Waters Of Taiwan Research Articles

Myxine formosana , a new species of hagfish (Myxiniformes: Myxinidae) from the southwestern waters of Taiwan

Myxine formosana, a new hagfish species, is described on the basis of the specimens from the Pacific Ocean southwest of Taiwan at depths 588–1500 m. It is five-gilled and white-headed with a three-cusp multicusp on the anterior set of cusps and a two-cusp multicusp on the posterior set. Myxine formosana, M. circifrons, M. mccoskeri, and M. robinsi are superficially rather similar, but M. formosana has low to vestigal caudal finfolds. It is the first record of the genus Myxine from Taiwan.

Color effects of lures on the hooking rates of mackerel longline fishing

SUMMARY: This study attempts to understand the color effects of artificial lures on the hooking rate of mackerel longline fisheries in Taiwan waters. From the results obtained from field work, the order of hooking rates from the different colored lures was red > black > yellow-green > yellow-orange = reddish orange = pink > white > blue > purple > transparent. Transparent, purple and blue lures had the smallest hooking rates and showed significant differences (least significant difference test) from the other colored lures. However, no significant differences could be found among the hooking rates of the other colored lures. In addition, the lumiunous reflectance of nine different gray lures did not show any significant difference in the hooking rates. Therefore, it is likely that the ‘spectral’ (colored) effects are the major influence causing the differences in hooking rates and the luminous effects play only a minor role in artificial lures.

Feasibility of using metals to remediate water containing TCE

The feasibility of treating underground water contaminated by a chlorinated organic compound with bimetallics Fe/Ni, Zn/Ni and Zn single metal was studied. Column tests to simulate a reactive permeable wall in a funnel-and-gate system were used. Research results indicated that bimetallic Fe 0/Ni 0 and Zn 0/Ni 0 all had a very strong degraded power to trichloroethylene (TCE ) at concentration up to 25 mg/l under different flow rates (27 cm/day–20 m/day). Furthermore, the concentrations of TCE and various ions in the treated effluent were nearly lower than the values specified in related standards for drinking water in Taiwan. These results showed that this technique could be effectively and safely used as an underground water remediation process.

Estimation of Potential Lifetime Cancer Risks for Trihalomethanes from Consuming Chlorinated Drinking Water in Taiwan

Data on concentrations of trihalomethanes (THMs) in raw and chlorinated water collected from three water treatment plants in Taiwan and estimates of the lifetime cancer risk for THMs from drinking water, using age-adjusted factors and volatilization terms, are presented. Data on THM levels in drinking water were obtained from the annual reports of the Environmental Protection Administration (EPA) of Taiwan. The methodology for estimation of lifetime cancer risks was taken from the USEPA. Chloroform was the major species of THMs, especially in the water plant of south Taiwan. Chloroform contributed the majority of the lifetime cancer risks (range: 87.5–92.5%) of total risks from the three water supply areas. All lifetime cancer risks for CHCl3, CHBrCl2, CHBr2Cl, and CHBr3 from consuming tap water in the three water supply areas were higher than 10−6. The sum of lifetime cancer risks for CHCl3, CHBrCl2, CHBr2Cl, and CHBr3 was highest (total risk for total THMs<1.94×10−4) for tap water from south Taiwan.

Spatio-temporal distribution of sergestid shrimp Acetes intermedius in the coastal waters of southwestern Taiwan

SUMMARY: Spatio-temporal variation of the sergestid shrimp Acetes intermedius in the coastal waters of southwestern Taiwan was investigated based on 1546 samples collected by 13 commercial fishing vessels from July to October 1996. Adult sergestid shrimp started a down-estuary migration with the increased river discharge associated with heavy summer rainfall. Fishing season for this species was to commence after that. In July, the shrimp stock was found on the shallow continental shelf off Tungkang and Fangshan. They mainly aggregated in Kaoping Canyon off Tungkang during August and September occurring at very high densities. In October, the shrimp returned to the coastal waters off Tungkang and Fangshan at lower densities. The heavy rainfall is a factor that triggers the shrimps to make a down-estuary migration that could reduce competition for food between adults and their offspring during the period of high river discharge. When the northeast monsoon prevailed, the sergestid shrimp moved back to the estuaries and the fishing season was terminated.

Evaluation of two concentration methods for detecting Giardia and Cryptosporidium in water

The cartridge filtration method and membrane filtration method based on the fluorescent antibody procedure were evaluated for their recovery efficiencies and detection limits of Giardia and Cryptosporidium. We assessed the performances of the two concentration methods for water samples collected from Taiwan water treatment plants. The membrane filtration method was characterized by higher recovery rate and detection limit comparing with the cartridge filtration method. The occurrences of both parasites, and the relationships of parasite concentrations with indicator microorganisms show inconsistency between the two methods. It was discovered that water turbidity reduced the recovery efficiencies, and raised the detection limits for both parasites regardless of the method used.

GPS observations of PW during the passage of a typhoon

The Global Positioning System (GPS) is used to provide hourly measurements of precipitable water (PW) in Taiwan during the passage of tropical cyclones. Typhoon Zeb, which caused serious damage in the Philippines, Taiwan, and Japan in mid-October 1998, is used as an example in this paper. GPS data are analyzed from the Central Weather Bureau’s (CWB’s) three weather stations in Taiwan, and from a site in Tsukuba, Japan. Bernese version 4.0 software is utilized to solve GPS signals for total delay due to the neutral atmosphere at the three CWB sites. Wet delay is obtained by subtracting surface pressure derived dry delay from total delay. Wet delay is then converted to PW through a simple calculation. GPS-observed PW time series demonstrate that PW is, in general, high before and during the occurrence of the typhoon, and low after the typhoon. PW increased from about 5 cm on DoY 285 (October 13) to near 8 cm or so on DoY 288 (October 16) when the typhoon was striking Taiwan, and, then, decreased to 2–3 cm after passage of the typhoon. In addition, GPS-observed PW depletion from 8 cm on DoY 288 to about 3 cm on DoY 290 is found to be consistent with radiosonde observations acquired at the Taipei weather station.

CHLORINATION OF DRINKING WATER AND SEX RATIO AT BIRTH IN TAIWAN

Chlorination has been the major strategy for disinfecting drinking water in Taiwan. The objective of the present study was to determine whether the chlorination of drinking water was associated with abnormal sex ratios, an indicator of exposure to pollutants. A "chlorinating municipality" (CHM) was defined as one in which more than 90% of the municipality population was served with chlorinated water. A "nonchlorinating municipality" (NCHM) was one in which less than 5% of the municipality population was served with chlorinated water. The results of this study found no association between the use of chlorinated drinking water and abnormal sex ratios at birth in Taiwan. The imbibing of chlorinated water may not reflect contaminant exposure using sex ratio as a biomonitor.

Association between Chlorination of Drinking Water and Adverse Pregnancy Outcome in Taiwan

Chlorination has been the major means of disinfecting drinking water in Taiwan. The use of chlorinated water has been hypothesized to lead to several adverse birth outcomes, including low birth weight and preterm delivery. We performed a study to examine the relationship between the use of chlorinated water and adverse birth outcomes in Taiwan. The study areas included 14 chlorinating municipalities (CHMs), which were defined as municipalities in which &gt; 90% of the municipal population was served by chlorinated water, and 14 matched nonchlorinating municipalities (NCHMs), defined as municipalities in which &lt; 5% of the municipal population is served by chlorinated water. The CHMs and NCHMs were similar to one another in terms of level of urbanization and sociodemographic characteristics. The study population comprised 18,025 women residing in the 28 municipalities who had a first parity singleton birth between 1 January 1994 and 31 December 1996 and for which complete information on maternal age, education, gestational age, birth weight, and sex of the baby were available. The results of our study suggest that there was no association between consumption of chlorinated drinking water and the risk of low birth weight.

Association between chlorination of drinking water and adverse pregnancy outcome in Taiwan.

Chlorination has been the major means of disinfecting drinking water in Taiwan. The use of chlorinated water has been hypothesized to lead to several adverse birth outcomes, including low birth weight and preterm delivery. We performed a study to examine the relationship between the use of chlorinated water and adverse birth outcomes in Taiwan. The study areas included 14 chlorinating municipalities (CHMs), which were defined as municipalities in which > 90% of the municipal population was served by chlorinated water, and 14 matched nonchlorinating municipalities (NCHMs), defined as municipalities in which < 5% of the municipal population is served by chlorinated water. The CHMs and NCHMs were similar to one another in terms of level of urbanization and sociodemographic characteristics. The study population comprised 18,025 women residing in the 28 municipalities who had a first parity singleton birth between 1 January 1994 and 31 December 1996 and for which complete information on maternal age, education, gestational age, birth weight, and sex of the baby were available. The results of our study suggest that there was no association between consumption of chlorinated drinking water and the risk of low birth weight.

CALCIUM AND MAGNESIUM IN DRINKING WATER AND THE RISK OF DEATH FROM BREAST CANCER

The relationship between mortality from breast cancer and the levels of calcium and magnesium in drinking water was examined using an ecological design. The study area consisted of 252 municipalities in Taiwan. Data on the levels of calcium and magnesium in drinking water were collected from the Taiwan Water Supply Corporation (TWSC). The age-standardized mortality rate (ASR) for breast cancer (1982?1991) was compared among municipalities with different levels of magnesium and calcium in drinking water. Weighted multivariate regression analysis was used, and after adjusting for fertility rates and urbanization, there was a significant inverse relationship between the levels of calcium and magnesium in drinking water and risk of death from breast cancer.

CALCIUM AND MAGNESIUM IN DRINKING WATER AND RISK OF DEATH FROM PROSTATE CANCER

The possible association between the increased risk of prostate cancer and the levels of calcium and magnesium in drinking water from municipal supplies was investigated in a matched cancer case-control study in Taiwan. All eligible prostate-cancer deaths (682 cases) of Taiwan residents from 1987 through 1993 were compared with deaths from other causes (682 controls). The levels of calcium and magnesium in the drinking water of these residents were also determined. Data on calcium and magnesium levels in drinking water throughout Taiwan were obtained from the Taiwan Water Supply Corporation (TWSC). The control group consisted of people who died from other causes, and the controls were pair-matched to the cases by year of birth and death. The adjusted odds ratios for prostate cancer death for those with higher magnesium levels in their drinking water, as compared to the lowest tertile, were 0.73 (95% CI = 0.51?1.03) and 0.64 (95% CI = 0.43?0.96), respectively. The adjusted odd ratios for the relationship between calcium levels in drinking water and prostate cancer were not statistically significant. The results of the present study show that there may be a significant protective effect of magnesium intake from drinking water and other dietary sources against the risk of prostate cancer development.

Clues and uncertainties in the risk assessment of arsenic in drinking water

On the basis of studies of the prevalence of skin cancer among users of As-rich well water in Taiwan, WHO experts recommended in 1984 a maximum As concentration of 50 μg/litre in drinking water. Since that time, a plethora of non-cancer as well as cancer effects has been observed in several other populations sustaining a chronic exposure to various As concentrations in drinking water. This prompted a revision of the standard and a provisional guideline of 10 μg/litre was recommended in 1993. While the uncertainty linked to the statistical inferences leading to the guideline are reduced by the fact that they are directly estimated from human data and result from extrapolations made relatively close to observed exposure levels, developed guideline depends strongly on the choice of the dose–response model (linear, quadratic, hockey-stick) and the accuracy of the exposure data. The potential exposure to As sources other than drinking water, dietary habits and genetic characteristics of the populations may also make more difficult the inference of a recommendation for As concentration in drinking water. Owing to the huge cost of strongly reducing the current As in water standard, many efforts are presently made to clarify the quantitative aspects of As-induced cancers, particularly at low dose levels. New data on the metabolism and carcinogenic mechanism of As in humans along with the results of epidemiological studies presently under way in several countries will help to reduce the uncertainty in the risk assessment of As.

Fluoride in Drinking Water and Cancer Mortality in Taiwan

The possibility that cancer risk is associated with naturally fluoridated water in Taiwan is examined. The 1982–1991 age-adjusted mortality rates for cancer for 10 municipalities whose water supplies contained the highest naturally occurring fluoride concentrations in Taiwan were compared to those rates for 10 matched municipalities with unfluoridated water. The two groups had similar urbanization levels and sociodemographic characteristics. Our study does not support the suggestion that fluoridation of water supplies is associated with an increase in cancer mortality in Taiwan.

Feasibility of utilizing Rhizoclonium in pulping and papermaking.

Material of Rhizoclonium from brackish water in Taiwan was investigated for its possible use in pulping and papermaking. After beating, this filamentous alga produced a pulp with a length to width ratio of about 10, much less than that of a typical wood pulp. Handsheets made from this pulp had a moderate breaking length of 4.02 km. Cooking pre-beaten pulp with a low chemical charge (5–25%NaOH) at a low cooking temperature (100 °C), and for a short time (30–120 min) gave high algal pulp yields (70–80%). This cooking process was sulfur-free, but the water requirement was high. After cooking and further caustic soda and bleaching treatments, wide-angle X-ray diffraction and FTIR spectroscopy showed that the crystallinity of the algal pulp increased substantially, but type I cellulose conformation was retained. The best pulp mechanical strengths (breaking length 5.23 km,zero-span tensile strength 79.2 Nm g-1, bursting index of 2.2 kpa m2 g-1) were obtained after cooking for 1 h with 20% NaOH. Because of the morphological characteristics of the algal strands, the pulp generally lacked bursting, tearing and folding strengths, but proper blending with softwood pulp increased the tensile breaking length to8.40 km, the tearing index to 14.5 mNm2 g-1, the bursting index to 6.42 kpam2 g-1 and the folding endurance to 4299 double folds, i.e. levels comparable to a typical kraft pulp. The algal pulp thus showed clear potential as a supplement for traditional medium strength wood pulps.

Inhalation exposure to THMs from drinking water in south Taiwan

Trihalomethanes (THMs) are important disinfection byproducts (DBPs) in drinking water. To understand the magnitude of exposure to THMs for the people in southern Taiwan, models are used to estimate the inhalation exposure associated with drinking water based on raw water quality. Two parts of models are used in this study, one for estimating THM concentration from raw water quality, and one for estimating inhalation exposure to people. Important raw water quality and operational parameters, including TOC, UV254, pH, temperature, chlorine dosage, and water residence time of a major water treatment plant in south Taiwan were collected. An empirical THM formation model was then employed to predict the THM concentration at consumers’ dwellings based on the parameters collected. Differences between the predicted results and experimental data were found to be small, indicating that the model is appropriate. The predicted THM concentration distribution was served as input parameters for the exposure models. Three major scenarios associated with probable inhalation exposure of THMs, including shower, pre- and post-cooking activities, and cooking processes, were considered in the exposure models. The model results show that the mean inhalation exposure of THMs for shower, pre- and post-cooking activities, and cooking processes are 26.4, 1.56, 3.29 μg/day, respectively. The total inhalation exposure (summation of the three scenarios) was found to be comparable with that for direct ingestion, indicating that inhalation is an important pathway for THM exposure from drinking water.

Esophageal Cancer Mortality and Total Hardness Levels in Taiwan's Drinking Water

The possible association between the risk of esophageal cancer and hardness levels in drinking water from municipal supplies was investigated in a matched case-control study in Taiwan. All eligible esophageal cancer deaths (2084 cases) of Taiwan residents from 1987 through 1996 were compared with deaths from other causes (2084 controls), and the hardness levels of the drinking water used by these residents were determined. Data on water hardness throughout Taiwan have been collected from the Taiwan Water Supply Corporation (TWSC). The control group consisted of people who died from other causes and the controls were pair-matched to the cases by sex, year of birth, and year of death. The results show that there is a 42% excess risk of mortality from esophageal cancer in relation to the use of soft water (adjusted odds ratio and 95% confidence intervals was 1.42 (1.22–1.66). This is an important finding for the Taiwan water industry and human health.

Biomass distribution and zooplankton composition of the sound-scattering layer in the waters of southern East China Sea

Fuzzy classification was used to analyse hydroacoustic survey data (Sv, an acoustic volume backscattering strength index of biomass) and oceanographic data (temperature, salinity, water density, and chlorophyll a fluorescence) collected from the waters of the southern East China Sea off northeastern Taiwan. Four types of water masses were identified. Type A water mass corresponded to warm continental-shelf mixed water and had a high acoustic volume backscatter (Sv>59.37 dB). Type D corresponded to cold upwelling Kuroshio subsurface water with Sv<65.24 dB, i.e. about 6 dB lower than that of Type A. Type B and C waters were intermediate between Type A and D waters. Twenty-two IKMT (net) samples were taken, and their estimated biomasses showed a significant relationship to corresponding average Sv values. Copepoda were most dominant in the zooplankton community. Decapoda, appendicularia, and chaetognatha were abundant in Type A waters, and proportionally rarer in the other three types of water masses. Conversely, the percentage contribution made by ostracoda and gastropoda was greater in Type D waters than in Type A waters. The combination of IKMT net sampling and hydroacoustic measurements was found to be useful for assessing the biomass distribution and species composition of zooplankton. We also conclude that the fuzzy classification method used here can usefully be applied to hydroacoustic data for the classification and identification of water masses and zooplankton composition in the ocean, particularly in an upwelling area. 1999 International Council for the Exploration of the Sea

Development and implementation of source water quality standards in Taiwan, ROC

The Environmental Protection Administration of ROC (ROCEPA) is seeking cost-effective alternatives to meet the drinking water standards. The alternatives include promulgating more stringent regulations to protect the drinking water sources and/or constructing advanced water treatment plants to comply with the requirements of drinking water standards. The objectives of this research were first to develop a rationale for selecting representative water quality parameters and then determining their respective contaminant level (or regulated value) for the source water quality standards in Taiwan, ROC. The implementation plans are proposed to achieve the goal of safe drinking water in Taiwan.

Calcium and magnesium in drinking water and the risk of death from hypertension

Many studies have demonstrated a negative association between blood pressure and calcium and magnesium levels. This report examines whether calcium and magnesium in drinking water are protective against hypertension. All eligible hypertension deaths (2336 cases) of Taiwan residents from 1990 through 1994 were compared with deaths from other causes (2336 controls), and the levels of calcium and magnesium in the drinking water of these residents were determined. Data on calcium and magnesium levels in drinking water throughout Taiwan have been obtained from the Taiwan Water Supply Corporation. The control group consisted of people who died from other causes and the controls were pair matched to the cases by sex, year of birth, and year of death. Magnesium levels in drinking water were inversely related to the risk of death from hypertension. The adjusted odds ratios (95% confidence interval) for the highest versus lowest quintiles of exposure was 0.63 (0.47 to 0.84). After adjustment for magnesium levels in drinking water, there was no difference between the groups with different levels of calcium. The results of the present study show that there is a significant protective effect of magnesium intake from drinking water on the risk of hypertension. This is an important finding for the Taiwan water industry and human health.