Yaw-Huei Hwang

Manganese induced parkinsonism: an outbreak due to an unrepaired ventilation control system in a ferromanganese smelter.

Several cases of parkinsonism were found in a ferromanganese smelter after the ventilation system had broken down and had not been repaired for eight months in 1985. To determine the aetiology and prevalence of parkinsonism, 132 workers were submitted to thorough medical examination and estimated air concentrations of carbon monoxide and manganese at different worksites. Only six of eight workers performing electrode fixation or welding during 1985 developed parkinsonism. They were exposed for 30 minutes each day, seven days a week, to high concentrations of air manganese (greater than 28.8 mg/m3). There was a consistent trend between the index of exposure to manganese and signs and symptoms exhibited by extrapyramidal systems. After repair of the ventilation system, the air concentration of manganese during electrode fixation and welding decreased to less than 4.4 mg/m3; furthermore, no new cases of parkinsonism have been observed. Workers with parkinsonism recovered partially after removal from original worksites and treatment with levodopa. It is concluded that the outbreak resulted from exposure to high concentrations of manganese fumes through the breakdown of the ventilation system.

Does prenatal cadmium exposure affect fetal and child growth

Objectives Cadmium is known to be a significant health hazard, but most information comes from studies of adults. The effects of exposure to cadmium during fetal life on early growth and development remain uncertain. In this study we investigated the placental transport of cadmium and the effects of prenatal cadmium exposure on fetal and child growth in Taiwan. Methods The data in this study were from a birth cohort study in Taiwan which started in 2004. Pregnant women were recruited from four hospitals and interviewed after delivery to collect information on themselves and their infants. Children were followed up to obtain information on growth up to 3 years of age. Whole blood cadmium concentrations in maternal and cord blood samples were measured and the relationship with birth size and growth assessed using linear regression and mixed models. Results 321 maternal blood samples and 402 cord blood samples were eligible for analysis. Among 289 pairs with maternal and cord blood suitable for measurement, the median cadmium concentration in cord blood (0.31 μg/l) was less than that in maternal blood (1.05 μg/l), with low correlation between the two (r=0.04). An increase in cord blood cadmium was found to be associated with newborn decreased head circumference and to be significantly and consistently associated with a decrease in height, weight and head circumference up to 3 years of age. Conclusions Placental transport of cadmium is limited. However, prenatal cadmium exposure may have a detrimental effect on head circumference at birth and child growth in the first 3 years of life.

Predicting health-related quality of life in patients with low back pain

Study Design. Cross-sectional surveys of health-related quality of life (HRQOL) in patients with low back pain at ambulatory clinics plus 8 weeks of follow-up. Objective. The objective of this study is to predict the HRQOL in patients with low back pain. Summary of Background Data. There is disagreement on the relative contribution of pain, physical impairment, functional status, and psychological factors on the disability and HRQOL in patients with low back pain. Methods. Data were collected from 232 patients with low back pain who were consecutively recruited from several clinics of physical medicine and rehabilitation. Every patient received physical examination and completed a set of questionnaire, including the Taiwan version of the Brief Questionnaire of the World Health Organization on quality of life (WHOQOL-BREF), Modified Roland and Morris Disability Questionnaire, and visual analogue scale for pain intensity and for HRQOL. These patients were observed with a mail questionnaire 8 weeks later. The results of WHOQOL-BREF were also compared to those obtained from another 213 healthy volunteers who were accompanied persons with patients, volunteer workers in hospitals, and hospital employees. Results. Results showed that there were significant correlations of HRQOL with pain intensity, disability scale, and disability days. Among the results of physical examination, lumbosacral radiculopathy was the only factor with moderate correlation with HRQOL. The significant predictors for HRQOL included physical domain, psychological domain, pain intensity, and family income. Among all the 232 study patients, 100 of them responded to thefollow-up questionnaire. Changes in environmental domain, disability days, educational level, receiving herb drugs, and physiotherapy were the significant predictors for the changes of HRQOL. Conclusions. The HRQOL of patients with low back pain depended on functional status and psychological factors more than simple physical impairment. Future intervention may need to put more emphasis on improving functional status and psychological stress for these patients.

Cardiopulmonary toxicity of pulmonary exposure to occupationally relevant zinc oxide nanoparticles.

Abstract Exposure to zinc oxide (ZnO) metal fumes is linked to adverse human health effects; however, the hazards of ZnO nanoparticles (ZnONPs) remain unclear. To determine pulmonary exposure to occupationally relevant ZnONPs cause cardiopulmonary injury, Sprague-Dawley rats were exposed to ZnONPs via intratracheal (IT) instillation and inhalation. The relationship between intrapulmonary zinc levels and pulmonary oxidative-inflammatory responses 72 h after ZnONP instillation was determined in bronchoalveolar lavage fluid (BALF). Instilled ZnONPs altered zinc balance and increased the levels of total cells, neutrophils, lactate dehydrogenase (LDH) and total protein in BALF and 8-hydroxy-2′-deoxyguanosine (8-OHdG) in blood after 72 h. The ZnONPs accumulated predominantly in the lungs over 24 h, and trivial amounts of zinc were determined in the heart, liver, kidneys and blood. Furthermore, the inflammatory-oxidative responses induced by occupationally relevant levels of 1.1 and 4.9 mg/m3 of ZnONP inhalation for 2 weeks were determined in BALF and blood at 1, 7 and 30 days post-exposure. Histopathological examinations of the rat lungs and hearts were performed. Inhalation of ZnONP caused an inflammatory cytological profile. The total cell, neutrophil, LDH and total protein levels were acutely increased in the BALF, and there was an inflammatory pathology in the lungs. There were subchronic levels of white blood cells, granulocytes and 8-OHdG in the blood. Cardiac inflammation and the development of fibrosis were detected 7 days after exposure. Degeneration and necrosis of the myocardium were detected 30 days after exposure. The results demonstrate that ZnONPs cause cardiopulmonary impairments. These findings highlight the occupational health effects for ZnONP-exposed workers.

In utero exposure to environmental lead and manganese and neurodevelopment at 2 years of age.

BACKGROUND AND OBJECTIVE Manganese, lead, arsenic and mercury are common neurotoxic metals in the environment. Nonetheless, the relationship between prenatal exposure to low doses of neurotoxic metals and neurodevelopment in children is not clear. The objective of this study was to explore the relationship between in utero exposure to environmental neurotoxic metals and neurodevelopment at 2 years of age. METHODS The population of this study came from the Taiwan Birth Panel Study. We included 230 pairs of non-smoking mothers without any occupational exposure and their singleton full-term children. The information about exposure during pregnancy was obtained using a structured questionnaire, and the manganese, lead, arsenic and mercury levels in umbilical cord blood samples were analyzed using inductively coupled plasma mass spectrometry. We used the Comprehensive Developmental Inventory for Infants and Toddlers (CDIIT) to evaluate the developmental status of each child at 2 years of age, and we examined the association of in utero exposure to environmental metals and neurodevelopment using linear regression models. RESULTS The median concentrations of manganese, lead, arsenic and mercury in the cord blood samples in this study were 47.90 µg/L (range, 17.88-106.85 µg/L), 11.41 µg/L (range 0.16-43.22 µg/L), 4.05 µg/L (range, 1.50-12.88 µg/L) and 12.17 µg/L (range, 1.53-64.87 µg/L), respectively. After adjusting for maternal age, infant gender, environmental tobacco smoke during pregnancy and after delivery, Home Observation for Measurement of the Environment Inventory results, and arsenic and mercury levels in cord blood, we found that manganese and lead levels above the 75th percentile had a significant adverse association with the overall (β=-7.03, SE=2.65, P=0.0085), cognitive (β=-8.19, SE=3.17, P=0.0105), and language quotients (β=-6.81, SE=2.73, P=0.0133) of the CDIIT. CONCLUSIONS In utero exposure to environmental manganese and lead may have an adverse association with neurodevelopment at 2 years of age, and there is an interaction effect between the manganese and lead levels in the cord blood that could aggravate the effect.

Possible association between nickel and chromium and oral cancer: A case–control study in central Taiwan

Oral cancer is one of the most common cancers in Taiwan. Changhua County, in central Taiwan, has an extremely high prevalence of oral cancer, along with a high concentration of metal-related industries and soil metal contamination. The aim of this study was to clarify the possible association between metals and oral cancer within this specific area. This study recruited 101 oral cancer patients and 104 controls from the Changhua Christian Hospital. All subjects completed a questionnaire that asked about demographic information; cigarette, alcohol, and betel quid use; and environmental and occupational exposure history. Blood samples were collected and tested for metal concentrations with inductively coupled plasma mass spectrometry. A multiple logistic regression model illustrated that oral cancer was significantly associated with the blood levels of nickel and chromium (both with P<0.0001) after controlling for potential confounders. This study suggested a potential role of these two metals in the mechanism of oral cancer development.

Effects of chlorination and heat disinfection on long-term starved Legionella pneumophila in warm water.

Aims:  To characterize the efficacy of widely accepted heat and chlorination on culturable and non‐culturable Legionella pneumophila in starved and warm water.

Effect of gestational smoke exposure on atopic dermatitis in the offspring

The adverse impact of smoking on respiratory diseases and birth outcomes in children is well‐known. However, the influence of smoke exposure including environmental tobacco smoke (ETS) and maternal smoking during pregnancy on atopic dermatitis (AD) is not clear. The purpose of this study was to evaluate the effect of gestational smoke exposure on the development of AD in the offspring on the basis of the maternal and cord blood cotinine. We recruited 261 mother and newborn pairs in 2004. Cord blood and information on perinatal factors of children were gathered at birth. At 2 yr of age, information about development of AD and environmental exposures were collected. We compared AD with non‐AD children for the concentration of cotinine in cord and maternal blood measured by high performance liquid chromatography–mass spectrometry. Multiple logistic regressions were performed to estimate the relationship of cotinine levels and AD. About 150 mother and child pairs completed the follow‐up study and specimen collection with 38 (25.3%) children developing AD. Two (1.3%) out of 150 mothers smoked during pregnancy, while 38 (25.3%) mothers reported having ETS exposure. Cotinine levels in cord blood and maternal blood were highly correlated (r = 0.71, p < 0.001). The risk of AD was found to increase with maternal and cord blood cotinine levels in a dose–response manner (p for trend = 0.01). Children exposed to high levels (>75th percentile) had a significantly increased risk of AD. Smoke exposure during pregnancy might increase the risk of AD in children. Avoidance of prenatal smoke exposure may be warranted for early prevention.

Urinary arsenic excretion as a biomarker of arsenic exposure in children

Urinary arsenic concentration has been used generally for the determination of exposure, but much concern has been raised over the most appropriate expression for urinary arsenic levels. In this study, we examined the influence of various adjustments of expressing urinary arsenic data. All children who were less than 72 mo of age and who were potty trained were invited to participate in the present study. Urine, soil, and dust samples were collected, and arsenic measurements were made. The geometric mean of speciated urinary arsenic among children who provided first-voided urine samples on 2 consecutive mornings was 8.6 microg/l (geometric standard deviation = 1.7, n = 289). Speciated urinary arsenic was related significantly to soil arsenic in bare areas (p < .0005). Use of a single urine sample versus the average of two first-voided urine samples collected on 2 consecutive mornings did not significantly alter the relationship between environmental arsenic and urinary arsenic levels. Furthermore, none of the adjustments to urinary concentration improved the strength of correlation between urinary arsenic and soil arsenic levels. Concentration adjustments may not be necessary for urinary arsenic levels obtained from young children who provide first-void samples in the morning.

Lead Contamination around a Kindergarten near a Battery Recycling Plant

Lead poisoning has been noticed for more than a thousand years. Increased lead absorption and/or impaired neurobehavioral function among children who lived nearby lead smelters were reported in many different countries. In November of 1987, a worker from a lead battery recycling smelter suffered from anemia and bilateral weakness of his extremities. He was diagnosed as lead poisoning at the National Taiwan University Hospital (NTUH). A subsequent epidemiological survey of the workers from this recycling smelter showed that 31 out of 64 who came for a medical examination suffered from lead poisoning. Since there was a kindergarten next to the factory, we performed this study to determine whether there was an increased lead absorption among children of the exposed kindergarten and its association with the extent of air and soil pollution in the surrounding area. 12 refs., 1 fig., 4 tabs.