Workers In Shanghai Research Articles

Risks of biliary tract cancer and occupational exposures among Shanghai women textile workers: A case‐cohort study

Biliary tract cancer (BTC) is a relatively rare malignancy worldwide. Little is known about potential etiologic contributions of occupational exposures. The associations between occupational exposures to textile dusts and chemicals and BTC are investigated in a cohort of 267,400 women textile workers in Shanghai, China. A nested case-cohort analysis of 162 BTC cases diagnosed during 1989-1998 was conducted with a reference subcohort of 3,188 workers. Exposures to workplace dusts and chemicals were reconstructed by linking complete work history data with a job-exposure matrix (JEM). Hazard ratios (HR) and dose-response trends were estimated by Cox proportional hazards modeling modified for case-cohort design. An elevated risk of > or = 1-year employment in maintenance jobs (HR 2.92, 95% CI: 1.48, 5.73) with a significant trend by duration is observed. Excess risk was also found for > or = 20 years exposure to metals (HR 2.50, 95% CI: 1.09, 5.72). Long-term exposure to maintenance work and metals in the textile industry may have increased BTC risk in this population.

Brain tumors and occupational exposures in a cohort of female textile workers in Shanghai, China

This study assessed the associations between brain tumors and specific processes and exposures among female textile workers in Shanghai, China. A case-cohort study was conducted that was nested in a cohort of textile workers originally included in a randomized trial of breast self-examination. Incident brain tumor cases (N=114) were identified from 1989 to 1998 from a tumor and death registry operated by the Shanghai Textile Industry Bureau. A subcohort (N=3188), representing an age-stratified random sample of the entire cohort, was selected as a comparison group. Job-exposure matrices were created to assess historical exposures to specific agents, including quantitative assessments for cotton dust and endotoxin exposure. Cox proportional hazards modeling, modified according to a case-cohort design, was used to analyze associations between jobs and exposures and the risk of brain tumors. Employment in maintenance workshops was associated with an increased brain tumor incidence (ever-never exposed hazard ratio 2.36, 95% confidence interval 1.12-4.97), with increasing hazard ratios by duration of employment in maintenance jobs. Handling or processing wool fibers was associated with an increased risk of brain tumors, as was specific exposure to wool fibers; however, estimates did not increase with duration of employment. These results provide some preliminary suggestion that employment in textile industry maintenance jobs and exposure to wool products may be associated with an increased risk of brain tumors.

Modeling, Estimation and Validation of Cotton Dust and Endotoxin Exposures in Chinese Textile Operations

In support of an epidemiological study of cancer incidence among cotton textile workers in Shanghai, PRC, historical estimates of exposure to cotton dust and endotoxin were developed for subjects drawn from a cohort of 267,400 female textile workers. A large dataset of historical cotton dust measurements were available from 56 of the study factories. Using these data, a series of models were developed to estimate cotton dust exposure by year, factory and process. Model estimates were validated by comparing with independently collected measurements gathered over a 15 year period and indicated a low relative bias (< 2%) and relative accuracy (+/- 61%). Endotoxin exposures were estimated using the endotoxin content of cotton dust by major processes obtained in five separate surveys in these factories. The validated exposures were assigned to the 7,242 jobs held by the 3,812 study subjects. Among the exposed workers, the mean cumulative exposure levels were 113.8 mg m(-3)*years for cotton dust and 6,707.7 EU m(-3)*years for endotoxin, respectively. The overall correlation among cotton dust and endotoxin exposures for these subjects was r = 0.58. Using an unusually rich set of historical cotton dust measurements, along with independently collected exposure measurements for validation and conversion to endotoxin levels, validated estimates of cumulative exposure were constructed for this large case-cohort study in the textile industry.

Levels of computer self-efficacy, computer use and earnings in China

Levels of self-efficacy in computer use were found to be positively related to computer use at work among a sample of workers in Shanghai. The simultaneous estimation of computer use and earnings indicated that an earnings premium for computer use accrues only to females, not to males.

Occupational Risk Factors for Esophageal and Stomach Cancers among Female Textile Workers in Shanghai, China

The authors evaluated associations between occupational exposures in the textile industry and the risks of esophageal cancer and stomach cancer. The authors conducted a case-cohort study nested in a cohort of female textile workers in Shanghai, China. One hundred and two workers with incident esophageal cancer and 646 workers with incident stomach cancer diagnosed between 1989 and 1998 were compared with an age-stratified reference subcohort (n = 3,188). Work histories were ascertained for all study subjects from factory personnel records or interviews. Exposures were reconstructed for chemicals and dusts by linking work history data with a job-exposure matrix developed for the Shanghai textile industry. Hazard ratios and 95 percent confidence intervals were calculated with Cox proportional hazards modeling adapted for the case-cohort design. Risk of esophageal cancer was associated with long-term (> or = 10 years) exposure to silica dust (hazard ratio = 15.8, 95% confidence interval: 3.5, 70.6) and metals (hazard ratio = 3.7, 95% confidence interval: 1.9, 7.1). Cumulative exposure to endotoxin, a contaminant of cotton dust, was inversely related to risks of both esophageal cancer (p-trend = 0.01) and stomach cancer (p-trend < 0.001) when exposures were lagged 20 years. Endotoxin has not been previously reported to be a protective factor for either stomach cancer or esophageal cancer and therefore warrants further study.

Occupational exposures and risks of liver cancer among Shanghai female textile workers—a case–cohort study

Liver cancer is the fifth most frequent malignancy worldwide. Viral hepatitis B and C, alcohol, and aflatoxin are the major established risk factors. Little is known about the aetiological contributions of occupational exposures, as previous occupational epidemiological studies of liver cancer suggest few agent-specific associations. We investigated associations of occupational exposures to dusts and chemicals in a cohort of female textile workers. Cancer incidence was determined among 267,400 female textile workers in Shanghai, China, who had been enrolled in an intervention trial of breast self-exam efficacy during 1989-98. Subjects were interviewed at baseline regarding basic demographics, smoking habits, alcohol consumption, and contraceptive practices. A case-cohort study of 360 liver cancer cases and 3,186 age-stratified randomly chosen subcohort subjects was conducted within this cohort. Exposures to workplace dusts and chemicals were reconstructed from complete work history data, historical exposure monitoring data for selected agents, and a specially designed job-exposure matrix for the textile industry. Relative risks and dose-response trends were estimated by Cox proportional hazards modelling, adapted for the case-cohort design. Latency analyses with different lag years were also applied. 2,095,904 person-years were contributed by this female cohort. The results of the case-cohort analysis revealed a protective effect of cotton fibre exposure years [adjusted hazards ratio (HR) = 0.64; 95% confidence interval (95% CI) 0.44-0.92] or endotoxin exposure (adjusted HR = 0.60; 95% CI 0.41-0.88) for the fourth quartile with significant trends for 20 year exposure lags. This study suggests that chronic exposure to endotoxin or some other component of cotton dust exposure may have reduced liver cancer risk in this population.

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...

Colorectal Cancer Incidence Among Female Textile Workers in Shanghai, China: A Case-cohort Analysis of Occupational Exposures

Previous studies have suggested increased risks of colorectal cancers among textile industry workers, potentially related to synthetic fibers. To investigate risks of colon and rectum cancers in relation to these and other textile industry exposures, we conducted a case-cohort study nested within a cohort study of female employees from the Shanghai Textile Industry Bureau (STIB). Cox proportional hazard regression modeling was used to estimate hazard ratios (HR) for colon and rectum cancers associated with duration of employment (e.g., 0, >0 to <10, 10 to <20 years, > or =20 years) in various jobs classified according to process type and exposures to specific agents. Our findings indicate that certain long term exposures may pose increased risk of colorectal cancers, especially dyes and dye intermediates with colon cancer (> or =20 years exposure versus never, HR=3.9; 95% CI: 1.4-10.6), and maintenance occupation (HR = 2.3; 95% CI: 1.0-5.7) and metals exposure (HR = 2.0; 95% CI: 1.1-3.6) with rectum cancer. A decreased risk of rectum cancer was associated with exposure to natural fibers such as cotton (HR = 0.7; 95% CI: 0.5-0.9), and a trend of decreasing rectum cancer incidence was observed by category of cumulative quantitative cotton dust or endotoxin exposures, when exposures were lagged by 20 years.

Reproductive history, occupational exposures, and thyroid cancer risk among women textile workers in Shanghai, China

Thyroid cancer risk has been previously associated with increased age at first pregnancy and history of miscarriage. Occupational risk factors for thyroid cancer, with the exception of radioactive iodine, have not been well investigated. We conducted a case-cohort study nested in a cohort of 267,400 female textile workers in Shanghai, China, who had been followed for cancer incidence during 1989-1998. The analysis included 130 incident thyroid cases and 3,187 subcohort non-cases. Reproductive history was determined by questionnaire at baseline. Historical exposures were reconstructed from work history and information on factory processes and exposures. Cox proportional hazards analysis was performed to estimate hazard ratios (HR) for reproductive factors and occupational exposures. Associations were observed between thyroid cancer and employment in jobs with 10 or more years of benzene exposure (HR 6.43, 95% CI: 1.08, 38) and formaldehyde exposure (HR 8.33, 95% CI: 1.16, 60). Administration workers also had an increased risk (HR 1.56, 95% CI: 1.08, 2.25). No associations between examined reproductive factors and thyroid cancer were observed in this study. Despite statistically imprecise risk estimates, the findings suggest potential associations with some occupational chemical exposures in this cohort of textile workers.

155: Reduced Lung Cancer Risk Associated with Cotton Dust Exposure in Women Textile Workers in Shanghai, China

155: Reduced Lung Cancer Risk Associated with Cotton Dust Exposure in Women Textile Workers in Shanghai, China

338-S: Occupational Risk Factors for Endometrial and Ovarian Cancers Among Textile Workers in Shanghai, China

338-S: Occupational Risk Factors for Endometrial and Ovarian Cancers Among Textile Workers in Shanghai, China

Migrant Workers in Shanghai

As China’s economy turns to globalisation, at home the issue of a floating workforce is becoming more intense and complex. In Shanghai, low-skilled migrants are subject to economic and social segregation. This comes with a social stigma and restricts the migrants to particular economic sectors within a fragmented labour market. Nonetheless, the itineraries the migrants follow allow them to acquire certain skills and resources. Their survival strategies produce what have been called “situations of affiliation and disaffiliation” within an overall situation of general insecurity.

Is chronic airway obstruction from cotton dust exposure reversible?

Exposure to cotton dust is known to cause chronic airway obstruction, but there is little information on whether the obstructive impairment is reversible after the exposure stops. Longitudinal changes in lung function were evaluated among 429 cotton textile workers and 449 silk workers in Shanghai, China, beginning in 1981. Both active and retired workers were tested every 4 to 6 years for 15 years. Overall, cotton workers had greater annual declines in forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC). Compared with active workers, retired cotton workers had lower annual loss of FEV1, although the retired workers had a greater loss during their active employment than the currently active workers. No such trends were detected in silk workers. Annual declines in FEV1 in retired cotton workers were smaller with increasing time since retirement. Multivariate analysis showed that retirement was a substantial contributing factor for improved FEV1 and FVC in the cotton workers, especially among those who did not smoke. Correspondingly, remission of airflow obstruction, defined as a ratio of FEV1 and FVC of less than 70%, was more common in retirees than in the active workers, and more common in nonsmokers than in smokers. Chronic airway obstruction related to long-term exposure to cotton dust may be partially reversible after the exposure ceases, although lung function does not return to the level found in unexposed workers.

Contraceptive methods and induced abortions and their association with the risk of colon cancer in Shanghai, China

267400 female textile workers in Shanghai, who were administered a questionnaire at enrollment into a randomised trial of breast self-examination between October 1989 and October 1991, were followed up until the middle of 2000. Based on the 655 women who developed colon cancer, rate ratios (RRs) were estimated and trends in risk assessed using Cox Proportional Hazards Models. Risk was increased in women who used oral contraceptives for over 3 years (RR=1.56, 95% Confidence Interval (CI) 1.01–2.40). A possible increase in risk was also observed in women who received progestational injections during pregnancy (RR=1.24, 95% CI 0.95–1.62), but not in relation to the use of injectable contraceptives. A possible reduction in risk was associated with tubal ligation (RR=0.86, 95% CI 0.71–1.03) and ever having had an induced abortion (RR=0.84, 95% CI 0.71–1.00). No trends in risk were observed in relation to the duration of hormonal contraceptive use or the number of induced abortions. Additional studies of the possible roles contraceptives may play in the aetiology of colon cancer in women at low risk of this disease are warranted.

Cancer among women textile workers in Shanghai, China: Overall incidence patterns, 1989–1998

Cancer incidence in women textile workers has not been adequately studied. The aim of this study was to examine site-specific cancer incidence patterns in a cohort of 267,400 women textile workers in Shanghai, China. Women employed by the Shanghai Textile Industry Bureau (STIB) were followed for cancer incidence from 1989 to 1998. Age-adjusted standardized incidence ratios (SIRs) and 95% confidence intervals (CI) were computed based on Shanghai Cancer Registry (SCR) rates. There was a decrease in cancer incidence for the cohort compared with urban Shanghai women (SIR = 0.91, 95% CI = 0.89-0.93). There were small increased risks of other endocrine tumors (SIR = 1.31, 95% CI = 1.02-1.65). There were decreased risks for esophageal (SIR = 0.54, 95% CI = 0.44-0.66), stomach (SIR = 0.79, 95% CI = 0.73-0.85), rectal (SIR = 0.88, 95% CI = 0.78-0.98), lung (SIR = 0.80, 95% CI = 0.74-0.86), cervical (SIR = 0.37, 95% CI = 0.28-0.50), ovarian (SIR = 0.85, 95% CI = 0.75-0.96), and bladder cancers (SIR = 0.63, 95% CI = 0.46-0.85). Women employed in the textile industry had a lower than expected cancer experience compared with urban Shanghai women. Further research on this cohort will examine associations between site-specific cancers and occupational exposures to dusts and chemicals.

Human capital development in Shanghai: lessons and prospects

This article reviews key findings of five sets of analyses, produced from a recent study of human capital development in Shanghai, China by the two authors. We were interested in the human capital development strategies that are utilized to cope with change. We analyze if such social infrastructure as government educational policies, provision of training and education, management in firms, promote and/or hinder human capital development in transition. In this study, economic development is viewed as a change process. We identify a set of key factors that determine on the operation of other variables. We found that economic transition has had an impact on strategies that firms and employees have adopted for their own survival and human capital development. Firms and workers in Shanghai have used continuing education as a major vehicle for compensating for the limitations of formal education and for the improvement of the quality of the workforce. However, government policies, relevance of education, and quality of training and education programs, the management in the workplace, as not appropriate and lagged, may impede efficacy of educational innovations.

Risk factors for fibroadenoma in a cohort of female textile workers in Shanghai, China.

Risk factors for fibroadenoma were investigated in a cohort of 265,402 female textile workers in Shanghai, China, who were interviewed at enrollment into a randomized trial of breast self-examination between October 1989 and October 1991 and followed until July 2000. Based on 1,507 women who developed fibroadenoma, relative risks and trends in risk were estimated using Cox regression. The risk of fibroadenoma was highest in women under 35 years of age, and it decreased with age after 35 and dropped markedly at the time of menopause. The risk decreased with increasing number of livebirths and with duration of oral contraceptive use. The risk increased with number of prior benign breast lesions and with decreasing age at the first benign lesion. The risk of a diagnosis of fibroadenoma was elevated in women who received instruction in breast self-examination. The development and persistence of fibroadenomas are dependent on the presence of ovarian hormones, and full-term pregnancies and exposure to exogenous estrogen-progesterone combinations before menopause may reduce risk by enhancing differentiation or reducing estrogen-induced proliferation in the mammary epithelium. The practice of breast self-examination detects some fibroadenomas that would otherwise not be detected.

Cotton dust and endotoxin exposure and long-term decline in lung function: results of a longitudinal study.

To evaluate the relationship between long-term exposure to cotton dust and Gram-negative bacterial endotoxin on lung function, we conducted an 11-year follow-up study of cotton textile workers in Shanghai, China. Workers at a nearby silk-thread manufacturing mill were used as a referent population. Ninety percent of the original cohort of 445 cotton and 467 silk textile workers--both active and retired--were identified for testing in the 11th year. Questionnaires and spirometric testing were performed, as well as cotton dust and endotoxin sampling at three points over the 11-year follow-up period: at baseline, at Year 5, and at Year 11. After excluding deaths and subjects on sick-leave, 84% of the original cohort had complete health and environmental data. The data were reanalyzed using generalized estimating equations feedback model which allow for subject transfer over time between work areas, various exposure levels to dust and endotoxin, and FEV1. Cotton workers had a larger loss of FEV1 during the first 5 years of study (-40 mls/yr) as compared with the second 6 years of follow-up (-18 mls/yr). During the same periods, the average decline among silk workers was slightly higher in the first period, but was more consistent (-30 mls/yr vs. -27 mls/yr), and these differences could not be explained by worker selection or dropout. When cumulative exposure to dust and endotoxin were estimated and used in a multivariate model (GEE) for FEV1 loss, cumulative dust, but not endotoxin, was associated with 11-year loss in FEV1 after adjustments for confounders. There was evidence of feedback between dust-exposure levels and FEV1, indicating the existence of a healthy-worker survivor effect. After accounting for a healthy-worker survivor effect, we found a significant relationship between dust exposure and FEV1 decline. Our results suggest that cotton dust is more strongly associated with chronic airflow limitation than associated endotoxins. Further work is needed to clarify potential reversibility after cessation of exposure, and the relative contributions of dust, endotoxin, and tobacco to chronic respiratory impairment in cotton and other vegetable-exposed workers.

Urinary excretion of phenol, catechol, hydroquinone, and muconic acid by workers occupationally exposed to benzene.

OBJECTIVES: Animal inhalation studies and theoretical models suggest that the pattern of formation of benzene metabolites changes as exposure to benzene increases. To determine if this occurs in humans, benzene...

Economic Ownership and Workers' Perceptions of the Workplace: An Exploratory Study of Manufacturing Workers in Shanghai

The Chinese urban economy has undergone substantial transformation since the industrial reforms in 1984. This article seeks to understand the impact of economic reforms on the institutional settings of the workplace, as seen from the workers' perspective, and their subsequent influence on workers' well-being, as indicated by job satisfaction. Data were collected from a 1996 survey of 300 urban workers in Shanghai, who were engaged in six organizations, including two state enterprises, two joint ventures and two private enterprises. Findings show that despite the long hours and relatively low income, workers in private enterprises report the most optimistic outlook for themselves in the organization as well as for the future development of the organization, and the highest level of job satisfaction. After controlling for the sociodemographic characteristics of workers and types of economic ownership, expectations for the future development of the organization is found to be the most significant predictor for job satisfaction. Implications of the findings are discussed.