Neighbourhood socioeconomic status and individual lung cancer risk: Evaluating long-term exposure measures and mediating mechanisms

Neighbourhood socioeconomic status (SES) has been associated with numerous chronic diseases, yet little information exists on its association with lung cancer incidence. This outcome presents two key empirical challenges: a long latency period that requires study participants' residential histories and long-term neighbourhood characteristics; and adequate data on many risk factors to test hypothesized mediating pathways between neighbourhood SES and lung cancer incidence. Analysing data on urban participants of a large Canadian population-based lung cancer case-control study, we investigate three issues pertaining to these challenges. First, we examine whether there is an association between long-term neighbourhood SES, derived from 20 years of residential histories and five national censuses, and lung cancer incidence. Second, we determine how this long-term neighbourhood SES association changes when using neighbourhood SES measures based on different latency periods or at time of study entry. Third, we estimate the extent to which long-term neighbourhood SES is mediated by a range of individual-level smoking behaviours, other health behaviours, and environmental and occupational exposures. Results of hierarchical logistic regression models indicate significantly higher odds of lung cancer cases residing in the most compared to the least deprived quintile of the long-term neighbourhood SES index (OR: 1.46; 95% CI: 1.13–1.89) after adjustment for individual SES. This association remained significant (OR: 1.38; 1.01–1.88) after adjusting for smoking behaviour and other known and suspected lung cancer risk factors. Important differences were observed between long-term and study entry neighbourhood SES measures, with the latter attenuating effect estimates by over 50 percent. Smoking behaviour was the strongest partial mediating pathway of the long-term neighbourhood SES effect. This research is the first to examine the effects of long-term neighbourhood SES on lung cancer risk and more research is needed to further identify specific, modifiable pathways by which neighbourhood context may influence lung cancer risk.     

Occupational risks for lung cancer among nonsmokers

We conducted a case-control study in 12 European study centers to evaluate the role of occupational risk factors among nonsmokers. We obtained detailed occupational histories from 650 nonsmoking cases (509 females/141 males) and 1,542 nonsmoking controls (1,011 females/531 males). On the basis of an a priori definition of occupations and industries that are known (list A) or suspected (list B) to be associated with lung carcinogenesis, we calculated odds ratios (ORs) for these occupations, using unconditional logistic regression models and adjusting for sex, age, and center effects. Among nonsmoking men, an excess relative risk was observed among those who had worked in list-A occupations [OR = 1.52; 95% confidence interval (C) = 0.78-2.97] but not in list-B occupations (OR = 1.05; 95%), CI = 0.60-1.83). Among nonsmoking women, there was an elevation of risk for list-A occupations (OR = 1.50; 95% CI = 0.49-4.53), although this estimate was imprecise, given that less than 1% of cases and controls were exposed. Exposure to list-B occupations was associated with an increase in relative risk (OR = 1.69; 95% CI = 1.09-2.63) in females, but not in males. Women who had been laundry workers or dry cleaners had an OR of 1.83 (95% CI = 0.98-3.40). Our findings confirm that certain occupational exposures are associated with an increased risk for lung cancer among both female and male nonsmokers; however, knowledge on occupational lung carcinogens is biased toward agents to which mainly men are exposed.     

Lung cancer risk of workers in shoe manufacture and repair

BACKGROUND: The occupational lung cancer risk in manufacturing and repair of shoes was studied by pooling of two major case-control studies from Germany. METHODS: Some 4184 incident hospital-based cases of primary lung cancer and 4253 population controls, matched for sex, age, and region of residence were intensively interviewed with respect to their occupational and smoking history. Based on the occupational coding and a free text search, all individuals who had ever worked in shoe manufacturing or repair for at least half a year were identified. Shoemaker-years were calculated as the cumulated duration of working in shoe manufacturing or repair. Odds ratios (OR) and 95% confidence intervals (CI) were calculated via conditional logistic regression. Additional adjustment for smoking and occupational asbestos exposure was used. RESULTS: Seventy-six cases and 42 controls who had ever worked in shoe manufacture or repair (OR = 1.89, 95% CI: 1.29-2.78). After adjustment for smoking, this risk was lowered to 1.69 (95% CI: 1.09-2.62). Further adjustment for asbestos exposure only slightly changed the risk estimates upwards. The smoking adjusted OR in males was 1.50 (95% CI: 0.93-2.41) and 2.91 (95% CI: 0.90-9.44) in females. Logistic regression modeling showed a positive dose-effect relationship between duration of exposure in shoe manufacture and repair and lung cancer risk. The odds ratio for 30 years of exposure varied between 1.98 and 2.24 depending on the model specified. CONCLUSIONS: The study demonstrates an increased lung cancer risk for shoemakers and workers in shoe manufacturing. The risk seems to double after being 30 years in these occupations.     

Sex differences in the associations of socioeconomic status with undiagnosed diabetes mellitus and impaired glucose tolerance in the elderly population: the KORA Survey 2000

BACKGROUND: Sex differences in the associations of socioeconomic status (SES) with prevalence of undiagnosed diabetes mellitus, impaired glucose tolerance (IGT) and known risk factors of type 2 diabetes mellitus were investigated in an elderly population. METHODS: Oral glucose tolerance tests were carried out in 1354 randomly selected subjects (697 men, 657 women) aged 55-74 years in the population-based KORA Survey 2000, Augsburg, Germany. Odds ratios (ORs) and 95% confidence intervals (CIs) for undiagnosed diabetes or IGT by education, occupation and income were estimated using logistic regression controlling for age, waist circumference, blood pressure, triglycerides, physical activity, smoking and alcohol intake. RESULTS: All three SES variables were significantly inversely related to body mass index, waist circumference and low physical activity in women (P < 0.05). In men, these associations were weaker or absent. Using the lowest category as reference, occupational status was significantly associated with undiagnosed diabetes in women (adjusted OR 0.5; 95% CI 0.3-0.8) after controlling for risk factors in multivariate regression. The OR was also reduced with higher income in women (adjusted OR, diabetes: 0.7; 95% CI 0.5-1.03). Among men, no significant relations of the SES indicators with unknown diabetes were observed. However, the odds of having IGT was lower with higher occupational status in men (adjusted OR 0.7; 95% CI 0.5-0.9). CONCLUSIONS: Undiagnosed type 2 diabetes was related to low SES defined by occupation or income in women only. In men, low occupational status was independently associated with higher IGT risk. Educational level was not related to glucose disorders in both sexes in the elderly population.     

Education,income, occupational status and health risk behaviour

Aim Socio-economic status is associated with a variety of health-related behaviours. In our study, we determined the independent effects of income, educational attainment and occupational status on overweight, smoking and physical activity in the German population. Subjects and methods The German National Health Interview and Examination Survey is a representative sample of the German adult population and includes 7,124 men and women. Prevalences of obesity, smoking and physical inactivity stratified for education, income and occupational status were calculated. Multiple logistic regression models were used to estimate the odds ratios (OR) and 95% confidence intervals (CI) for education, income, occupational status and health-related behaviour, adjusted for age and gender. Results Health risk behaviours were more prevalent in subjects with lower education, income or occupational status. After mutual adjustment, education, income and occupation were independently associated with physical inactivity. Low education was strongly associated with both obesity (OR: 2.58, 95% CI: 1.99–3.34) and smoking (OR: 2.09, 95% CI: 1.71–2.54). Low income was associated with smoking (OR: 1.40, 95% CI: 1.07–1.83), but not with obesity, and low occupational status was associated with obesity (OR: 1.42, 95% CI: 1.05–1.92), but not with smoking. High income or occupation could not compensate for the impact of low education on obesity and smoking. Conclusion Low socio-economic status is associated with health risk behaviours. Concerning obesity and smoking, education was more important than income or occupational status. Public health programmes to reduce these risk factors should focus on early-life health education.     

Socioeconomic status and multiple myeloma among US blacks and whites

OBJECTIVES: This study examined the relation between socioeconomic status (SES) and risk of multiple myeloma among Blacks and Whites in the United States. METHODS: This population-based case-control study included 573 cases (206 Blacks and 367 Whites) with new diagnoses of multiple myeloma identified between August 1, 1986, and April 30, 1989, and 2131 controls (967 Blacks and 1164 Whites) from 3 US geographic areas. Information on occupation, income, and education was obtained by personal interview. RESULTS: Inverse gradients in risk were associated with occupation-based SES, income, and education. Risks were significantly elevated for subjects in the lowest categories of occupation-based SES (odds ratio [OR] = 1.71, 95% confidence interval [CI] = 1.16, 2.53), education (OR = 1.36, 95% CI = 1.06, 1.75), and income (OR = 1.43, 95% CI = 1.05, 1.93). Occupation-based low SES accounted for 37% of multiple myeloma in Blacks and 17% in Whites, as well as 49% of the excess incidence in Blacks. Low education and low income accounted for 17% and 28% of the excess incidence in Blacks, respectively. CONCLUSIONS: Our results indicate that the measured SES-related factors account for a substantial amount of the Black-White differential in multiple myeloma incidence.     

中国非吸烟女性肺癌危险因素的病例-对照研究

目的探讨中国非吸烟女性患肺癌的危险因素。方法应用1∶2配对的病例对照方法,收集2001年9月~2004年2月在北京、上海和成都指定医院经病理诊断确诊的非吸烟女性新发肺癌住院病例157例,按照性别、年龄(±2岁)、不吸烟等配对因素选取医院对照和人群对照。利用统一调查表对调查对象进行面对面问卷调查,收集病例和对照有关危险因素的暴露史等情况。通过单因素分析和多因素条件Logistic回归分析筛选肺癌的主要危险因素。结果单因素分析发现28个暴露因素与非吸烟女性肺癌发生有关。多因素分析发现,被动吸烟指数≥50人年(OR=1·77,95%CI为1·07~2·92)、经常吃动物内脏(OR=1·85,95%CI为1·06~3·22)、职业接触粉尘(OR=2·47,95%CI为1·21~5·03)和工作场所通风不良(OR=4·02,95%CI为1·74~9·29)为非吸烟女性肺癌发生的危险因素;常吃蔬菜(OR=0·26,95%CI为0·12~0·59)、经常服用维生素(OR=0·53,95%CI为0·30~0·93)、结婚后家庭人均月收入≥500元(OR=0·50,95%CI为0·28~0·91)和初次生育年龄在24~30岁之间(OR=0·53,95%CI为0·32~0·90)为非吸烟女性肺癌发生的保护因素。趋势性检验发现,被动吸烟与非吸烟女性发生肺癌的相对危险度之间存在一定剂量反应关系。结论被动吸烟、职业接触粉尘、经常吃动物内脏和工作场所通风不良会增加非吸烟女性患肺癌的危险性。常吃蔬菜和经常服用维生素等因素可以降低非吸烟女性发生肺癌的危险性。     

Is occupation a risk factor for thyroid cancer? Canadian Cancer Registries Epidemiology Research Group

A Canadian case-control study explored the etiology of thyroid cancer, including occupational exposure. Analysis of job history from 1272 thyroid cancer patients and 2666 controls revealed statistically significant risks among the following occupations: Wood Processing, Pulp and Papermaking (odds ratio [OR] = 2.54, 95% confidence interval [CI] = 1.11-5.83); Sales and Service (OR = 1.26, 95% CI = 1.05-1.52); and Clerical (OR = 0.81, 95% CI = 0.67-0.97). ORs were adjusted for age, sex, province, cigarette smoking, education, self-reported exposure to radiation at work, and duration of employment. Exposure to ionizing radiation or electromagnetic fields at work (inferred from job histories) did not affect risk, nor did socioeconomic status, measured by education, income, or occupational prestige. Possible explanations for the results and further investigations are discussed.     

Cancer and construction: what occupational histories in a Canadian community reveal

From 2000 to 2002, male patients at a Canadian cancer treatment center with new-incident head-and-neck or esophageal cancers were invited to participate in a population-based study. The study population included 87 cases and 172 controls. A lifetime-history questionnaire was administered. Odds ratios (ORs) were calculated for occupational groups with a minimum of five cases, adjusted for duration of employment, age, smoking, alcohol, education, and income. A significantly increased risk was shown for construction workers (OR = 2.20; 95% CI 1.25-3.91). This investigation of a set of rare cancers over a limited time period demonstrates the feasibility of this research approach. The increased risk among construction workers supports the need for more comprehensive study of exposures in this occupational group.     

Smoking and lung cancer in China: combined analysis of eight case-control studies.

Smoking is well established as a principal risk factor for lung cancer. The risk of lung cancer is about ten times higher in smokers in Western countries. In China, a number of epidemiological studies have investigated the association between lung cancer and smoking and in the present paper, a combined analysis of eight such case-control studies is described. The summary odds ratio (OR), calculated by the Mantel-Haenszel method, and attributable risk (AR) of lung cancer associated with smoking were calculated from the combined data which were obtained from a literature review. The eight case-control studies were conducted in Beijing, Shanghai, Shenyang, Nanjing, Harbin, Zhengzhou, Taiyuan, and Nanchang, yielding a total of 4081 lung cancer cases and 4338 controls. The summary OR of lung cancer associated with smoking was 2.17 (95% CI (confidence interval): 1.98-2.39). The OR were 3.09 (95% CI: 2.61-3.66) for males and 2.30 (95% CI: 1.96-2.69) for females. The AR were 38.2% for both sexes, 56.7% for males and 25.5% for females. Risks of 1.00, 1.03, 2.04, and 3.33 showed a dose-response relationship between lung cancer and number of cigarettes smoked per day. There were also significant dose-response relationships of lung cancer with duration of smoking (OR = 1.00, 1.02, 2.66), and age at start of smoking (OR = 1.00, 3.30, 2.36, 1.18). The OR and AR of lung cancer associated with smoking in China were much lower than those reported in Western countries and the possible reasons for this are discussed.     

Occupational risk factors for sinonasal cancer: a case-control study in France.

A case-control study was conducted in France to examine occupational risk factors for sinonasal cancer; 207 cases and 409 controls were included in the study. Detailed information was collected on occupational history and other potential risk factors for nasal cancer. Results are presented for three histologic types: adenocarcinoma, squamous cell carcinoma, and others. Among males, the risk of adenocarcinoma was significantly elevated for cabinetmakers (odds-ratio = 35.4, 95% confidence interval = 18.1-69.3), carpenters and joiners (OR = 25.2, 95% CI = 14.6-43.6), and wood-working machine operators (OR = 7.4, 95% CI = 3.4-15.8), whereas the odds-ratios were less than 1 for loggers and wood preparation workers. Odds-ratios associated with cabinetmakers (OR = 11.2, 95% CI = 2.7-45.9)) and carpenters and joiners (OR = 5.8, 95% CI = 1.8-18.6) were also significantly elevated for the other-histologic-types category. Significant excesses in risk of squamous cell cancer were noted for "bakers, pastry cooks, grain millers" (OR = 3.9, 1.2-12.8), construction workers (OR = 3.7, 95% CI = 1.7-8.0), and carpenters and joiners having worked for at least 15 years in the wood manufacturing industry (OR = 8.1, 95% CI = 1.3-50.3). Among females, a significant increase in risk of squamous cell carcinoma (OR = 9.5, 95% CI = 1.7-54.1) and a moderate increase in risk of adenocarcinoma (OR = 4.0, 95% CI = 0.7-23.5) was observed for textile workers. Elevated risks of squamous cell cancer were noted for farm workers of both sexes (males: OR = 2.2, 95% CI = 1.1-4.4; females: OR = 4.9, 95% CI = 1.0-24.9).     

Occupational risk factors for urothelial carcinoma: agent-specific results from a case-control study in Germany. MURC Study Group. Multicenter Urothelial and Renal Cancer

BACKGROUND: This multicentre population-based case-control study was conducted to estimate the urothelial cancer risk for occupational exposure to aromatic amines, polycyclic aromatic hydrocarbons (PAH), and chlorinated hydrocarbons besides other suspected risk factors. METHODS: In a population-based multicentre study, 1035 incident urothelial cancer cases and 4298 controls matched for region, sex, and age were interviewed between 1991 and 1995 for their occupational history and lifestyle habits. Exposure to the agents under study was self-assessed as well as expert-rated with two job-exposure matrices and a job task-exposure matrix. Conditional logistic regression was used to calculate smoking adjusted odds ratios (OR) and to control for study centre and age. RESULTS: Urothelial cancer risk following exposure to aromatic amines was only slightly elevated. Among males, substantial exposures to PAH as well as to chlorinated solvents and their corresponding occupational settings were associated with significantly elevated risks after adjustment for smoking (PAH exposure, assessed with a job-exposure matrix: OR = 1.6, 95% CI: 1.1-2.3, exposure to chlorinated solvents, assessed with a job task-exposure matrix: OR = 1.8, 95% CI: 1.2-2.6). Metal degreasing showed an elevated urothelial cancer risk among males (OR = 2.3, 95% CI: 1.4-3.8). In females also, exposure to chlorinated solvents indicated a urothelial cancer risk. Because of small numbers the risk evaluation for females should be treated with caution. CONCLUSIONS: Occupational exposure to aromatic amines could not be shown to be as strong a risk factor for urothelial carcinomas as in the past. A possible explanation for this finding is the reduction in exposure over the last 50 years. Our results strengthen the evidence that PAH may have a carcinogenic potential for the urothelium. Furthermore, our results indicate a urothelial cancer risk for the use of chlorinated solvents.     

Mortality in Florida professional firefighters, 1972 to 1999

BACKGROUND: Exposure to occupational hazards among firefighters may lead to increased mortality from cancer, lung, or heart disease. METHODS: Age- and gender-adjusted mortality rates of 34,796 male and 2,017 female Florida professional firefighters between 1972 and 1999 were compared with the Florida general population. RESULTS: One thousand four hundred eleven male and 38 female firefighter deaths with known causes were identified. In male firefighters, mortality due to all causes and most non-malignant diseases was significantly less than expected. There was no excess overall mortality from cancer, but excesses existed for male breast cancer [standardized mortality ratio (SMR = 7.41; 95% confidence interval (CI): 1.99-18.96) and thyroid cancer (SMR = 4.82; 95% CI: 1.30-12.34)]. Mortality from bladder cancer was increased and approached statistical significance (SMR = 1.79; 95% CI: 0.98-3.00). Firefighters certified between 1972 and 1976 had excess mortality from bladder cancer (SMR = 1.95; 95% CI: 1.04-3.33). Female firefighters had similar morality patterns to Florida women except for atherosclerotic heart disease (SMR = 3.85; 95% CI: 1.66-7.58). CONCLUSIONS: Excess mortality risk from bladder cancer may be related to occupational exposure during firefighting. The thyroid cancer and breast cancer risk in males, as well as the excess risk of cardiovascular disease mortality noted in females warrant further investigation.     

Race disparities in cardiovascular disease risk factors within socioeconomic status strata

Purpose

Racial differences in socioeconomic status (SES) explain some, but not all, of racial disparities in cardiovascular disease (CVD) risk. To address this, race disparities among higher SES individuals need to be assessed. The purpose of this study was to assess whether racial disparities in CVD risk factors differ by SES levels.

我国四城市部分职业人群慢性病患病及其公平性分析

目的 了解我国城市职业人群的慢性病患病状况及影响因素,并评价不同社会经济地位（socioeconomic status,SES）职工的慢性病患病公平性。方法 采用分层整群抽样的方法,在北京、厦门、泉州和呼和浩特4个城市共5类工作场所中抽取3 553名职工进行问卷调查。结果 调查对象的慢性病总体患病率为14.8%（男性16.7%,女性12.5%）。Logistic回归分析显示,年龄越大,慢性病患病风险越高（均有P<0.05）;本科/大专及以上文化程度（OR=2.020,95%CI:1.567~2.605）、高职业紧张（OR=1.328,95%CI:1.091~1.617）、超重/肥胖（OR=1.530,95%CI:1.249~1.875）、吸烟（OR=1.436,95%CI:1.148~1.798）和饮酒（OR=1.976,95%CI:1.409~2.771）是慢性病患病的危险因素,而外地户籍（OR=0.756,95%CI:0.604~0.945）为保护因素。按性别分层分析,不同SES职工的慢性病患病率差异均有统计学意义（均有P<0.05）,慢性病患病集中指数均为正值,且收入集中指数最高。结论 研究人群慢性病患病率相对较低,慢性病患病与年龄、文化程度、职业紧张和生活方式相关,且不同SES的职工患病状况存在不公平性。     

Occupational risk factors associated with voice disorders among teachers

PURPOSE: This study was designed to determine the occupational risk factors associated with voice disorders among schoolteachers, a high-risk population for developing voice problems. METHODS: Telephone interviews were completed by 1243 teachers from Utah and Iowa. Response rates were 98% and 95%, respectively. Bivariate analyses were computed and assessed using chi-square test and Cochran-Mantel-Haenszel test, and logistic regression analyses were performed and resulting odds ratios assessed using 95% confidence intervals. RESULTS: Teachers of vocal music, drama, other performing arts and chemistry were at significantly greater risk of having a voice disorder (OR=2.2, 95% CI: 1.2-4.0; OR=2.1, 95% CI: 0.9-4.8; OR=1.6, 95% CI: 1.0-2.4; OR=2.0, 95% CI: 1.1-3.4), while teachers of special and vocational education had a significantly lower risk (OR=0.5, 95% CI: 0.3-0.7; OR=0.6, 95% CI: 0.4-0.9). When adjusted for the intensity of vocalization, only teachers of chemistry were significantly at risk (OR=2.0, 95% CI: 1.1-3.5) while teachers of special education continued to have less of a risk (OR=0.5, 95% CI: 0.4-0.8). Chronic voice disorders were more prevalent among teachers of vocal music (OR=4.1, 95% CI: 2.2-7.9) and less prevalent among teachers of vocational education (OR=0.29, 95% CI: 0.09-0.95). CONCLUSIONS: These findings suggest that teachers of specific courses are at greater risk of developing a voice disorder.     

Occupational risk factors for lung cancer among young men

OBJECTIVES: This study evaluated whether occupational exposure plays a role for lung cancer at a very young age. METHODS: In a pooled analysis of 2 German case-referent studies including 3498 incident cases among men and 3541 male population referents, a group of men (187 cases and 202 referents) aged > or =45 years was compared with a group of 2186 cases and 2146 referents aged 55-69 years. Occupational exposure to known (A list) or suspected (B list) lung carcinogens was assessed using job and industry codes, and exposure to asbestos was assessed using job-specific supplementary questionnaires. A conditional logistic regression was used to calculate the odds ratios (OR) and to control for smoking. RESULTS: Asbestos exposure showed an odds ratio (OR) of 2.39 [95% confidence interval (95% CI) 1.41-4.04] for the younger group and 1.46 (95% CI 1.24-1.72) for the older group. Having ever worked in a job belonging to the A list as compared with never working in an A- or B-list job was associated with a significantly increased risk for the younger (OR 2.06, 95% CI 1.03-4.12) and older (OR 1.35, 95% CI 1.10-1.65) groups, adjusted for asbestos. Lung cancer risk for those working in A-list jobs at a very young age (under 16 years) was increased in the younger group (OR 6.14, 95% CI 1.41-28.01) in contrast to the older group (OR 1.19, 95% CI 0.91-1.63). CONCLUSION: Occupational risk factors play an important role for lung cancer among young men. Early age at first exposure may favor an early age of the onset of lung cancer.     

Case-control study of exposure to carbon black in the occupational setting and risk of lung cancer

Although it has been hypothesized that carbon black exposure may carry an excess risk of lung cancer, evidence to date is insufficient to assess the hypothesis properly. The relationship between workplace exposure to carbon black and lung cancer risk was examined in a population-based case-control study carried out in Montreal, Canada. Detailed job histories were elicited from 857 incident cases with histologically confirmed lung cancer as well as from 1,360 cancer controls and 533 population controls. Job histories were evaluated by a team of hygienists and chemists for evidence of exposure to a host of occupational substances, including carbon black. Logistic regression analyses adjusting for smoking and other nonoccupational and occupational potential confounders suggested no significant increase in risk with relatively low exposure to carbon black. Some increase in risk for all lung cancers was apparent with relatively high exposure using cancer controls (OR = 2.17; 95% CI = 0.95–4.91) and population controls (OR = 1.52; 95% CI = 0.58–3.97). Individuals with relatively high exposure had a significantly greater risk of oat-cell carcinoma using either control series (OR = 5.05; 95% CI = 1.72–14.87 using cancer controls and OR = 4.82; 95% CI = 1.36–17.02 using population controls). These results provide some evidence for an association between exposure to carbon black and lung cancer. © 1996 Wiley-Liss, Inc.     

Occupational exposure to diesel motor exhaust and risk of lung cancer by histological subtype: a population-based case–control study in Swedish men

We investigated occupational exposure to diesel motor exhaust (DME) and the risk of lung cancer by histological subtype among men, using elemental carbon (EC) as a marker of DME exposure. 993 cases and 2359 controls frequency-matched on age and year of study inclusion were analyzed by unconditional logistic regression in this Swedish case–control study. Work and smoking histories were collected by a questionnaire and telephone interviews. DME was assessed by a job-exposure matrix. We adjusted for age, year of study inclusion, smoking, occupational exposure to asbestos and combustion products (other than motor exhaust), residential exposure to radon and exposure to air pollution from road traffic. The OR for lung cancer for ever vs. never exposure to DME was 1.15 (95% CI 0.94–1.41). The risk was higher for squamous and large cell, anaplastic or mixed cell carcinoma than for alveolar cell cancer, adenocarcinoma and small cell carcinoma. The OR in the highest quartile of exposure duration (≥34 years) vs. never exposed was 1.66 (95% CI 1.08–2.56; p for trend over all quartiles: 0.027) for lung cancer overall, 1.73 (95% CI 1.00–3.00; p: 0.040) for squamous cell carcinoma and 2.89 (95% CI 1.37–6.11; p: 0.005) for the group of undifferentiated, large cell, anaplastic and mixed cell carcinomas. We found no convincing association between exposure intensity and lung cancer risk. Long-term DME exposure was associated with an increased risk of lung cancer, particularly to squamous cell carcinoma and the group of undifferentiated, large cell, anaplastic or mixed carcinomas.     

Socioeconomic health inequalities in Latvia: a cross-sectional study

AIMS: Socioeconomic health differences have been studied elaborately for many Western societies. Relatively little is know about the social variations in health in the former communist states of Eastern Europe. This study investigated socioeconomic health inequalities in Latvia. METHODS: Cross-sectional analysis was undertaken of the 1999 Norbalt-II Living Conditions Survey, a random population-based sample in Latvia, and included males and females aged 25 to 70. RESULTS: Lower educated subjects had higher rates of self-assessed poor health than those with tertiary education (men OR 2.21; 1.31-3.71 95% CI, and women OR 2.48; 1.74-3.54 95% CI). After adjusting for income, educational differences were significant only for women. Income differences were larger than educational differences in self-assessed poor health for both genders (OR of highest vs. lowest quintile for men: 5.10; 2.26-11.5 95% CI, women: OR 3.26; 1.92-5.51 95% CI). For long-standing health problems socioeconomic differences were smaller. After adjusting for income no educational differences were found, but income differences were significant (men: OR 2.06; 1.15-3.69 95% CI, women: OR 1.42; 1.12-2.63 95% CI). The economically non-active were in worse health than the (self-)employed subjects (men: OR 6.12; 3.65-10.3 95% CI, women: OR 2.79; 1.66-3.39 95% CI). CONCLUSIONS: Substantial social inequalities in self-assessed poor health and longstanding health problems exist in Latvia for both sexes. Inequalities by material circumstances, as measured by income, appear to be larger than educational differences. Economic activity was also strongly associated with health. There were no inequalities with regard to urbanization and ethnic differences were found only for long-standing health problems among women.