Previously unrecognized potential threat to children from manganese in groundwater in rohingya refugee camps in Cox's Bazar, Bangladesh

Geogenic manganese and iron in groundwater of Southeast Asia and Bangladesh - Machine learning spatial prediction modeling and comparison with arsenic

Naturally occurring, geogenic manganese (Mn) and iron (Fe) are frequently found dissolved in groundwater at concentrations that make the water difficult to use (deposits, unpleasant taste) or, in the case of Mn, a potential health hazard. Over 6000 groundwater measurements of Mn and Fe in Southeast Asia and Bangladesh were assembled and statistically examined with other physicochemical parameters. The machine learning methods random forest and generalized boosted regression modeling were used with spatially continuous environmental parameters (climate, geology, soil, topography) to model and map the probability of groundwater Mn > 400 μg/L and Fe > 0.3 mg/L for Southeast Asia and Bangladesh. The modeling indicated that drier climatic conditions are associated with a tendency of elevated Mn concentrations, whereas high Fe concentrations tend to be found in a more humid climate with elevated levels of soil organic carbon. The spatial distribution of Mn > 400 μg/L and Fe > 0.3 mg/L was compared and contrasted with that of the critical geogenic contaminant arsenic (As), confirming that high Fe concentrations are often associated with high As concentrations, whereas areas of high concentrations of Mn and As are frequently found adjacent to each other. The probability maps draw attention to areas prone to elevated concentrations of geogenic Mn and Fe in groundwater and can help direct efforts to mitigate their negative effects. The greatest Mn hazard is found in densely populated northwest Bangladesh and the Mekong, Red and Ma River Deltas of Cambodia and Vietnam. Widespread elevated Fe concentrations and their associated negative effects on water infrastructure pose challenges to water supply. The Mn and Fe prediction maps demonstrate the value of machine learning for the geospatial prediction modeling and mapping of groundwater contaminants as well as the potential for further constituents to be targeted by this novel approach.

Climate Risks and Truncated Opportunities: How Do Environmental Challenges Intersect with Economic and Social Disadvantages for Rohingya Adolescents in Bangladesh?

Integration of environmental, economic, and social approaches to development is crucial to achieve the United Nations Sustainable Development Goals. Global evidence reflects that this integration is often imbalanced, with development policies and programs in many low- and middle-income countries placing greater emphasis on economic needs than environmental vulnerabilities. Drawing on qualitative research undertaken in mid-2021, this article explores how limited integration of environmental, economic, and social aspects has affected the development of Rohingya refugee adolescents who were forcibly displaced from Myanmar to the Cox’s Bazar district of Bangladesh. Cox’s Bazar is one of the most climate-vulnerable areas in Bangladesh and is subject to extreme rainfall, landslides, and flash floods. The article highlights the ways in which Rohingya adolescents are highly vulnerable to both the direct and indirect consequences of these environmental conditions due to poverty, and inadequate housing infrastructure and water, sanitation, and hygiene facilities. It discusses the ways in which these environmental challenges intersect with socioeconomic disadvantage, especially limited education, skills development, and livelihood opportunities for young people, which are in turn compounded by limited voice and agency, and a dearth of security and protection measures. For some Rohingya adolescent girls and boys, the findings suggests that these multi-dimensional vulnerabilities place them at risk of exploitation by traffickers, smugglers, extremist groups, and criminals. The article concludes by highlighting the importance of explicitly integrating environmental aspects into policy and programs that support Rohingya adolescents to develop their full capabilities, and encouraging their meaningful participation in policy dialogues and accountability processes.

Characterization of drinking groundwater quality in rural areas of Inner Mongolia and assessment of human health risks

Groundwater is an important natural resource of drinking water in rural areas in Inner Mongolia, China. In this study, 4438 drinking groundwater samples were collected from the rural areas of 81 counties in Inner Mongolia, and were analyzed for 16 parameters, including pH, total hardness (TH), chemical oxygen demand (COD), total dissolved solids (TDS), sulfate (SO42-), chloride (Cl-), fluoride (F-), iron (Fe), manganese (Mn), arsenic (As), cadmium (Cd), hexavalent chromium (Cr), lead (Pb), aluminum (Al), cuprum (Cu), zinc (Zn). The groundwater quality was evaluated with water quality index (WQI) and human health risk assessment (HRA). Monte Carlo simulation were applied for the uncertainty and sensitivity analysis in the health risk assessment. The spatial map was employed based on the inverse distance weighted (IDW) interpolation technique. The results reveal that while the hazard quotient (HQ) suggests that the risk of single element contamination is feeble, the hazard index (HI) indicates a potential health risk for the local population. The observed cumulative carcinogenic risk (CCR) indicates a probable risks of carcinogenic health hazards in the study area. The sensitivity analysis revealed that daily ingestion rate (IR), exposure frequency (EF), and the concentrations of As, Mn, F-, and Cr are the most influential parameters for health hazards. The highly polluted areas are mainly distributed in the central and western regions of Inner Mongolia, including Xianghuangqi, New Barag Zuoqi, and Togtoh. It is observed that the groundwater may cause a potential health risk after long-term ingestion. The results of this study will contribute to groundwater management and protection in Inner Mongolia.