VOC concentration in Taiwan's household drinking water

The objective of this study is to analyze volatile organic compound (VOC) concentrations in Taiwan's drinking water supply. Focusing on Taiwan's three major metropolitan areas--Taipei, Taichung and Kaohsiung (in the north, middle and south, respectively)--171 samples were taken from tap water and 68 from boiled water. Tests showed VOC concentrations were highest in Kaohsiung. This is due to different water sources and methods of treatment. Except for bromoform, trihalomethane (THM) concentrations were highest. Detection rates of toluene and 1,2-dichloroethane were slightly higher than other VOC compounds. VOC concentrations decreased significantly after water was boiled. THMs had a removal rate from 61% to 82%. The authors conclude that the three metropolitan areas contain significantly different levels of VOCs and that boiling can significantly reduce the presence of VOCs. Other sources of pollution that contaminate drinking water such as industrial plants and gas stations must be further investigated.

60Co contamination in recycled steel resulting in elevated civilian radiation doses: causes and challenges

Since late 1992, more than 100 building complexes containing public and private schools and nearly 1,000 apartments have been identified in Taiwan with elevated levels of gamma-radiation from construction steel contaminated with 60Co. Due to improper handling of 60Co contaminated scrap steel in late 1982 and 1983, contaminated construction materials have been widely distributed throughout the country. These contaminated construction materials have generated elevated radiation exposures to members of the public in Taiwan. As of early 1996, more than 4,000 people, including young students, have been identified as receiving more than 1 mSv y(-1) above the local background for up to 12 y. This report provides a detailed discussion of the sources of the 60Co contamination in construction steel, its discovery in the building complexes, and preliminary evaluation and remediation activities.

Cytogenetic effect of chronic low-dose, low-dose-rate gamma-radiation in residents of irradiated buildings

BACKGROUND

Many people in Taiwan have been living in buildings constructed with cobalt-60-contaminated steel rods. To study the biological effects of chronic low-dose ionising radiation on the residents of one such building, micronucleus formation in these individuals was compared with that in controls.

METHODS

The 73 residents had 77 age-and-sex-matched controls: 31 had 31 close relatives as controls (group A controls); eight of the 31 had a second set of close relatives; and the other controls were 38 residents in neighbouring buildings. Two micronucleus assays were used-a cytochalasin B (CBMN) assay and another involving incubation with cytarabine (CBMNA). Assay results are given as "frequency", or the number of binucleate cells containing one micronucleus per 1000 randomly examined binucleate cells.

FINDINGS

The CBMN and CBMNA mean (SD) frequencies for 31 exposed individuals (0.016 [0.009] and 0.025 [0.013] respectively) were greater than those for their group A controls (0.009 [0.004] and 0.016 [0.009], respectively) (p = 0.0006 and 0.0002, respectively). The mean CBMN and CBMNA frequencies for all the exposed individuals (0.017 [0.011] and 0.030 [0.014], respectively) were significantly greater than those for all controls (0.011 [0.008] and 0.019 [0.01]; p = 0.0001 for both comparisons). The ranges of the differences in CBMN or CBMNA frequencies between 31 exposed individuals and their group A controls were 0.003 to 0.020 and 0.001 to 0.032, respectively. After adjustment for age, sex, and cigarette smoking, the adjusted relative risks of micronucleus formation from radiation exposure in all 73 residents was 1.58 (95% CI 1.42-1.71; p = 0.0001) by the CBMN assay and 1.64 (1.53-1.77; p = 0.0001) by the CBMNA assay.

INTERPRETATION

These findings suggest that chronic low-dose and low-dose-rate gamma-ray environmental exposure may induce cytogenetic damage in human beings.

[Using polymerase chain reaction to detect Helicobacter heilmannii in gastric biopsy materials]

Helicobacter heilmannii is one of the species of Helicobacter other than Helicobacter pylori noticed in human gastric mucosa. In our study, a polymerase chain reaction (PCR) was designed for the detection of Helicobacter heilmannii in gastric biopsy specimens. Two broad-range bacterial 16S rDNA primers and one Helicobacter genus-specific 16S rDNA primer were matched for detecting Helicobacter genus bacteria. A Hp-specific primer pair was used simultaneously to exclude the presence of Hp. The PCR assay detected 11 out of 12 Hh strains which were confirmed by smears, but did not amplify DNA extracts from some other enteric bacteria such as E. coli, C. jejuni, bifidobacteria. Serial dilution experiments revealed the detection of as little as 0.1 pg DNA by PCR and 0.01 pg by nested PCR. Our data showed that PCR is a rapid, accurate and sensitive method for the detection of Hh and is thought valuable in the epidemiological investigation of Helicobacter and follow-up studies after treatment.

Effects of occupational and nonoccupational factors on liver function tests in workers exposed to solvent mixtures

A total of 368 workers from six paint-manufacturing factories participated in this study. The workers were classified according to type of exposure: direct, intermittent, and no exposure. The workers' liver-function tests were influenced greatly by gender, hepatitis B, alcohol consumption, and body mass index. Both the serum concentration and the odds of abnormality of total serum bile acids were elevated among the directly exposed group. The authors concluded that analysis of covariance should take into account occupational and nonoccupational factors on liver-function tests to avoid any errors. Total serum bile acids also indicated liver dysfunction from solvent exposure.

Predictive pulmonary function of school children in an area of low air pollution in Taiwan

The objective of this study was to determine the effect of different parameters on a predictive model of pulmonary function for elementary school children in an area of low air pollution in Taiwan. Healthy children aged 7 to 12 years from three elementary schools in low-air-pollution areas (Da-Chen, Mai-Liau and Tai-Si) participated in the study. A total of 836 children (423 boys and 413 girls) were included in the study. During summer vacation, each child underwent a physical examination including a screening spirometry. A questionnaire regarding respiratory symptoms and indoor air pollutants was also completed by the children's parents. Air monitoring showed that the levels of outdoor pollutants were relatively low. Multiple linear regression analysis was performed with FVC (forced vital capacity) and FEV1 (forced expiratory volume in 1 sec) as dependent variables. Gender, age, height, weight, technician and indoor air pollution parameters were the independent variables. The results showed that gender,height, weight and technician were the most significant variables for predicting FVC and FEV1. The various indoor air pollution parameters seemed to have no influence on the pulmonary function of children, except that mildew in bedrooms mildly decreased FEV1. Regression analysis showed that all the pulmonary function parameters measured had a positive correlation with height, whereas weight correlated only with certain parameters. Because both indoor and outdoor air pollution was relatively low, we suggest that this model could be used as a basic predictive model of pulmonary function for elementary school children in Taiwan.

Neurobehavioral effects of occupational exposure to low-level organic solvents among Taiwanese workers in paint factories

At six paint factories in northern Taiwan, 325 workers participated in a detailed evaluation that included medical and occupational questionnaires, blood sampling, neurobehavioral tests, vibratory perception threshold tests, and thermal perception threshold tests. Because of cultural differences, a Chinese test battery was modified from the Neurobehavioral Evaluation System 2. Eleven tests were performed: finger tapping, continuous performance, associated learning, symbol-digit, pattern comparison, pattern memory, visual digit span, switch attention, associated delayed recognition, mood scales, and vocabulary. Air concentrations of organic solvents were measured by passive personal samplers and analyzed by gas chromatography. Results showed that major solvents to which the workers were exposed were toluene, xylene, n-hexane, methyl iso-butyl ketone, and n-butyl acetate. The exposure index (EI) was classified by different exposure patterns and different air concentrations in the breathing zone as follows: EI 0, nonexposure; EI 1, low exposure; and EI 2, high exposure (the medians of 8-hr hygienic effects were 0, 0.03, and 0.25, respectively). Because of their diverse socioeconomic status and demographic characteristics, the workers were divided into two groups for additional analysis: one group comprised white-collar workers, including technicians and administrative staff, and the other comprised blue-collar workers. By using multiple linear regression analysis controls for age, sex, education, and alcohol intake, significant associations were found between increased exposure to solvent mixtures and performance on some neuropsychologic tests. In the blue-collar group, significantly prolonged response latencies were observed in the tests of continuous performance, pattern comparison, and pattern memory. Among white-collar workers, significant impairment was observed in the continuous performance test. All three tests involved visual attention and perceptual (speed and memory) functions. It was concluded that these may be the earliest neurotoxic signs of occupational exposure to low-level organic solvents in paint manufacturing workers.

The GST T1 and CYP2E1 genotypes are possible factors causing vinyl chloride induced abnormal liver function

Vinyl chloride monomer (VCM) is hepatotoxic as well as carcinogenic in humans. There are reports that exposure to VCM seems to induce abnormal liver function, liver fibrosis, cirrhosis, portal hypertension, and angiosarcoma of the liver. In vivo, VCM is metabolized by cytochrome P450 2E1 (CYP2E1) to form the electrophilic metabolites, chloroethylene oxide (CEO) and chloroacetaldehyde (CAA), which may either cause cell damage or be further metabolized and detoxified by glutathione S-transferases (GSTs). This study investigated whether or not the genotypes CYP2E1, glutathione S-transferase theta (GST T1) and mu (GST M1) correlated with abnormal liver function found in vinyl chloride exposed workers. For this study, 251 workers from five polyvinyl chloride plants were enrolled. The workers were classified into two exposure groups (high and low) and the degree of exposure was determined based on their job titles and airborne VCM concentration. The activity of serum alanine aminotransferase (ALT) was used as the parameter of liver function. The genotypes CYP2E1, GST T1 and GST M1 were determined by polymerase chain reaction and restriction fragment length polymorphism on peripheral white blood cell DNA. Other potential risk factors were also ascertained and the confounding effect was adjusted accordingly. Stratified analyses were used to explore the correlation between the alteration of liver function and the genotypes CYP2E1, GST T1 and GST M1 among the workers exposed to different levels of VCM. The following results were obtained (1) at low VCM exposure, the odds ratio (OR) of positive GST T1 on abnormal ALT was 3.8 (95% CI 1.2-14.5) but the CYP2E1 genotype was not associated with abnormal ALT. (2) At high VCM exposure, a c2c2 CYP2E1 genotype was associated with increased OR on abnormal ALT (OR 5.4, 95% CI 0.7-35.1) and positive GST T1 was significantly associated with decreased OR on abnormal ALT (OR 0.3, 95% CI 0.1-0.9). (3) Multiple linear and logistic regression also showed strong interactions of the VCM exposure to CYP2E1 as well as to the GST T1 genotype. These observations suggest that the two genotypes, CYP2E1 and GST T1, may play important roles in the biotransformation of VCM, the effect of which leads to liver damage.

Respiratory and irritant health effects of a population living in a petrochemical-polluted area in Taiwan

Reported herewith are the results from an ongoing study of outdoor air pollution and the health of persons living in the communities in close proximity to petrochemical industrial complexes. To determine if there is an excess of adverse health outcomes in the population exposed to petrochemical industrial emissions, a health survey was undertaken in 1996 in this area and in one reference area which has no local industrial emissions. The subjects were 436 adults (30-64 years of age) living in the Sanwei area (exposed area) and 488 in Taicei (reference area). For several indicators of respiratory health, including cough, wheezing, and chronic bronchitis, the prevalence rates were not significantly different between the study and the control populations. Acute irritative symptoms (eye irritation, nausea, throat irritation, and chemical odor perception) were significantly more common in the exposed area, particularly perception of chemical odors (84.6% vs 2.1%). It is concluded that exposure to petrochemical air emissions may be associated with increased rates of acute irritative symptoms. Future studies are needed to identify the potential role of petrochemical industrial emissions (particularly volatile organic compounds) in the genesis of acute irritative symptoms in a nearby petrochemical industrial area.

Establishment of a work-related diseases surveillance system in Taiwan, Republic of China

BACKGROUND

The occurrence of occupational illness and injury has been seriously underestimated in Taiwan, which subsequently contributes to difficulties in performing effective control of occupational hazards and implementing intervention programs for protecting workers.

METHODS

Based on the successful experience of the nationwide blood lead level surveillance program, the Department of Health, the Executive Yuan, Taiwan, Republic of China, has established a work-related diseases surveillance system. This government-administered system requests practicing physicians to report the suspected cases suffering from six categories of work-related disorders.

RESULTS

An occupational illness and injury surveillance program in Taiwan has been in operation since June of 1995.

CONCLUSION

Background information of work-related diseases obtained from this surveillance system will be useful for providing better management of available resources for occupational medicine, for preventing hazards, and for enforcing occupational diseases prevention programs. Our experience in establishing this surveillance system will be used in other countries and settings.

Determinants of Economic Cost Related to Low Back Pain among Nurses at a University Hospital

The objectives of this study were to determine the economic cost related to low back pain (LBP) among nurses, and to identify factors associated with this cost. All 998 nurses at the National Taiwan University Hospital (NTUH) were asked to complete a questionnaire designed to examine whether the nurses had experienced LBP and whether their LBP had been related to the incurring of economic cost between May 1, 1990, and April 30, 1991. Of the 863 respondents, 417 had had LBP and 102 of these had incurred economic costs related to the LBP. Personal interviews of the 102 nurses, as well as of an additional four nurses who had resigned due to LBP within the 12 months, were performed to determine the related economic costs. The total monthly costs over the 12 months ranged from U.S. $105,405 to $149,083. Twenty percent of the 106 cases were responsible for 70% of the total overall cost. There was no difference in demographics between the two groups of non-LBP and LBP-without-cost. However, statistical analysis using logistic regression showed that the occurrence of economic cost was positively associated with subjective pain, lifting and carrying babies and small children at home, and age or work years or parity. In addition, multiple linear regression analysis showed that medical cost was positively associated with parity and sick leave; and productivity loss was associated with sick leave, lifting and carrying babies at home, unspecified housework, patient transport, and performing cardiopulmonary resuscitation.

Age-period-cohort analysis of motor vehicle mortality in Taiwan, 1974-1992

The aim of this study was to examine the effects of age, calendar period of death and birth cohort in motor vehicle mortality in Taiwan over the period 1974-1992. A log-linear model modified from the method of Osmond and Gardner (Stat. Med. 1: 245-259; 1982) was used. Age turned out to be a significant predictor of motor vehicle mortality. The most risky group (over 70 years) had 27.1 and 16.3 times the mortality of the least risky group (5-9 years, 10-14 years) for males and females respectively. The period effect showed a continuously increasing mortality trend since 1974 in females. The pattern in males is similar except that it has slightly leveled off in recent years. The birth cohorts at the highest risk of motor vehicle death were those born between 1979 and 1983 for both sexes. However, males born between 1929 and 1933 also had a high mortality. This analysis provided a better understanding of the trend of mortality from motor vehicle crashes.

Outbreak of contact dermatitis related to Acticide EP paste in a paint manufacturing factory

An outbreak of severe itching, erythematous and edematous dermatitis over the extremities and upper back developed in 8 of 17 workers in the raw-materials department of a paint manufacturing factory. The outbreak occurred during a 2-month period when Acticide EP paste (Thor Chemical, Cheshire, UK) was used in place of Metatin as a microbiocide (Acima Chemical, Buchs, Switzerland). To evaluate the frequency and the etiologic agent of this outbreak, a plant walk-through, examination and review of photographs of skin lesions followed by statistical analysis for association between the development of dermatitis and exposure to Acticide paste were performed. Three guinea pigs were subjected to patch tests comparing the dermatotoxicity of Acticide EP and Metatin. The results showed that 8 out of 17 workers (47%) suffered from contact dermatitis during the 2-month period. Stratification by occupational exposure further confirmed the association between the development of dermatitis and exposure to the Acticide paste. The dermatotoxicity test on guinea pigs revealed the marked corrosive effect of the paste and the absence of dermatotoxicity of Metatin. After the removal of the paste from the raw material, there were no new cases of contact dermatitis at the 6 month follow-up. We conclude that Acticide EP paste was the responsible offending agent. Because isothiazolinone derivatives are well-known antigens and 2-n-octyl-4-isothiazolin-3-one is the active ingredient in Acticide EP paste, 2-n-octyl-4-isothiazolin-3-one is the likely cause of the dermatitis.

Prevalence of dermatoses and skin sensitisation associated with use of pesticides in fruit farmers of southern Taiwan

OBJECTIVES

Agricultural workers are known to have occupational skin diseases. The prevalence and pattern of skin diseases are unknown in Taiwanese fruit farmers. The objective of this study is to determine the work exposure, prevalence of skin diseases, and sensitivity to common skin allergens and agricultural chemicals in fruit farmers of southern Taiwan.

METHODS

122 fruit farmers who regularly prepared and sprayed pesticides and a group of 63 printing press workers with no known exposure to pesticides were examined and patch tested with common skin allergens and agricultural chemicals. The farmers were also interviewed for their work habits, use of protective clothing, and exposure to pesticides.

RESULTS

Most farmers reported regular use of hat, boots, and mask, but not gloves, raincoat, and goggles. This resulted in frequent skin contact with pesticides especially on the hands and face. About 30% of farmers had hand dermatitis, and more than two thirds had pigmentation and thickening on the hands. Fungal infection of the skin was noted in a quarter of subjects. By patch test, farmers and the printing press workers had a similar rate of sensitivity to common skin allergens. 40% of farmers were sensitive to agricultural chemical allergens, which was about twofold higher than that of the comparison group. Farmers were most frequently sensitive to Captofol, Folpet, and Captan which were associated with dermatitis on the volar aspects of the hands.

CONCLUSIONS

Fruit farmers in southern Taiwan had a high prevalence of skin diseases related to use of pesticides, and appropriate protective measures and work practices should be taken to prevent such problems.

Progesterone receptor immunoreactivity at the maternofetal interface of first trimester pregnancy: a study of the trophoblast population

The aim of our study was to localize oestrogen receptor (ER) and progesterone receptor (PR) in the trophoblast population at the maternofetal interface in early pregnancy. Rat monoclonal antibodies to human ER and PR were used to study 44 cases of chorionic villi and 82 cases of decidua using an immunocytochemical method. The PR-immunoreactive products were localized in the nuclei of syncytiotrophoblast and cytotrophoblast cells of the villi. Specific staining was also present in the cytoplasm. Villous stroma and vessels were stained occasionally. Using cytokeratin staining in an adjacent section or double staining with PR and cytokeratin, the distribution of invading trophoblast cells and their PR expression were examined. In decidual stroma, a type of interstitial cell was identified which simultaneously expressed cytokeratin and PR in the cytoplasm, indicating that the invading trophoblast cells may express PR. All extravillous populations at the interface were positive for PR, including the syncytial lining of the decidual surface, the cytotrophoblast column, the cytotrophoblast shell and the interstitial trophoblast. The immunoreactivity of PR was also localized in the nuclei of vascular endothelial cells, whereas Factor VIII was localized in the cytoplasm of the same cells, thus confirming their endothelial nature. In contrast to PR, little ER could be detected in the trophoblast cell population using anti-ER antibody D75 in our study.

Estimation of expected quality adjusted survival by cross-sectional survey

To compare both mortality and quality of life (QOL) across different illnesses, we propose an estimator to calculate the expected quality adjusted survival (QAS) by multiplying the QOL into the survival function. While the survival function can be determined by the usual life table method, the QOL data can be collected by a cross-sectional survey among patients who are currently surviving. The area under the QAS curve is thus the expected utility of health of the specific illness, which may take a common unit of quality adjusted life year ready for outcome evaluation and policy decision. A simulation is performed to demonstrate that the proposed estimator and its standard error are relatively accurate. The limitations and guidelines for using this estimator are also discussed.

Cumulative injury rate and potential workdays and salary lost

OBJECTIVES

The purpose of this study was to examine alternative methods for quantifying occupational injuries and to estimate the costs of foregone earnings due to these injuries.

METHODS

A model based on the three possible outcomes of occupational injuries (premature death, permanent disability, and temporary dysfunction) was proposed, and several new indices were developed to measure the frequency and severity of occupational injuries. In the calculations, the human capital method was employed to measure potential salary lost due to occupational injury. An example was adopted from a steel corporation to demonstrate these indices.

RESULTS

The cumulative injury rates, based on age and duration of employment, represented the average cumulative risk of acquiring occupational injuries by lifetime work duration and by employment duration, respectively. The severity index revealed the rate of estimated potential workdays lost by incorporating both the age at which an injury occurred and the severity weighting factors of various disabilities into the formula. After the estimated potential workdays lost was divided by the total employees' potential affordable workdays, the proportion of potential workdays lost showed a result that adjusted for the varied age distribution in each year implicitly. The potential loss in salary calculated the foregone earnings of occupational injuries, which could be considered as a lower limit of the monetary cost estimated by the willingness-to-pay method.

CONCLUSIONS

Such indices supplement disabling frequency and severity rates. They cannot only be applied to occupational safety monitoring, but also to the policy-making process in occupational safety and health.

Case-control study of the effectiveness of different types of helmets for the prevention of head injuries among motorcycle riders in Taipei, Taiwan

A total of 1,351 victims of motorcycle accidents, brought to one of 15 hospitals responsible for emergency care in Taipei, Taiwan, between August 1 and October 15, 1990, were enrolled in a case-control study to investigate the effectiveness of different types of helmets for the prevention of head injuries. A total of 562 of those with head injuries were assigned to the case group, while the remaining 789 victims without head injuries were considered as emergency room controls. The case group was subdivided into daytime and evening cases, according to the time of accident. For each daytime case, we took four pictures of passing motorcycles at the same time and place during the week after each accident. Of the 254 daytime cases, we successfully took pictures for 224 (88%) and identified 1,094 motorcycle riders in the pictures as street controls. Logistic regression analyses were used to determine the roles of the following variables in predicting risk of head injury: age, sex, riding position, weather, place of accident, helmet type, and motorcycle type, and status of helmet wearing. The relative risk of head injury among motorcycle riders was significantly reduced by wearing a full-face helmet, but not by wearing a full- or a partial-coverage helmet.