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Jung-Der Wang

Publications and source records attributed to Jung-Der Wang.

At least 55 records · Page 3Linked to original sources
PubMed2004

Integrating health profile with survival for quality of life assessment.

In cohort studies or clinical trials, measurements of quality of life (QoL) were averaged across available individuals for each group at given points in time to produce single measures for comparisons. However, estimates of these single measures may be severely biased if substantial mortality occurs over time. The objective of this study is to develop a method that integrates QoL measurement and survival for long-term evaluation of health services. We defined a mean QoL score function over time for an index population as the average QoL score of all individuals both alive and dead at each time point in the population. While a living subject's QoL can be assessed by asking one's subjective preference, the score of a decedent can be assigned a fixed value depending on the specific facet on health profile. The mean QoL score function over time is reduced to a single measure of expected cumulative QoL score, which is the area under the curve of mean QoL score function over a given time interval and can be estimated by taking a random sample from a cross-sectional survey. For the QoL score function to be extrapolated to life-long, it requires the assumption that the disease causes premature death or a long-term moderate impairment of QoL. We provided methods and computer programs for estimating mean QoL score functions and the reduced single measures for use in comparisons. A cohort of 779 breast cancer patients from Chiangmai, Thailand were followed for 12 years to demonstrate the proposed methods. The data included the 12-year complete survival records and QoL scores on 233 patients collected from a cross-sectional survey using WHOQOL questionnaire and standard gamble method. The expected cumulative QoL scores using utility and psychometric scales were compared among patients in four groups of clinical stages in this cohort for time from onset up to 12 years and life-long. We conclude that such an integration of QoL measurement with survival can be useful for the evaluation of health service and clinical decision.

Attitude to Health↗
PubMed2004

Expression of connexin 26 in the lateral wall of the rat cochlea after acoustic trauma.

OBJECTIVE: Although the mutation in the Gap Junction Beta 2-encoding gap junction protein connexin 26 (Cx26) has been related to hereditary non-syndromic deafness and maturation of cochlear development, the physiological role of Cx26 in the cochlear lateral wall remains unclear. It has been suggested to be responsible for the recycling of K+ in the endolymph and for maintenance of the endocochlear potential (EP). In noise-induced hearing loss, alterations in the EP and the K+ concentration in endolymph have been observed. Thus Cx26, which is widely expressed in the cochlear lateral wall, may play a role in the mechanism of acoustic trauma. MATERIAL AND METHODS: We used a rat model of noise-induced hearing impairment to detect changes in Cx26 expression in the cochlear lateral wall. By means of immunofluorescent staining and Western blotting, we investigated whether Cx26 was involved in the pathophysiological mechanism of acoustic trauma. RESULTS: The results indicated that abundant Cx26 protein was found on fibrocytes of the spiral ligament in the cochlear lateral wall. Protein extract of cochlear lateral wall expressed Cx26 with a molecular weight of approximately 21 kDa. After noise exposure, with an increasing threshold of the auditory brainstem response (ABR) of approximately 54.2 +/- 21.8 dB SPL, the expression of Cx26 protein increased significantly (p < 0.05) as revealed by semi-quantitative analysis from Western blotting. CONCLUSION: Cx26 protein was present in the cochlear lateral wall of rats and was upregulated when the ABR threshold shifted after intense noise exposure. Cx26 protein was involved in the pathogenesis of acoustic trauma.

Animals↗
PubMed2004

Development of a monitoring system for keyboard users' performance.

To precisely evaluate the typing performance of a VDT user, a program named KBlog was developed to record the typing activity under the Microsoft Windows operating system. This program is small and simply framed in order to avoid overloading of the operating system. Without interfering with the typing task, this program can record the time of every pressing and releasing movement of each keystroke at the millisecond level. The accuracy and reliability of KBlog was tested by comparing time intervals recorded by KBlog to time intervals of keyboard output electrical signals recorded by an oscilloscope. In the regression analysis on these two indicators, results of high correlation coefficients of almost 1.000 and intercepts within acceptable levels of around 1 ms indicated sufficient accuracy and reliability of this program. Further applications are discussed in this paper concerning both laboratory and field researches.

Computer Peripherals↗
PubMed2004

Liver fibrosis in asymptomatic polyvinyl chloride workers.

This study was designed to determine whether vinyl chloride monomer (VCM) exposure is associated with liver fibrosis. A total of 347 workers with occupational exposure to VCM were systemically examined using liver ultrasonography and routine liver function tests. Vinyl chloride monomer cumulative dose (ppm-month) was estimated by summing the products of air VCM concentration levels and months of employment. Liver fibrosis was defined in subjects with precirrhosis and cirrhosis of liver diagnosed using ultrasonography. Significantly increased risks of developing liver fibrosis were found in workers who had history of high exposure jobs (odds ratio 5.5, 95% confidence interval 1.7-25.4) when compared with workers who did not have history of high exposure jobs. We concluded that there was an increased risk of developing liver fibrosis in PVC workers who had high exposure to VCM.

Adult↗
PubMed2004

Reduction of acute respiratory illness (ARI) due to a voluntary workplace influenza vaccination program: who are more likely to get the benefit?

The study investigated the overall effectiveness and its determinants of an influenza vaccination in the reduction of acute respiratory illness (ARI) clinic visits and sickness absence for a working population. We collected and compared the data of clinic visits and hours of sick leave among vaccinated and non-vaccinated workers during January and April in 1998 and 1999. A multiple regression analysis was conducted to explore possible determinants. The incidence rate of ARI clinic visits dropped 37.9% in 1999, with 57.3% reduction in vaccinated and 14.1% in un-vaccinated workers. Multiple regression analysis showed that the reduction was significantly associated with vaccination status, a history of diabetes, and occurrence of ARI clinic visits in 1998. Influenza vaccination is effective in reducing ARI clinic visits and sickness absence. Workers with a previous history of ARI, diabetes, and possibly young workers living with children were more likely to get the benefit. The identification of potential susceptible subpopulations can also minimize confusion on company policy for isolation during an epidemic of new infectious disease with flu-like symptoms.

Acute Disease↗
PubMed2004

Environmental and occupational health response to SARS, Taiwan, 2003.

Industrial hygiene specialists from the National Institute for Occupational Safety and Health (NIOSH) visited hospitals and medical centers throughout Taiwan. They assisted with designing and evaluating ventilation modifications for infection control, developed guidelines for converting hospital rooms into SARS patient isolation rooms, prepared designs for the rapid conversion of a vacated military facility into a SARS screening and observation facility, assessed environmental aspects of dedicated SARS hospitals, and worked in concert with the Taiwanese to develop hospital ventilation guidelines. We describe the environmental findings and observations from this response, including the rapid reconfiguration of medical facilities during a national health emergency, and discuss environmental challenges should SARS or a SARS-like virus emerge again.

Cross Infection↗
PubMed2004

Prevalence of and major risk factors for adult bronchial asthma in Taipei City.

BACKGROUND AND PURPOSE: The prevalence of bronchial asthma has been on the rise worldwide, but the prevalence of adult asthma in Taiwan has not been reported. The objective of this study was to determine the current 1-year and lifetime asthma prevalence rates, and to identify major risk factors for adult asthma in Taiwan. METHODS: A cluster sampling was conducted in 1999, where 21 clusters and 4549 adults (age > or = 18 years) were selected randomly. Face-to-face interviews were conducted with a total of 2076 adults (45.6%; men/women, 987/1089) using a questionnaire designed to assess asthma and asthma-like symptoms adapted from the American Thoracic Society with minor modifications to include information about current asthma status. RESULTS: The results showed that 50 cases had a previous diagnosis of asthma and 94 had been classified as probably having asthma with intermittently audible wheezing. The lifetime prevalence rate of asthma in adults in Taipei City was 7.8%. Seventy three out of 144 patients had asthmatic symptoms or wheezing in the past 12 months. The 1-year prevalence of asthma was 4.1%. A multiple logistic regression model showed the odds ratio (95% confidence interval) of a history of maternal asthma to be 5.8 (2.77 to 12.18), that of allergic rhinitis to be 3.2 (2.03 to 5.16), that of paternal asthma to be 2.2 (0.91 to 5.21), that of older age (> or = 50 years) to be 2.0 (1.25 to 3.19), and that of smoking habit to be 1.7 (1.02 to 2.72). CONCLUSIONS: The lifetime prevalence rate of adult bronchial asthma in Taipei City was 7.8% and related to both genetic and environmental factors, which included maternal or paternal history of asthma, history of allergic rhinitis, older age (> or = 50 years), and smoking habits.

Adolescent↗
PubMed2004

Chronic hepatitis B virus infection and dyslipidemia.

BACKGROUND AND PURPOSE: The association of chronic hepatitis B virus (HBV) infection and decreased levels of high-density lipoprotein cholesterol (HDL-C) has been well documented. However, the relationship between dyslipidemia and asymptomatic chronic HBV infection is still unclear. METHODS: In 1997, 1330 medical center employees (405 men and 925 women) were recruited to evaluate the effects of chronic HBV infection on serum lipid profile, including total cholesterol (TC), HDL-C, low-density lipoprotein cholesterol, and triglycerides (TG). Among these patients, 195 were found to have chronic HBV infection and 35 (17.9%) of them were found to have elevated alanine aminotransferase (ALT). Multiple linear regression analyses were used to evaluate the effects of chronic HBV infection on serum lipids. RESULTS: The most significant finding was that levels of TC and HDL-C were decreased by 5.8 and 2.7 mg/dL respectively, among patients with asymptomatic chronic HBV infection (serum ALT < 40 U/L). After controlling for other determinants, male gender, old age, higher body mass index (BMI) and waist-to-hip ratio, current smoking, and hepatitis B surface antigen-negative status with ALT > or = 40 U/L were associated with lower serum HDL-C and higher TG levels. However, moderate to heavy alcohol drinking, physically active lifestyle, and lower BMI were associated with higher levels of HDL-C. CONCLUSIONS: Asymptomatic chronic HBV infection was associated with lower serum levels of TC and HDL-C. Elevation of ALT was also an indicator of lower levels of HDL-C in patients with chronic hepatitis B and lower serum HDL-C and higher TG levels in patients without HBV infection. These findings also indicated the need to monitor the risk of atherosclerotic diseases in patients with asymptomatic chronic HBV infection, especially those with lower HDL-C levels.

Adult↗
PubMed2003

XRCC1, CYP2E1 and ALDH2 genetic polymorphisms and sister chromatid exchange frequency alterations amongst vinyl chloride monomer-exposed polyvinyl chloride workers.

Vinyl chloride monomer (VCM) is a known human carcinogen, which may be metabolized by cytochrome P450 2E1 (CYP2E1), aldehyde dehydrogenase 2 (ALDH2), and glutathione S-transferase T1 (GSTT1). A DNA-repair gene, X-ray repair cross-complementing group 1 ( XRCC1, exon 10), may also be implicated in the process of VCM-related carcinogenesis. Thus, VCM-exposed workers with inherited susceptible metabolic and DNA-repair genotypes may experience an increased risk of genotoxiciy. This study was designed to investigate whether metabolic and DNA-repair genotypes affected sister chromatid exchange (SCE) frequency in occupationally VCM-exposed workers from polyvinyl chloride (PVC) manufacturing plants. Study subjects comprised 61 male workers having experienced VCM exposure, and 29 male controls. Questionnaires were administered to obtain detailed histories of cigarette-smoking habits, alcohol consumption behavior, and occupation. The frequency of SCE in peripheral lymphocytes was determined using a standardized method, and genotypes of CYP2E1, ALDH2, GSTT1 and XRCC1 were identified by the polymerase chain reaction (PCR) procedure. Our results demonstrated that smoking, age and VCM exposure and XRCC1 ( P=0.03), CYP2E1 ( P=0.04), and ALDH2 ( P=0.08) were significantly associated with an increased SCE frequency. Further analysis of gene combinations, including CYP2E1, ALDH2 and XRCC1, revealed an increased trend for these genotypes to influence SCE frequencies for the low VCM-exposure group ( P<0.01), but not so for the high VCM-exposure group ( P=0.29) or for controls ( P=0.49). These results suggest that workers with susceptible metabolic and DNA-repair genotypes, may experience an increased risk of DNA damage elicited by VCM exposure.

Adult↗
PubMed2003

Association of hepatitis virus infection, alcohol consumption and plasma vitamin A levels with urinary 8-hydroxydeoxyguanosine in chemical workers.

Urinary 8-hydroxydeoxyguanosine (8-OHdG) DNA adduct has been used as a biomarker in epidemiological studies. However, the determinants for urinary 8-OHdG have not been clearly identified. We tested urinary 8-OHdG levels in 205 male workers who had been exposed to vinyl chloride monomer (VCM). Epidemiological information was obtained by an interviewer-administered questionnaire. Hepatitis B surface antigen (HBsAg) and anti-hepatitis C antibody (anti-HCV) were also determined by immunoassay. Plasma antioxidants including Vitamins A and E, alpha- and beta-carotenes were assayed by high performance liquid chromatography. Median of urinary 8-OHdG level was 9.8 ng/mg creatinine (range, 1.4-60.1). Multiple linear regression analysis showed that alcohol drinkers had higher urinary 8-OHdG than those who did not, but there was no dose-response between the amount of alcohol consumption and urinary 8-OHdG. Workers with positive HBsAg, anti-HCV and elevated plasma Vitamin A level were independently associated with higher levels of urinary 8-OHdG, whereas age, smoking, body mass index, plasma alpha- and beta-carotenes, Vitamin E levels, or VCM exposure did not show such an association. The results suggest that active inflammation of hepatitis B and C, alcohol consumption and higher Vitamin A level can induce oxidative stress. Thus, we conclude that potential determinants need to be considered in epidemiological studies when urinary 8-OHdG is used as a biomarker.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2003

Molecular epidemiology of plasma oncoproteins in vinyl chloride monomer workers in Taiwan.

AIMS: To determine the presence of Asp13-p21-ki-ras oncoprotein and p53 oncoprotein in the plasma of vinyl chloride monomer (VCM)-workers in Taiwan. METHODS: We used enhanced chemiluminescence (ECL) western blotting to detect Asp13-p21-ki-ras and ELISA to detect mutant p53 protein (p53-Ag) and anti-p53 antibodies (p53-Ab) in the plasma of VCM-exposed workers. RESULTS: Twenty-five out of 251 (10%) VCM-workers were positive for Asp13-p21-ki-ras in plasma, but 0 out of 36 controls were positive. There were 15 out of 95 (15.8%) plasma-positives among the more highly exposed (> 480 ppm-month) workers and 10 out of 156 (6.4%) plasma-positives among the lesser exposed (< or = 480 ppm-month). Compared to the unexposed controls, age and drinking adjusted odds ratios (95% CI) were 1.2 (0.1, 9.8) in the lower exposed workers, and 4.8 (0.8, 28) in the higher exposed workers, and there was a significant linear trend between exposure and plasma positivity (P=0.001). Thirty-three out of 251 (13.2%) VCM-workers were positive for the p53 over-expression (10% with positive p53-Ag and 2.8% with positive p53-Ab). There was a significant association between cumulative VCM exposure concentration and positive p53 expression (P=0.032) among VCM-workers after adjusting for age, hepatitis, drinking and smoking status. CONCLUSIONS: Asp13-p21-ki-ras oncoprotein and p53 over-expression (p53-Ag or p53-Ab) can be found in the plasma of VCM-workers in Taiwan, and a significant dose-response relationship exists between plasma oncoproteins expression and VCM exposure.

Adult↗
PubMed2003

Survival-weighted health profile for long-term survivors of acute myelogenous leukemia.

The objective of this study was to use survival-weighted psychometric scores (SWPS) to construct a 'health profile' for long-term survivors of acute myelogenous leukemia (AML). The study cohort included all patients who had been diagnosed and treated in our institution from 1985 to 1999 and achieved complete remission after standard chemotherapy (n = 259). One hundred and four patients were interviewed by the European Organization for the Research and Treatment of Cancer (EORTC)-QLQ-C30 questionnaire and the brief form of World Health Organization quality of life questionnaire (WHOQOL-BREF) to estimate the quality of life (QOL) function of the cohort. Forty-one patients underwent bone marrow transplantation (BMT) as consolidation or salvage therapy; 63 received chemotherapy alone. SWPS for every functioning domain and symptom item was obtained by direct integration of the mean QOL function with the survival function of the cohort. A Monte Carlo method was used to extrapolate the life-long SWPS beyond the follow-up limit. The mean scores of EORTC-QLQ-C30 and WHOQOL-BREF did not differ significantly between patients who received BMT or those who received chemotherapy only (p > 0.01). In mean SWPS, patients who received BMT had significantly (p < 0.01) better SWPS in all of the functioning domains and symptom items of EORTC-QLQ-C30 and all four domains of WHOQOL-BREF. However, when the life-long extrapolation of SWPS was made, these differences diminished in global health and several symptom items of EORTC-QLQ-C30 as well as in the social and environmental domains of WHOQOL-BREF. Patients' perspective on QOL may be domain-specific and may evolve over time. SWPS may be useful to evaluate the efficacy of different treatment strategies for AML. Confirmation of the relative merit of BMT vs. chemotherapy alone from prospective studies is needed.

Adolescent↗
PubMed2003

Interaction of vinyl chloride monomer exposure and hepatitis B viral infection on liver cancer.

Vinyl-chloride monomer (VCM), a human carcinogen, has caused angiosarcoma of the liver. Recent studies have shown that VCM exposure is associated with hepatocellular cancer. In Taiwanese studies, the majority of VCM-exposed workers with liver cancer had history of hepatitis B virus (HBV) infection. To determine the role of HBV on the development of liver cancer in the VCM-exposed workers, we conducted a case-control study from a previously established polyvinyl chloride (PVC) cohort consisting of 4096 male workers from six PVC polymerization plants. A total of 18 patients with liver cancer, and 68 control subjects matched for age and specific plant of employment were selected. Detailed history of the participants that included alcohol consumption status, cigarette use, occupation, and family history of chronic liver disease were obtained using an interviewer-administered questionnaire. When the HBV surface antigen (HBsAg)-negative subjects without history of tank-cleaning were used as the reference, the HBsAg-negative subjects with history of tank-cleaning demonstrated a 4.0-fold greater risk of liver cancer (95% confidence interval: 95% CI = 0.2-69.1). The HBsAg carriers without history of tank-cleaning revealed a 25.7-fold greater risk of liver cancer (95% CI = 2.9-229.4). Whereas the HBsAg carriers with history of tank-cleaning revealed the greatest risk (matched odds ratio (ORm) 396.0, 95% CI = 22.6 -infinity) of developing liver cancer among subjects with different VCM-exposure status and HBsAg status categories. Further analysis showed the interaction term was significant (P < .01). Therefore, our results suggest an interaction between occupational VCM exposure and HBV infection for the development of liver cancer.

Case-Control Studies↗
PubMed2002

Monitoring of arsenic exposure with speciated urinary inorganic arsenic metabolites for ion implanter maintenance engineers.

For wafer fabrication in the semiconductor industry, maintenance engineers are potentially exposed to hazards during their work of disassembling machine components for cleanup. One special concern is the presence of arsenic or arsenic compounds in the working environment. This study analyzed speciated urinary inorganic arsenic metabolites of the maintenance engineers using high-performance liquid chromatography-hydride generation atomic absorption spectrometry to study the potential arsenic exposure during their maintenance work. In total, from six wafer fabrication facilities, 30 maintenance engineers were recruited as the exposed group and another 12 office-based engineers served as the control group. First morning-voided urine samples of each study subject were collected for 7 consecutive days. The levels of total urinary inorganic arsenic metabolites for the exposed group were 1.7+/-1.4, 1.4+/-1.1, 6.2+/-6.7, 20.2+/-14.1, and 29.5+/-17.2 micro g/L for As3+, As5+, monomethylarsonic acid, dimethylarsinic acid, and total inorganic arsenic, respectively. Both the concentration of monomethylarsonic acid and its percentage in total urinary inorganic arsenic metabolites showed significantly ascending trends for the control group, for the engineers without preventative maintenance work prior to their urine sampling, and for the engineers with such work prior to their urine sampling (P<0.05 and P<0.0005, respectively). The data also suggested that, at low-level occupational arsenic exposure, the concentration of total urinary inorganic arsenic metabolites might be misleading due to the confounding effect resulting from intake of seafood, such as arsenosuger. Nevertheless, monitoring of urinary arsenic species by using the percentage change of monomethylarsonic acid in total urinary inorganic arsenic metabolites as an indicator for the verification of arsenic exposure is helpful and appropriate in such cases.

Adult↗
PubMed2002

Health risk assessment on residents exposed to chlorinated hydrocarbons contaminated in groundwater of a hazardous waste site.

We conducted this study to estimate residents' chronic hazard and carcinogenic risk in a groundwater-contaminated community after on-site remediation in Taiwan during 1999-2000. We followed guidelines for assessing hazardous waste sites of the U.S. Environmental Protection Agency (EPA) and used empirically measured contaminant levels and exposure parameters to perform health risk assessment on seven chlorinated hydrocarbons. We measured groundwater concentrations of vinyl chloride, tetrachloroethylene, trichloroethylene, 1,1-dichloroethylene, 1,1,1-trichloroethane, cis-1,2-dichloroethylene, and 1,1-dichloroethane in 49 off-site residential wells by gas chromatography/mass spectrometry. Exposure parameters were mainly derived from our field survey of 382 residents, and partially from U.S. EPA default values. Total exposure dose estimation included routes of inhalation during showering and dermal absorption of showers and other activities involved with hand-water contacts. The ingestion route of water was not included because most residents drank boiled water with negligible contaminants. We calculated a hazard index (HI) for all seven chlorinated hydrocarbons and carcinogenic risks for known human carcinogen of vinyl chloride and probable human carcinogens of tetrachloroethylene and trichloroethylene, which had the same target organ, the liver. The HI values for reasonable maximal exposure (RME) and average exposure were 14.3 and 0.2, respectively. The cancer risks based on RME and average exposure (in parentheses) for vinyl chloride, tetrachloroethylene, and trichloroethylene were 8.4 x 10(-6) (7.3 x 10(-9)), 1.9 x 10(-4) (1.3 x 10(-7)), and 1.4 x 10(-4) (1.2 x 10(-6)), respectively. We applied Monte Carlo simulations to the sensitivity analysis, which showed that the contaminant levels, exposure duration, and time for showers were major determinants of health risks. We concluded that the contaminated groundwater was still unsafe for use even after the contaminated site underwent remediation by extraction and treatment in 1997.

Baths↗
PubMed2002

Chronic toxicity of a mixture of chlorinated alkanes and alkenes in ICR mice.

The aim of this study was to determine the chronic toxicity of a mixture of chlorinated alkanes and alkenes (CA) consisting of chloroform, 1,1-dichloroethane, 1,1-dichloroethylene, 1,1,1-trichloroethane, trichloroethylene, and tetrachloroethylene. These chlorinated organic solvents were present in the underground water near an electronic appliances manufactory in Taoyuan, Taiwan. Male and female weanling ICR mice were treated with low-, medium-, and high-dose CA mixtures in drinking water for 16 and 18 mo, respectively. A significant number of male mice treated with the high-dose CA mixture developed tail alopecia and deformation, which was not prominent in CA-treated female mice. Medium- and high-dose CA mixtures induced marginal increases of liver and lung weights, blood urea nitrogen, and serum creatinine levels in male mice. In female mice, the high-dose CA mixture increased liver, kidney, and uterus and ovary total weights, without affecting serum biochemistry parameters. CA mixtures had no effects on the total glutathione content or the level of glutathione S-transferase activity in the livers and kid- neys of male and female mice. Treatments with CA mixtures produced a trend of increasing frequency of hepatocelluar neoplasms in male mice, compared to male and female controls and CA-treated female mice. The high-dose CA mixture induced a significantly higher incidence of mammary adenocarcinoma in female mice. The calculated odds ratios of mammary adenocarcinoma in female mice induced by low-, medium-, and high-dose CA mixtures were 1.14, 1.37, and 3.53 times that of the controls, respectively. The low-dose CA mixture induced a higher incidence of cysts and inflammation in and around the ovaries. This study has demonstrated that the CA mixture is a potential carcinogen to male and female mice. These animal toxicology data may be important in assessing the health effects of individuals exposed to the CA mixture.

Alkanes↗
PubMed2002

Prolonged time to pregnancy in female workers exposed to ethylene glycol ethers in semiconductor manufacturing.

BACKGROUND: Previous research on reproductive effects of working in the semiconductor industry is limited and has produced conflicting results. METHODS: This retrospective cohort study was designed to investigate the risk factors for female fertility in a wafer-manufacturing company of Taiwan in 1997. Waiting time to pregnancy and potential confounders were collected by face-to-face interview. Exposure was assessed by directors and senior engineers in manufacturing, administrative, and safety and health departments according to safety records, personnel records, and job histories from questionnaires, using a tiered exposure-assessment approach. Of a total 842 female workers, 720 (85.5%) participated. There were 292 pregnancies from 173 workers eligible for analysis. Relative fecundability (fecundability ratio, or FR) was calculated using Cox's proportional hazard models to evaluate the effect of occupational exposure to ethylene glycol ethers on female fertility. RESULTS: Waiting time to pregnancy of female workers in the photolithography area was longer than that of those in the nonfabrication area (FR = 0.77; 95% CI = 0.45-1.32), and those who were potentially exposed to ethylene glycol ethers showed longer time to pregnancy compared with those not exposed (FR = 0.59; 95% CI = 0.37-0.94). CONCLUSION: This study provides further evidence that ethylene glycol ethers may cause female subfertility.

Ethers↗