In situ conservation of endangered tree species (Elaeocarpus venustus Bedd.) habitated in Agasthiyamalai Biosphere Reserve,Southern Western Ghats,India

Environmental Science and Pollution Research - Elaeocarpus venustus is an endemic as well as endangered tree species habitated in the wet evergreen forests of Southern Western Ghats (SWG), India....     

Metal contents in the groundwater of Sahebgunj district, Jharkhand, India, with special reference to arsenic

A detailed study has been presented on groundwater metal contents of Sahebgunj district in the state of Jharkhand, India with special reference to arsenic. Both tubewell and well waters have been studied separately with greater emphasis on tubewell waters. Groundwaters of all the nine blocks of Sahebgunj district have been surveyed for iron, manganese, calcium, magnesium, copper and zinc in addition to arsenic. Normal distribution statistic, exploratory data analysis and robust Z-score analysis have been employed to find out the distribution pattern, localisation of data, outliers and other related information. Groundwaters of three blocks of Sahebgunj, namely, Sahebgunj, Rajmahal and Udhawa have been found to be alarmingly contaminated with arsenic present at or above 10 ppb. Arsenic distribution patterns in these blocks are highly asymmetric in nature with the common feature of increasing width from first to fourth quartile. A very broad fourth quartile in each case represents a long asymmetric tail on the right of the median. Tubewell waters of at least two more blocks require regular monitoring to identify the outbreak of arsenic at the onset. Groundwaters of Sahebgunj district in general contain high iron and manganese. It is by and large soft in nature. Well waters have been found to be better with regard to arsenic but iron and manganese contents do not vary significantly. Normal distribution analysis (NDA), box and whisker (BW) plot and Z-score analysis together can provide a reasonably complete statistical picture of metal contents in Sahebgunj district groundwaters.     

Groundwater quality in Imphal West district, Manipur, India, with multivariate statistical analysis of data

The aim of this paper was to analyze the groundwater quality of Imphal West district, Manipur, India, and assess its suitability for drinking, domestic, and agricultural use. Eighteen physico-chemical variables were analyzed in groundwater from 30 different hand-operated tube wells in urban, suburban, and rural areas in two seasons. The data were subjected to uni-, bi-, and multivariate statistical analysis, the latter comprising cluster analysis (CA), principal component analysis (PCA), and factor analysis (FA). Arsenic concentrations exceed the Indian standard in 23.3 % and the WHO limit in 73.3 % of the groundwater sources with only 26.7 % in the acceptable range. Several variables like iron, chloride, sodium, sulfate, total dissolved solids, and turbidity are also beyond their desirable limits for drinking water in a number of sites. Sodium concentrations and sodium absorption ratio (SAR) are both high to render the water from the majority of the sources unsuitable for agricultural use. Multivariate statistical techniques, especially varimax rotation of PCA data helped to bring to focus the hidden yet important variables and understand their roles in influencing groundwater quality. Widespread arsenic contamination and high sodium concentration of groundwater pose formidable constraints towards its exploitation for drinking and other domestic and agricultural use in the study area, although urban anthropogenic impacts are not yet pronounced.     

Geochemical behaviour of dissolved trace elements in a monsoon-dominated tropical river basin,Southwestern India

The study presents a 3-year time series data on dissolved trace elements and rare earth elements (REEs) in a monsoon-dominated river basin, the Nethravati River in tropical Southwestern India. The river basin lies on the metamorphic transition boundary which separates the Peninsular Gneiss and Southern Granulitic province belonging to Archean and Tertiary–Quaternary period (Western Dharwar Craton). The basin lithology is mainly composed of granite gneiss, charnockite and metasediment. This study highlights the importance of time series data for better estimation of metal fluxes and to understand the geochemical behaviour of metals in a river basin. The dissolved trace elements show seasonality in the river water metal concentrations forming two distinct groups of metals. First group is composed of heavy metals and minor elements that show higher concentrations during dry season and lesser concentrations during the monsoon season. Second group is composed of metals belonging to lanthanides and actinides with higher concentration in the monsoon and lower concentrations during the dry season. Although the metal concentration of both the groups appears to be controlled by the discharge, there are important biogeochemical processes affecting their concentration. This includes redox reactions (for Fe, Mn, As, Mo, Ba and Ce) and pH-mediated adsorption/desorption reactions (for Ni, Co, Cr, Cu and REEs). The abundance of Fe and Mn oxyhydroxides as a result of redox processes could be driving the geochemical redistribution of metals in the river water. There is a Ce anomaly (Ce/Ce*) at different time periods, both negative and positive, in case of dissolved phase, whereas there is positive anomaly in the particulate and bed sediments. The Ce anomaly correlates with the variations in the dissolved oxygen indicating the redistribution of Ce between particulate and dissolved phase under acidic to neutral pH and lower concentrations of dissolved organic carbon. Unlike other tropical and major world rivers, the effect of organic complexation on metal variability is negligible in the Nethravati River water.     

Ethnobotanical skills and clearance of tropical rain forest for agriculture: a case study in the lowlands of Bolivia

Indigenous peoples are often considered potential allies in the conservation of biological diversity. Here we assess whether ethnobotanical skills of indigenous people contribute to a reduction in the clearance of tropical rain forest. We measured ethnobotanical skills of male household heads and area of rain forest cleared for agriculture among 128 households of Tsimane', a native Amazonian group in Bolivia. We used multivariate regressions to estimate the relation between ethnobotanical skills and area of rain forest cleared while controlling for schooling, health status, number of plots cleared, adults in household, and village of residency. We found that when the ethnobotanical skills of the male household head were doubled, the amount of tropical rain forest cleared per household was reduced by 25%. The association was stronger when the area of old-growth forest cleared was used as the dependent variable than when the area cleared from fallow forest was used as the dependent variable. People who use the forest for subsistence might place a higher value on standing forest than people who do not use it, and thus they may be more reluctant to cut down the forest.     

Monsoon rain chemistry and source apportionment using receptor modeling in and around National Capital Region (NCR) of Delhi,India

Studies on monsoon precipitation chemistry were carried out to understand the nature of rainwater and sources of pollution at eight different locations in and around the National Capital Region (NCR) of Delhi during southwest monsoon in the years 2003–2005. These sites were Bulandshahr (BUL), Garhmuktesar (GAR), Muradnagar (MUR), Sardhana (SAR), Panipat (PAN), Charkhi Dadri (CHA), Hodal (HOD) and Bahror (BAH). The rainwater samples, collected at these locations, were analyzed for major anions, cations and pH. The data were assessed for its quality. In general, the order of concentrations of major ions was observed to be: Ca²⁺>SO₄²⁻>HCO₃⁻>NH₄⁺>Cl⁻>NO₃⁻>Na⁺>Mg²⁺>K⁺>F⁻. The average pH of rainwater at these stations was observed to be 6.39, ranging from 5.77 to 6.62, indicating alkaline nature. However, a few rain events, 31% at Panipat, 12% at Muradnagar and 29% at Sardhana, were observed to be acidic (pH<5.6). Acidity observed at Panipat and Muradnagar is attributed to industrial influence but at Sardhana to weak organic acids contributed by surrounding vegetation. No definite trends are found for most of the components at all the sites. However, concentrations of Cl⁻ at Bulandshahr; NO₃⁻ at Muradnagar and Hodal; F⁻ at Panipat and Bahror; Na⁺ at Bulandshahr; K⁺ at Bahror and Bulandshahr; Ca²⁺ at Bulandshahr, Muradnagar, Charkhi Dadri and Sardhana; Mg²⁺ at Panipat, Bahror, Bulandshahr, Hodal and Sardhana have increased from 2003 to 2005. For source identification, principal component analysis (PCA) was made, which showed that in general, at all the sites; suspended soil–dust and sea salts which are natural sources, were identified as the most dominating. Sources like agriculture including cattle, brick kilns and industries were reflected in third or fourth PC indicating moderate influence of anthropogenic activities in this region.     

Source apportionment of the ionic components in precipitation over an urban region in Western India

Introduction  

Inorganic ion concentrations in event-based wet-only precipitation samples collected during the south-west (SW) monsoon at an urban location in Western India, Ahmedabad between July 2000 and September 2002 were measured by Rastogi and Sarin (2007).     

Toxic cyanobacteria and microcystin dynamics in a tropical reservoir: assessing the influence of environmental variables

Environmental Science and Pollution Research - Toxic cyanobacterial blooms (TCBs) have become a growing concern worldwide. The present study investigated the dynamic of toxic cyanobacteria and...     

Carbon mineralization,microbial activity and metal dynamics in tailing ponds amended with pig slurry and marble waste

A field experiment was set up in Cartagena-La Unión Mining District, SE Spain, aimed at evaluating the short-term effects of pig slurry (PS) amendment alone and together with marble waste (MW) on organic matter mineralization, microbial activity and stabilization of heavy metals in two tailing ponds. These structures pose environmental risk owing to high metals contents, low organic matter and nutrients, and null vegetation. Carbon mineralization, exchangeable metals and microbiological properties were monitored during 67 d. The application of amendments led to a rapid decrease of exchangeable metals concentrations, except for Cu, with decreases up to 98%, 75% and 97% for Cd, Pb and Zn, respectively. The combined addition of MW + PS was the treatment with greater reduction in metals concentrations. The addition of PS caused a significant increase in respiration rates, although in MW + PS plots respiration was lower than in PS plots. The mineralized C from the pig slurry was low, approximately 25–30% and 4–12% for PS and MW + PS treatments, respectively. Soluble carbon (Csol), microbial biomass carbon (MBC) and β-galactosidase and β-glucosidase activities increased after the application of the organic amendment. However, after 3 d these parameters started a decreasing trend reaching similar values than control from approximately day 25 for Csol and MBC. The PS treatment promoted highest values in enzyme activities, which remained high upon time. Arylesterase activity increased in the MW + PS treatment. Thus, the remediation techniques used improved soil microbiological status and reduced metal availability. The combined application of PS + MW reduced the degradability of the organic compounds.     

Distribution and behaviour of persistent organochlorine insecticides in paddy soil and sediments in the tropical environment: a case study in South India

Paddy soil and sediment samples collected from the Vellar River watershed, Tamil Nadu state, South India from December, 1987 to January, 1989 were analysed to understand the comprehensive behaviour of organochlorine insecticides (HCH and DDT) in the tropical environment. HCH (BHC) showed higher levels in soil during wet season, reflecting the application of technical HCH largely during the flowering season of rice. On the other hand, DDT residues were low and did not show a significant seasonal trend in soil or sediment, indicating small quantities of DDT utilized at present for agricultural purposes in India. When compared to soil, the residue levels in sediments are low and the seasonal variation is less pronounced. This indicates that in tropical watersheds, the relative flux of residues into the aquatic environment is smaller than the amount volatilized to the atmosphere.     

Organochlorine residues in water from the Mahala water reservoir, Jaipur, India

Residues of p,p'-DDE, p,p'-DDT alpha-, beta-, gamma-isomers of HCH, aldrin and heptachlor in water, from four different sites of the Mahala water reservoir were monitored periodically from September 1985 to October 1987. All the samples contained the above residues in varying concentrations. Isomers of HCH predominated and were followed in relative dominance by aldrin, total DDT and heptachlor residues, p,p'-DDE and p,p'-DDD constituted the major fraction of total p,p'-DDT. Monthly total organochlorine residue levels in water ranged between 1.07 and 81.23 microg litre-1. The variation is attributed to the run-off or subsoil water movement from the catchment area.     

Cadmium availability to wheat in five soil series from the Yonne district, Burgundy, France

Preliminary results from the French ASPITET programme demonstrated that Cd background levels in agricultural soils can vary greatly (0.02-6.9 mg Cd kg(-1)) depending on parent material and pedogenic processes (Baize, 1997). However, the total Cd content in soil is often not significantly related to the Cd concentration in edible plant parts. A field case study was undertaken across the southern part of the Yonne district, Burgundy, France. This area has various soil series with either low or high geochemical Cd content in the topsoil. Cd availability in soils sampled at 16 sites belonging to five soil series was investigated using single extractions. In addition, shoots (at stem elongation) and grains (at harvest) of field-grown wheat were collected at the same sites and analysed for macronutrients and trace elements. Cd concentrations in grain varied from 0.015 to 0.146 mg Cd kg(-1) DM depending on soil characteristics, soil series, and plant mineral composition. Cd grain concentrations did not reflect total Cd content in the surface soil layer; however, they were correlated with Cd extracted by a 0.1 M calcium nitrate unbuffered solution, and to a lesser extent with either soil pH or CEC. These three parameters may be useful guides to predict Cd in wheat grain harvested in the Yonne district. An inverse relationship was found between Cd and Cu contents in grain. The highest Cd concentrations in wheat grain occurred in plants grown on Aubues soils which had marginal Cu and Zn deficiencies in shoots. In order of Cd accumulation in wheat grain, soil series may be ranked as follows: Domérien < Carixien, Terres Noires < Sols Marron < Aubues.     

Leaching of Cu,Cd, Pb,and phosphorus and their availability in the phosphate-amended contaminated soils under simulated acid rain

Environmental Science and Pollution Research - Phosphate amendments have been used to immobilize heavy metal-contaminated soils. However, phosphate amendments contain large amounts of phosphorus,...     

Butyltins in water, biofilm, animals and sediments of the west coast of India

Biofilm, fish, oyster, mussel, clam, surface seawater, suspended particulate matter (SPM), and sediment samples were collected from marine and/or estuarine waters of the west coast of India. These samples were analysed for butyltin derivatives such as dibutyltin (DBT) and tributyltin (TBT). The concentrations DBT plus TBT varied between 2.4 and 8.3, 163 and 363 ng/l, 5 and 2853 ng/g dry wt in the SPM, seawater and sediment samples, respectively, of the Marmugao harbour. The values of DBT plus TBT ranged between 0.60 and 29, 123 and 242 ng/l and 1.4 and 65 ng/g dry wt in SPM, water and sediment samples, respectively, collected from the Mandovi estuary. In the Dona Paula Bay the DBT plus TBT varied from 10 to 89 ng/l in surface seawater, and TBT from 10 to 513 ng/g in biofilm samples. For the coastal sediment samples the concentration of DBT plus TBT ranged between 36 and 133 ng/g dry wt of sediment. For the animal samples the DBT plus TBT ranged between 58 and 825 ng/g dry wt of the tissue. Mussel tissues contained the highest amount of DBT plus TBT (825 ng/g dry wt tissue), whereas highest TBT concentration was recorded in the oyster (732 ng/g dry wt). TBT was generally the most abundant butyltin compound in most of the samples suggesting fresh inputs and/or less degradation of TBT. A wide range of the observed butyltin concentrations suggests the presence of localized areas of contamination. Leaching of tributyltin-containing antifouling paints from the ocean going ships, fishing and recreational boats, barges, and the inputs of TBT from the Goa shipyard and dry dock facility situated in the harbour are the probable sources of the DBT and TBT in the samples of the west coast of India. Higher levels of TBT were observed in biofilm relative to that in the surrounding seawater. When fed on TBT contaminated biofilm of the diatom Navicula subinflata, butyltin concentrations in the clam Paphia malabarica increased over the period of feeding suggesting the importance of biofilm in the transfer of butyltins to higher group of organisms.     

Chlorinated pesticide residues in surface sediments from the River Kaveri, south India

Chlorinated compounds have preferential attraction for organic phases found in sediments. Usage of chlorinated pesticides in agriculture and vector control is more in developing countries. The residue levels of HCH isomers, and DDT, and its metabolites were quantified in surface sediments from the River kaveri and Coleroon in Tamil Nadu state, South India. The concentration of HCH ranged from 4.35 to 158.4 ng g-1 (dry wt.). Among the isomers of HCH, alpha-HCH is predominant followed by beta and gamma-HCH. The levels of DDT varied from 0.69 to 4.85 ng g-1 (dry wt.). Among the DDT compounds, p,p'-DDE quantified more (> 40%) in all the sites. This suggests that p,p'-DDE is a major breakdown (dehydrochlorination) product of DDT in the sediment compartment. Higher concentration of HCH residues reveals its large usage in agriculture. The flux of pesticide residues from land to river including downward flux to sediment is less.     

Organochlorine pesticides in Avicennia marina from the Mumbai mangroves, India

This paper examines the concentration levels of organochlorine pesticides (OCPs) such as hexachlorocyclohexane (HCH) (α, β and γ), Aldrin, Endosulfan (α, β), DDE, DDD, and DDT in the leaf, root and sediment part of Avicennia marina, a dominantly distributed mangrove species in Mumbai. The overall pattern of accumulation of OCPs was observed as ∑HCH > ∑DDT > ∑Endosulfan > Aldrin. The occurrence of αHCH was found to be frequent in all the samples. The leaf and root samples showed better uptake of organochlorine pesticides whereas lower concentration levels of OCPs was observed in case of sediment samples. The mean concentration of OCPs was observed highest in case of root samples. This study indicated towards the capability of A. marina in bioaccumulation of the OCPs. The present data will serve as the baseline against which future study of OCPs uptake in the mangrove plant species may be assessed.     

Hydrogeochemical comparison and effects of overlapping redox zones on groundwater arsenic near the Western (Bhagirathi sub-basin, India) and Eastern (Meghna sub-basin, Bangladesh) margins of the Bengal Basin

Although arsenic (As) contamination of groundwater in the Bengal Basin has received wide attention over the past decade, comparative studies of hydrogeochemistry in geologically different sub-basins within the basin have been lacking. Groundwater samples were collected from sub-basins in the western margin (River Bhagirathi sub-basin, Nadia, India; 90 samples) and eastern margin (River Meghna sub-basin; Brahmanbaria, Bangladesh; 35 samples) of the Bengal Basin. Groundwater in the western site (Nadia) has mostly Ca-HCO(3) water while that in the eastern site (Brahmanbaria) is much more variable consisting of at least six different facies. The two sites show differences in major and minor solute trends indicating varying pathways of hydrogeochemical evolution However, both sites have similar reducing, postoxic environments (p(e): +5 to -2) with high concentrations of dissolved organic carbon, indicating dominantly metal-reducing processes and similarity in As mobilization mechanism. The trends of various redox-sensitive solutes (e.g. As, CH(4), Fe, Mn, NO(3)(-), NH(4)(+), SO(4)(2-)) indicate overlapping redox zones, leading to partial redox equilibrium conditions where As, once liberated from source minerals, would tend to remain in solution because of the complex interplay among the electron acceptors.