIONS: Differences in HNC aetiology according to age group may exist. The lower AF of cigarette smoking and alcohol drinking in young adults may be due to the reduced length of exposure due to the lower age. Other characteristics, such as those that are inherited, may play a more important role in HNC in young adults compared with older adults.

E-Cigarettes: A Review of New Trends in Cannabis Use.

The emergence of electronic cigarettes (e-cigs) has given cannabis smokers a new method of inhaling cannabinoids. E-cigs differ from traditional marijuana cigarettes in several respects. First, it is assumed that vaporizing cannabinoids at lower temperatures is safer because it produces smaller amounts of toxic substances than the hot combustion of a marijuana cigarette. Recreational cannabis users can discretely "vape" deodorized cannabis extracts with minimal annoyance to the people around them and less chance of detection. There are nevertheless several drawbacks worth mentioning: although manufacturing commercial (or homemade) cannabinoid-enriched electronic liquids (e-liquids) requires lengthy, complex processing, some are readily on the Internet despite their lack of quality control, expiry date, and conditions of preservation and, above all, any toxicological and clinical assessment. Besides these safety problems, the regulatory situation surrounding e-liquids is often unclear. More simply ground cannabis flowering heads or concentrated, oily THC extracts (such as butane honey oil or BHO) can be vaped in specially designed, pen-sized marijuana vaporizers. Analysis of a commercial e-liquid rich in cannabidiol showed that it contained a smaller dose of active ingredient than advertised; testing our laboratory-made, purified BHO, however, confirmed that it could be vaped in an e-cig to deliver a psychoactive dose of THC. The health consequences specific to vaping these cannabis preparations remain largely unknown and speculative due to the absence of comprehensive, robust scientific studies. The most significant health concerns involve the vaping of cannabinoids by children and teenagers. E-cigs could provide an alternative gateway to cannabis use for young people. Furthermore, vaping cannabinoids could lead to environmental and passive contamination.

Smoking cessation and the incidence of pre-diabetes and type 2 diabetes: a cohort study.

AIMS: Smoking cessation has been suggested to increase the short-term risk of type 2 diabetes mellitus (T2DM). This study aimed at assessing the association between smoking cessation and incidence of T2DM and impaired fasting glucose (IFG). METHODS: Data from participants in the CoLaus study, Switzerland, aged 35-75 at baseline and followed for 5.5years were used. Participants were classified as smokers, recent (≤5years), long-term (>5years) quitters, and non-smokers at baseline. Outcomes were IFG (fasting serum glucose (FSG) 5.6-6.99mmol/l) and T2DM (FSG ≥7.0mmol/l and/or treatment) at follow up. RESULTS: 3,166 participants (63% women) had normal baseline FSG, of whom 26.7% were smokers, 6.5% recent quitters, and 23.5% long-term quitters. During follow-up 1,311 participants (41.4%) developed IFG (33.6% women, 54.7% men) and 47 (1.5%) developed T2DM (1.1% women, 2.1% men). Former smokers did not have statistically significant increased odds of IFG compared with smokers after adjustment for age, education, physical activity, hypercholesterolemia, hypertension and alcohol intake, with OR of 1.29 [95% confidence interval 0.94-1.76] for recent quitters and 1.03 [0.84-1.27] for long-term quitters. Former smokers did not have significant increased odds of T2DM compared with smokers with multivariable-adjusted OR of 1.53 [0.58-4.00] for recent quitters and 0.64 [0.27-1.48] for long-term quitters. Adjustment for body-mass index and waist circumference attenuated the association between recent quitting and IFG (OR 1.07 [0.78-1.48]) and T2DM (OR 1.28 [0.48-3.40]. CONCLUSION: In this middle-aged population, smoking cessation was not associated with an increased risk of IFG or T2DM.

Association between smoking and recurrence of venous thromboembolism and bleeding in elderly patients with past acute venous thromboembolism.

BACKGROUND: While the association between smoking and arterial cardiovascular events has been well established, the association between smoking and venous thromboembolism (VTE) remains controversial. OBJECTIVES: To assess the association between smoking and the risk of recurrent VTE and bleeding in patients who have experienced acute VTE. PATIENTS/METHODS: This study is part of a prospective Swiss multicenter cohort that included patients aged ≥65years with acute VTE. Three groups were defined according to smoking status: never, former and current smokers. The primary outcome was the time to a first symptomatic, objectively confirmed VTE recurrence. Secondary outcomes were the time to a first major and clinically relevant non-major bleeding. Associations between smoking status and outcomes were analysed using proportional hazard models for the subdistribution of a competing risk of death. RESULTS: Among 988 analysed patients, 509 (52%) had never smoked, 403 (41%) were former smokers, and 76 (8%) current smokers. After a median follow-up of 29.6months, we observed a VTE recurrence rate of 4.9 (95% confidence interval [CI] 3.7-6.4) per 100 patient-years for never smokers, 6.6 (95% CI 5.1-8.6) for former smokers, and 5.2 (95% CI 2.6-10.5) for current smokers. Compared to never smokers, we found no association between current smoking and VTE recurrence (adjusted sub-hazard ratio [SHR] 1.05, 95% CI 0.49-2.28), major bleeding (adjusted SHR 0.59, 95% CI 0.25-1.39), and clinically relevant non-major bleeding (adjusted SHR 1.21, 95% CI 0.73-2.02). CONCLUSIONS: In this multicentre prospective cohort study, we found no association between smoking status and VTE recurrence or bleeding in elderly patients with VTE.

Six-month outcomes of a multi-campus smoking cessation contest

Background: Up to 40% of North American post-secondary students smoke at least occasionally, and most want to quit. Given students' preferences for free, easy-to-access, self-directed, convenient cessation methods, a motivational, incentive-based cessation contest may be an effective way to assist students to quit. The current study describes 3- and 6-month outcomes experienced by post-secondary student smokers who entered the 'Let's Make A Deal!' contest. Methodology: Contestants from five university campuses who chose to quit completely ('Quit For Good') or reduce their tobacco consumption by 50% ('Keep The Count') were invited to participate in a study of the contest. Three and six months after registration, participants were contacted by phone to assess their smoking and quitting behaviours. Qualitative and quantitative measures were collected, including weekly tobacco consumption, efficacy to resist temptations to smoke, use of quitting aids, and strategies to cope with withdrawal. Quitting was assessed using 7-day point prevalence and continuous abstinence. Results: Seventy-four (64.9%) of the 114 participants recruited for the study completed the follow-ups. Over 31 % of participants who entered Quit For Good and 23.5% of participants who entered Keep The Count were identified as quitters at the 6-month follow-up. Among the quitters, 45.5% experienced sustained abstinence from smoking for the 6-month duration of the study. Keep The Count contestants reduced their tobacco consumption by 57.2% at 3-month follow-up and sustained some of this reduction through to the 6-month follow-up. Qualitative data provides insights into how quitters coped with withdrawal and what hampered continuing smokers' efforts to quit. Significance: A motivational, incentive-based contest for post-secondary students can facilitate both smoking cessation and harm reduction. The contest environment, incentives, resources, and "buddies" provide positive structural and social supports to help smokers overcome potential barriers to quitting, successfully stop smoking, and manage potential triggers to relapse. The contest cessation rates are higher than the typical 5-7% associated with unassisted quitting.

The influence of familial smoking behaviours on adolescent smoking behaviours

The ability to identify adolescents who are at risk for becoming smokers may prove useful in developing effective smoking prevention programs. The purpose of this stUdy was to assess the importance of familial smoking behaviours on adolescent smoking patterns. The results were based on responses to The Grade 7 Lincoln County Smoking Survey designed by Chudzik and Partington (1994), and are a part of the "Peer Assisted Learning Program· (PAL) presented by the Niagara Regional Health Services Department, with the cooperation of a local Board of Education (Region of Niagara). The results indicate that 12% of the total group of 450 Grade 7 student respondents were current smokers at the time the data were collected (13% males and 11% females), while more than 37% of individuals indicated that they had tried smoking previously. Of the individuals who were classified as smokers, 11% reported that they smoked because their parents smoked, but only 6% reported that they smoked because their siblings smoked. More concerning, however, is the finding that 4% of smokers reported that they felt pressured to smoke by their relatives. In a society that is becoming increasingly concerned about health, it is also alarming to observe that only 50% of the respondents within this sample reported that there were no smokers (parents/siblings) in their homes. The results also indicate that 33% percent of respondents had grandparents who continued to smoke, and 53% of respondents indentified other relatives who continued to smoke.

The impact of tobacco control policies on university students' smoking in Ontario

Objective. Despite steady declines in the prevalence of tobacco use among Canadians, young adult tobacco use has remained stubbornly high over the past two decades (CTUMS, 2005a). Currently in Ontario, young adults have the highest proportion of smokers of all age cohorts at 26%. A growing body of evidence shows that smoking restrictions and other tobacco control policies can reduce tobacco use and consumption among adults and deter initiation among youth; whether young adult university students' smoking participation is influenced by community smoking restrictions, campus tobacco control policies or both remains an empirical question. The purpose of this study is to examine the relationship among current smoking status of students on university campuses across Ontario and various tobacco control policies, 3including clean air bylaws of students' home towns, clean air by-laws of the community where the university is situated, and campus policies. Methods. Two data sets were used. The 200512006 Tobacco Use in a Representative Sample of Post-Secondary Students data set provides information about the tobacco use of 10,600 students from 23 universities and colleges across Ontario. Data screening for this study reduced the sample to 5,114 17-to-24 year old undergraduate students from nine universities. The second data set is researcher-generated and includes information about strength and duration of, and students' exposure to home town, local and campus tobacco control policies. Municipal by-laws (of students' home towns and university towns) were categorized as weak, moderate or strong based on criteria set out in the Ontario Municipal By-law Report; campus policies were categorized in a roughly parallel fashion. Durations of municipal and campus policies were calculated; and length of students' exposure to the policies was estimated (all in months). Multinomial logistic regression analyses were used to examine the relationship between students' current smoking status (daily, less-than-daily, never-smokers) and the following policy measures: strength of, duration of, and students' exposure to campus policy; strength of, duration of, and students' exposure to the by-law in the university town; and, strength of, duration of, and students' exposure to the by-law in the home town they grew up in. Sociodemographic variables were controlled for. Results. Among the Ontario university students surveyed, 7.0% currently use tobacco daily and 15.4% use tobacco less-than-daily. The proportions of students experiencing strong tobacco control policies in their home town, the community in which their university is located and at their current university were 33.9%,64.1 %, and 31.3% respectively. However, 13.7% of students attended a university that had a weak campus policy. Multinomial logistic regressions suggested current smoking status was associated with university town by-law strength, home town by-law strength and the strength of the campus tobacco control policy. In the fmal model, after controlling for sociodemographic factors, a strong by-law in the university town and a strong by-law in students' home town were associated with reduced odds of being both a less-than-daily (OR = 0.64, 95%CI: 0.48-0.86; OR = 0.80, 95%CI: 0.66-0.95) and daily smoker (OR = 0.59, 95%CI: 0.39-0.89; OR = 0.76, 95%CI: 0.58-0.99), while a weak campus tobacco control policy was associated with higher odds of being a daily smoker (OR = 2.08, 95%CI: 1.31-3.30) (but unrelated to less-than-daily smoking). Longer exposure to the municipal by-law (OR = 0.93; 95%CI: 0.90-0.96) was also related to smoking status. Conclusions. Students' smoking prevalence was associated with the strength of the restrictions in university, and with campus-specific tobacco control policies. Lessthan- daily smoking was not as strongly associated with policy measures as daily smoking was. University campuses may wish to adopt more progressive campus policies and support clean air restrictions in the broader community. More research is needed to determine the direction of influence between tobacco control policies and students' smoking.

Socio-demographic factors, smoking, symptoms, morbidities and pulmonary function and quality of life in individuals with a heavy smoking history

Objective: To determine which socio-demographic, exposure, morbidity and symptom variables are associated with health-related quality of life among former and current heavy smokers. Methods: Cross sectional data from 2537 participants were studied. All participants were at ≥2% risk of developing lung cancer within 6 years. Linear and logistic regression models utilizing a multivariable fractional polynomial selection process identified variables associated with health-related quality of life, measured by the EQ-5D. Results: Upstream and downstream associations between smoking cessation and higher health-related quality of life were evident. Significant upstream associations, such as education level and current working status and were explained by the addition of morbidities and symptoms to regression models. Having arthritis, decreased forced expiratory volume in one second, fatigue, poor appetite or dyspnea were most highly and commonly associated with decreased HRQoL. Discussion: Upstream factors such as educational attainment, employment status and smoking cessation should be targeted to prevent decreased health-related quality of life. Practitioners should focus treatment on downstream factors, especially symptoms, to improve health-related quality of life.

Lung cancer risk associated with occupational exposure to nickel, chromium VI, and cadmium in two population-based case-control studies in Montreal.

Cancer du poumon associé à l’exposition au nickel, au chrome VI et au cadmium dans le milieu de travail utilisant deux études populationnelles cas-témoins à Montréal. Au début des années 1990, le nickel, le chrome VI et le cadmium ont été classés en tant qu’agents cancérigènes de classe 1 par le CIRC (Centre International de Recherche sur le Cancer). Cependant, les résultats des études ayant permis la classification de ces métaux n’ont pas toujours été reproduits, et d’importantes questions demeurent quant aux effets de ces métaux à de faibles niveaux d’exposition. Un plus grand nombre de recherches empiriques est donc nécessaire afin de réaffirmer la cancérogénicité de ces agents, et d’identifier les circonstances dans lesquelles ils peuvent être néfastes. L'objectif de cette étude était d'explorer la relation entre l’exposition à un des métaux (soit le nickel, le chrome VI, ou le cadmium) et les risques subséquents de développer un cancer du poumon chez des travailleurs provenant de différents milieux de travail qui sont exposés à ces métaux à de différents degrés. Deux études cas-témoins de base populationnelle menées à Montréal ont fourni les données nécessaires pour examiner la cancérogénicité de ces métaux. La première étude était menée entre 1979 et 1986 chez des hommes âgés de 35 à 70 ans ayant un cancer dans l’un de 19 sites anatomiques de cancer sélectionnés. La seconde étude était menée entre 1996 et 2001 chez des hommes et des femmes âgés de 35 à 75 ans, avec un diagnostic de tumeur maligne au poumon. Dans ces deux études, les cas ont été recensés dans tous les hôpitaux de l'île de Montréal, tandis que les contrôles populationnels appariés par âge et stratifiés par sexe, ont été sélectionnés des listes électorales. Une entrevue avec chaque sujet a permis d'obtenir un historique d'emploi détaillé ainsi que des informations précises sur les facteurs de risques socio-économiques et personnels. Les descriptions de poste ont été évaluées par une équipe d'experts chimistes et hygiénistes afin de déterminer si le sujet a été exposé à chaque agent, et pour mesurer à la fois la concentration et la durée de chaque exposition, ainsi que l’exposition cumulative tout au long de la vie de chaque participant. Pour déterminer si une exposition à l’un des trois métaux en cause était associée à une augmentation de l'incidence du cancer du poumon, des données ont été analysées par régression logistique : des ajustements ont été effectués pour des facteurs de confusion pertinents incluant un historique détaillé du tabagisme. Des mesures catégoriques d'exposition cumulée ont été également analysées, ainsi que la modification des effets par le tabagisme. Les deux études ont été analysées séparément, puis par la suite combinées afin d'augmenter la puissance statistique. Les niveaux d'exposition mesurés dans cette population ne semblaient pas poser un excès de risque de cancer du poumon pour les travailleurs exposés au chrome VI. Cependant, ceux qui ont été exposés au nickel ont subi une augmentation significative du risque, et ce, quel que soit leur niveau d'exposition. Le risque de développer un cancer du poumon suite à une exposition au cadmium était élevé, mais pas de manière significative. Pour chacun des trois métaux, le risque de cancer du poumon était très élevé parmi les non-fumeurs, mais pas parmi les fumeurs. L’effet combiné du tabagisme et de l’exposition aux métaux était compatible avec un excès de risque additif. Cependant, les intervalles de confiance dans cette étude tendaient à être larges, et une faiblesse de puissance statistique peut limiter l’interprétation de certains résultats. Cette étude est unique dans la mesure où elle a fourni des preuves empiriques sur les risques de développer le cancer du poumon liés aux faibles niveaux d’exposition au nickel, au chrome VI, ou au cadmium provenant de divers contextes de travail. Dans la plupart des autres études, la majorité des expositions pertinentes n’ont pas été bien contrôlées. À l'inverse, cette étude a bénéficié de la collecte et de la disponibilité d'information détaillée concernant le tabagisme et d’autres facteurs de risque. Les résultats de cette étude ont d'importantes conséquences pour la santé publique, tant au niveau de la détermination des risques pour les travailleurs actuellement exposés à ces métaux, qu'au niveau de l’évaluation des risques pour la population en général, elle-même exposée à ces métaux par le biais de la pollution et de la fumée de cigarette. Cette analyse contribuera fort probablement à une réévaluation par le CIRC de la cancérogénicité de ces métaux. L'exploration de la relation entre les risques de cancer du poumon et l'exposition au nickel, au chrome VI et au cadmium est donc opportune et pertinente.

Consommation alimentaire d’antioxydants et risque de cancer du poumon : une étude cas-témoins montréalaise

Objectif : Examiner l’association entre la consommation alimentaire de caroténoïdes (β-carotène, α-carotène, β-cryptoxanthine, lutéine/zéaxanthine, lycopène) et de vitamine C et le risque de cancer du poumon, selon le sexe, l’intensité de tabagisme et le sous-type histologique de la tumeur. Méthodes : Les données proviennent d’une étude cas-témoins menée à Montréal, Canada. Des entrevues ont été effectuées auprès de 1 105 cas incidents de cancer du poumon et 1 449 témoins issus de la population générale. Leur fréquence de consommation moyenne de 49 fruits et légumes deux ans auparavant a été convertie en apports en antioxydants. Les rapports de cotes (RC) et les intervalles de confiance (IC) à 95% caractérisant l’association entre les antioxydants et le risque de cancer du poumon ont été estimés à l’aide de modèles de régression logistique et polytomée, en tenant compte de facteurs de confusion potentiels. Résultats : Une consommation élevée en antioxydants était généralement associée à une diminution du risque de cancer du poumon de l’ordre de 30%. Un effet protecteur a été observé chez les hommes et les femmes, pour les non fumeurs, les fumeurs quelque soit l’intensité de tabagisme, ainsi que pour les carcinomes à petites cellules, épidermoïde et l’adénocarcinome. Conclusions : Plusieurs antioxydants alimentaires protégeraient du cancer du poumon. Les efforts de prévention bénéficieraient de cibler la promotion de la consommation de fruits et de légumes riches en caroténoïdes et en vitamine C.