Bor-Cheng Han

Daily intake of TBT, Cu, Zn, Cd and As for fishermen in Taiwan

The consumption of contaminated seafood has been reported as an important route of human exposure to metals in Taiwan. We consider the concentrations of TBT, Cu, Zn, Cd, As, and the consumption of oysters of Taiwanese to be the important information related to public health in Taiwan. Therefore, the aim of this study was to evaluate the public health risks associated with TBT, Cu, Zn, Cd and As from shellfish for the general population and fishermen of Taiwan. In general, TBT concentrations in various oysters ranging from 0.32 to 1.51 microg/g dry wt. varied with sampling locations. The highest TBT, Cu, and Zn geometric mean (GM) concentrations in oysters of 1.51, 1180 and 1567 microg/g dry wt. were obtained from the Hsiangshan coastal area. The values of oyster consumption for fishermen were 94.1 and 250 g/day for typically and maximally exposed individuals, respectively. In particular, the highest intake (250 g/day) from fishermen was almost two times greater than that of the general population (139 g/day). The THQ (target hazard quotient) values of Hsiangshans fishermen are 3.87 and 20.50 for TBT and Cu for maximally exposed individuals are higher than other oyster culture areas. It is interesting that those consuming oysters from Hsiangshan, Lukang, Taishi caused abnormally high THQs of TBT and other metals (100% over 1.0), and TBT was attributed to only 3-21% of the total THQs in different fishermen of Taiwan. Our results suggest that current environmental levels of TBT and other metals are associated with a significant potential threat to human health for fishermen resident in coastal areas of Taiwan.

Pharmacokinetic model of daily selenium intake from contaminated seafood in Taiwan

Contaminated seafood has been reported as an important source of human exposure to metals in Taiwan. Seafood represents a non-negligible source of selenium in the human diet. This study was designed to determine the concentration of selenium in different types of seafood and predict the concentration of selenium in the blood of Taiwanese using a one-compartment steady-state pharmacokinetic (PK) model. Samples involved three subgroups, including fish, crustaceans and bivalve molluscs. Quantitative analysis for selenium was performed using an ICP-AES (Perkin Elmer) instrument. Selenium concentrations in seafood ranged from 0.63 to 2.01 microg/g wet wt. The highest selenium concentration found in fish was 2.01+/-0.36 microg/g wet wt in Salmo salar Linnaeus. In general, selenium concentration increased in the order of bivalve molluscs<crustacean<fish. The daily selenium intakes resulting from a high-seafood diet and an average diet were 145.2 and 60.2 microg/day, respectively. Daily selenium intake from seafood alone is higher than the US recommended daily allowance (RDA) of 55 microg/day and the World Health Organization (WHO) normative requirement of 40 microg/day. From PK model estimates, the concentrations of selenium in the blood of a typical seafood consumer and a high-seafood consumer were approximately 93 and 224 microg/l based on daily seafood intake of 60.2 and 145.2 microg/day, respectively.

Leptin, Superoxide Dismutase, and Weight Loss: Initial Leptin Predicts Weight Loss

Objective: Our goal was to study how plasma leptin concentration, superoxide dismutase (SOD) activity, and weight loss are related in obese adults.

Monitoring lead pollution near a storage battery recycling plant in Taiwan, Republic of China

This study presents the distribution of blood lead levels and lead in various environmental samples (water, sediments, soils, and air) near the Shing-Yie storage battery recycling plant in Taiwan before (July 1990 to June 1991) and after (July 1992 to June 1993) amelioration. Before amelioration, the average blood lead levels in the neighborhood of the plant were in the range of 10.55±5.7 to 12.28±7.9 μg/dl. After amelioration, relatively lower average concentrations of blood lead (range 8.35±3.0 to 9.13±2.5 μg/dl) were generally found; however, these averages were still higher than that (7.79±3.5 μg/dl) from other lead-unpolluted areas of Taiwan. An exceedingly high geometric mean (GM) lead concentration (128 μg/L) was found in the downstream river water of the Tawulum River passing by the plant. The concentrations of lead (GM=372 and 418 μg/g) in the downstream river sediments were higher than those (GM=123 and 158 μg/g) in the upstream river sediments before and after amelioration, respectively. Furthermore, lead species in river sediments were analyzed by a sequential leaching technique. The sum of phases I, II, and III accounted for 83.7% of total lead at station R2 (nearest to the plant). Maximum lead concentration (GM=2402 μg/g) in dust at the soil surface from station S1 (nearest to the plant) was much higher than those from the other stations by about 18 times before amelioration. However, the maximum value dropped to 1,155 μg/g after amelioration. On the whole, the geometric mean concentration of lead in dust at the soil surface nearest to the plant was >1,000 μg/g and decreased to <100 μg/g in the 15–30 cm depth soil about 2 km away from the plant. Before amelioration, the geometric mean lead concentration of 4.57 μg/m3 (range 0.102–37.6 μg/m3) in the air near the plant was higher than that at the background locations, the geometric mean value of which was 0.08 μg/m3.

Decline in semen quality in men in Northern Taiwan between 2001 and 2010

Semen quality is a key indicator of the male reproductive ability. The decline in semen quality has been debated for several decades. However, data on decline in semen quality might be inconsistent given factors such as geographical area, ethnicity, environmental exposure and lifestyle changes. This study aimed to provide information on the semen quality of men in Northern Taiwanese. We recruited 7,187 male participants between 2001 and 2010 from a reproductive medical center. The age of the participants ranged from 26 to 57 years, with a mean age of 36.9 ± 4.77 years. Semen analysis was performed through standardized methods outlined in the World Health Organization laboratory manual. Increasing age (per year) was significantly and negatively associated with semen volume (1.006 ml), progressive sperm motility, rapid progressive sperm motility and sperm with normal morphology (reduction by 1.010%, 1.013% and 1.002% per year, respectively). In addition, sperm concentration, semen volume, number of sperms, progressive sperm motility, rapid progressive sperm motility, and sperm with normal morphology were significantly reduced annually by 1.013 × 10⁶/ml, 1.015 ml, 1.028 × 10⁶, 1.021 %, 1.017% and 1.016%, respectively). Age-period-cohort (APC) analyses revealed that age and cohort had effects on reduction of the progressive and rapid progressive sperm motility. Moreover, all the sperm parameter values were significantly reduced annually. Our findings provide useful information for clinical practice and public health investigations of male reproductive health.

Glutathione S-Transferase genotype may be a modifier on urothelial cell cycle in dyestuff manufacturing workers

Objectives In the past study, the latent period of bladder cancer caused by occupational exposure is 6 months to 40–8 years. Benzidine-based dyes have been produced and used in Taiwan until 1992. It can be expected that new patients with urothelial cancer in the near future. This study was designed to investigate the association of GSTT1, GSTM1 and GSTP1 genotype with the urothelial cells cycle in dye workers. Methods A cross-sectional study was designed to investigate the association between occupational exposure and cell cycle of urothelial epithelium. A total of 225 subjects who were working in a dyestuff-manufacturing factory, which established over 20 years and located at northern part of Taiwan, were sampled. A questionnaire was used to collect the demographical characteristics and work history. Urine and blood samples were also collected. The urinary epithelium cell cycle was analysed by flow cytometer. Polymorphisms of GSTM1 and GSTT1 genotype were identified by PCR, while polymorphism of GSTP1 was then followed by restriction enzyme length polymorphism technique. Results As a result of our study exhibited those who carries genotype of GSTM1 null and GSTT1 null would influence the DNA ploidy of urothelial cells to become abnormal under the exposure of benzidine. In smoking group, who carries genotype of GSTM1 null, GSTT1 null and slow GSTP1 would in higher risk of abnormal urothelial cells. Conclusions Polymorphisms of GSTM1, GSTT1 and GSTP1 genotype may be enhancing the association between occupational exposure and cell cycle of urothelial epithelium in dye manufacturing workers.

Normalization of Sedimentary Lipid Biomarker Concentrations to Total Organic Carbon in Principal Component Analysis

Abstract The objective of this study is to demonstrate the importance of normalizing lipid biomarker concentrations in sediment to total organic carbon (TOC) for principal component analysis (PCA) by using n-alkanols and aliphatic hydrocarbons in marine sediments collected from the East China Sea shelf off northern Taiwan. In performing PCA, logarithmically transformed data and z-score function transformed data along with the raw data were compared with TOC normalized data. Results show that the positions of n-alkanol variables in the loading plot using TOC normalized data are in good agreement with the organic geochemical knowledge in terms of sources. For aliphatic hydrocarbons, the positions of samples in the score plot using TOC normalized data are different from those using the raw data and z-score function transformed data. It is suggested that normalization of lipid biomarker concentrations with TOC be taken into consideration in performing PCA when the grain size distributions of sediments in a st...