Evaluating Surface Water Quality in Ninh Kieu District, Can Tho City, Vietnam

This study aimed to evaluate water quality in the canals in Ninh Kieu district, Can Tho city in the period of 2018-2019. Monitoring data were collected at 10 locations distributed on Tham Tuong canal (TT1, TT2), Cai Khe canal (CK1-CK4), Bun Xang lake (BX1-BX2), Cai Son - Hang Bang canal (HB1, HB2). Water quality parameters assessed include temperature, pH, turbidity, total suspended solids (TSS), biological oxygen demand (BOD), chemical oxygen demand (COD), orthophosphate (PO43--P), nitrate (NO3-- N), ammonia (NH4+-N), nitrite (NO2-- N) and coliforms. The results showed that water quality in the canals in Ninh Kieu district, Can Tho city were contaminated with coliforms, TSS, BOD, and COD. The temperature and pH parameters were very little fluctuated, while BOD, coliforms, and DO tended to decrease in the period from 2018-2019. Particularly, the mean P-PO43- in 2019 was higher than that in 2018. BOD, COD, TSS, P-PO43-, and coliforms in Tham Tuong canal were higher than those in other water bodies because several production and business activities are taking place. Water pollution problem in Ninh Kieu district, Can Tho city needs to be solved as soon as possible to ensure healthy environment, attracting tourists to visit in Can Tho city

Evaluating Current Water Quality Monitoring System on Hau River, Mekong Delta, Vietnam Using Multivariate Statistical Techniques

This study aims to assess the sampling sites and frequencies of sampling of the existing surface water quality monitoring on Hau River using multivariate analysis techniques. Principal Component Analysis (PCA) and Cluster Analysis (CA) were used to analyze the water quality monitoring data collected every month in 2018 from 8 sampling stations. Surface water quality parameters including pH, temperature, dissolved oxygen (DO), total suspended solids (TSS), nitrate (N-NO3-), phosphate (P-PO43-), chemical oxygen demand (COD) and coliforms were used in the PCA and CA analyses. The findings indicated that the Hau River water quality was polluted by TSS, COD and coliforms in which COD was high in dry season, TSS was high in wet season and coliforms were high all year round. The PCA revealed that pH, temperature, DO, TSS, N-NO3-, P-PO43-, COD and coliforms influenced on the water quality, therefore, relevant for examination in the water samples. These water quality variables were affected by various polluting sources, for examples, runoff, human activities, and hydrological influence. Cluster analysis suggested that the current monitoring program could be reduced from 8 to 3-4 points and 12 to 3-4 times per year. This monitoring program could save the total budget for up to 42%. The findings of the present study could be useful to the policy maker especially to those who are dealing with surface water monitoring systems. The multivariate statistical techniques could be used to assess the surface water quality monitoring network

Risks of Surface Water Pollution in Southern Vietnam

The study was carried out to assess surface water quality and ecological risks in water bodies in the southern region of Vietnam. The study used monitoring data at 58 locations, which were collected in March, May, June, July, August, October, November, and December of 2022, with 11 water quality parameters (temperature, pH, DO, TSS, BOD, COD, NH4+-N, NO3--N, Fe, Pb, and Cd). Comprehensive pollution index (CPI), ecological risk level, and multivariate statistical analysis methods were utilized. The values of CPI showed that the surface water quality was mildly polluted, moderately polluted, and severely polluted, accounting for 37.93, 46.93, and 15.52%, respectively. In particular, heavy pollution was concentrated in the water bodies of the Sai Gon and Vam Co Rivers. TSS, BOD, COD, NH4+-N, and Fe had a moderate to high level of risk, while water samples contaminated with NO3--N, Pb, and Cd had a level of risk from low to safe. High levels of risk were concentrated in the water bodies of the Sai Gon River and Vam Co River, typically BOD and COD. Based on the impact level, the positions were classified into five groups, with the locations on the Sai Gon River and Vam Co River (Groups 4 and 5) being affected by various waste sources in the inner city of Ho Chi Minh City. The PCA results presented three sources, such as discharge from residential areas, soil erosion, and agriculture, that have caused water quality fluctuations and increased the impact on the water quality of water bodies. Measures to protect water resources according to environmental protection laws must be implemented soon to minimize ecological risks from water-polluting sources. Doi: 10.28991/CEJ-2023-09-11-06 Full Text: PD

Recommending Surface Water Quality Monitoring for the Nature Reserve Using Multivariate Statistical Methods

Lung Ngoc Hoang Nature Reserve has a crucial role in conserving and protecting the natural ecosystem and biodiversity in the Mekong Delta, Vietnam, and the local communities also receive great benefits from aquatic resources in this nature reserve. This study was conducted to assess water quality in the Lung Ngoc Hoang Nature Reserve and to provide important information for the monitoring program using multivariate statistical methods. Water samples were collected bimonthly from fifteen locations belonging to five functional zones of the nature reserve (i.e., buffer zone, main canal, administrative and service zone, ecological restoration zone, and strictly protected zone). The physiochemical properties of water samples were measured, including temperature, pH, electrical conductivity (EC), total suspended solids (TSS), dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP), sulfate (SO42-), iron (Fe2+), and aluminum (Al3+). The results showed that the levels of TSS, COD, and Fe2+ exceeded the Vietnamese standard on surface water quality, and the DO level was also far below the standard. Besides, the concentrations of TN, TP, and Al3+ in the nature reserve area showed the risk of eutrophication and negative effects on aquatic organisms. Problems of water quality were observed in the main canal and the administrative and service zones more than in the other zones. Cluster analysis (CA) suggested a reduction in the number of monitoring frequencies and locations to four months (i.e., January, April, July, and September) and twelve locations, respectively. This reduction allows for a decrease in the effort and cost of the monitoring program with adequate information to evaluate water quality. Moreover, principal component analysis (PCA) identified five principal components, which could explain 80.98% of the total variance of the initial dataset. Potential pollution sources were also recognized based on PCA, including the nature properties of sulfate-acid soils, livestock, fertilizer, and domestic activities. The findings of this study can enhance our understanding of water quality in the nature reserve area and the effectiveness of future monitoring programs. Doi: 10.28991/CEJ-SP2023-09-015 Full Text: PD

Ecological Risk Associated with the Occurrence of Heavy Metals in Agricultural Soil in Soc Trang Province, Vietnam

The study aimed to evaluate the content and potential ecological risks due to the presence of toxic elements (Pb, Cu, Cr, Zn, As) in agricultural soil in Soc Trang province. Data of five heavy metals and physical factors at eight sites (from D1 to D8) in three ecological zones (fresh, brackish and saline agricultural activities) in the study were collected from the Department of Natural Resources and Environment of Soc Trang province. Multivariate statistical analyzes, including principal component analysis (PCA), correlation analysis (Pearson), cluster analysis (CA) and potential ecological risk index (RI), were used in the study. The results showed that the content of Pb, Cu, Cr, Zn and As fluctuated in the range of 8.54–30, 21.90–28.10, 20.60–38.70, 46.80–86, 1.35–11.30 mg/kg, respectively, within the allowable limits of QCVN 03-MT:2015/BTNMT. The soil in the study area has moderate to neutral acidity, suitable for growing crops. The Pearson and PCA results showed that the inputs in local agricultural development (fertilizers, pesticides, fungicides, and herbicides) have contributed to the increase of heavy metal content in the soil. The results of the CA grouped eight soil samples into two large groups belonging to the ecological areas (brackish, saline) and freshwater. The mean RI value of 68.84 indicated low potential ecological risks in agricultural land in Soc Trang province. However, As and Cr are heavy metals that would pose significant potential risks to the environment and humans. Thus, measures are needed to strictly control the sources of these metals

Seasonal Variations in Groundwater Quality under Different Impacts Using Statistical Approaches

The objective of this study was to evaluate seasonal fluctuations in groundwater quality, determine the effects of different stressors on this resource, and recognize the potential pollution sources in a coastal region of southern Vietnam. Eleven samples collected in Ben Tre province during the dry and wet seasons were then analyzed for sixteen parameters, including pH, total dissolved solids (TDS), salinity, total hardness (TH), ammonium (NH₄⁺-N), nitrite (NO₂ˉ-N), nitrate (NO₃ˉ-N), sulfate (SO₄²ˉ), chloride (Clˉ), iron (Fe), manganese (Mn), lead (Pb), mercury (Hg), arsenic (As), coliforms, and Escherichia coli (E. coli). Pearson correlation analysis, principal component analysis (PCA), and cluster analysis (CA) were employed. The results indicated that total dissolved solids, salinity, total hardness, Clˉ, E. coli and coliform were detected as contaminants in groundwater samples. The trend of fluctuations in the parameters was mostly higher in the dry season. Which Mn and coliform significantly fluctuated between the dry and wet seasons. Activities in industrial-craft areas, landfills and seawater-intruded areas negatively impacted groundwater quality, typically TDS in industrial-craft areas, coliform and E.coliat the landfill area. Six principal components obtained from PCA could explain 93.6% of the variance, and all parameters are responsible for variations in groundwater quality. Geology, discharged wastewater, landfill leachate, agricultural activities, and saltwater intrusion can be considered representative factors. CA grouped the collected samples into four clusters based on the similarity in water properties. The analysis results showed that the locations in each cluster have outstanding water quality characteristics, clusters I and III have high TDS characteristics, cluster II has coliforms, and cluster IV sets of locations with high salinity. This study is promised to partially fill the gap in comprehensive information on groundwater quality in the coastal province so that policymakers can develop sustainable water management strategies in the future. Doi: 10.28991/CEJ-2023-09-03-01 Full Text: PD

THE STATUS OF PARTICIPATION IN EXTRACURRICULAR SPORT TRAINING OF STUDENTS IN SOC TRANG PROVINCE, VIETNAM

The method of sociological investigation is used in the article to survey students' opinions at colleges in Soc Trang province and provided information on the status of participation in extracurricular sports of students at colleges in Soc Trang province by gender, ethnicity and purpose.  Article visualizations

Epidemiology and Clinical Features of Dengue Hemorrhagic Fever in Ho Chi Minh City and the Centre for Tropical Diseases; Viet Nam

Dengue haemorrhagic fever (DHF) is one of the major infectious diseases in Viet Nam. In the south of Viet Nam, DHF occurs all the year round. The number of DHF cases has been recorded as the greatest one among many countries in the world (1983: 77,087 cases and 1,301 deaths; 1987: 83,905 cases and 904 deaths). The DHF morbidity rate in children in south of Viet Nam was high (380.73/100,000 population in the 1983 epidemic and 378.37/100,000 population in the 1987 epidemic). The mortality rate in Ho Chi Minh city (1981-1990) is 1.05 (/100,000 population) and the mean mortality rate (/total of cases) is 0.55%. The majority of confirmed cases were children of 5-9 years old. In the DHF with shock, hepatomegaly relates to the severe grades. In the traetment of DHF without shock, patients were given fluid to drink on the first day to prevent shock