Arsenic toxicity in garden cress (Lepidium sativum Linn.): significance of potassium nutrition

In a hydroponic culture, experiments were performed to study the influence of potassium (K) supplementation (0, 20, 40, 60, 80, and 100 mg L^?1) on the arsenic (As; 0, 8, and 10 mg L^?1)-accrued changes in growth traits (plant biomass, root–shoot length) and the contents of lepidine, As and K, in garden cress (Lepidium sativum Linn.) at 10 days after treatment. The changes in these traits were correlated with shoot proline content, protein profile, and the activities of antioxidant enzymes namely superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), glutathione reductase (GR, EC 1.8.1.7), and ascorbate peroxidase (APX, EC 1.11.1.11). In general, As-alone treatments significantly decreased the growth traits but lead to significant enhancements in shoot proline and enzyme activities. K-supplementation to As-treated L. sativum seedlings decreased shoot-As content, reduced As-induced decreases in growth traits but enhanced the content of shoot proline, and the activities of the studied enzymes maximally with K₁₀₀ + As₈ and As₁₀ mg L^?1. Both 8 and 10 mg L^?1 of As drastically downregulated the shoot proteins ranging from 43–65 kDa. With As₁₀ mg L^?1, there was a total depletion of protein bands below 23 kDa; however, K₈₀ mg L^?1 maximally recovered and upregulated the protein bands. Additionally, protein bands were downregulated (at par with As-alone treatment) above K₈₀ mg L^?1 level. Interestingly, As-stress increased lepidine content in a dose-dependent manner which was further augmented with the K-supplementation. It is suggested that K protects L. sativum against As-toxicity by decreasing its accumulation and strengthening antioxidant defense system and protein stability.     

Multivariate analysis of accumulation and critical risk analysis of potentially hazardous elements in forage crops

Environmental Monitoring and Assessment - Few estuaries remain unaffected by water management and altered freshwater deliveries. The Caloosahatchee River Estuary is a perfect case study for...     

Phosphate-arsenate relations to affect arsenic concentration in plant tissues,growth, and antioxidant efficiency of sunflower (Helianthus annuus L.) under arsenic stress

Environmental Science and Pollution Research - Relations between phosphate and arsenate are important but inconsistent to influence arsenic (As) phytotoxicity depending on many plant and soil...     

Environmental toxicology and associated human health risks

Environmental Science and Pollution Research -     

A field study of lead phytoextraction by various scented Pelargonium cultivars

Phytoremediation appears to be a promising technique for metal soil clean up, although its successful application on a large scale still remains a challenge. Field experiments for six scented Pelargonium cultivars, conducted on two Pb-contaminated calcareous and acidic soils, revealed vigorous plant growth, with no symptoms of morpho-phytotoxicity in spite of high Pb accumulation levels. Lead contents in the harvestable parts of all plants grown on the acidic and more contaminated soil were significantly higher than those grown on the calcareous soil. Three cultivars (Attar of Roses, Clorinda and Atomic Snowflake) are Pb-hyperaccumulator plants: they accumulated more than 1000 mg Pb kg⁻¹ DW, with high biomass produced.     

Polycyclic aromatic hydrocarbons in crude oil-contaminated soil: A two-step method for the isolation and characterization of PAHs

A two-step analytical method is developed for the isolation and characterization of polycyclic aromatic hydrocarbons (PAHs) in crude oil contaminated soil. In the first step, those crude oil components were isolated which are easily mobilized with water from the contaminated soil (determination of groundwater pollution potential). In the second step, the fraction containing the remaining crude oil compounds was extracted using toluene. After the cleanup of the fractions, both fractions were analyzed using high-performance liquid chromatography (HPLC). The HPLC of the toluene extracted fraction shows that along with the sixteen priority pollutants from the US-EPA list, many other polycyclic aromatic hydrocarbons (PAHs) are present as well. It is evident from the chromatograms that a significant amount of PAHs are present as is also the case in the fractions eluted by water. The described method allows the determination of total organic pollutants from crude oil, some of them being potential groundwater contaminants. The major part of the total pollutants could not be mobilized by water and therefore remains in the soil, which was extracted in the second step.     

Protective role of L-ascorbic acid against cypermethrin-induced oxidative stress and lipid peroxidation in Wistar rats

Cypermethrin is a synthetic pyrethroid insecticide used for pest control in agriculture and as an acaricide in man and animals. This study was undertaken with the objective to investigate the propensity of cypermethrin to induce oxidative stress in rats following repetitive dermal exposure and its possible attenuation by L-ascorbic acid. Results obtained showed that cypermethrin significantly (p < 0.05) increased malonaldehyde levels, activity of catalase in rat erythrocytes and plasma protein levels. Whereas, activities of glutathione (GSH), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) were significantly (p < 0.05) reduced in the cypermethrin exposed rats as compared to the control. Supplementation of L-ascorbic acid in cypermethrin-exposed rats decreased lipid peroxidation of erythrocytes, total plasma protein and catalase activity significantly (p < 0.05) compared to non-cypermethrin-exposed group. However, L-ascorbic acid did not alleviate the negative effects of cypermethrin on the activities of SOD and GSH. This study revealed that the presence of L-ascorbic acid diminishes the adverse effects of cypermethrin on some oxidative stress parameters.     

Determination of pesticide residues in muscle of Cyprinus carpio from River Ravi

The levels of dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE), endosulfan, endosulfan sulfate, carbofuran, and cartap were determined in muscles of Cyprinus Carpio sampled from 10 different sites of River Ravi between Shahdara to Balloki Headworks to assess level of contamination of these pesticides by GC-ECD (gas chromatograph equipped with electron capture detector) method. All fish samples were found contaminated with different concentrations of DDT, DDE, endosulfan, and carbofuran. DDT and DDE concentrations were higher than maximum residue limits (MRL) in food standards, while endosulfan sulfate and cartap were not detected. These findings indicate that pesticide concentrations in fish muscles decreased in the order: DDT > DDE > carbofuran > endosulfan. Furthermore, the sampling sites after Degh fall and beyond Hudiara Nulla Fall river sampling sites were more polluted. It is proposed that constant monitoring programs are needed to assess potential exposure risks.     

Water resources management strategy for adaptation to droughts in China

Water Scarcity and drought are recurrent phenomena in China. In the context of environmental change, an increasing tendency in drought frequency and severity is observed in China in recent years. Therefore, it is imperative to take necessary initiatives to reduce the impacts of drought. In this paper, an attempt is made to identify the best water management strategies to cope with droughts. For this objective the records of historical droughts and their impacts in China over the period of 1950?C2009 are analyzed. It is observed that the drought affected area has increased nearly by 12 folds and the drought damaged area has increased by about 22 times in China in last 60?years. Over 87,000 reservoirs were built with a total water storage capacity of about 7,064 billion m³ to cope with droughts. However, this structural supply-based management strategy was not enough to meet the increasing water demand caused by rapid economic development and population growth. A typical relationship between socio-economic development and water resources management strategy to attain sustainability in water management is developed in this study. The relationship shows that the demand-side water management strategies can be the best option to meet the challenges posed by increased severity of drought, population growth, economic development and possible climate change. The concept is later verified through the analysis of changing pattern of water consumptions by different sectors in last 60?years.     

Microelectrophoretic study of environmentally induced DNA damage in fish and its use for early toxicity screening of freshwater bodies

This study investigates the potential of the comet and micronucleus assays of fish DNA as a means of screening the toxicity of aquatic environments. Catla catla and Cirrhinus mrigala collected from the River Chenab in Pakistan were used as a case study for the application of comet and micronucleus techniques. Comet and micronucleus assays were used to compare DNA damage in C. catla and C. mrigala collected from polluted areas of the River Chenab and farmed fish. Atomic absorption spectrophotometry showed an acute level of toxicity from Cd, Cu, Mn, Zn, Pb, Cr, Sn, and Hg in river water. Comet assay showed significant (p < 0.05) DNA damage in C. catla representing 17.33 ± 2.42, 11.53 ± 2.14, and 14.17% DNA in the comet tail, averaged from three sites of the polluted area of the river. Tail moment was observed as 10.06 ± 2.71, 3.11 ± 0.74, and 14.70 ± 1.89, while olive moment was 8.85 ± 1.84, 3.83 ± 0.76, and 7.11 ± 0.73, respectively. Highly significant (p < 0.01) damage was reported in C. mrigala as 37.29 ± 2.51, 34.96 ± 2.53, and 38.80 ± 2.42% DNA in comet tail, tail moment was 23.48 ± 3.90, 19.78 ± 4.26, and 14.30 ± 1.82, and olive moment was 16.22 ± 2.04, 13.83 ± 1.96, and10.99 ± 0.90. Significant (p < 0.05) differences were observed in genotoxicity between farmed and polluted area fish. Micronucleus assay showed a similar picture of significant difference in respect to single and double micronucleus induction: i.e., 23.20 ± 4.19 and 2.80 ± 1.07‰ in C. catla and 44.80 ± 3.73 and 06.20 ± 0.97‰, respectively, in C. mrigala. Nuclear abnormalities were found as 6.00 ± 0.84 and 09.60 ± 1.72/thousand cells, respectively, in both species. The results of this study suggest that these novel fish DNA damage assays can be used as an expedient toxicity screening for aquatic environments.