Fate of arsenic in swine waste from concentrated animal feeding operations

Swine diets are often supplemented by organoarsenicals, such as 3-nitro-4-hydroxyphenylarsonic acid (roxarsone) to treat animal diseases and promote growth. Recent work reported roxarsone degradation under anaerobic conditions in poultry litter, but no such data exist for swine wastes typically stored in lagoons nearby concentrated animal feeding operations (CAFOs). The objectives of this study were to: (i) characterize a suite of swine wastes collected from 19 randomly selected CAFOs for soluble arsenate [As(V)], arsenite [As(III)], dimethylarsenic acid (DMA), monomethylarsonic acid (MMA), 3-amino-4-hydroxyphenylarsonic acid (3-HPPA), p-arsanilic acid, and roxarsone, and (ii) determine the geochemical fate of roxarsone in storage lagoons nearby CAFOs. Swine waste suspensions were spiked with roxarsone and incubated under dark/light and aerobic/anaerobic conditions to monitor roxarsone degradation kinetics. Arsenic speciation analysis using liquid chromatography and inductively coupled plasma mass spectrometry (LC-ICPMS) illustrated the prevalence of As(V) in swine waste suspensions. Roxarsone underwent degradation to either organoarsenicals (3-HPPA) or As(V) and a number of unidentified metabolites. Roxarsone degradation occurred under anaerobic conditions for suspensions low in solids content, but suspensions higher in solids content facilitated roxarsone degradation under both anaerobic and aerobic conditions. Increased solids content enhanced roxarsone degradation kinetics under aerobic conditions. According to current waste storage and sampling practices, arsenic in swine wastes stored in lagoons has been overlooked as a possible environmental health issue.     

High uptake of 2,4,6-trinitrotoluene by vetiver grass--potential for phytoremediation?

2,4,6-Trinitrotoluene (TNT) is a potent mutagen, and a Group C human carcinogen that has been widely used to produce munitions and explosives. Vast areas that have been previously used as ranges, munition burning, and open detonation sites are heavily contaminated with TNT. Conventional remediation activities in such sites are expensive and damaging to the ecosystem. Phytoremediation offers a cost-effective, environment-friendly solution, utilizing plants to extract TNT from contaminated soil. We investigated the potential use of vetiver grass (Vetiveria zizanioides) to effectively remove TNT from contaminated solutions. Vetiver grass plants were grown in hydroponic systems containing 40 mg TNTL(-1) for 8d. Aqueous concentrations of TNT reached the method detection limit ( approximately 1 microg L(-1)) within the 8-d period, demonstrating high affinity of vetiver for TNT, without any visible toxic effects. Results from this preliminary hydroponic study are encouraging, but in need of verification using TNT-contaminated soils.     

Detecting Extinction Risk from Climate Change by IUCN Red List Criteria

Anthropogenic climate change is a key threat to global biodiversity. To inform strategic actions aimed at conserving biodiversity as climate changes, conservation planners need early warning of the risks faced by different species. The IUCN Red List criteria for threatened species are widely acknowledged as useful risk assessment tools for informing conservation under constraints imposed by limited data. However, doubts have been expressed about the ability of the criteria to detect risks imposed by potentially slow‐acting threats such as climate change, particularly because criteria addressing rates of population decline are assessed over time scales as short as 10 years. We used spatially explicit stochastic population models and dynamic species distribution models projected to future climates to determine how long before extinction a species would become eligible for listing as threatened based on the IUCN Red List criteria. We focused on a short‐lived frog species (Assa darlingtoni) chosen specifically to represent potential weaknesses in the criteria to allow detailed consideration of the analytical issues and to develop an approach for wider application. The criteria were more sensitive to climate change than previously anticipated; lead times between initial listing in a threatened category and predicted extinction varied from 40 to 80 years, depending on data availability. We attributed this sensitivity primarily to the ensemble properties of the criteria that assess contrasting symptoms of extinction risk. Nevertheless, we recommend the robustness of the criteria warrants further investigation across species with contrasting life histories and patterns of decline. The adequacy of these lead times for early warning depends on practicalities of environmental policy and management, bureaucratic or political inertia, and the anticipated species response times to management actions. Detección del Riesgo de Extinción a partir del Cambio Climático por medio del Criterio de la Lista Roja de la UICNKeith et al.     

Characterization of cadmium-resistant Klebsiella pneumoniae MCC 3091 promoted rice seedling growth by alleviating phytotoxicity of cadmium

Environmental Science and Pollution Research - Cadmium (Cd) phytotoxicity in agricultural land is a major global concern now-a-days resulting in very poor yield. Plant growth-promoting...     

Monitoring and evaluating the spatiotemporal variations of the water quality of a stretch of the Bhagirathi-Hugli River,West Bengal,India, using geospatial technology and integrated statistical methods

Environmental Science and Pollution Research - Water quality is a critical environmental issue because all forms of life depend on the water. The present study primarily focused on the...     

Food selectivity and reproductive biology of small indigenous fish Indian river shad,Gudusia chapra (Hamilton, 1822) in a large tropical reservoir

Environmental Science and Pollution Research - Assessment of life history strategies of economically important small indigenous fishes (SIF) which are rich in nutritive values is essential and...