Cohort mortality study of prostate cancer among chemical workers

A retrospective cohort mortality study was conducted at a chemical plant producing acetic acid and acetic anhydride, two chemicals essential in the synthesis of cellulose triacetate fiber. Previously, we reported excess mortality from biliary tract and prostate cancers among workers in cellulose triacetate fiber manufacturing plants. In the present investigation, an excess of prostate cancer (SMR = 330.4; 95% confidence interval = 121.3–719.1) was observed among former chemical plant workers, some of whom had been exposed to both acetic acid and acetic anhydride. These apparent increases in mortality are difficult to interpret biologically, particularly in light of recent suggestions concerning the role of endocrine factors. Additional work is planned to more fully characterize potential occupational exposures that might explain the etiology of prostate cancer. Am. J. Ind. Med. 33:293–296, 1998. © 1998 Wiley-Liss, Inc.     

Cohort mortality study among French asphalt workers

BACKGROUND: In conjunction with the European cohort study among asphalt workers coordinated by the International Agency for Research on Cancer (IARC), we studied the mortality of 15,011 French men who were followed for 17 years for a total of 175,062 persons-years. This group contained 2,506 subjects who had ever been employed as asphalt workers: they contributed 30,692 person-years of risk. A reference group was composed of 6,675 subjects (i.e., 61,856 persons-years) who had been employed only in building or ground construction. METHODS: Mortality ratios standardized for age and period were computed with their 95% confidence intervals (CI) from the age and period mortality rates of all French men for the years covered by the study (1979-1996). We also compared the mortality of exposed workers and the reference group with Poisson regression models after adjustment for age, calendar period, and either duration of employment or length of follow-up. RESULTS: Mortality from lung cancer was equivalent to the expected rate [SMR = 1.01 95% CI (0.6-1.6)], but was 40% greater than among the non-exposed reference group [RR = 1.4 95% CI (0.7-2.8)]. We also found an excess of gastrointestinal cancers, especially of the esophagus [SMR = 1.94, 95% CI (0.9-3.6)] and stomach [SMR = 2.2, 95% CI (0.8-4.7)]. Comparison with the internal reference group confirmed these findings, especially for stomach cancer [RR = 2.8, 95% CI (0.7-11.4)]. CONCLUSIONS: Although our results are not statistically significant, they suggest that road-paving workers may have a slightly higher rate of lung cancer and a moderately higher rate of stomach cancer than their non-exposed counterparts. The excess of lung cancer may be due to potential confounding factors, including the occupational risk factor of coal tar exposure and the lifestyle risk factor of smoking. A nested case-control study is under way that will make it possible to control for smoking and other potential carcinogenic exposures; this is necessary before any definitive conclusions can be drawn.     

Mortality study of cancer risk among oil refinery workers

The mortality experience of 1595 male workers employed in one of the largest Italian refineries in the period from 1949-1982 was examined. From the comparison with national and local death rates, increases in mortality owing to lung and kidney cancers, brain tumors, and leukemias emerged. No definite trends according to duration of exposure and years since first exposure were apparent. The increases regarding cancer of the lung, kidney and brain appeared to be associated with the early period of operations. Analysis by exposure category suggested an association of the increased mortality from leukemias with working in production (observed = 2; expected = 0.61). Kidney cancer mortality was elevated among maintenance workers (obs. = 2; exp. = 0.18). Small numbers prevented firmer conclusions. Workers in the moving department had a significantly increased mortality from all cancers (obs. = 22; exp. = 11.7), and lung cancer (obs. = 11; exp. = 3.6). Confounding by smoking could be excluded as sufficient explanation of the three-fold increase in lung cancer deaths. It was in moving that highest airborne levels of polynuclear aromatic hydrocarbons had been discovered in an independent environmental investigation.     

Assessment of cardiometabolic risk among shift workers in Hungary

Aim  

Shift workers may be at risk of different diseases. In order to assess cardiometabolic risk in shift workers, a cross-sectional study was performed among active workers.     

Prevalence and correlates of sexual risk among male and female sex workers in Tijuana, Mexico

We investigated prevalence and correlates of sexual risk behaviours among male and female sex workers in Tijuana, Mexico, the busiest border crossing area on the US - Mexico border, analysing survey data from a purposive, cross-sectional sample of male and female sex workers who worked in a range of indoor and outdoor settings. Logistic regression was used to determine factors that were associated with sexual risk-taking, defined as failing to use a condom with last client. In bivariate regression models, gender, work setting (e.g., indoor vs. outdoor), poverty, engaging in survival sex, marital status and perceived drug addiction were correlated with sexual risk. When controlling for work location, housing insecurity, poverty, survival sex, marital status and perceived drug addiction, male sex workers were still 10 times more likely than female sex workers (FSW) to engage in sex without a condom during their last encounter with a client. And, although FSW were significantly more likely than males to have used a condom with a client, they were significantly less likely than males to have used a condom with their regular partner. Future research should further examine how gender shapes sexual risk activities in both commercial and non-commercial relationships.     

Increased risk for male bladder cancer among a cohort of male and female hairdressers from Geneva

A cohort of 703 male and 677 female hairdressers born from 1880 onwards, who started to run salons in Geneva between 1900 and 1964 was followed-up to the end of 1982. Cause-specific mortality was analysed from 1942 to 1982 and a significant excess mortality from bladder cancer (observed deaths = 10, expected deaths = 3.9) was found among males. Cancer incidence recorded for the years 1970 to 1980 showed a significant increase among males for all neoplasms (O = 65, E = 51.4), cancer of the buccal cavity and pharynx (O = 6, E = 2.5), cancer of the prostate (O = 12, E = 6.1), and bladder cancer (O = 11, E = 5.3). Among female hairdressers no significant increase in mortality or in cancer incidence was found. Mean age at diagnosis of the 18 deaths and/or incident cases from bladder cancer found among the male hairdressers was 68.6 years (range 51-88) and mean latency period since first exposure was 52.2 years (range 24-73). Occupational history was obtained for most of the 18 cases and of 54 controls randomly selected from the cohort. Little evidence was found of a causal relationship between exposure to hair dyes and the excess risk for bladder cancer among the male hairdressers. It is a suggestion that this excess might be related to some colouring agent(s) in brilliantines which were widely used in men's hairdressing salons in Geneva until about 1950.     

Cancer risk among female agricultural workers: a multi-center case-control study.

BACKGROUND: Cancer risk among women engaged in farming has been poorly investigated. This group of female workers is of particular interest, however, since they may experience exposure to several potential agricultural hazards. METHODS: A hospital-based case-control study was conducted in five Italian rural areas to examine the association between cancer and farming among women. The areas selected were located in three different regions (i.e., Piedmont, Tuscany, and Emilia-Romagna). The following cancer sites were selected for the study: stomach, colon, rectum, lung, skin melanoma, skin non-melanoma, breast, cervix and corpus uteri, ovary, bladder, kidney. Cases of non-Hodgkin's lymphoma were also included. Altogether, 1,044 newly diagnosed cases aged 20-75 years were ascertained from hospital records from March 1990 to September 1992, and for 945 of them detailed information was collected by a standard questionnaire. The analyses of data were performed comparing each case series to a reference group drawn from among the other sites. Unconditional logistic regression models were used in the statistical analyses. RESULTS: Statistically significant increased risks in association with farming were estimated for skin melanoma (OR 2.7, 95% CI 1.2-5.8) and bladder cancer (OR 2.7, 95% CI 1.2-6.1). Lung cancer was also found increased but not at a statistically significant level (OR 1.7, 95% CI 0.7-4.4). An OR lower than unity was observed for postmenopausal breast cancer (OR 0.4, 95% CI 0.3-0.7). CONCLUSIONS: The present study suggests that women in farming might experience increased risk of cancers, not usually found in excess among male farmers, as well as a protective effect for postmenopausal breast cancer. The role of different patterns of exposure or gender specific responses should be considered in further studies.     

A prospective cohort study of shift work and risk of ischemic heart disease in Japanese male workers

This study prospectively examined the association between shift work and the risk of ischemic heart disease among Japanese male workers. A baseline survey, which involved 110,792 inhabitants (age range: 40-79 years) from 45 areas throughout Japan, was conducted between 1988 and 1990. The causes of death were identified from death certificates. The analysis was restricted to 17,649 men (age range: 40-59 years) who were employed at the time of the baseline survey. All subjects were asked to indicate the most regular shift work that they had undertaken previously: day work, rotating-shift work, or fixed-night work. The Cox proportional hazards model was used to estimate the risks of shift work for ischemic heart disease. During the 233,869 person-years of follow-up, a total of 1,363 deaths were recorded, 86 of which were due to ischemic heart disease. Compared with the day workers, the rotating-shift workers had a significantly higher risk of death due to ischemic heart disease (relative risk = 2.32, 95% confidence interval: 1.37, 3.95; p = 0.002), whereas fixed-night work was not associated with ischemic heart disease (relative risk = 1.23, 95% confidence interval: 0.49, 3.10; p = 0.658). In addition, subjects with coronary risk factors, such as hypertension, overweight, habitual alcohol consumption, and smoking, were highly susceptible to the effect of rotating-shift work on the risk of death due to ischemic heart disease.     

The productivity of female shift workers

The productivity of female shift workers, working on a weekly rotating three-shift system, was examined. The afternoon shift was found to be the most productive and the night shift the least productive one. The greatest difference in productivity between shifts was found in the first two days of the week, when the productivity on night shift was significantly lower than that on the other two shifts. From the third day on there were no longer significant differences in productivity between shifts. The most productive and the least productive workers on night shift did not significantly differ in extraversion or in sleep duration after the night shift. Family responsibility was found to be associated with the duration of sleep after the night shift: married women slept significantly shorter after the night shift than unmarried women. However, this difference in sleep duration was not associated with productivity on night shift. Sleep duration after the afternoon shift (8 hours 40 minutes) was on average two hours longer than after the other two shifts. The difference in sleep duration after different shifts, along with circadian variations in alertness, readiness for work and performance efficiency, could be responsible for differences in productivity between shifts.     

A retrospective cohort study of shift work and risk of cancer-specific mortality in German male chemical workers

Objectives

Human evidence of carcinogenicity concerning shift work is inconsistent. In a previous study, we observed no elevated risk of total mortality in shift workers followed up until the end of 2006. The present study aimed to investigate cancer-specific mortality, relative to shift work.

Methods

The cohort consisted of male production workers (14,038 shift work and 17,105 day work), employed at BASF Ludwigshafen for at least 1 year between 1995 and 2005. Vital status was followed from 2000 to 2009. Cause-specific mortality was obtained from death certificates. Exposure to shift work was measured both as a dichotomous and continuous variable. While lifetime job history was not available, job duration in the company was derived from personal data, which was then categorized at the quartiles. Cox proportional hazard model was used to adjust for potential confounders, in which job duration was treated as a time-dependent covariate.

Results

Between 2000 and 2009, there were 513 and 549 deaths among rotating shift and day work employees, respectively. Risks of total and cancer-specific mortalities were marginally lower among shift workers when taking age at entry and job level into consideration and were statistically significantly lower when cigarette smoking, alcohol intake, job duration, and chronic disease prevalence at entry to follow-up were included as explanatory factors. With respect to mortality risks in relation to exposure duration, no increased risks were found in any of the exposure groups after full adjustment and there was no apparent trend suggesting an exposure–response relation with duration of shift work.

Conclusions

The present analysis extends and confirms our previous finding of no excess risk of mortality associated with work in the shift system employed at BASF Ludwigshafen. More specifically, there is also no indication of an increased risk of mortality due to cancer.     

Occupational risk factors for nasopharyngeal cancer among female textile workers in Shanghai, China

Aims

To investigate whether occupational exposure to dusts and chemicals in the Chinese textile industry are associated with risk of nasopharyngeal cancer.

Methods

Sixty seven nasopharyngeal carcinoma (NPC) cases identified during 1989–98 and a random sample (n = 3188) of women were included in a case cohort study nested in a cohort of 267 400 women textile workers in Shanghai, China. A complete occupational history of work in the textile industry was obtained for each woman. A job exposure matrix developed by experienced industrial hygienists was used to assess exposures to specific dusts and chemicals.

Results

Risk of NPC is associated with cumulative exposure to cotton dust. The hazard ratio for women cumulatively exposed to >143.4 mg/m³ × years of cotton dust was 3.6 (95% CI 1.8 to 7.2) compared with unexposed women. Trends of increasing risk were also found with increasing duration of exposure to acids and caustics (p = 0.05), and with years worked in dyeing processes (p = 0.06). Women who worked at least 10 years in dyeing processes had a 3.6‐fold excess risk of NPC (95% CI 1.0 to 12.1).

Conclusions

Occupational exposure to cotton dust, acids, and caustics, and work in dyeing and printing jobs in the textile industry may have increased risk of NPC in this cohort.     

Occupational risk factors for pancreatic cancer among female textile workers in Shanghai, China

ObjectivesTo investigate whether occupational exposures to dusts and chemicals in the Shanghai textile industry are associated with risk of pancreatic cancer.MethodsA case cohort study nested in a cohort of 267 400 female textile workers in Shanghai, China was conducted among 180 incident pancreatic cancer cases and an age stratified randomly selected comparison subcohort (n = 3188). A complete occupational history of work in the textile industry was obtained for each woman, and was linked to a job exposure matrix developed for the textile industry to estimate exposures to specific dusts and chemicals. Cumulative exposures to cotton dust and endotoxin were reconstructed from historical and contemporaneous measurements.ResultsAfter adjusting for smoking status, a trend of decreasing risk of pancreatic cancer was observed for increasing cumulative exposures to cotton dust and endotoxin with a lag of 20 years. The hazard ratios for women cumulatively exposed to >143.4 mg/m³× years of cotton dust and >3530.6 EU/m³× years of endotoxin were 0.6 (95% CI 0.3 to 0.9) and 0.5 (95% CI 0.3 to 0.9), respectively, compared to unexposed women. There was little evidence that exposures to other textile dusts and chemicals were associated with risk of pancreatic cancer.ConclusionsOccupational exposure to cotton dust and endotoxin in the textile industry may have reduced risks of pancreatic cancer in this cohort. These associations should be replicated by others before making a firm conclusion of their possible effects on pancreatic cancer.     

Nutrient intake among female shift workers in a computer factory in Japan

Based on a 4-day questionnaire survey for all meals and snacks consumed by female workers in a computer factory in Japan, consisting of 44 daytime workers and 93 weekly-rotating shift workers (of whom 47 and 46 were engaged in, respectively, early-shift work and late-shift work during the survey week), the present study aimed to clarify the effects of shift work on their nutrient intakes in association with food consumption patterns. Their dietary intakes for 3 working days and an off day were assessed by self-registered food consumption records with the aid of a photographic method, and intakes of energy, protein, fat, carbohydrate, calcium and iron were estimated. The inter-group differences were prominent in the working days. The shift workers, particularly the late-shift workers, took smaller amounts of energy and nutrients than the daytime workers, implying that the former group's nutritional status has been worsened, judged from the recommended dietary allowance for Japanese. Their inadequate nutrient intake was due to lower meal frequency and poor meal quality, both of which were conditioned by shift work.     

Nutrient intake among female shift workers in a computer factory in Japan

Based on a 4-day questionnaire survey for all meals and snacks consumed by female workers in a computer factory in Japan, consisting of 44 daytime workers and 93 weekly-rotating shift workers (of whom 47 and 46 were engaged in, respectively, early-shift work and late-shift work during the survey week), the present study aimed to clarify the effects of shift work on their nutrient intakes in association with food consumption patterns. Their dietary intakes for 3 working days and an off day were assessed by self-registered food consumption records with the aid of a photographic method, and intakes of energy, protein, fat, carbohydrate, calcium and iron were estimated. The inter-group differences were prominent in the working days. The shift workers, particularly the late-shift workers, took smaller amounts of energy and nutrients than the daytime workers, implying that the former group's nutritional status has been worsened, judged from the recommended dietary allowance for Japanese. Their inadequate nutrient intake was due to lower meal frequency and poor meal quality, both of which were conditioned by shift work.     

Cross-sectional study on risk factors of HIV among female commercial sex workers in Cambodia

To describe epidemiological features on HIV prevalence among female commercial sex workers (CSWs), a cross-sectional study on sexual behaviour and serological prevalence was carried out in Cambodia. The CSWs were interviewed on their demographic characters and behaviour and their blood samples were taken for testing on sexually transmitted diseases, including HIV, Chlamydia trachomatis, syphilis, and hepatitis B. Associations between risk factors and HIV seropositivity were analysed. High seroprevalence of HIV and Chlamydia trachomatis IgG antibody (CT-IgG-Ab) was shown among the CSWs (54 and 81.7%, respectively). Univariate logistic regression analyses showed an association between HIV seropositivity and age, duration of prostitution, the number of clients per day and CT-IgG-Ab. Especially, high-titre chlamydial seropositivity showed a strong significant association with HIV prevalence. In multiple logistic regression analyses, CT-IgG-Ab with higher titre was significantly independently related to HIV infection. These suggest that existence of Chlamydia trachomatis is highly related to HIV prevalence.     

倒班作业女职工月经情况的调查

选择不同职业的270名倒班女职工(倒班组)和对应单位210名不倒班女职工(对照组)进行月经生理职业流行病学调查。结果显示,倒班组月经异常患病率、经期异常率、周期异常率和痛经率均明显高于对照组且差异具有统计学意义(P0.05)。倒班组女职工月经周期异常率随倒班工龄的增加有线性增高的趋势,经趋势卡方检验有统计学意义,不同职业女职工间月经异常患病率差异无统计学意义(P0.05)。提示建立合理、人性化的劳动制度对保护倒班作业女工的生殖健康十分必要。