Potable groundwater quality in some villages of Haryana, India: focus on fluoride

The fluoride concentration in ground water was determined in ten villages of Rohtak district of Haryana state (India). The fluoride concentration in the underground water of these villages varied from 0.034-2.09 mg/l. Various other water quality parameters, viz., pH, electrical conductivity, total dissolved salts, total hardness, total alkalinity sodium, potassium, calcium, magnesium, carbonate, bicarbonate, chloride and sulfate were also measured. A systematic calculation of correlation coefficients among different physicochemical parameters indicated considerable variations among the analyzed samples with respect to their chemical composition. Majority of the samples do not comply with Indian as well as WHO standards for most of the water quality parameters measured. Overall water quality was found unsatisfactory for drinking purposes. Fluoride content was higher than permissible limit in 50% samples.     

Persistence of carbaryl and its risk assessment through consumption of treated grapes

The average initial deposits of carbaryl were observed to be 1.4 and 3.1?mg?kg^?1, respectively, following four applications of the insecticide at 4.95 and 9.9?kg active ingredient per hectare. Residues of carbaryl dissipated below its limit of quantification of 50?µg?kg^?1 after 7 and 10 days at single and double the application dosage, respectively. The half-life values (t _1/2) of carbaryl were worked out to be 1.3 and 0.7 days, respectively, at single and double dosages. The acceptable daily intake (ADI) for carbaryl has been fixed at 8?µg?kg^?1 body weight per day. Keeping in view the residues of carbaryl observed one day after the last application, a child of 10?kg and an adult of 60?kg will have an intake of 77 and 154?µg carbaryl after consumption of 100 and 200?g grapes, in comparison to its ADI of 80 and 480?µg; thus, no health risk is to be expected. Therefore, a waiting period of 1 day has been suggested for the safe consumption of carbaryl-treated grapes to avoid any health hazards.     

Cement-based solidification/stabilization of lead-contaminated soil at a utah highway construction site

This article describes portland cement-based solidification/stabilization (S/S) treatment of heavy metal-contaminated soil. The soil was discovered during highway construction in West Jordan, Utah. Environmental Chemical Corporation (ECC) performed an emergency response to remediate the soil under contract with the EPA and the United States Bureau of Reclamation (USBR). The soil was treated by S/S. Treatment of the soil, contaminated with lead and arsenic, involved: (1) excavation, (2) size segregation, (3) reduction of oversized particles, (4) addition and mixture of portland cement and cement kiln dust, and (5) beneficial reuse of the treated soil as a subbase. S/S treatment successfully reduced Toxicity Characteristic Leaching Procedure (TCLP) concentrations of the contaminants to below regulatory levels.     

A HYDROCLIMATIC APPLICATION STRATEGY FOR THE POISSON PARTIAL DURATION MODEL1

ABSTRACT: A strategy for formulating and testing the Poisson partial duration extreme value model is presented. The procedure is demonstrated using recorded Streamflow series from a humid subtropical region of the southern United States. The observed data series are partitioned by climatic causes and tested for both the Poisson assumption and the validity of the exponential as marginal distributions. Several statistical tests are utilized in making these determinations. Some important aspects of the model as applied to humid climates are demonstrated. It was found that a majority of Streamflow series could be represented by the model and that significant differences do exist between the arrival structures of floods resulting from different climatic mechanisms. However, these differences generally do not exist in the distribution of the flood magnitudes. In addition, it is possible that model validity is restricted by drainage basin size.     

Comparative assessment of pesticide residues in grain, soil, and water from IPM and non-IPM trials of basmati rice

The integrated pest management (IPM) modules of pesticide schedule on Basmati rice were validated at field experiments conducted in Northern India for consecutive 3 years (2005–2008). The pesticide residues were found below the detectable limit (<0.01–0.001 mg/kg) in soil and irrigation water samples of Kaithal region. In Dehra Dun region of Uttrakhand, the residues of carbendazim in rice grains and soil were detected below <0.01 mg/kg level. In second year experiments (2006–2007), only four non-IPM soil samples indicated the presence of chlorpyrifos and endosulfan in the range of ND <0.001 to 0.07 mg/kg, out of 45 samples analyzed. Carbendazim applied as seed treatment at Dehradun and Kaithal field trials was found below detectable limit in both IPM and non-IPM rice grains (<0.01 mg/kg) and irrigation water (0.01 μl/ml). Chlorpyrifos was detected in five water samples from Kaithal and one from Pant Nagar in the range of 0.003–0.006 μl/L, α- and β-isomer of endosulfan in the range of 0.005–0.03, and 0.005–0.02 μl/ml, respectively, in one sample from Pant Nagar and two from Kaithal, out of a total of 22 samples. In the region of Uttrakhand and Uttar Pradesh during 2007–2008, four non-IPM samples of soil indicated trace levels of endosulfan, out of 16 samples analyzed. The residues were detected below detection limit for carbendazim (<0.01 mg/kg) in soil samples of Dehradun IPM fields and for endosulfan and carbendazim (0.001–0.01 μl/L) in water samples each from IPM and non-IPM fields of Uttar Pradesh. The results of 3-year trials of IPM module indicated basmati rice as safe and economical with pesticide residue-free rice grains.     

Biodiversity and present status of freshwater fishes in Lohit river basin of India

Lohit is a major tributary of the river Brahmaputra in India and is famous for its rich and diverse fish fauna. The river has a difficult terrain, but has high hydropower potential. A large number of storage-based hydropower plants are envisaged on this river in the near-future. This study aims at presenting the existing diverse fish fauna in Lohit river basin. A total of 74 fish species are identified in this river basin and can be classified into seven orders, 20 families, and 52 genera. Further, it has been highlighted that there are seven species which have been categorized as endangered, 12 species are categorized to be vulnerable, three species have been categorized as data-deficient, and the remaining species are in the least concern category. It is expected that the construction of proposed storage-based power plants in this basin will affect the flow and storage characteristics, as well as the temperature of the water, which, in turn, will affect the rich fish fauna. This study emphasizes the need for preparing a comprehensive plan for the adoption of appropriate in situ conservation measures, as well as an awareness program, so as to save the rich and diverse fish fauna of Lohit river basin.     

Novel degradation pathway of 4-chloro-2-aminophenol via 4-chlorocatechol in Burkholderia sp. RKJ 800

Burkholderia sp. RKJ 800 utilized 4-chloro-2-aminophenol (4C2AP) as the sole carbon and energy source and degraded it with release of chloride and ammonium ions. The metabolic pathway of degradation of 4C2AP was studied and a novel intermediate, 4-chlorocatechol was identified as a major degradation product of 4C2AP using high-performance liquid chromatography and gas chromatography–mass spectrometry. Enzyme activities for 4C2AP-deaminase and 4-chlorocatechol-1,2-dioxygenase were detected in the crude extracts of the 4C2AP-induced cells of strain RKJ 800. The activity of the 4C2AP-deaminase confirmed the formation of 4-chlorocatechol from 4C2AP and the 4-chlorocatechol-1,2-dioxygenase activity suggested the cleavage of 4-chlorocatechol into 3-chloro-cis,cis-muconate. On the basis of the identified metabolites, we have proposed a novel degradation pathway of 4C2AP for Burkholderia sp. RKJ 800. Furthermore, the potential of Burkholderia sp. RKJ 800 to degrade 4C2AP in soil was also investigated using microcosm studies under laboratory conditions. The results of microcosm studies conclude that Burkholderia sp. RKJ 800 was able to degrade 4C2AP in soil and may be used to remediate 4C2AP-contaminated site. This is the first report of (1) the formation of 4-chlorocatechol and 3-chloro-cis,cis-muconate in the degradation pathway of 4C2AP and (2) bioremediation of 4C2AP by any bacterium.     

Silver-modified clinoptilolite for the removal of Escherichia coli and heavy metals from aqueous solutions

This paper investigates the potential of using the silver antibacterial properties combined with the metal ion exchange characteristics of silver-modified clinoptilolite to produce a treatment system capable of removing both contaminants from aqueous streams. The results have shown that silver-modified clinoptilolite is capable of completely eliminating Escherichia coli after 30-min contact time demonstrating its effectiveness as a disinfectant. Systems containing both E. coli and metals exhibited 100 % E. coli reduction after 15-min contact time and maximum metal adsorption removal efficiencies of 97, 98, and 99 % for Pb²⁺, Cd²⁺, and Zn²⁺ respectively after 60 min; 0.182–0.266 mg/g of metal ions were adsorbed by the zeolites in the single- and mixed-metal-containing solutions. Nonmodified clinoptilolite showed no antibacterial properties. This study demonstrated that silver-modified clinoptilolite exhibited high disinfection and heavy metal removal efficiencies and consequently could provide an effective combined treatment system for the removal of E. coli and metals from contaminated water streams.     

Induction of apoptosis in A431 cells via ROS generation and p53-mediated pathway by chloroform fraction of Argemone mexicana (Pepaveraceae)

Environmental Science and Pollution Research - Argemone mexicana(Pepaveraceae) is an important medicinal plant commonly known as ‘maxican prickly poppy’ and is traditionally used to...