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This study was performed in a climatic chamber to evaluate the combined effects of noise intensity, heat stress, workload, and exposure duration on both noise-induced temporary threshold shift (TTS) and the recovery time by adopting Taguch's method. Fourteen subjects without previous significant noise exposure and smoking history were recruited to participate in this study. All hearing threshold levels at eight different frequencies (250 to 8,000 Hz) of better ear were measured in an audiometric booth by using the ascending method in 2 dB steps before each exposure condition. The test was also carried out after exposure to evaluate TTS at various times. The TTS recovery time was assessed using an audiometric test on all subjects at post-exposure times of 2, 20, 40, 60, 80 and 120 min, respectively. It was found that TTS depended mainly on the exposed noise dose and was enhanced by workload and heat stress. The TTS recovery time is dependent upon the magnitude of the initial hearing loss. In conclusion, TTS driven by noise exposure is enhanced by heat and workload. Further studies are required to evaluate the effects of workload with extreme temperature in a workplace environment.

The purpose of this study is to evaluate the non-ionizing radiation (NIR) exposure, especially optical radiation levels, and potential health hazard from aluminum arc welding processes based on the American Conference of Governmental Industrial Hygienists (ACGIH) method. The irradiance from the optical radiation emissions can be calculated with various biological effective parameters [i.e., S(lambda), B(lambda), R(lambda)] for NIR hazard assessments. The aluminum arc welding processing scatters bright light with NIR emission including ultraviolet radiation (UVR), visible, and infrared spectra. The UVR effective irradiance (Eeff) has a mean value of 1,100 microW cm at 100 cm distance from the arc spot. The maximum allowance time (tmax) is 2.79 s according to the ACGIH guideline. Blue-light hazard effective irradiance (EBlue) has a mean value of 1840 microW cm (300-700 nm) at 100 cm with a tmax of 5.45 s exposure allowance. Retinal thermal hazard effective calculation shows mean values of 320 mW cm(-2) sr(-1) and 25.4 mW (cm-2) (380-875 nm) for LRetina (spectral radiance) and ERetina (spectral irradiance), respectively. From this study, the NIR measurement from welding optical radiation emissions has been established to evaluate separate types of hazards to the eye and skin simultaneously. The NIR exposure assessment can be applied to other optical emissions from industrial sources. The data from welding assessment strongly suggest employees involved in aluminum welding processing must be fitted with appropriate personal protection devices such as masks and gloves to prevent serious injuries of the skin and eyes upon intense optical exposure.

Objectives Our aim is to analyze the association between polycyclic aromatic hydrocarbon (PAH) exposure and the temporal change of urinary 1-hydroxypyrene (1-OHP). Methods Two personal air samples, eight spot urine samples, and questionnaires were used to collect PAH exposure, urinary 1-OHP, demographic data, and environmental pollutants. Results Topside-oven workers had significantly higher levels of PAH exposure and 1-OHP than side-oven workers. Urinary 1-OHP was a biomarker for PAH exposure. In topside-oven workers, the trend of 1-OHP increased sharply and reached the top in the sixth day after work and declined dramatically on days off. In side-oven workers, such a trend was not found, and those who smoked showed a slight increase in urinary 1-OHP levels on days off. Conclusions We suggest that the pattern of temporal change of urinary 1-OHP levels is different between topside-oven and side-oven workers.

The electronics industry is becoming an important mainstream in the workforce in some developed countries and in Taiwan. Among patients with occupational hand dermatitis in northern Taiwan, workers from electronics industries were one of the most important groups. We conducted a field investigation to determine the prevalence, patterns and risk factors of occupational hand dermatoses among electronics workers. The survey was conducted in five electronics plants using a self-administered questionnaire on skin symptoms and risk factors. Skin examination and patch testing were followed for those with symptoms compatible with hand dermatitis. A total of 3070 workers completed the questionnaire. Among them, 302 (9.8%) reported to have symptoms (itching and with either redness/scaling) compatible with contact dermatitis on hands. Hand dermatitis was associated with working in the fabrication unit and personal history of atopy and metal allergy, as well as the following job titles: wafer bonding, cutting, printing/photomasking, softening/degluing, impregnation and tin plating. Among those with reported hand dermatitis, 183 completed skin examination and patch testing, 65/183 (35.5%) were diagnosed as having irritant contact dermatitis (ICD) and 7/183 (3.8%) allergic contact dermatitis. The most important allergens were nickel, cobalt and phenylenediamine. In conclusion, Taiwanese electronics workers have a high risk of having hand dermatitis, especially ICD. Preventive efforts should be focused on the workers with risk factors or at certain worksites.

Background Plastics manufacturing factories are the fifth largest category of factories in industrial estates in Taiwan. It is known that complex airborne compounds and pungent odours are emitted during plastic injection-moulding processes. Workers exposed to acrylonitrile-butadiene-styrene (ABS) thermal decomposition products (TDP) may have olfactory loss. Aims This study examined olfactory loss in injection-moulding workers exposed to ABS TDP. Methods The method recommended by the Connecticut Chemosensory Clinical Research Center (CCCRC) was used to test the olfactory function of subjects, including 1-butanol threshold and odour identification, both pre- and post-work. The study sample included 52 ABS plastic injection-moulding workers (exposed group), as well as 72 workers from other departments (reference group). Results The results revealed that the exposed group had lower olfactory function after work than the reference group. The decrease in olfactory function after 1 workday was statistically significant. The prevalence of abnormal olfactory function post-work in the exposed group was higher than in the reference group. Conclusions The findings of this study implied the ABS plastic injection-moulding process may worsen olfactory function among workers. Notably, this effect decreased olfactory threshold scores, not odour identification scores.

Objectives. We explored a postulated association between daily driving time and knee pain. Methods. We used data from the Taxi Drivers’ Health Study to estimate 1-year prevalence of knee pain as assessed by the Nordic musculoskeletal questionnaire. Results. Among 1242 drivers, the prevalence of knee pain, stratified by duration of daily driving (≤ 6, > 6 through 8, > 8 through 10, and > 10 hours), was 11%, 17%, 19%, and 22%, respectively. Compared with driving 6 or fewer hours per day, the odds ratio of knee pain prevalence for driving more than 6 hours per day was 2.52 (95% confidence interval = 1.36, 4.65) after we adjusted for socioeconomic, work-related, and personal factors in the multiple logistic regression. Conclusions. The dose-related association between driving duration and knee pain raises concerns about work-related knee joint disorders among professional drivers.

Coke-oven workers (COWs) are occupationally exposed to high concentrations of polycyclic aromatic hydrocarbons (PAH). Urinary 8-hydroxy-2-deoxyguanosine (8-OH-dG) and 1-hydroxypyrene (1-OHP) are biological markers of oxidative DNA damage and PAH metabolism, respectively. We investigated the relationship between urinary 8-OH-dG and 1-OHP in 217 Taiwanese COWs, 55 topside-oven, and 162 sideoven workers. For topside-oven workers, mean 8-OH-dG and 1-OHP concentrations (ng/ml ± SD) were 13.8 ± 12.0 and 93.5 ± 104.4, respectively. These levels were significantly higher than those for sideoven workers: 10.2 ± 7.9 ng/ml (P = 0.04) and 19.8 ± 28.6 ng/ml (P < 0.001), respectively. Individual urinary 8-OH-dG concentrations were directly correlated with urinary 1-OHP concentrations: the higher the 1-OHP level, the higher the 8-OH-dG level (Spearman correlation coefficients: r = 0.43, P < 0.0001, n = 217). Multiple regression analysis indicated that a 10-fold increase in 1-OHP was associated with a 1.91-fold increase in 8-OH-dG. Compared to no vitamin intake, intake of at least one multiple vitamin pill per week reduced 8-OH-dG excretion (P = 0.02). Our findings suggest that urinary 1-OHP and 8-OH-dG reflect occupational PAH exposure and oxidative DNA damage in COWs. In addition, multiple vitamins may reduce oxidative stress caused by PAH exposure. Environ. Mol. Mutagen. 42:98–105, 2003. © 2003 Wiley-Liss, Inc.

We initiated an investigation to examine the possible association between the cancer risk and the chlorinated organic solvents exposure in an electronic factory. To obtain information on the incidence of the various types of cancer among the exposed and comparison groups, the cohort populations were merged with the National Mortality Database, the National Cancer Registry Database, and the National Insurance Hospitalization Database from the Department of Health (DOH), as well as the Labor Insurance Hospitalization Database from the Bureau of Labor Insurance (BLI). The proportionate cancer morbidity ratio (PCMR) was used to estimate the cancer risk of the exposed workers in comparison with either textile workers or electronics workers. After adjustment for age, only the PCMR for breast cancer in the exposed female employees was significantly elevated when compared with the two comparison groups. The increased risk of breast cancer was mainly found in the category of 1989-1997 for year of diagnosis when stratified by calendar year. However, there was no dose-response relationship between female breast cancer risk and duration of employment. Although some PCMRs for the cancers were also increased in the exposed group, female breast cancer was consistently increased when compared with both textile and electronics comparison groups using different exclusion criteria. The results obtained in the present study suggest a possible association between exposure to chlorinated organic solvents and female breast cancer. Since this association has never been reported in the previous studies, further study is needed to clarify the association.

Carbon disulfide (CS2) is a man-made product utilized primarily in the manufacture of viscose rayon. Overexposure to CS2 has been associated with an increase in coronary heart disease. The aims of this study were to examine the dose-response relationship of CS2 exposure and elevated lipid profile tests among CS2-exposed workers in Taiwan. A total of 132 workers were recruited from two viscose rayon plants. Air sampling was performed to determine the CS2 exposure of workers. Demographic data and work history were gathered by a standard self-administered questionnaire. Lipid profile tests were also performed by routine methods. The average CS2 exposure concentration was 50.6 +/- 25.6 ppm (range: 24-127 ppm) in the high-exposure group, 12.9 +/- 5 ppm (range: 5.2-22.3 ppm) in the mid-exposure group, and 3.5 +/- 1.2 ppm (range 0.97-5.2 ppm) in the low-exposure group. There were 21 out of 33 (63.7%) elevated triglyceride levels among high-CS2-exposure workers, 27 out of 64 (42.2%) among the middle-CS2-exposure, and 14 out of 35 (40%) among low-CS2-exposure workers, respectively. Compared to the low-CS2-exposure workers, the age- and weight-adjusted odds ratios (and 95% confidence intervals) of the prevalence of elevated triglyceride value were 1.12 (0.5, 2.7) for middle-CS2-exposure workers, and 2.81 (1.02, 7.8) for high-CS2-exposure workers. There was a significant linear trend between CS2 exposure and the prevalence of elevated triglyceride value (P = 0.046) after adjusting for other factors. There was also a lower prevalence of elevated HDL level in high-CS2-exposure workers than low-CS2-exposure workers (15.2% versus 31.4%). Compared to the low-CS2-exposure workers, the age- and weight-adjusted odds ratio (and 95% confidence intervals) of elevated HDL level were 0.34 (0.1, 1.18) for high-CS2-exposure workers, which was borderline significant. In conclusion, this study suggests that elevated triglyceride level and decreased HDL level are associated with CS2 exposure. The study also suggests that exposure to CS2 (concentration > 23.2 ppm, which was above the current TLV-TWA of 10 ppm) are significantly associated with increased risk and decreased protective effect for coronary heart disease.

Purpose A retrospective cohort mortality study based on standardized mortality ratios (SMRs) was conducted to investigate the possible association between exposure to chlorinated organic solvents and various types of cancer deaths. Methods Vital status and causes of death of study subjects were determined from January 1, 1985 to December 31, 1997 by linking cohort data with the National Mortality Database. Person-year accumulation began on the date of entry to the cohort, or January 1, 1985 (whichever came later), and ended on the closing date of the study (December 31, 1997), if alive; or the date of death. Results This retrospective cohort study examined cancer mortality among 86,868 workers at an electronics factory in the northern Taiwan. Using various durations of employment and latency and adjusting for age and calendar year, no significantly elevated SMR was found for any cancer in either male or female exposed workers when compared with the general Taiwanese population. In particular, the risk of female breast cancer was not found to be increased. Although ovarian cancer suggested an upward trend when analyzed by length of employment, ovarian cancer risk for the entire female cohort was not elevated. Conclusions It is concluded that this study provided no evidence that exposure to chlorinated organic solvents was associated with human cancer risk.

Objectives Indium Tin Oxide (ITO) is widely used in many kinds of touch panels nowadays. Workers could expose to ITO particles from sintering granules, splashing, pulverisation, cutting, and grinding processes. This study aimed to assess the relationship between ITO exposure and lung inflammation and oxidative damage in ITO workers. Method We recruited 148 exposed workers and 38 control workers from ITO powder process, recycling and ITO target manufacturing plants in Taiwan. Indium in serum (S-In) and urine (U-In) was determined as biomarkers of exposure. Exposed group was further divided as high (S-In > 3 µg/L and low exposed groups (S-In £3 µg/L). Urinary and plasma 8-hydroxy-2-deoxyguanosine (8-OHdG), serum Clara cell protein (CC16), and fractional exhaled nitric oxide (FENO) were measured as biomarkers of oxidative damage and pulmonary inflammation, respectively. Results The geometric mean air concentrations of indium were 0.0041 ± 2.49 mg/m 3 by area sampling and 0.017 ± 5.20 mg/m 3 by personal sampling. The mean S-In level and U-In level in high exposed group were 8.01 ppb and 3.45 ppb, respectively. The mean levels of S-In and U-In in high exposed group were significantly higher than those of low exposed group. The mean levels of serum CC16 and urinary 8-OHdG in high exposed group were also significantly higher than those of low exposed groups. After adjusting potential confounders, dose-response gradients were found between S-In and CC16 (p = 0.020) and between S-In and urinary 8-OHdG (p = 0.027), respectively. Conclusions We concluded that indium particles exposure may induce lung inflammation and DNA oxidative damage.

Construction workers are known to have occupational dermatoses. The prevalence of such dermatoses was unknown in Taiwanese construction workers. The objective of this study was to determine the work exposure, prevalence of skin manifestations, and sensitivity to common contact allergens in cement workers of southern Taiwan. A total of 1147 current regular cement workers were telephone-interviewed about skin problems during the past 12 months, work exposure, and personal protection. Among those interviewed, 166 were examined and patch tested with common contact allergens. A high % of cement workers reported skin problems in the past 12 months. More men (13.9%) reported skin problems possibly related to work than women (5.4%). Prevalence was associated with lower use of gloves, duration of work as cement worker, and more time in jobs involving direct manual handling of cement, especially tiling. A high % of dermatitis was noted in the 166 workers examined, which correlated with reported skin problems. On patch testing, construction workers had a high frequency of sensitivity to chromate. Sensitivity to chromate or cobalt was associated with reported skin problems, or dorsal hand dermatitis on examination. These workers' dermatitis was under-diagnosed and inadequately managed. It is concluded that cement workers in southern Taiwan had a high prevalence of skin problems related to cement use. Protective measures, work practice, and physician education should be improved to prevent or manage such problems.

It is well known that exposure to excessive noise for long durations can cause a significant noise-induced hearing loss (NIHL). Although most research has focused on occupational sources of NIHL, there is growing concern about the potential damage caused by non-occupational noise exposure such as that from portable stereo system headphones. The purpose of current study was to measure the sound level generated by headphones of portable stereo system, and provide hearing conservation guidelines. Using a B&K Torso and a personal computer, output sound levels across volume control set by thirty participants were measured from headphone driven by music samples of five different genres. Three different styles of headphones (in-ear, circum-aural, supra-aural) were used to determine if styles of headphone influence sound level inside of ears. The study results suggested that the supra-aural headphone used by listener in noisy environment shall set a higher volume, in a result of a larger sound level in eardrum. The authors would like to thank the Institute of Occupational Safety and Health of Taiwan for the support that made the completion of this work possible.

Objectives The aim of this study is to explore the effects of exercise on the relationship between job stress and the components of metabolic syndrome. Methods A 12-week long worksite exercise program was developed for banking and insurance enterprises with a total of 89 workers participating in it. Participants were divided into three (low, medium and high) levels of exercise intervention subgroups. All were asked to complete a structured questionnaire which contained demographic and lifestyle data, SF-36, and measurements for job stress pre- and post-intervention. The profiles of metabolic syndrome (BMI, waist circumference, fasting blood glucose, triglyceride, and high-density lipoprotein cholesterol) were also measured before and after the intervention. Results The scores of individual fatigue (an indicator of job strain reaction) were significantly improved in medium and high intervention groups, and notable improvements (p Conclusions This study demonstrated an effective approach to worksite exercise intervention in banking and insurance enterprises. The present results show a triangular connection between job stress, metabolic syndrome and physical activity.