Biological effects of water soluble fraction of crude oil on the Arctic sea ice amphipod Gammarus wilkitzkii

With increasing petroleum related activity in the Barents Sea and the subsequent risk of accidents, there is a demand for knowledge about the effect of oil pollution in Arctic ecosystems. In the present study, the sea ice amphipod Gammarus wilkitzkii was exposed to a water soluble fraction (WSF) of oil in two experiments, using a rock column system. First, three groups of adult females were exposed for 36 days for control (n=9), low dose (n=10) (initial and final oil concentration: 14, 115 and 120 μ g/l) and high dose (n=10) (initial and final oil concentration: 78, 764 and 395 μ g/l). Total oxyradical scavenging capacity (TOSC), malondialdehyde (MDA), catalase activity (CAT), respiration rate and mortality were measured. In the second experiment, moulting rate was measured in immature individuals of two groups, control (n=10) and exposed (n = 20), over 113 days. No mortality was observed in either of the experiments. There was a dose-related significant increase in respiration rate (40.69 (±22.82), 55.63 (±20.98), 94.57 (±22.80)) mg O₂ h^?1g ww^?1 in control, low dose and high dose, respectively. A higher MDA level was detected in the low dose group (25.04 (±6.00) nmol g^?1 of tissue) compared to both control (20.44 (±2.62) nmol g^?1 of tissue) and high dose groups (20.93 (±4.79) nmol g^?1 of tissue). Likewise, the low dose group had the highest value of TOSC towards hydroxyl (727.74 (±475.58), 1157.58 (±278.62), 1067.30 (±369.22) TOSC unit value mg^?1 of protein for control, low and high dose, respectively). Although no difference in the catalase activity between control and exposed groups was detected, higher activity was measured at 0 °C (average: 248 μ mol^?1 min^?1 mg^?1 of protein) than at the standard temperature for catalase measurement of 25 °C (average: 140 μ mol^?1 min^?1 mg^?1 of protein), indicating a need to optimise the standard operational procedure when working with Arctic organisms. No effect of WSF exposure on moulting rate was detected. In conclusion, little mortality was observed during the experiments, indicating some degree of tolerance levels. However, the biomarker results indicated sub-lethal effects in G. wilkitzkii after exposure to WSF.     

Potential hepatoprotective effects of vitamin E and Nigella sativa oil on hepatotoxicity induced by chronic exposure to malathion in human and male albino rats

Malathion is an organophosphorus (OP) insecticide and has a wide range of use in agriculture, veterinary medicine, and public health. Malathion and other OP insecticides produce hepatotoxic effects. The objective of the present study was to investigate the protective effects of Nigella sativa oil and α-tocopherol (vitamin E) on the hepatotoxicity induced by malathion on workers involved in the formulation of pesticides, chronically exposed to malathion, and in male albino rats orally administrated malathion. This study was conducted on both human and experimental animals, the human study was conducted on 30 control subjects working as administrators and 45 subjects working in formulation of pesticides and exposed to malathion (≥3 years), all were males with age ranges from 30 to 60 years. The 45 males working in pesticides formulation were classified into three groups; (1) 15 workers exposed to pesticides (2) 15 workers exposed to pesticides and received vitamin (E), in a dose of 10 mg kg?1 day^?1 orally for 60 days, and (3) 15 workers exposed to pesticides and received 100 mg kg^?1 day^?1 of N. sativa oil for 60 days. The animal experiment was conducted on 40 adult male albino rats weighing 150–200 g. They were divided into four groups (10 rats in each group). First group served as the control group, the second group received malathion in a dose of 50 mg kg^?1 orally per day for 60 days, the third group received malathion (in the same dose and route of administration) and vitamin E in a dose of 10 mg kg^?1 day^?1 orally for 60 days, and the fourth group received malathion (in the same dose and route of administration) and N. sativa oil in a dose of 100 mg kg^?1 day^?1 orally for 60 days. Liver function tests (alanine aminotransferase [ALT], aspartate aminotransferase [AST], serum alkaline phosphatase [ALP], albumin, globulin, albumin/globulin ratio, and total proteins), antioxidant enzymes (catalase (CAT), superoxide dismutase (SOD), and total glutathione peroxidase (GPx)), and lipid peroxidation [MDA] were analyzed in both human and animal experiments. The results of both human and animal study revealed that, exposure to malathion produced significant increases in AST, ALT, and lipid peroxidation. There were significant decrease in albumin, albumin/globulin ratio, total protein, and antioxidant enzymes. There was no significant change in ALP. In addition exposed workers showed significant decreases in serum globulin. Nigella sativa oil or vitamin E administration showed significant improvement of liver function tests, lipid peroxidation, and antioxidant enzymes impairment induced by malathion. Thus, dietary supplement, N. sativa oil, or vitamin E may represent a potential therapeutic agent in reducing malathion-induced hepatotoxicity.     

Subacute chlorpyrifos-induced alterations in serum lipids and some oxidative stress biomarkers in male Wistar rats: beneficial effect of acetyl-L-carnitine

The present study evaluated the beneficial effect of acetyl-L-carnitine (ALC) on subacute chlorpyrifos (CPF)-induced alterations in serum lipid profiles and some biomarkers of oxidative stress in Wistar rats. Twenty-eight adult male rats divided into four groups of seven animals each (group I–IV) were used: I (S/oil) received soya oil (2 ml kg^?1), II (ALC) received ALC (300 mg kg^?1); III (CPF) received CPF (8.5 mg kg^?1 ～ 1/10th LD₅₀); IV (ALC+CPF) was pretreated with ALC (300 mg kg^?1) and then exposed to CPF (8.5 mg kg^?1), 30 min later. The treatment was orally for 28 days duration. Sera obtained from blood samples were evaluated for the levels of triglyceride (TG), total cholesterol (TC), high density lipoprotein-cholesterol (HDL-c), malondialdehyde (MDA), and the activities of superoxide dismutase (SOD) and catalase (CAT). The levels of low density lipoprotein-cholesterol (LDL-c), very low density lipoprotein-cholesterol (VLDL-c), and atherogenic index (AI) were calculated. The result showed that elevated levels of TG, TC, LDL-c, VLDL-c, AI, and MDA, and the decreased levels of HDL-c, CAT, and SOD induced by CPF were modulated by ALC. It was concluded that ALC ameliorated the alterations in serum lipid and oxidative stress induced by CPF exposure in the rats, partly through its antioxidant properties.     

Arsenic concentration in rice, fish, meat and vegetables in Cambodia: a preliminary risk assessment

To assess arsenic contaminations and its possible adverse health effects, food samples were collected from Kandal, Kratie and Kampong Cham in Cambodia. The highest and the lowest concentrations were observed in fish (mean 2,832 ng g^?1, ww) collected from Kandal province and cattle stomach (1.86 ± 1.10 ng g^?1, ww) collected from Kratie, respectively. The daily intake of arsenic via food consumption was 604, 9.70 and 136 μg day^?1 in Kandal, Kratie and Kampong Cham, respectively. The arsenic dietary intake in Kandal ranked No. 1 among all the 17 compared countries or regions. Fish consumption contributed the greatest proportion of total arsenic daily intake in Kandal (about 63.0 %) and Kampong Cham (about 69.8 %). It is revealed to be a much more important exposure pathway than drinking water for residents in Kampong Cham. The results of risk assessment suggested that the residents in Cambodia, particularly for people in Kandal province, suffer high public health risks due to consuming arsenic-contaminated food.     

Primary production and phytoplankton community structure during a winter shelf-scale phytoplankton bloom off Western Australia

Regions of high primary production along the oligotrophic west coast of Australia between 34 and 22°S in May–June 2007 (midway through the annual phytoplankton bloom) were found around mesoscale features of the Leeuwin Current. At 31°S, an anticyclonic eddy-forming meander of the Leeuwin Current had a mixed layer depth of >160 m, a depth-integrated chlorophyll a (Chl a)-normalised primary production of 24 mg C mg Chl a ^?1 day^?1 compared to the surrounding values of <18 mg C mg Chl a ^?1 day^?1. In the north between 27 and 24°S, there were several stations in >1,000 m of water with a shallow (<100 m) and relatively thin layer of high nitrate below the mixed layer but within the euphotic zone. These stations had high primary production at depths of ~100 m (up to 7.5 mg C m^?3 day^?1) with very high rates of production per unit Chl a (up to 150 mg C mg Chl a ^?1 day^?1). At 27–24°S, the majority of the phytoplankton community was the ubiquitous tropical picoplankters, Synechococcus and Prochlorococcus. There was a decline in the dominance of the picoplankters and a shift towards a more diverse community with more diatoms, chlorophytes, prasinophytes and cryptophytes at stations with elevated production. Photosynthetic dinoflagellates were negligible, but heterotrophic dinoflagellate taxa were common. Haptophytes and pelagophytes were also common, but seemed to contribute little to the geographical variation in primary production. The mesoscale features in the Leeuwin Current may have enhanced horizontal exchange and vertical mixing, which introduced nitrate into the euphotic zone, increasing primary production and causing a shift in phytoplankton community composition in association with the annual winter bloom.     

Population health risk via dietary exposure to trace elements (Cu,Zn, Pb,Cd, Hg,and As) in Qiqihar,Northeastern China

The estimated daily intakes (EDIs) of six trace elements (Cu, Zn, Pb, Cd, Hg, and As) in vegetables (leafy vegetable, i.e., bok choy, fruit vegetables, i.e., cucumber and tomato, and other categories, i.e., mushroom, kidney bean, and potato), cereals (rice and wheat flour), and meats (pork, mutton, and beef) most commonly consumed by adult inhabitants of Qiqihar, Northeastern China, were determined to assess the health status of local people. The average EDIs of Cu, Zn, Pb, Cd, Hg, and As were with 20.77 μg (kg bw)^?1 day^?1 of Cu, 288 μg (kg bw)^?1 day^?1 of Zn, 2.01 μg (kg bw)^?1 day^?1 of Pb, 0.41 μg (kg bw)^?1 day^?1 of Cd, 0.01 μg (kg bw)^?1 day^?1 of Hg, and 0.52 μg (kg bw)^?1 day^?1 of As, respectively, which are below the daily allowance recommended by FAO/WHO. However, the maximum EDIs of Pb and Cd were 4.56 μg (kg bw)^?1 day^?1 and 1.68 μg (kg bw)^?1 day^?1, respectively, which are above the recommended levels [i.e., 3.58 μg (kg bw)^?1 day^?1 for Pb and 1.0 μg (kg bw)^?1 day^?1 for Cd] by FAO/WHO. This finding indicates that the potential health risk induced by daily ingestion of Pb and Cd for the local residents should receive a significant concern. Similarly, we detected elevated Pb and Cd concentrations, i.e., with average of 13.58 and 0.60 mg kg^?1 dw, respectively, in the adult scalp hairs. Consumption of rice, potato, bok choy, and wheat flour contributed to 75 and 82% of Pb and Cd daily intake from foodstuffs. Nevertheless, human scalp hair is inappropriate biological material for determination of the nutritional status of trace elements in this region.     

Isolation and characterisation of a carbofuran degrading Burkholderia sp. PCL3 from carbofuran-phytoremediated rhizosphere soil

A bacterial strain capable of degrading carbofuran as the sole carbon source was isolated from carbofuran-phytoremediated rhizosphere soil of rice. A 16S rRNA study identified the strain as Burkholderia sp. (isolate PCL3). Free cells of isolate PCL3 possessed inhibitory-type degradation kinetics with a q _max of 0.087 day^?1 and S _m of 248.76 mg·L^?1. Immobilised PCL3 on corncob and sugarcane bagasse possessed Monod-type degradation kinetics with a q _max of 0.124 and 0.098 day^?1, respectively. The optimal pH and temperature with the highest degradation rate coefficient of carbofuran were pH 7.5 and 35 °C, respectively.     

Diuron herbicide degradation catalyzed by low molecular weight humic acid-like compounds

Phenylureas such as diuron are major herbicides used worldwide to control undesirable weeds. The environmental fate of phenylureas is of great interest because massive amounts of those herbicides are used. It is known that abiotic degradation of phenylureas in soil–water systems is catalyzed by humic acids. However, due to the chemical heterogeneity and large molecular sizes of humic acids, the specific effects of functional groups during catalysis have not been elucidated. Therefore, we studied here for the first time the kinetics of diuron degradation in the presence of low molecular weight humic acid-like compounds such as benzoic acid derivatives. Experiments were carried out at various pH and temperature, and monitored by high-performance liquid chromatography. Results show that all benzoic acid derivatives efficiently catalyzed diuron hydrolysis. The catalytic efficiency decreased in the following order: 0.88 M^?1 day^?1 for 3,4-dihydroxybenzoic acid, 0.72 M^?1 day^?1 for 4-hydroxybenzoic acid, 0.23 M^?1 day^?1 for phthalic acid, 0.11 M^?1 day^?1 for 2-hydroxybenzoic acid, and 0.09 M^?1 day^?1 for 2,4-dihydroxybenzoic acid. These differences in the catalytic efficiency are explained by steric hindrance affecting the accessibility of reactive sites and hence influencing the rate of the overall process. Steric factors are therefore expected to control the catalytic activity of humic acids because of the chemical similarities between humic acids and low molecular weight humic acid-like compound. Our results should help predict more accurately the fate and abiotic degradation mechanism of phenylureas in the environment.     

Arsenic in freshwater ecosystems of the Bengal delta: status,sources and seasonal variability

The study aimed to examine the contamination status of arsenic (As) in excavated small water bodies, commonly known as ponds – the integral part of daily life in the arsenic-affected rural areas of West Bengal, India in comparison to the unaffected areas. The ponds of the contaminated area had higher levels of As: water 2–174 µg L^?1 (mean 31 ± 2 µg L^?1) and sediment 1.3–37.3 mg kg^?1 (mean 10.3 ± 0.4 mg kg^?1), than those from the unaffected area: water 1–8 µg L^?1 (mean 4 ± 0 µg L^?1) and sediment 1.4–5.3 mg kg^?1 (mean 3.0 ± 0.1 mg kg^?1). A moderate positive correlation was observed between the water and sediment arsenic content of the ponds of the arsenic-affected region (r = 0.688, n = 277, p < 0.0001). Contaminated ground water, either as direct input or through agricultural washings, was found to be the major contributor of arsenic pollution to these ecosystems. Seasonal variations were not prominent. This study emphasized the beneficial role of using the studied ecosystems over the highly contaminated ground water for various livelihood activities in the Gangetic delta region.     

As(V)-reduction to As(III) by arsenic-resistant Bacillus spp. bacterial strains isolated from low-contaminated sediments of the Oliveri-Tindari Lagoon,Italy

Five arsenic-resistant bacterial strains designated MT1, MT2, MT3, V1 and V2 were isolated from sediments of the Oliveri-Tindari Lagoon (Italy), which comprises six small lakes whose sediments contain low arsenic concentrations. Phylogenetic analysis of the 16S rRNA gene sequences assigned them to the genus Bacillus. Bacillus sp. strain MT3 showed higher tolerance to As(III) and As(V), as indicated by minimum inhibitory concentrations of 14 and 135 mmol^?1, respectively. Bacillus sp. strain V1 showed growth inhibition at 14 mmol^?1 in the presence of As(III) and at 68 mmol^?1 in the presence of As(V), whereas the arsenic resistance of Bacillus sp. strain MT1 was 10 and 27 mmol^?1 for As(III) and As(V), respectively. The strains Bacillus spp. MT2 and V2 showed low levels of As(III) and As(V) resistance, as it was unable to grow at concentrations>7 and 14 mmol^?1, respectively. The isolated arsenic-resistant Bacillus spp. strains were able to reduce As(V) to As(III), especially Bacillus spp. strain MT3. This study suggests that the isolated bacterial strains play a role in the arsenic biogeochemical cycle of arsenic-poor sediments in the Oliveri-Tindari Lagoon.     

Nitrate levels in fresh vegetables and berries from central Japan

Nitrate concentrations in 326 recent vegetables and berries sold in Niigata, located in central Japan, were investigated. Maximum nitrate concentrations of 6600 mg kg^?1 were detected in samples of komatsuna (Brassica campestris var. perviridis) and mizuna (B. campestris L.). Mean concentrations ranged from 4 mg kg^?1(blueberry) to 3500 mg kg^?1 (mizuna). Concentrations in spinach ranged from 10 to 6000 mg kg^?1 (mean 1500 mg kg^?1). Nitrate intake from spinach and Japanese radish (Raphanus sativus) were estimated to be 0.7 and 0.8 mg kg^?1 day^?1, respectively. These values are equivalent to 19% and 23% of the acceptable daily intake (ADI). Nitrate intake at the 90th percentile was estimated to be 1.3 mg kg^?1 day^?1 (35% of the ADI) from spinach and 1.6 mg kg^?1 day^?1 (43% of the ADI) from Japanese radish.     

The influence of solid matrices on arsenic toxicity to Corophium orientale

In marine ecosystems, benthic organisms are really important because they are the first step in the transfer of contaminants from environment to biota. To this end, this study focused on biological assays with the amphipod Corophium orientale exposed to two different molecules of arsenic: arsenate (As^V), the most abundant form in sediments, and dimethyl-arsinate (DMA), expected to be moderately toxic as an intermediate in the process of detoxification. The toxicity of arsenic compounds was measured after exposure to three different matrices: water, spiked natural sediment and inert spiked quartz sand. LC₅₀ values were calculated for each exposure, and the results confirmed the highest toxicity of As^V, in addition to underlining the importance of matrix of exposure. Water exposure was the matrix which presented the highest toxicity for inorganic arsenic (As^V LC₅₀=3.51 mg L^?1 vs DMA LC₅₀=54.65 mg L^?1), spiked natural sediment demonstrated its capability to chelate arsenate toxicity (As^V LC₅₀=34.27 mg kg^?1 vs. DMA LC₅₀=52.19 mg kg^?1) and spiked quartz sand presented intermediate values for As^V (LC₅₀=25.26 mg kg^?1), whereas for DMA a lower toxicity was registered (LC₅₀=872.35 mg kg^?1). This study can provide some useful data linked with chemical speciation of arsenic and exposure matrix, for improving the correct management of contaminated sediment.     

Seasonal changes in biomass,growth rates and production of subantarctic calanoid copepods in the Bay of Morbihan,Kerguelen Islands

The present study addresses the ecology of two dominant copepod species in the Bay of Morbihan, Kerguelen Archipelago. The biomass of the herbivore Drepanopus pectinatus (from 2 mg m^?3 in winter up to 500 mg m^?3 in summer) is tightly coupled to seasonal changes in chlorophyll a concentration in the region, whereas the biomass of the predatory euchaetiid Paraeuchaeta antarctica increases during two distinct periods over the year: 250 mg m^?3 in early summer, with the recruitment of the annual generation, and 100 mg m^?3 in autumn, with the deposition of lipids as energy reserves in C5 stages and adults. The juvenile growth rates predicted by temperature-dependent models (0.09 day^?1) closely approximate those observed in D. pectinatusin summer, but are much greater than those observed in P. antarctica (from 0.001 to 0.04 day^?1 depending on developmental stages). This difference can be explained by the reproductive strategies and trophic positions of the two species and may also result from the dependence of larval growth on energy reserves in P. antarctica. The production rates are five- and tenfold greater in juvenile stages than in adults, respectively, for D. pectinatus and P. antarctica. The secondary production by D. pectinatusis insufficient to support P. antarcticaduring winter, when the predatory species probably shifts to alternate prey. In summer the predation by P. antarctica accounts for only a minor part of the mortality estimated for D. pectinatus (from 20% to 60% depending on the examined station). At two of the three stations examined in the Bay of Morbihan, the production of P. antarctica could potentially support the dietary requirements of planktivorous seabirds in the region (~2,000 kg prey day^?1 for common diving petrels, Pelecanoides urinatrix, and ~90 kg prey day^?1 for rockhopper penguins, Eudyptes chysocome filholi).     

Evaluation of vitamin E and calcium effects on fluoride toxicity-induced fertility impairment

Chronic fluoride (Fl) toxicity is a serious public health problem globally where drinking water contains more than 1 ppm of Fl. Sodium fluoride (NaF) produced male reproductive system toxicity. The aim of the present study was to evaluate the amelioration of Fl toxicity-induced fertility impairment by vitamin E and calcium during the withdrawal period. The study was carried out on 70 adult male albino rats divided into five main groups: group I control; subdivided into group Ia (maintained on standard diet and water ad libitum for 60 days) and group Ib (maintained on standard diet and water ad libitum for 120 days), group II was administered NaF and subdivided into group IIa (administered NaF for 60 day and sacrificed) and group IIb (administered NaF for 60 day then maintained on standard diet and water ad libitum for a further 60 days), and treated groups III, IV, and V were administered NaF. Rats were maintained during withdrawal from NaF, on vitamin E (10 mg kg^?1 day^?1 for 60 days), calcium (50 mg kg^?1 day^?1 orally for 60 days), and both vitamin E and calcium, respectively. The duration of NaF administration was 60 days at a dose 20 mg kg^?1 day^?1 for all treated groups. The following parameters were determined: body and organ weights, sperm motility, sperm morphology, sperm viability, fertility test, and hormone assays: testosterone, in vitro testosterone production, luteinizing hormone, and follicular stimulating hormone. The combined administration of vitamin E and calcium during withdrawal from NaF showed significant improvement from chronic FL-induced toxicity on male reproductive organs.     

High soil and groundwater arsenic levels induce high body arsenic loads,health risk and potential anemia for inhabitants of northeastern Iran

Arsenic bioavailability in rock, soil and water resources is notoriously hazardous. Geogenic arsenic enters the body and adversely affects many biochemical processes in animals and humans, posing risk to public health. Chelpu is located in NE Iran, where realgar, orpiment and pyrite mineralization is the source of arsenic in the macroenvironment. Using cluster random sampling strategy eight rocks, 23 soils, 12 drinking water resources, 36 human urine and hair samples and 15 adult sheep urine and wool samples in several large-scale herds in the area were randomly taken for quantification of arsenic in rock/soil/water, wool/hair/urine. Arsenic levels in rock/soil/water and wool/hair/urine were measured using inductively coupled plasma spectroscopy and atomic absorption spectrophotometry, respectively. While arsenic levels in rocks, soils and water resources hazardously ranged 9.40–25,873.3 mg kg^?1, 7.10–1448.80 mg kg^?1 and 12–606 μg L^?1, respectively, arsenic concentrations in humans’ hair and urine and sheep’s wool and urine varied from 0.37–1.37 μg g^?1 and 9–271.4 μg L^?1 and 0.3–3.11 μg g^?1 and 29.1–1015 μg L^?1, respectively. Local sheep and human were widely sick and slightly anemic. Hematological examination of the inhabitants revealed that geogenic arsenic could harm blood cells, potentially resulting in many other hematoimmunological disorders including cancer. The findings warn widespread exposure of animals and human in this agroecologically and geopolitically important region (i.e., its proximity with Afghanistan, Pakistan and Turkmenistan) and give a clue on how arsenic could induce infectious and non-infectious diseases in highly exposed human/animals.     

Arsenic contamination of natural waters in San Juan and La Pampa, Argentina

Arsenic (As) speciation in surface and groundwater from two provinces in Argentina (San Juan and La Pampa) was investigated using solid phase extraction (SPE) cartridge methodology with comparison to total arsenic concentrations. A third province, Río Negro, was used as a control to the study. Strong cation exchange (SCX) and strong anion exchange (SAX) cartridges were utilised in series for the separation and preservation of arsenite (As^III), arsenate (As^V), monomethylarsonic acid (MA^V) and dimethylarsinic acid (DMA^V). Samples were collected from a range of water outlets (rivers/streams, wells, untreated domestic taps, well water treatment works) to assess the relationship between total arsenic and arsenic species, water type and water parameters (pH, conductivity and total dissolved solids, TDS). Analysis of the waters for arsenic (total and species) was performed by inductively coupled plasma mass spectrometry (ICP-MS) in collision cell mode. Total arsenic concentrations in the surface and groundwater from Encon and the San José de Jáchal region of San Juan (north-west Argentina within the Cuyo region) ranged from 9 to 357 μg l^?1 As. Groundwater from Eduardo Castex (EC) and Ingeniero Luiggi (LU) in La Pampa (central Argentina within the Chaco-Pampean Plain) ranged from 3 to 1326 μg l^?1 As. The pH range for the provinces of San Juan (7.2–9.7) and La Pampa (7.0–9.9) are in agreement with other published literature. The highest total arsenic concentrations were found in La Pampa well waters (both rural farms and pre-treated urban sources), particularly where there was high pH (typically > 8.2), conductivity (>2,600 μS cm^?1) and TDS (>1,400 mg l^?1). Reverse osmosis (RO) treatment of well waters in La Pampa for domestic drinking water in EC and LU significantly reduced total arsenic concentrations from a range of 216–224 μg l^?1 As to 0.3–0.8 μg l^?1 As. Arsenic species for both provinces were predominantly As^III and As^V. As^III and As^V concentrations in San Juan ranged from 4–138 μg l^?1 to <0.02–22 μg l^?1 for surface waters (in the San José de Jáchal region) and 23–346 μg l^?1 and 0.04–76 μg l^?1 for groundwater, respectively. This translates to a relative As^III abundance of 69–100% of the total arsenic in surface waters and 32–100% in groundwater. This is unexpected because it is typically thought that in oxidising conditions (surface waters), the dominant arsenic species is As^V. However, data from the SPE methodology suggests that As^III is the prevalent species in San Juan, indicating a greater influence from reductive processes. La Pampa groundwater had As^III and As^V concentrations of 5–1,332 μg l^?1 and 0.09–592 μg l^?1 for EC and 32–242 μg l^?1 and 30–277 μg l^?1 As for LU, respectively. Detectable levels of MA^V were reported in both provinces up to a concentration of 79 μg l^?1 (equating to up to 33% of the total arsenic). Previously published literature has focused primarily on the inorganic arsenic species, however this study highlights the potentially significant concentrations of organoarsenicals present in natural waters. The potential for separating and preserving individual arsenic species in the field to avoid transformation during transport to the laboratory, enabling an accurate assessment of in situ arsenic speciation in water supplies is discussed.     

Protective effect of Tamarindus indica fruit pulp extract on collagen content and oxidative stress induced by sodium fluoride in the liver and kidney of rats

Fluorosis is a serious public health problem in many parts of the world. The generation of reactive oxygen species and lipid peroxidation has been considered to play an important role in the pathogenesis of chronic fluoride toxicity. The present study was undertaken to evaluate the protective effect of Tamarindus indica fruit pulp extract on the collagen content and oxidative stress in liver and kidney of fluoride-exposed rats. The first group served as control. The second group received 200 mg L^?1 of sodium fluoride through drinking water. The third and fourth groups received T. indica fruit pulp extract (200 mg kg^?1 body weight) alone and along with fluorinated drinking water respectively, daily by gavage for a period of 90 days. At the end of the experiment, blood samples were collected from all groups, and liver and kidney samples were taken concurrently. Levels of malondialdehyde and glutathione and the activities of superoxide dismutase and catalase were evaluated in the liver and kidney of experimental rats. Furthermore, level of hydroxyproline and histological examination of liver and kidney along with serum biochemical parameters were evaluated. In conclusion, fluoride was determined to cause adverse effects in rats, and the supplementation of tamarind to these animals alleviated the adverse effects of fluoride.     

Seasonal variations in physicochemical characteristics and cyanobacterial diversity of a lake in Northern India

Physicochemical analyses and cyanobacterial diversity of Ramgarh Lake water were performed at five sampling sites during winter, summer, and monsoon seasons. Higher load of solids, carbon, and nutrients were persistent throughout the analysis that indicates the conversion of lake from oligotrophic to eutrophic nature. High nutrients load enhanced cyanobacterial biomass, while low nutrients load produced relatively less biomass. The physicochemical parameters of water samples revealed minimum 2.9 mg L^?1 dissolved oxygen (DO) at site-1 during summer, while maximum (5.6 mg L^?1) at site-4 in monsoon season. Maximum biochemical oxygen demand (BOD) (40 mg L^?1) and chemical oxygen demand (COD) (126 mg L^?1) were recorded at site-1 during summer, whereas minimum BOD (18 mg L^?1) and COD (52 mg L^?1) were evident at site-3 in monsoon season. Minimum concentration of nitrate (0.72 mg L^?1) was recorded at site-3 in summer, whereas maximum 2.7 mg L^?1 was present at site-5 in winter season. The phosphate concentration was maximum (0.52 mg L^?1) at site-5 in summer, and minimum (0.18 mg L^?1) was observed at site-4 in monsoon season. Cyanobacterial diversity was higher during all the seasons, and dominated by the species of Microcystis at all the five sampling sites.     

Impacts of sublethal lead exposure on the hemato-immunological parameters in tilapia (Oreochromis mossambicus)

The effects of exposure of tilapia (Oreochromis mossambicus) to sublethal concentrations of lead on hematological and immunological parameters were investigated. The fish were semistatically exposed to low (L) (0.5 mg L^?1), medium (M) (2.5 mg L^?1), and high (H) (5 mg L^?1) lead concentrations for 14 days. At the end of the trial, red blood cell (RBC) count, hematocrit (Hct) ratio and hemoglobin levels showed significant decreases in M and H groups, while RBC was significantly increased in L group compared to control group. Lysozyme activity showed a decrease in all groups on day 14 compared to control. A decrease in myeloperoxidase activity was seen in M and H groups on day 7, and in all treatment groups on day 14. In conclusion, it was found that exposure of O. mossambicus to lead concentrations affected hematological and immunogical parameters adversely.     

Assessment of heavy metals in a soil contaminated by oil spill: a case study in Nigeria

Surface and subsurface soil samples contaminated with crude oils were collected from an impacted site at Bodo City in the Niger Delta, Nigeria, after a field reconnaissance survey. An uncontaminated soil sample collected 100 m from the impacted site, but within the same geographical area, was used as a control. Trace elements such as, As, Cu, Cr, Cd, Fe, Pb, Ba, Ni, V, Hg and cation-exchange capacity constituents of the contaminated and uncontaminated soils were determined by atomic absorption spectroscopy. Trace element concentrations were: Cu, 0.5–13.4 mg kg^{? 1}; Cr, 0.2–0.8 mg kg^{? 1}; Fe, 6.2–8.7 mg kg^{? 1}; Ba 80.0–108.0 mg kg^{? 1}; Ni, 0.6–4.8 mg kg^{? 1}; and V, 4.0–9.4 mg kg^{? 1}; cation-exchange capacity ranged from 43.6 to 57.2 mg kg^{? 1} in surface and subsurface soils. Results showed that eigenvalues for the two first principal components represent up to 49% of the total variance. A positive correlation of the first principal component with Cu, Cr and cation-exchange capacity shows pollution from oil spillage, while a positive correlation of the second principal component with Cr, Fe, V, and dissolved oxygen (DO) shows both oil pollution and allochthonous inputs.