Impact of precipitation disparity on groundwater fluctuation in a semi-arid region (Vellore district) of southern India using geospatial techniques

Environmental Science and Pollution Research - In the present study, impact of precipitation disparity on groundwater level fluctuation was carried out in Vellore district, Tamil Nadu, India, using...     

Mortality due to haematological cancer in cities close to petroleum refineries in Spain

Controversy exists as to whether working or living in the vicinity of a petroleum refinery (RF) increases the risk of haematological cancer (HC). The European Pollutant Release and Transfer Register obliges petroleum refineries to notify their emissions of toxic substances which include carcinogenic substances. Our objective is to determine if living in the proximity of an RF is associated with a greater risk of mortality due to HC in the census tracts (CTs) of the Spanish cities of Bilbao, Cartagena, Castellón, La Coruña, Huelva, and Santa Cruz de Tenerife. This is an ecological study of mortality in the years 1996–2007 which includes 968 CTs with 1,263,371 inhabitants. Exposure has been measured as the distance from the centroid of each CT to the RF. The Besag–York–Mollié autoregressive spatial model has been fitted by R-INLA to estimate the relative risk (RR) and 95 % credible intervals (95 % CrI) for distance in quintiles. The most distant quintile has been taken as the reference. A total of 2,574 persons died of HC. The distances from the CTs to RFs ranged from 0.5 to 22.5 km (median?=?7.6 km). All of the RRs for the quintiles of distances in Huelva were greater than 1. Statistically significant excess risk was shown in Cartagena in the nearest CT (1.8 to 6.8 km; RR?=?1.43, 95 % CrI 1.02 to 2.02). Radial effects have not been detected between the CT of residence and the petroleum RF in mortality due to HC in any of the cities.     

A Call for Urgent Monitoring of Food and Water Security Based on Relevant Indicators for the Arctic

This perspective paper argues for an urgent need to monitor a set of 12 concrete, measurable indicators of food and water security in the Arctic over time. Such a quantitative indicator approach may be viewed as representing a reductionist rather than a holistic perspective, but is nevertheless necessary for actually knowing what reality aspects to monitor in order to accurately understand, quantify, and be able to project critical changes to food and water security of both indigenous and non-indigenous people in the Arctic. More relevant indicators may be developed in the future, taking us further toward reconciliation between reductionist and holistic approaches to change assessment and understanding. However, the potential of such further development to improved holistic change assessment is not an argument not to urgently start to monitor and quantify the changes in food and water security indicators that are immediately available and adequate for the Arctic context.     

A New Audit Technique for EPA Method 25

A simple, inexpensive, and accurate technique for evaluating or auditing the sampling, recovery, and analytical phases of EPA Source Reference Method 25 has been developed. The technique involves spiking a U-shaped stainless steel cartridge containing Tenax® with known quantities of selected organic compounds and thermally desorbing them at temperatures from 160°C to 180°C to generate organic vapors quantitatively. The major advantages of this technique are that no other measurement methods can be used to determine the generated organic concentrations in lieu of Method 25; and that the cartridge can easily be taken to the field for evaluation. The organic compounds generated in test runs are collected and analyzed using the Method 25 procedure. The generation of organics is quantitative and recoveries were found to be 100 ± 10%. The time required for desorption of the majority of organics is generally less than forty-five minutes at a flow rate of 100 mL/min; however, based on laboratory experience the recommended sampling time is sixty minutes. These spiked cartridges are stable at room temperature over a two-month period. Results of interlaboratory studies showed close agreement with the expected concentrations based on calculations from the mass loadings and sample volumes.     

A validated 2-D diffusion–advection model for prediction of drift from ground boom sprayers

Correct field drift prediction is a key element in environmental risk assessment of spraying applications. A reduced order drift prediction model based on the diffusion–advection equation is presented. It allows fast assessment of the drift potential of specific ground boom applications under specific environmental wind conditions that obey the logarithmic wind profile. The model was calibrated based on simulations with a validated Computational Fluid Dynamics (CFD) model. Validation of both models against 38 carefully conducted field experiments is successfully performed for distances up to 20 m from the field edge, for spraying on flat pasture land. The reduced order model succeeded in correct drift predictions for different nozzle types, wind velocities, boom heights and spray pressures. It used 4 parameters representing the physical aspects of the drift cloud; the height of the cloud at the field edge, the mass flux crossing the field edge, the settling velocity of the droplets and the turbulence. For the parameter set and range considered, it is demonstrated for the first time that the effect of the droplet diameter distribution of the different nozzle types on the amount of deposition spray drift can be evaluated by a single parameter, i.e., the volume fraction of droplets with a diameter smaller than 191 μm. The reduced order model can be solved more than 4 orders of magnitude faster than the comprehensive CFD model.     

Impact of carbon nanomaterials on the behaviour of 14C-phenanthrene and 14C-benzo-[a] pyrene in soil

The impact of fullerene soot (FS), single-walled (SWCNTs) and multi-walled (MWCNTs) carbon nanotubes on the behaviour of two ¹⁴C-PAHs in sterile soil was investigated. Different concentrations of carbon nanomaterials (0, 0.05, 0.1 and 0.5%) were added to soil, and ¹⁴C-phenanthrene and ¹⁴C-benzo[a]pyrene extractability assessed over 80 d through dichloromethane (DCM) and hydroxypropyl-β-cyclodextrin (HPCD) shake extractions. Total ¹⁴C-PAH activity in soils was determined by combustion, and mineralisation of ¹⁴C-phenanthrene was monitored over 14 d, using a catabolically active pseudomonad inoculum. No significant loss of ¹⁴C-PAH-associated activity from CNM-amended soils was observed over the ‘aging’ period. CNMs had a significant impact on HPCD-extractability of ¹⁴C-PAHS; extractability decreased with increasing CNM concentration. Additionally, ¹⁴C-phenanthrene mineralisation was inhibited by the presence of CNMs at concentrations of ≥0.05%. Differences in overall extents of ¹⁴C-mineralisation were also apparent between CNM types. It is suggested the addition of CNMs to soil can reduce PAH extractability and bioaccessibility, with PAH sorption to CNMs influenced by CNM type and concentration.     

Effects of waterborne exposure to 4-nonylphenol on plasma sex steroid and vitellogenin concentrations in sexually mature male carp (Cyprinus carpio)

4-Nonylphenol (NP) has been shown to elicit estrogenic responses both in vivo and in vitro. The mechanism by which NP exerts estrogenic and other endocrine-modulating effects in vivo remains unclear, however. The goal of this study was to evaluate the ability of NP to elicit estrogenic responses through indirect mechanisms of action involving the modulation of endogenous steroid hormone concentrations. Sexually mature male common carp (Cyprinus carpio) were exposed to aqueous NP concentrations ranging from <0.05 to 5.4 microg NP/l for 28-31 d. Approximately 0.5-3.5 ppm of NP was detected in pooled plasma samples or tissue samples from the carp studied. NP exposure did not significantly increase plasma concentrations of 17beta-estradiol (E2), testosterone (T) or vitellogenin (VTG). Excluding outliers, plasma E2 concentrations ranged from <175 to 700 pg E2/ml. T concentrations ranged from 940 to 24,700 pg T/ml plasma. The greatest VTG concentration detected was 52 microg/ml. One-third of the plasma samples tested contained <1 microg VTG/ml. Overall, the results of this study did not support the hypothesis that exposure to waterborne NP can modulate concentrations of steroid hormones in the plasma of sexually mature male carp. The results did, however, raise a number of questions regarding the utility of estradiol equivalent (EEQ) estimates as a means of predicting in vivo effects of estrogenic substances. Furthermore, they provide information regarding the concentrations and variability of E2, T, and VTG in the plasma of sexually mature male carp, which may aid in design and interpretation of future studies.     

Validation studies of turbulence closure schemes for high resolutions in mesoscale meteorological models – A case of gas dispersion at the local scale

This work is a contribution to a large project, aimed at the development of an advanced environmental assessment modelling system to be used in Japan. The modelling system here considered consisted of the RAMS and HYPACT coupled models. The RAMS code was modified to properly simulate local scale phenomena using a fine mesh size of 250 m. In this direction, the main aim here was to investigate the effect of the choice of the turbulence closure scheme on the dispersion of pollutants. Our modified version of the RAMS/HYPACT model chain was validated using field experiments which were carried out by the Japan Atomic Energy Research Institute (JAERI) in the area of Mt. Tsukuba (Japan). The mean flow, turbulence and concentration fields obtained using two alternative turbulence closure schemes are compared. A discussion on the different performances of the turbulence closures is presented and the influence of the closure schemes over the plume dispersion is investigated.     

Comparison among model estimates of critical loads of acidic deposition using different sources and scales of input data

The critical load (CL) of acidic atmospheric deposition represents the load of acidity deposited from the atmosphere to the earth’s surface at which harmful acidification effects on sensitive biological receptors are thought to occur. In this study, the CL for forest soils was estimated for 27 watersheds throughout the United States using a steady-state mass balance approach based on both national and site-specific data and using different approaches for estimating base cation weathering. Results suggested that the scale and source of input data can have large effects on the calculated CL and that the most important parameter in the steady-state model used to estimate CL is base cation weathering. These results suggest that the data and approach used to estimate weathering must be robust if the calculated CL is to be useful for its intended purpose.