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Fish is the main source of animal protein and micronutrients for inhabitants in the lower Mekong River basin. Consumption of fish in the basin ranges from 41 to 51 kg capita(-1) year(-1). Thus, concerns of human health impacts caused by daily intake of metals contained in fish, and the incidence of bacterial contamination from Listeria and Escherichia coli have been raised. This study was conducted to 1) determine concentrations of metals, fecal indicator organisms, and Listeria spp. in cultivated common diet fish, and 2) assess human health risks as results of fish consumption on a daily basis. The results showed significant impacts of metal accumulation in fish especially from the intensive aquaculture. Chemical use to promote the rapid allometric growth of fish was expected to be the explanation for this finding. Concentrations of metals contained in different fish species were not statistically different with the exceptions of Na, Mn, and Zn. This might be due to the mobility of elements in aquaculture farms. Listeria and E. coli log CFU/g were 1.36 ± 0.11 (standard error) and 1.57 ± 0.1 s.e., respectively with higher counts observed in samples collected in market sites. Lastly, for human health risk assessment via fish consumption, it was found that hazard quotients of consuming As, Cu, and Zn contained in all fish species could contribute adverse health effects to the local residents (hazard quotients higher than 1). Therefore, risk management measures must be promoted and implemented in all study areas to reduce potential risks to local Vietnamese residents.
Penradee Chanpiwat; Suthipong Sthiannopkao; Kenneth Widmer; Seiichiro Himeno; Hideki Miyataka; Ngoc-Ut Vu; Van-Viet Tran; Thi-Tuyet-Ngan Pham. Assessment of metal and bacterial contamination in cultivated fish and impact on human health for residents living in the Mekong Delta. Chemosphere 2016, 163, 342 -350.
AMA StylePenradee Chanpiwat, Suthipong Sthiannopkao, Kenneth Widmer, Seiichiro Himeno, Hideki Miyataka, Ngoc-Ut Vu, Van-Viet Tran, Thi-Tuyet-Ngan Pham. Assessment of metal and bacterial contamination in cultivated fish and impact on human health for residents living in the Mekong Delta. Chemosphere. 2016; 163 ():342-350.
Chicago/Turabian StylePenradee Chanpiwat; Suthipong Sthiannopkao; Kenneth Widmer; Seiichiro Himeno; Hideki Miyataka; Ngoc-Ut Vu; Van-Viet Tran; Thi-Tuyet-Ngan Pham. 2016. "Assessment of metal and bacterial contamination in cultivated fish and impact on human health for residents living in the Mekong Delta." Chemosphere 163, no. : 342-350.
In the Mekong River basin, groundwater from tube-wells is a major drinking water source. However, arsenic (As) contamination in groundwater resources has become a critical issue in the watershed. In this study, As species such as total As (AsTOT), As(III), and As(V), were monitored across the watershed to investigate their characteristics and inter-relationships with water quality parameters, including pH and redox potential (Eh). The data illustrated a dramatic change in the relationship between AsTOT and Eh over a specific Eh range, suggesting the importance of Eh in predicting AsTOT. Thus, a Bayesian change-point model was developed to predict AsTOT concentrations based on Eh and pH, to determine changes in the AsTOT-Eh relationship. The model captured the Eh change-point (∼-100±15mV), which was compatible with the data. Importantly, the inclusion of this change-point in the model resulted in improved model fit and prediction accuracy; AsTOT concentrations were strongly negatively related to Eh values higher than the change-point. The process underlying this relationship was subsequently posited to be the reductive dissolution of mineral oxides and As release. Overall, AsTOT showed a weak positive relationship with Eh at a lower range, similar to those commonly observed in the Mekong River basin delta. It is expected that these results would serve as a guide for establishing public health strategies in the Mekong River Basin.
Yoonkyung Cha; Young Mo Kim; Jae-Woo Choi; Suthipong Sthiannopkao; Kyung Hwa Cho. Bayesian modeling approach for characterizing groundwater arsenic contamination in the Mekong River basin. Chemosphere 2016, 143, 50 -56.
AMA StyleYoonkyung Cha, Young Mo Kim, Jae-Woo Choi, Suthipong Sthiannopkao, Kyung Hwa Cho. Bayesian modeling approach for characterizing groundwater arsenic contamination in the Mekong River basin. Chemosphere. 2016; 143 ():50-56.
Chicago/Turabian StyleYoonkyung Cha; Young Mo Kim; Jae-Woo Choi; Suthipong Sthiannopkao; Kyung Hwa Cho. 2016. "Bayesian modeling approach for characterizing groundwater arsenic contamination in the Mekong River basin." Chemosphere 143, no. : 50-56.
The Chao Phraya River in Thailand has been greatly affected by climate change and the occurrence of extreme flood events, hindering its economic development. This study assessed the hydrological responses of the Chao Phraya River basin under several climate sensitivity and greenhouse gas emission scenarios. The Soil and Water Assessment Tool (SWAT) model was applied to simulate the streamflow using meteorological and observed data over a nine-year period from 2003 to 2011. The SWAT model produced an acceptable performance for calibration and validation, yielding Nash-Sutcliffe efficiency (NSE) values greater than 0.5. Precipitation scenarios yielded streamflow variations that corresponded to the change of rainfall intensity and amount of rainfall, while scenarios with increased air temperatures predicted future water shortages. High CO2 concentration scenarios incorporated plant responses that led to a dramatic increase in streamflow. The greenhouse gas emission scenarios increased the streamflow variations to 6.8%, 41.9%, and 38.4% from the reference period (2003–2011). This study also provided a framework upon which the peak flow can be managed to control the nonpoint sources during wet season. We hope that the future climate scenarios presented in this study could provide predictive information for the river basin.
Mayzonee Ligaray; Hanna Kim; Suthipong Sthiannopkao; Seungwon Lee; Kyung Hwa Cho; Joon Ha Kim. Assessment on Hydrologic Response by Climate Change in the Chao Phraya River Basin, Thailand. Water 2015, 7, 6892 -6909.
AMA StyleMayzonee Ligaray, Hanna Kim, Suthipong Sthiannopkao, Seungwon Lee, Kyung Hwa Cho, Joon Ha Kim. Assessment on Hydrologic Response by Climate Change in the Chao Phraya River Basin, Thailand. Water. 2015; 7 (12):6892-6909.
Chicago/Turabian StyleMayzonee Ligaray; Hanna Kim; Suthipong Sthiannopkao; Seungwon Lee; Kyung Hwa Cho; Joon Ha Kim. 2015. "Assessment on Hydrologic Response by Climate Change in the Chao Phraya River Basin, Thailand." Water 7, no. 12: 6892-6909.
Chemical analyses of metal (Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Mo, Ba, and Pb) concentrations in hair, nails, and urine of Cambodians in arsenic-contaminated areas who consumed groundwater daily showed elevated levels in these biomarkers for most metals of toxicological interest. The levels of metals in biomarkers corresponded to their levels in groundwater, especially for As, whose concentrations exceeded the WHO guidelines for drinking water. About 75.6% of hair samples from the population in this study contained As levels higher than the normal level in unexposed individuals (1 mg·kg−1). Most of the population (83.3%) showed As urinary levels exceeding the normal (<50 ng·mg−1). These results indicate the possibility of arsenicosis symptoms in residents of the areas studied. Among the three biomarkers tested, hair has shown to be a reliable indicator of metal exposures. The levels of As (r2 = 0.633), Ba (r2 = 0.646), Fe (r2 = 0.595), and Mo (r2 = 0.555) in hair were strongly positively associated with the levels of those metals in groundwater. In addition, significant weak correlations (p < 0.01) were found between levels of exposure to As and As concentrations in both nails (r2 = 0.544) and urine (r2 = 0.243).
Penradee Chanpiwat; Seiichiro Himeno; Suthipong Sthiannopkao. Arsenic and Other Metals’ Presence in Biomarkers of Cambodians in Arsenic Contaminated Areas. International Journal of Environmental Research and Public Health 2015, 12, 14285 -14300.
AMA StylePenradee Chanpiwat, Seiichiro Himeno, Suthipong Sthiannopkao. Arsenic and Other Metals’ Presence in Biomarkers of Cambodians in Arsenic Contaminated Areas. International Journal of Environmental Research and Public Health. 2015; 12 (11):14285-14300.
Chicago/Turabian StylePenradee Chanpiwat; Seiichiro Himeno; Suthipong Sthiannopkao. 2015. "Arsenic and Other Metals’ Presence in Biomarkers of Cambodians in Arsenic Contaminated Areas." International Journal of Environmental Research and Public Health 12, no. 11: 14285-14300.
Groundwater contamination with arsenic (As) is one of the major issues in the world, especially for Southeast Asian (SEA) countries where groundwater is the major drinking water source, especially in rural areas. Unfortunately, quantification of groundwater As contamination is another burden for those countries because it requires sophisticated equipment, expensive analysis, and well-trained technicians. Here, we collected approximately 350 groundwater samples from three different SEA countries, including Cambodia, Lao PDR, and Thailand, in an attempt to quantify total As concentrations and conventional water quality variables. After that, two machine learning models (i.e. artificial neural network (ANN) and support vector machine (SVM)) were applied to predict groundwater As contamination using conventional water quality parameters. Prior to modeling approaches, the pattern search algorithm in MATLAB software was used to optimize the ANN and SVM model parameters, attempting to find the best parameters set for modeling groundwater As concentrations. Overall, the SVM showed the superior prediction performance, giving higher Nash–Sutcliffe coefficients than ANN in both the training and validation periods. We hope that the model developed by this study could be a suitable quantification tool for groundwater As contamination in SEA countries.
Yongeun Park; Mayzonee Ligaray; Young Mo Kim; Joon Ha Kim; Kyung Hwa Cho; Suthipong Sthiannopkao. Development of enhanced groundwater arsenic prediction model using machine learning approaches in Southeast Asian countries. DESALINATION AND WATER TREATMENT 2015, 57, 12227 -12236.
AMA StyleYongeun Park, Mayzonee Ligaray, Young Mo Kim, Joon Ha Kim, Kyung Hwa Cho, Suthipong Sthiannopkao. Development of enhanced groundwater arsenic prediction model using machine learning approaches in Southeast Asian countries. DESALINATION AND WATER TREATMENT. 2015; 57 (26):12227-12236.
Chicago/Turabian StyleYongeun Park; Mayzonee Ligaray; Young Mo Kim; Joon Ha Kim; Kyung Hwa Cho; Suthipong Sthiannopkao. 2015. "Development of enhanced groundwater arsenic prediction model using machine learning approaches in Southeast Asian countries." DESALINATION AND WATER TREATMENT 57, no. 26: 12227-12236.
This study constitutes the first systematic risk assessment in the Lao PDR of the safety of groundwater for consumption. Groundwater and hair samples were collected from seven Lao provinces to determine the quantitative health impact of heavy metals through ingestion exposure. Contamination levels for arsenic (As; 46.0 %) and barium (Ba; 16.2 %) exceeded World Health Organization (WHO) guidelines, especially in Mekong River floodplains. A USEPA assessment model for health risks from daily groundwater ingestion, with adjustments for local water consumption values, was applied to estimate the size of the population at risk for noncarcinogenic and carcinogenic health problems. As was the only element contributing to noncarcinogenic health risks in all contaminated areas. The populations of Bolikhamxai, Savannakhet, Saravane, Champasak, and Attapeu, moreover, were at risks of cancer. In addition to the As groundwater concentration factor, noncarcinogenic and carcinogenic risks were positively correlated with the average daily dose of As, exposure duration, and subject body weight. The level of As in hair correlated with groundwater consumption and average daily dose of As. 25.5 % of the population (n = 228) showed As levels in hair above the toxicity level.
Penradee Chanpiwat; Byung-Tae Lee; Kyoung-Woong Kim; Suthipong Sthiannopkao. Human health risk assessment for ingestion exposure to groundwater contaminated by naturally occurring mixtures of toxic heavy metals in the Lao PDR. Environmental Monitoring and Assessment 2014, 186, 4905 -4923.
AMA StylePenradee Chanpiwat, Byung-Tae Lee, Kyoung-Woong Kim, Suthipong Sthiannopkao. Human health risk assessment for ingestion exposure to groundwater contaminated by naturally occurring mixtures of toxic heavy metals in the Lao PDR. Environmental Monitoring and Assessment. 2014; 186 (8):4905-4923.
Chicago/Turabian StylePenradee Chanpiwat; Byung-Tae Lee; Kyoung-Woong Kim; Suthipong Sthiannopkao. 2014. "Human health risk assessment for ingestion exposure to groundwater contaminated by naturally occurring mixtures of toxic heavy metals in the Lao PDR." Environmental Monitoring and Assessment 186, no. 8: 4905-4923.
Discarded electronic goods contain a range of toxic materials requiring special handling. Developed countries have conventions, directives, and laws to regulate their disposal, most based on extended producer responsibility. Manufacturers take back items collected by retailers and local governments for safe destruction or recovery of materials. Compliance, however, is difficult to assure, and frequently runs against economic incentives. The expense of proper disposal leads to the shipment of large amounts of e-waste to China, India, Pakistan, Nigeria, and other developing countries. Shipment is often through middlemen, and under tariff classifications that make quantities difficult to assess. There, despite the intents of national regulations and hazardous waste laws, most e-waste is treated as general refuse, or crudely processed, often by burning or acid baths, with recovery of only a few materials of value. As dioxins, furans, and heavy metals are released, harm to the environment, workers, and area residents is inevitable. The faster growth of e-waste generated in the developing than in the developed world presages continued expansion of a pervasive and inexpensive informal processing sector, efficient in its own way, but inherently hazard-ridden.
Suthipong Sthiannopkao; Ming Hung Wong. Handling e-waste in developed and developing countries: Initiatives, practices, and consequences. Science of The Total Environment 2013, 463-464, 1147 -1153.
AMA StyleSuthipong Sthiannopkao, Ming Hung Wong. Handling e-waste in developed and developing countries: Initiatives, practices, and consequences. Science of The Total Environment. 2013; 463-464 ():1147-1153.
Chicago/Turabian StyleSuthipong Sthiannopkao; Ming Hung Wong. 2013. "Handling e-waste in developed and developing countries: Initiatives, practices, and consequences." Science of The Total Environment 463-464, no. : 1147-1153.
We investigated the potential contamination of trace elements in shallow Cambodian groundwater. Groundwater and hair samples were collected from three provinces in the Mekong River basin of Cambodia and analyzed by ICP-MS. Groundwater from Kandal (n = 46) and Kraite (n = 12) were enriched in As, Mn, Ba and Fe whereas none of tube wells in Kampong Cham (n = 18) had trace elements higher than Cambodian permissible limits. Risk computations indicated that 98.7% and 12.4% of residents in the study areas of Kandal (n = 297) and Kratie (n = 89) were at risk of non-carcinogenic effects from exposure to multiple elements, yet none were at risk in Kampong Cham (n = 184). Arsenic contributed 99.5%, 60.3% and 84.2% of the aggregate risk in Kandal, Kratie and Kampong Cham, respectively. Sustainable and appropriate treatment technologies must therefore be implemented in order for Cambodian groundwater to be used as potable water.
Kongkea Phan; Samrach Phan; Laingshun Huoy; Bunseang Suy; Ming Hung Wong; Jamal Hisham Hashim; Mohamed Salleh Mohamed Yasin; Syed Mohamed Aljunid; Suthipong Sthiannopkao; Kyoung-Woong Kim. Assessing mixed trace elements in groundwater and their health risk of residents living in the Mekong River basin of Cambodia. Environmental Pollution 2013, 182, 111 -119.
AMA StyleKongkea Phan, Samrach Phan, Laingshun Huoy, Bunseang Suy, Ming Hung Wong, Jamal Hisham Hashim, Mohamed Salleh Mohamed Yasin, Syed Mohamed Aljunid, Suthipong Sthiannopkao, Kyoung-Woong Kim. Assessing mixed trace elements in groundwater and their health risk of residents living in the Mekong River basin of Cambodia. Environmental Pollution. 2013; 182 ():111-119.
Chicago/Turabian StyleKongkea Phan; Samrach Phan; Laingshun Huoy; Bunseang Suy; Ming Hung Wong; Jamal Hisham Hashim; Mohamed Salleh Mohamed Yasin; Syed Mohamed Aljunid; Suthipong Sthiannopkao; Kyoung-Woong Kim. 2013. "Assessing mixed trace elements in groundwater and their health risk of residents living in the Mekong River basin of Cambodia." Environmental Pollution 182, no. : 111-119.