Effects of benzo[a]pyrene as an environmental pollutant and two natural antioxidants on biomarkers of reproductive dysfunction in male rats

Benzo[a]pyrene (B[a]P) is an environmental toxicant and endocrine disruptor. Therefore, the aim of the present study was to investigate the toxicity of B[a]P in testis of rats and also to study the role of silymarin and thymoquinone (TQ) as natural antioxidants in the alleviation of such toxicity. Data of the present study showed that levels of testosterone, estrogen and progesterone were significantly decreased after treatment of rats with B[a]P. In addition, B[a]P caused downregulation of the expressions of steroidogenic enzymes including CYP17A1 and CP19A1, and decreased the activity of 17-β hydroxysteroid dehydrogenase (17β-HSD). Moreover, B[a]P decreased the activities of antioxidant enzymes including catalase (CAT), glutathione peroxidase (GP_X) and superoxide dismutase (SOD), and significantly increased free radicals levels in testis of male rats. However, pretreatment of rats with silymarin prior to administration of B[a]P was found to restore the level of free radicals, antioxidant status, and activities of steroidogenic enzymes to their normal levels in testicular tissues. Moreover, histopathological finding showed that silymarin recovered the abnormalities occurred in tubules caused by B[a] P in testis of rats. On the other hand, TQ showed pro-oxidant effects and did not ameliorate the toxic effects of B[a] P on the testicular tissue since it decreased antioxidant enzymes activities and inhibited the protein expression of CYP11A1 and CYP21A2 compared to control rats. Moreover, TQ decreased the levels of testosterone, estrogen, and progesterone either in the presence or absence of B[a]P. It is concluded that B[a]P decreased testosterone levels, inhibited antioxidant enzymes activities, caused downregulation of CYP isozymes involved in steroidogenesis, and increased free radical levels in testis. Moreover, silymarin was more effective than TQ in restoring organism health and alleviating the deleterious effects caused by B[a]P in the testis of rats. Due to its negative impact, it is highly recommended to limit the use of TQ as a dietary supplement since millions of people in the Middle East are using it to improve their health.

     

First inter-laboratory comparison exercise for the determination of anticancer drugs in aqueous samples

The results of an inter-laboratory comparison exercise to determine cytostatic anticancer drug residues in surface water, hospital wastewater and wastewater treatment plant effluent are reported. To obtain a critical number of participants, an invitation was sent out to potential laboratories identified to have the necessary knowledge and instrumentation. Nine laboratories worldwide confirmed their participation in the exercise. The compounds selected (based on the extent of use and laboratories capabilities) included cyclophosphamide, ifosfamide, 5-fluorouracil, gemcitabine, etoposide, methotrexate and cisplatinum. Samples of spiked waste (hospital and wastewater treatment plant effluent) and surface water, and additional non-spiked hospital wastewater, were prepared by the organising laboratory (Jo?ef Stefan Institute) and sent out to each participant partner for analysis. All analytical methods included solid phase extraction (SPE) and the use of surrogate/internal standards for quantification. Chemical analysis was performed using either liquid or gas chromatography mass (MS) or tandem mass (MS/MS) spectrometry. Cisplatinum was determined using inductively coupled plasma mass spectrometry (ICP-MS). A required minimum contribution of five laboratories meant that only cyclophosphamide, ifosfamide, methotrexate and etoposide could be included in the statistical evaluation. z-score and Q test revealed 3 and 4 outliers using classical and robust approach, respectively. The smallest absolute differences between the spiked values and the measured values were observed in the surface water matrix. The highest within-laboratory repeatability was observed for methotrexate in all three matrices (CV?≤?12 %). Overall, inter-laboratory reproducibility was poor for all compounds and matrices (CV 27–143 %) with the only exception being methotrexate measured in the spiked hospital wastewater (CV?=?8 %). Random and total errors were identified by means of Youden plots.     

Fe-pillared clay as a Fenton-type heterogeneous catalyst for cinnamic acid degradation

Fe-pillared montmorillonite has been used as a Fenton-type heterogeneous catalyst for the removal of cinnamic acid in water. The influences of the cinnamic acid, catalyst and H2O2 concentrations and pH on the removal rate of cinnamic acid have been studied. The results show that the efficiency of Fe-pillared montmorillonite is higher than that of the Fe ions in the homogeneous phase, and less sensitive to pH.     

Estimating Potential Climate Change Effects on the Upper Neuse Watershed Water Balance Using the SWAT Model

Climate change poses water resource challenges for many already water stressed watersheds throughout the world. One such watershed is the Upper Neuse Watershed in North Carolina, which serves as a water source for the large and growing Research Triangle Park region. The aim of this study was to quantify possible changes in the watershed’s water balance due to climate change. To do this, we used the Soil and Water Assessment Tool (SWAT) model forced with different climate scenarios for baseline, mid‐century, and end‐century time periods using five different downscaled General Circulation Models. Before running these scenarios, the SWAT model was calibrated and validated using daily streamflow records within the watershed. The study results suggest that, even under a mitigation scenario, precipitation will increase by 7.7% from the baseline to mid‐century time period and by 9.8% between the baseline and end‐century time period. Over the same periods, evapotranspiration (ET) would decrease by 5.5 and 7.6%, water yield would increase by 25.1% and 33.2%, and soil water would increase by 1.4% and 1.9%. Perhaps most importantly, the model results show, under a high emission scenario, large seasonal differences with ET estimated to decrease by up to 42% and water yield to increase by up to 157% in late summer and fall. Planning for the wetter predicted future and corresponding seasonal changes will be critical for mitigating the impacts of climate change on water resources.     

Evaluation of pollution by heavy metals of an abandoned Pb-Zn mine in northern Tunisia using sequential fractionation and geostatistical mapping

This study investigates the contents of lead, zinc, and cadmium in 109 near-surface soil samples collected around the abandoned mine of Fedj Lahdoum, northern Tunisia, to assess the risk of pollution they generate. The study involved some analytical procedures such as pH measurements, X-ray diffraction techniques, sequential fractionation, and geostatistical mapping using the ordinary Kriging techniques. The sequential fractionation revealed that the bioavailability of Pb, Zn, and Cd follows the orders F5?>?F3 » F4?>?F2 » F1, F5?>?F3 » F4 » F2?>?F1 and F5?>?F2 » F4?>?F1, respectively; their associations with organic matter and residual sulfides (F4) are relatively low. However, their high cumulated contents are dominantly associated with the residual (F5) and reducible (F3) fractions. The geostatistical mapping was endeavored to predict the spatial distribution of the studied heavy metals at unsampled sites and to produce a cumulated risk map of soil pollution. The latter is discussed with emphasis of the main factors responsible for the scattering of the pollution as much as the landscape conditions, the chemical composition of the mine tailings, the surface drainage of meteoric water and the wind. This study provides insight into the delineation of the spatial spreading of Pb, Zn, and Cd around the abandoned mine Fedj Lahdoum and their surrounding urban areas. It reveals that the mine infrastructure areas encompassing both extraction and processing and tailing deposition areas are the main sources of contamination. And the landscape conditions together with the surface drainage of meteoric water and the wind are the main factors responsible for the scattering of the pollution.

     

Assessment of coastal ecosystems vulnerability to pollution: Algiers coast,Algeria

Coastal areas are frequently influenced by direct and/or indirect multiple anthropogenic pressures, which impacts marine life. Those perturbations may act in a heterogeneous way with a different intensity and are related to the complexity of coastal ecosystems. To visualize all these interactions at a local scale, a methodology inspired from many researches has been implemented in order to search, identify, and classify coastal ecosystems according to their sensitivity to anthropic pressure exerted by coastal cities. Thus, producing vulnerability maps will be essential tools to local coastal managers. We have applied this methodology on five coastal municipalities in Algiers. Firstly, the environmental sensitivity of coastal ecosystems was assessed by analyzing these four sub-indices: biological sensitivity, geomorphological sensitivity, hydrodynamic characteristics, and pollution intensity. Secondly, an assessment of the anthropogenic pressures presented by each municipality was carried out. Five sub-indexes have been taken into consideration when conducting this assessment: human activities, infrastructures, vectors of pollution, urbanization, and regulatory protection. Then, vulnerability maps were produced by the overlapping of sensitivity and anthropic pressure maps. The results assessed for the environmental vulnerability indicated that most areas are moderately to highly vulnerable, especially in the municipalities of Bab El Oued, Rais Hamidou, and Ain Bénian. The analysis of the obtained results shows the potential applicability of this methodology because they accurately reflect the reality. Therefore, these results can be useful to decision-makers by providing them with a relatively rational decision-making tool to prioritize future management and planning efforts.

     

An LC-MS/MS method for creatine and creatinine analysis in paraquat-intoxicated patients

Abstract

A sudden increase in serum creatinine after paraquat intoxication has been reported in several clinical studies. However, this dramatic change of creatinine may be possibly due to an interconversion of creatine-creatinine in relation to paraquat toxicity. In order to investigate the creatine-creatinine relationship, a liquid chromatography tandem mass spectrometry in combination with electrospray ionization was developed and validated for simultaneous determination of creatine and creatinine in the serum. The chromatographic separation was achieved on a Gemini® C₆-Phenyl column with a gradient elution consisting of 0.1% formic acid in ultrapure water and methanol as the mobile phase. The method yielded suitable levels of specificity and selectivity, and calibration curves of creatine and creatinine in serum were linear over the concentration range of 0.5–200?µg mL^?1. The limit of quantification of both compounds was 0.5?µg mL^?1, and the method was accurate within the recovery range of 96.23–102.75%, indicating the robustness of the method. The method was successfully applied to toxicological samples from paraquat-intoxicated patients, and the concentrations of creatine and creatinine were quantified. High creatine concentrations in serum samples were observed which may lead to high serum creatinine despite normal kidney function as creatine is converted to creatinine in proportion to its concentration.     

Molecular,functional, and cellular alterations of oocytes and cumulus cells induced by heat stress and shock in animals

Environmental Science and Pollution Research - Global warming is considered as the main environmental stress affecting ecosystems as well as physiological and biochemical characteristics, and...     

Protective effects of thymoquinone against acrylamide-induced liver,kidney and brain oxidative damage in rats

Environmental Science and Pollution Research - Acrylamide (AA), an industrial monomer, may cause multi-organ toxicity through induction of oxidative stress and inflammation. The antioxidant...     

Value addition in the services sector and its heterogeneous impacts on CO2 emissions: revisiting the EKC hypothesis for the OPEC using panel spatial estimation techniques

Environmental Science and Pollution Research - This study examines the Environmental Kuznets Curve (EKC) hypothesis in the context of 12 members of the OPEC by utilizing data on both the aggregate...