Oxidative and cellular stress as bioindicators for metal contamination in freshwater mollusk Lamellidens marginalis

Environmental Science and Pollution Research - The concentrations of 14 metals, namely, chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), selenium (Se), arsenic (As),...     

Occurrence of phthalates in aquatic environment and their removal during wastewater treatment processes: a review

Phthalates are plasticizers and are concerned environmental endocrine-disrupting compounds. Due to their extensive usage in plastic manufacturing and personal care products as well as the potential to leach out from these products, phthalates have been detected in various aquatic environments including drinking water, groundwater, surface water, and wastewater. The primary source of their environmental occurrence is the discharge of phthalate-laden wastewater and sludge. This review focuses on recent knowledge on the occurrence of phthalate in different aquatic environments and their fate in conventional and advanced wastewater treatment processes. This review also summarizes recent advances in biological removal and degradation mechanisms of phthalates, identifies knowledge gaps, and suggests future research directions.     

Agricultural innovation and adaptation to climate change: empirical evidence from diverse agro-ecologies in South Asia

While impacts of climate change on agricultural systems have been widely researched, there is still limited understanding of what agricultural innovations have evolved over time in response to both climatic and non-climatic drivers. Although there has been some progress in formulating national adaptation policies and strategic planning in different countries of South Asia, research to identify local-level adaptive strategies and practices is still limited. Through eight case studies and a survey of 300 households in 15 locations in India, Nepal and Bangladesh, this paper generates empirical evidence on emerging agricultural innovations in contrasting socio-economic, geographical and agro-ecological contexts. The study demonstrates that several farm practices (innovations) have emerged in response to multiple drivers over time, with various forms of institutional and policy support, including incentives to reduce risks in the adoption of innovative practice. It further shows that there is still limited attempt to systematically mainstream adaptation innovations into local, regional and national government structures, policies and planning processes. The paper shows that the process of farm-level adaptation through innovation adoption forms an important avenue for agricultural adaptation in South Asia. A key implication of this finding is that there is a need for stronger collaborations between research institutions, extension systems, civil society and the private sector actors to enhance emerging adaptive innovations at the farm level.     

Green synthesis of ZrO2 nanoparticles and nanocomposites for biomedical and environmental applications: a review

Environmental Chemistry Letters - Pollution and diseases such as the coronavirus pandemic (COVID-19) are major issues that may be solved partly by nanotechnology. Here we review the synthesis of...     

An Improved Rating System for Assessing Surface Water Contamination Potential from MSW Landfills

Leachate emission from uncontrolled municipal solid waste landfills (referred to as waste sites in the present study) is a major threat to the environment and living beings in its vicinity. Surface water contamination potential resulting from leachate may be used as one of the criteria for prioritization of sites for remediation purposes. The existing hazard rating systems that prioritize waste sites considering surface water contamination potential as one of the criteria are mainly suited for the developed countries where these were developed initially. In developing countries like India, the set of conditions differ from those in developed countries, and therefore the existing systems may not be suitable for developing countries. Thus in the present study, an improved system is proposed to assess surface water contamination potential from MSW sites. The system is based on the concept of Source, Pathway and Receptor. The proposed system employs parameters derived from the review of existing rating systems and selects their best and worst values based on literature review, design standards and field conditions. The importance weights of the system parameters have been decided based on expert judgment using Delphi technique. Sensitivity analysis of the system shows that the improved system is more sensitive than the existing systems for the site conditions encountered in developing countries. Monte Carlo analysis of the proposed system confirms the spread of the scores obtained from the system over the full scale of 0–1000. The improved system is compared with existing systems by applying it to waste sites from metropolitan cities of India and performing clustering analysis on the rating scores. The clustering analysis shows that the rating scores from the improved system are less clustered as compared to the scores from the existing systems. This demonstrates that the improved system makes a better tool to distinctly prioritize the waste sites for remediation purpose.     

Morphological changes at Vellar estuary, India--impact of the December 2004 tsunami

Coastal subsystems formed by interaction of various processes, impacted by natural hazards like tsunami and storms, pose irreversible morphological changes. Vellar estuary, located on the southeast coast of India, with huge sand dunes (of 3-6m height and spread to 560ha) and barrier islands, has undergone extensive morphological changes due to the giant Indian Ocean tsunami that occurred on 26th December 2004. The damage caused by the tsunami has been quantified using extensive field data collected during pre- and post-tsunami periods through Real Time Kinematic GPS (for mapping coastal features and beach profiles) and Geographic Information System (GIS) couple. The tsunami with a wave height as high as 4m not only inundated the entire coastal land up to a maximum of 2km but also eroded the sand dunes and deposited the eroded material at the inlet, which ultimately formed as a vast tidal flat spread over 31ha. The estuary has suffered immensely due to the tsunami especially in terms of (i) loss of natural protection barriers (sand dunes), which made this coastal area more vulnerable to storm attack, and (ii) shallowness of inlet creating hindrance to navigation of fishing vessels. Based on the observations made at Vellar coast and past recovery experiences of tsunami/hurricanes elsewhere in the world, we contend that the morphological loss might take at least two annual cycles to regain its original form and the rebuilding of sand dunes may even take a decade.     

Phytoconstituents evaluation and antihyperglycemic and antihyperlipidemic effects of Mahonia leschenaultia Takeda in streptozotocin-induced diabetic rats

Hyperlipidemia is an associated complication of diabetes mellitus. Many spices and herbs are known to be hypoglycemic. Mahonia leschenaultia Takeda (Berberidaceae) (MLT) is a traditional medicinal plant that is commonly used against diseases in India and other Asian countries. The aim of this study is to identify the phytoconstituents by gas chromatography–mass spectrography (GC–MS) and evaluate the antihyperglycemic and antihyperlipidemic effects of the ethanol extract of MLT on streptozotocin (STZ)-induced diabetic rats. Phytoconstituents like oleicacid, 9,12-octadecadienoic acid (Z, Z)-n-hexadecanoic acid were identified as high % peak when compared with other compounds by GC–MS. STZ-induced diabetic animals were fed with plant extracts at different doses (250 or 500 mg kg^?1 body wt) of ethanol extract of MLT. The results of the study revealed a significant increase in total hemoglobin and glycosylated hemoglobin along with the reduction in hyperglycemia and hyperlipidemia effects in MLT-treated STZ-induced diabetic rats compared to diabetic only rats. Further, ethanol extracts of MLT-treated animals at 500 mg kg^?1 showed that shrinkage of β cells of islets of Langerhans was restored as evidenced by histological studies of pancreas of diabetic animals. Thus the ethanol extract of MLT might serve as a reliable adjuvant for antihyperglycemic and antihyperlipidemic effects of STZ, and may be promising for development of phytomedicines for diabetes mellitus.     

Air quality mapping using GIS and economic evaluation of health impact for Mumbai City,India

Mumbai, a highly populated city in India, has been selected for air quality mapping and assessment of health impact using monitored air quality data. Air quality monitoring networks in Mumbai are operated by National Environment Engineering Research Institute (NEERI), Maharashtra Pollution Control Board (MPCB), and Brihanmumbai Municipal Corporation (BMC). A monitoring station represents air quality at a particular location, while we need spatial variation for air quality management. Here, air quality monitored data of NEERI and BMC were spatially interpolated using various inbuilt interpolation techniques of ArcGIS. Inverse distance weighting (IDW), Kriging (spherical and Gaussian), and spline techniques have been applied for spatial interpolation for this study. The interpolated results of air pollutants sulfur dioxide (SO₂), nitrogen dioxide (NO₂) and suspended particulate matter (SPM) were compared with air quality data of MPCB in the same region. Comparison of results showed good agreement for predicted values using IDW and Kriging with observed data. Subsequently, health impact assessment of a ward was carried out based on total population of the ward and air quality monitored data within the ward. Finally, health cost within a ward was estimated on the basis of exposed population. This study helps to estimate the valuation of health damage due to air pollution.

Implications: Operating more air quality monitoring stations for measurement of air quality is highly resource intensive in terms of time and cost. The appropriate spatial interpolation techniques can be used to estimate concentration where air quality monitoring stations are not available. Further, health impact assessment for the population of the city and estimation of economic cost of health damage due to ambient air quality can help to make rational control strategies for environmental management. The total health cost for Mumbai city for the year 2012, with a population of 12.4 million, was estimated as USD8000 million.