Monitoring of organochlorine pesticide residues in the Indian marine environment.

Organochlorine pesticide residues in sediment and fish samples collected from the east and west coasts of India are presented. HCH isomers and DDT and its metabolites are the predominantly identified compounds in most of the samples. Despite the higher quantity of consumption, HCH and DDT levels in fish in India were lower than those in temperate countries suggesting a lower accumulation in tropical fish, which could be due to rapid volatilization and degradation of these insecticides in the tropical environment. The predominance of alpha- and beta-HCH reflect the use of technical grade HCH in India. The high temperature in the tropics also enhances the elimination rate of chemicals in fish, as the biological half-lives of semivolatile compounds such as DDT are short at high temperature.     

Spatio-temporal changes associated with natural and anthropogenic factors in wetlands of Great Rann of Kachchh,India

Studies about wetlands have been identified as a key component of environmental change. The present study assesses the spatio-temporal changes in the wetlands of the Great Rann of Kachchh, in the Kachchh Biosphere Reserve, India, using remote sensing and GIS techniques. Satellite time-series data from Landsat (1977, 1990 and 1999) and IRS P6 (2006, 2008–2012) were used. The Normalised Difference Water Index (NDWI) was derived for each year and the layers were manually edited to obtain a high classification accuracy. The analysis found that the area has undergone considerable change from 1977 to 2011. The natural wetland area of 30.6 km² was converted to salt pans. An area of about 255 km² (41.6 %) of natural grassland was invaded by Prosopis juliflora, which raises further conservation concerns and emphasises the importance of having intervention plans to manage this ecosystem. The highest water spread of 1171 km² was observed in September 2011, followed by 2010, 2009 and 2008 in the same month. The present study is useful in planning the long-term management and conservation of the Great Rann of Kachchh wetland.     

Use of pyrite for pH control during hydrogenotrophic denitrification using metallic iron as the ultimate electron donor

Maintenance of stable pH through provision of adequate buffering is of importance to many pollutant removal processes where either acid or base is produced as a reaction product. The objective of this study was to evaluate the suitability of pyrite (FeS2) as an in situ buffering agent for arresting pH increase during metallic iron assisted hydrogenotrophic denitrification. Pyrite is considered promising for this purpose because it is a mineral which is unstable under moderately reducing, i.e., anoxic conditions, where such denitrification takes place, and therefore expected to consume hydroxide ions produced due to hydrogenotrophic denitrification reactions and get oxidized to ferrous hydroxide Fe(OH)2. The theoretical basis for this buffering action was established through chemical speciation studies using the chemical speciation software, MINEQL+. Experimental evaluation of the buffering efficiency of pyrite showed that it was effective in arresting pH increase associated with denitrification in both batch systems and during flow through reactive porous media. Further, addition of pyrite had no demonstrable toxic effect on the denitrifying microorganisms, though elevated sulfate concentration was seen in the effluent after denitrification.     

Climate vulnerability index - measure of climate change vulnerability to communities: a case of rural Lower Himalaya,India

Climate Vulnerability Index (CVI) is being proposed to assess climate change vulnerability of communities with a case study. The index consists of household parameters of all the three dimensions of vulnerability such as Exposure, Sensitivity and Adaptive Capability. Exposure is defined by ‘Natural disaster and Climate variability’, however Sensitivity by ‘Health’, Food’, and ‘Water’ and Adaptive Capability by ‘Socio-demographic profile’, ‘Livelihood strategies’, and ‘Social networks’. Respective parameters were based on the peers and literature. The CVI vulnerable status ranges from high (0) to low (1). Household questionnaire survey was undertaken from two regions namely, near to district (NDH) and away to district (ADH), in Srinagar, Uttrakhand, India. Data for desired parameters for CVI was collected from 50 randomly selected households. Data were aggregated using a composite index and differential vulnerabilities were compared. High vulnerability was observed for livelihood strategies, food and natural disaster for ADH households, and health and water for NDH households. It was found that the adaptive capability and sensitivity of ADH households was higher than NDH, however, exposure realization was similar in both the regions. The CVI was 0.69 and 0.64 for NDH and ADH, respectively, suggests high vulnerability to NDH households. This pragmatic CVI approach may be used to assess and monitor vulnerability under various stress condition, and/or evaluate potential program/ policy effectiveness in various data-scarce regions by comparing various anticipated scenarios with baseline. Further, the result obtained by index may have implications for developing adaptation or coping strategies to the region.     

Unravelling the molecular mechanism of mutagenic factors impacting human health

Environmental Science and Pollution Research - Environmental mutagens are chemical and physical substances in the environment that has a potential to induce a wide range of mutations and generate...     

Intake of ²³⁸U and ²³²Th through the consumption of foodstuffs by tribal populations practicing slash and burn agriculture in an extremely high rainfall area

The concentration of naturally occurring radionuclides ²³²Th, ²³⁸U was determined using Instrumental Neutron Activation Analysis (INAA) in different food groups namely cereals, vegetables, leafy vegetables, roots and tubers cultivated and consumed by tribal population residing around the proposed uranium mine. The study area is a part of rural area K. P. Mawthabah (Domiasiat) in the west Khasi Hills District of Meghalaya, India located in the tropical region of high rainfall that remains steeped in tribal tradition without much outside influence. Agriculture by Jhum (slash and burn) cultivation and animal husbandry are the main occupation of the tribal populations. A total of 89 samples from locally grown food products were analyzed. The concentration of ²³⁸U and ²³²Th in the soil of the study area was found to vary 1.6-15.5 and 2.0-5.0 times respectively to the average mean value observed in India. The estimated daily dietary intake of ²³⁸U and ²³²Th were 2.0 μg d⁻¹ (25 mBq d⁻¹) and 3.4 μg d⁻¹ (14 mBq d⁻¹) is comparable with reported range 0.5-5.0 μg d⁻¹ and 0.15-3.5 μg d⁻¹ respectively for the Asian population.     

Practical ways to recycle plastic: current status and future aspects

Journal of Material Cycles and Waste Management - With sky-rocketing demand and unrestricted global production, plastics have become an inseparable part of daily human life and the circular economy...     

Mutagenic factors in the environment impacting human and animal health

Environmental Science and Pollution Research -