Emerging nitrate contamination in groundwater: Changing phase in a fast-growing state of India.

The consumption of nitrate-contaminated groundwater is often associated with potential health risks, particularly in children. This study aimed to assess the hydrochemistry and nitrate contamination in groundwater of Kerala state, India for the years 2010 and 2018 and evaluate the potential human health risks due to nitrate exposure in adults, and children through oral ingestion and dermal contact pathways. Nitrate-contaminated zones were identified by spatial mapping of nitrate concentration based on groundwater quality data of 324 wells. Groundwater is typically acidic to slightly alkaline, and the electrical conductivity (EC) varied from 33 to 1180 µS/cm in 2010 and 34.6-2500 mg/L in 2018 indicating a noticeable increase over the years. Most samples fall within low salt enrichment category. The nitrate concentration in groundwater varied from 0 to 173 mg/L with a mean of 15.4 mg/L during 2010 and 0 to 244 with a mean of 20.3 mg/L during 2018. Though nitrate concentrations show uneven spatial distributions due to both natural and anthropogenic sources, the spatial clustering of higher concentrations remains almost same in both periods. In 2010, non-carcinogenic risk, as measured by Health Index Total (HITotal) values in groundwater for the investigated region, ranged from 0.005 to 4.170 (mean of 0.349) for males, 0.005 to 4.928 (mean of 0.413) for females, and 0.008 to 7.243 (mean of 0.607) for children, while in 2018, the corresponding values varied from 0.001 to 5.881 (mean of 0.501) for males, 0.002 to 6.950 (mean of 0.592) for females, and 0.003 to 10.215 (mean of 0.870) for children, indicating a substantial increase in risk, for females and children. Greater health risk is observed in children during both the periods. The findings emphasize the need for proper water quality management, especially in regions with higher vulnerability to nitrate pollution, to safeguard human health and well-being.

Ensemble of fuzzy-analytical hierarchy process in landslide susceptibility modeling from a humid tropical region of Western Ghats, Southern India.

The western flanks of the Western Ghats are one of the major landslide hotspots in India. Recent rainfall triggered landslide incidents in this humid tropical region necessitating the accurate and reliable landslide susceptibility mapping (LSM) of selected parts of Western Ghats for hazard mitigation. In this study, a GIS-coupled fuzzy Multi-Criteria Decision Making (MCDM) technique is used to evaluate the landslide-susceptible zones in a highland segment of the Southern Western Ghats. Fuzzy numbers specified the relative weights of nine landslide influencing factors that were established and delineated using the ArcGIS, and the pairwise comparison of these fuzzy numbers in the Analytical hierarchy process (AHP) system resulted in standardized causative factor weights. Thereafter, the normalized weights are assigned to corresponding thematic layers, and finally, a landslide susceptibility map is generated. The model is validated using the area under the curve values (AUC) and F1 scores. The result reveals that about 27% of the study area is classified as highly susceptible zones followed by 24% area in moderately susceptible zone, 33% in low susceptible, and 16% in a very low susceptible area. Also, the study shows that the plateau scarps in the Western Ghats are highly susceptible to the occurrence of landslides. Moreover, the predictive accuracy estimated by the AUC scores (79%) and F1 scores (85%) shows that the LSM map is trustworthy for future hazard mitigation and land use planning in the study area.

Recent advancements in coral health, microbiome interactions and climate change.

Corals are the visible indicators of the disasters induced by global climate change and anthropogenic activities and have become a highly vulnerable ecosystem on the verge of extinction. Multiple stressors could act individually or synergistically which results in small to large scale tissue degradation, reduced coral covers, and makes the corals vulnerable to various diseases. The coralline diseases are like the Chicken pox in humans because they spread hastily throughout the coral ecosystem and can devastate the coral cover formed over centuries in an abbreviated time. The extinction of the entire reef ecosystem will alter the ocean and earth's amalgam of biogeochemical cycles causing a threat to the entire planet. The current manuscript provides an overview of the recent advancement in coral health, microbiome interactions and climate change. Culture dependent and independent approaches in studying the microbiome of corals, the diseases caused by microorganisms, and the reservoirs of coral pathogens are also discussed. Finally, we discuss the possibilities of protecting the coral reefs from diseases through microbiome transplantation and the capabilities of remote sensing in monitoring their health status.

Solar Photocatalysis for the Decontamination Of Water from Emerging Pharmaceutical Pollutant Chloroquine Using Nano ZnO as the Catalyst.

Photo-driven advanced oxidation process (AOP) with pharmaceutical wastewater has been poorly investigated so far. This paper presents the results of an experimental investigation on the photocatalytic degradation of emerging pharmaceutical contaminant chloroquine (CLQ) in water using zinc oxide (ZnO) nanoparticles as the catalyst and solar light (SL) as the source of energy. The catalyst was characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDAX), and transmission electron microscopy (TEM). The effect of various operating parameters such as catalyst loading, the concentration of target substrate, pH, and the effect of oxidants and anions (salts) on the efficiency of degradation was tested. The degradation follows pseudo-first-order kinetics. Surprisingly, contrary to the observation in most photocatalytic studies, the degradation is more efficient under solar radiation, with 77% under solar (SL) irradiation and 65% under UV light in 60 min. The degradation leads to slow and complete COD removal through several intermediates identified by the liquid chromatography-mass spectrometry (LC-MS) technique. The results suggest the possibility of using inexpensive natural, non-renewable solar energy for the purification of CLQ-contaminated water, thereby enabling the reuse of scarce water resources.

Microplastics in terrestrial ecosystem: Sources and migration in soil environment.

Plastics, especially microplastics in soils, are considered a severe environmental issue worldwide. However, globally, the main research focus is on microplastic pollution in the marine environment, the microplastic pollution on soils and sediments remains on the sideline so far. But the fact is that microplastics are omnipresent in terrestrial systems in the form of microbeads in industrial systems and in sewage sludge. Their presence in agricultural soils and sediments is enormously increased due to plastic mulching, plastic greenhouses and compost and extensive use of controlled release fertilizers. Therefore, this review outlines the global scenario regarding plastics and microplastics production, consumption, and possible pathways of penetration into the soil environment. Various mechanisms to restrict and manage the pathways of plastics and microplastics into the soil environment are also discussed. This review also focuses on the challenges and limitations on the use of plastic alternates such as bioplastics and oxo plastics. Also, the knowledge gaps on the source of microplastics in the environment and their deleterious effects on properties of soil, soil health and focused light on their soil trophic transfer in food chains via plants. This review provides a detailed insight on the management and possible control measures to alleviate the potential risk caused by microplastics pollution in the soil environment and the overall ecosystem's health. In spite of the occurrence and fate of microplastics on terrestrial environment, knowledge gaps and challenges for tackling this contamination are also explored which facilitates the policy makers to develop regulatory measures towards the containment of microplastics in living ecosystem.

Analysis of Risk Factors and Consequences of Consecutive Proximal Femur Fractures in Elderly Patients.

Background Proximal femur fracture (PFF) carries significant morbidity, mortality, and cost implications to the health system. Subsequent contralateral fracture further decreases patient performance and increases the healthcare burden. This study aimed to identify and evaluate potential risk factors for consecutive PFF. Methodology Pilgrim Hospital PFF database from 2012 to 2019 was retrospectively analyzed. Patients over 60 years with low-energy fractures were included. Pathological and atypical fractures and polytrauma were excluded. Results There were 114 patients (4.18%) with contralateral hip fractures out of a total of 2727 PFF patients; 80% were females. The mean age was 82 years for the first hip fracture and 85 years for the second. The average time interval between fractures was 36 months. The fracture pattern was the same on both sides in 74.3% of patients (P<0.0001). Out of 53 patients with cemented hip hemiarthroplasty (CHH) on one side, 31 patients (59%) had a second CHH for the contralateral side. Likewise, out of 48 patients who had dynamic hip screw fixation during the first admission, 33 patients (69%) had the same procedure on the contralateral side too. During the two consecutive admissions, the length of hospital stay was not significantly different (P=0.30), median American Society of Anesthesiologists (ASA) grades were 3, hyponatremia increased from 25% to 29% (P=0.5), mean decline in abbreviated mental test score (AMTS) was 0.4, deterioration of Clinical Frailty Score and Charlson morbidity index were from 4.5 to 5.9 (P<0.0001), and from 5.4 to 6.1, respectively, and institutional residency was increased from 23 to 46 (P>0.0014). Conclusion The similarity of fracture pattern bilaterally requiring similar surgical procedures is comparable with other literature. Even though there is minimal or no change in the ASA, AMTS, and hospital stay between the two admissions, there is a significant decline in clinical frailty, mobility status, and an increase in residential dependency following a subsequent fracture. Our findings demonstrate the importance of emphasizing secondary preventive measures to prevent a consecutive fracture.

Comprehending the groundwater recharge of a coastal city in humid tropical setting using stable isotopes.

Unscientific urbanization in coastal cities has enforced the need for understanding groundwater recharge sources and processes for sustainable development. In this paper, stable isotope compositions of precipitation, groundwater and river water were determined to understand the significant recharge sources of phreatic aquifers in the two differently urbanized environments, viz. urban and peri urban clusters of Kozhikode District, Kerala, and southern India. The two monsoon systems viz., southwest and northeast, are the major source of groundwater recharge in the region, but due to change in landuse pattern in the last decade has significantly altered groundwater recharge. Hence with the aid of stable isotope ratios of water, estimation of point recharge of rainwater to the groundwater in different hydrgeological setting of the area was done. The monsoon rains contributed 35% in the urban alluvial aquifers, up to 39% in the urban laterite aquifer and 42% in the peri urban laterite aquifer. An attempt was made to correlate the landuse changes in the past decade in the region with the groundwater availability.

Assessment of water quality in a tropical ramsar wetland of southern India in the wake of COVID-19.

The novel SARS-CoV-2 virus influenced the world severely in the first half of 2020 caused shut down of all kind of human activities. It is reported that a word-wide ecological improvement in terms of air quality and water quality during this lock down period. In the present study, an attempt has been made to study the progression in water quality through examining suspended particulate matter using remote sensing data in a tropical Ramsar site viz, Asthamudi Lake in Southern India. The change in spectral reflectance of water along the study area were analyzed and suspended particulate matter (SPM) is estimated from Landsat 8 OLI images. A comparison analysis of pre and co lockdown periods reveal that the concentration of SPM values during lockdown (mean SPM 8.01 mg/l) is lower than that of pre-lockdown (10.03 mg/l). The time series analysis of last five-year data from 2015 to 2020 also shows an average decrease of 43% in SPM concentration during lockdown period compared to the last five-year average value of 9.1 mg/l. The reasons for improvement of SPM in water quality during the lockdown period in April-May 2020 was discussed, in terms of the role of anthropogenic activities and strategies for the sustainable management of coastal ecosystems and water resources in the Asthamudi Lake were also presented.

Assessment of drought with a real-time web-based application for drought management in humid tropical Kerala, India.

Geospatial techniques are useful for near real-time monitoring of drought and towards devising local-level effective drought management plan. Based on the historic and current remote sensing data, one can identify the influence of drought on the vegetation status by analyzing the anomaly/drought condition of a particular area of interest (AOI) through different digital image processing techniques. In this study, an attempt has been made to develop a web-based application for generating drought maps and district-wise drought information at real time in the web server using Hypertext Preprocessor (PHP) and Python scripts. A web-based application was developed and drought conditions existing in the study area were understood both spatially and temporally. The results of the application showed distinct variation of drought prevalence within the administrative boundaries. This web-based application was validated with drought analysis carried out using different drought indices, viz., standard precipitation index and reconnaissance drought index. The results established that this validated approach could be used for developing disaster management plan well in advance to combat the consequences of drought across the globe and to evolve strategic decisions which will have implications in the various sectors of the economy.

Drought risk mapping of south-western state in the Indian peninsula - A web based application.

Application of geospatial technology is very shimmering in drought monitoring. Drought severity in crops for six northern districts of Kerala has been attempted using Geospatial Techniques. Normalized Difference Vegetation Index (NDVI) is the major parameter used to measure vegetation health obtained from MODIS, Terra satellite products MOD13Q1, MOD02QKM. The mean Normalized Difference Vegetation Index (NDVI) of Kerala state over 13 years was calculated. The daily anomalies of NDVI from its long term mean NDVI over the same period was determined based on which drought risk classification was done. High negative NDVI anomaly areas are susceptible to drought and the severity of drought risk on each crop can be identified using Land Use/Land Cover data. Overlaying daily NDVI Anomaly based drought risk map on land use/land cover map gives the drought risk for different crops. Based on this, a web application has been developed for Northern districts of Kerala state in India. This web application can be used to plan for drought management measures and can also serve as a database for drought analysis.

Critical coastal issues of Sagar Island, east coast of India.

Sagar Island, situated in the east coast of India and one of the biggest deltas in Sundarban group, faces coastal erosion and degradation of coastal vegetation and various natural hazards. Erosion is mainly due to clay mining, wave activities, and the impact of river and tidal currents of Muri Ganga and Hugly Rivers. Further, the coastal zone of Sagar Island faces increasingly severe problems of rapidly growing human population, deteriorating environmental quality, and loss of critical habitats. Sagar Island has been victimized several times by tropical cyclones and influenced daily by tidal fluctuations. The island needs immediate attention on the coastal zone in order to protect the shoreline and ecosystem. The capability of satellite remote sensing to provide synoptic, repetitive, and multispectral data has proved to be very useful in the inventory and monitoring of critical coastal issues. Sagar Island and its environs are subjected to both natural and anthropogenic activities that continuously modify the region.

Assessment on seasonal variation of groundwater quality of phreatic aquifers - a river basin system.

Spatial distribution of pH, electrical conductivity (EC), total dissolved solids (TDS), fluoride and total iron content of ground water samples collected from the muvattupuzha river basin, Kerala, India, has been studied for pre monsoon and post monsoon periods of year 2001. Results showed the groundwater of the basin is acidic for which the pH values ranged between 5.5 and 8.0. Average EC was found to be less than 100 microS/cm, for most of the study region. The pre monsoon minimum and maximum TDS were found as 25.6 and 227.84 mg/L respectively, where as post monsoon values ranged between 16 and 162.56 mg/L. The relatively low EC and TDS values found both during the seasons in the lateritic terrain of the river basin signifies the lower residence time of ground water with the country rock. This makes the groundwater quality of this river basin as good. Pre monsoon season samples showed high total iron content than that during the post monsoon period. During the study period values of the fluoride contents were found to be within the permissible limits.