A comprehensive review on spatial and temporal variation of arsenic contamination in Ghaghara basin and its relation to probable incremental life time cancer risk in the local population

Health and ecological risk assessment of metals in surface water from the Himalayan tributaries of the Ganga river, India

This study investigates the trace element concentrations in the surface waters of four north-joining Himalayan tributaries of the Ganga river (Ramganga, Ghaghara, Gandak, and Kosi), highlighting the combined effects of geogenic processes and anthropogenic activities on trace element chemistry and water quality. A knowledge gap exists in understanding the sources of trace elements in these tributaries and the contribution of trace elements from these tributaries to the Gangariver. The novelty of the study lies in its assessment of sources, human health risks, and ecological impacts. The investigation was conducted by assessing trace element concentrations and comparing them with national and international standards. Various human health and ecological risk indicators, including the Heavy Metal Pollution Index (HPI), Hazard Quotient (HQ), Health Index (HI), Chronic Daily Intake (CDI), and the Potential Ecological Risk Index (PERI), were applied. The results reveal high concentrations of copper (Cu), zinc (Zn) and lead (Pb) in the Ramganga, indicating contamination from industrial activities in the catchment. Although most trace element concentrations are within safe limits, Pb concentration in the Ramganga exceeds the limit prescribed by WHO. The Ramganga shows the highest health risks, with a HItotal of 1.876 for adults and 1.616 for children. In contrast, the Ghaghara, Gandak, and Kosi exhibit lower but moderate contamination levels. HPI values for these rivers- 93.74 for the Ghaghara, 83.95 for the Kosi, 83.13 for the Gandak, and 80.43 for the Ramganga-indicate that although contamination is below critical thresholds, targeted mitigation strategies are needed. The findings provide valuable insights into trace metal sources and their implications for human health and ecological risks, and emphasize the need for frequent monitoring and pollution control measures for maintaining sustainable water quality in these tributaries.

Integrated application of selenium and silica reduce arsenic accumulation and enhance the level of metabolites in rice grains

In this study, rice plants were co-exposed to selenium (Se) and silica (Si) under arsenic (As) stress to evaluate As accumulation in rice grains, associated cancer risk, and its impact on the types and numbers of grain metabolites. A total of 58 metabolites were identified, of which, 19 belong to sugars, and drastically altered during different treatments. Arsenic exposure significantly reduced monosaccharides, i.e., D-glucose (83%) >D-galactose (60%) >D-fructose (57%) >D-ribose (29%) but increased that monosaccharide units which have antioxidant properties (i.e. α-D-glucopyranoside and melibiose). However, the levels of D-galactose, fructose, and ribose were significantly increased during co-supplementation of selenite (SeIV) and Si under As stress. Other groups of rice grain metabolites, like sugar alcohols, organic acids, polyphenols, carboxylic acids, fatty acids, and phytosterols, were also significantly altered by As exposure and increased in grains of SeIV and Si supplemented rice compared to alone As exposure. In brief, rice growing in As-affected areas may have a low level of different metabolites. However, supplementation by selenite (SeIV) with Si not only increased metabolites and amylose/amylopectin ratio but also reduced ∼90% of As accumulation in grains. Thus, the use of SeIV with Si might be advantageous for the locals to provide a healthy diet of rice and limit As-induced cancer risk up to 10-fold.

Reported Behavioral Patterns and Concern Surrounding Well Water Testing for Arsenic in Midwestern Homeowners with Children

Toxins from ingested water can significantly affect overall physical health in children and adults. In the United States, domestic water wells are not commonly tested for any heavy metal contaminants. It is well-known that chronic arsenic ingestion from water is linked to serious health effects. We surveyed patients at our academic institution via emailed questionnaires in 2023 to determine whether those with children living at home reported different patterns of behavior around well water testing as compared to those without. Survey data were collected from 8994 respondents in the U.S. Midwest who reported using residential well water. Results were used to evaluate the influence of children in the home on testing behaviors, and secondarily, whether parental demographics affected testing frequency. Respondents with children at home did not report increased testing frequency compared to those without. In parents who did report testing, having more children, being younger, and living in Wisconsin were associated with an increased frequency. Parental gender, race, and ethnicity did not correlate with testing behaviors. A total of 70% of respondents did not feel concerned about their water safety and 85% were not concerned about arsenic specifically in their water. Increased risk of toxicity to children from arsenic does not appear to influence reported well water testing behavior among parents.

Combined effects of climate stressors and soil arsenic contamination on metabolic profiles and productivity of rice (Oryza sativa L.)

Rice productivity and quality are increasingly at risk in arsenic (As) affected areas, challenge that is expected to worsen under changing climatic conditions. Free-Air Concentration Enrichment experiments revealed that eCO2, eO3, and eTemp, whether acting individually or in combination with low and high As irrigation, significantly impact rice yield and grain quality. Elevated CO₂ significantly increased shoot biomass, with minimal impact on root biomass, except under low As irrigation conditions. In contrast, eTemp alone reduced both shoot and root biomass, though the effect was not significant; eO₃ alone had little to no effect. Combined climatic stressors showed slight positive effects on growth. Under low As irrigation, eCO2 and eO3 promoted root growth but reduced shoot growth, while eTemp significantly suppressed both. High As irrigation exacerbated yield reductions, with the most severe decline observed under eTemp (66 %), followed by eCO2 (48 %), eO3 (36 %), and their combination (35 %). Arsenic irrigation, whether low or high, reduced macro and micronutrient concentrations in rice grains, with calcium being sole exception, remaining stable or even increasing. Sugar metabolites decreased under eCO2, eO3, and eTemp, but increased with As irrigation. Interestingly, climatic variables generally reduced grain As levels, high As irrigation combined with eCO2 exposure resulted in elevated grain As. This poses a dual concern: increased cancer risk due to As but potential benefit for individuals with diabetes, as the higher amylose content contributes to lower glycemic index. However, rice grown under high As irrigation exhibited significant nutritional imbalances, being rich in maltose and amylose but deficient in organic acids, phytosterols, fatty acids, organosilicons, and carboxylic acids. These findings underscore the dual threat of climate change and As contamination to rice productivity and quality. Developing resilient rice varieties with low grain As content is essential to ensure sustainable agricultural production and nutritional security in As affected regions.

Techno-economic feasibility and life cycle assessment analysis for a developed novel biosorbent-based arsenic bio-filter system

Significant aquifers around the world is contaminated by arsenic (As), that is regarded as a serious inorganic pollution. In this study, a biosorbent-based bio-filter column has been developed using two different plant biomasses (Colocasia esculenta stems and Artocarpus heterophyllus seeds) to remove total As from the aqueous system. Due to its natural origin, affordability, adaptability, removal effectiveness, and possibility for integration with existing systems, the biosorbent-based bio-filter column presents an alluring and promising method. It offers a practical and eco-friendly way to lessen the damaging impacts of heavy metal contamination on ecosystems and public health. In this system, As (III) is oxidized to As (V) using chlorine as an oxidant, after this post-oxidized As-contaminated water is passed through the bio-filter column to receive As-free water (or below World Health Organization permissible limit for As in drinking water). Optimization of inlet flow rate, interference of co-existing anions and cations, and life cycle of the column were studied. The maximum removal percent of As was identified to be 500 µg L-1 of initial concentration at a flow rate of 1.5 L h-1. Furthermore, the specifications of the biosorbent material was studied using elemental analysis and Zeta potential. The particle size distribution, morphological structures, and chemical composition before and after binding with As were studied using dynamic light scattering (DLS), scanning electron microscope-energy dispersive X-Ray spectroscopy (SEM-EDX), and fourier's transform infrared spectroscopy (FTIR) analysis, respectively. SuperPro 10 software was used to analyze the techno-economic viability of the complete unit and determine its ideal demand and potential. Life cycle assessment was studied to interpret the environmental impacts associated alongside the process system. Therefore, this bio-filtration system could have a potential application in rural, urban, and industrial sectors.