Trend analysis in water quality of Al-Wehda Dam,north of Jordan

Temporal status and trends in water quality of Al-Wehda Dam, Jordan, from 2006 to 2012 indicate that the dam is subject to a combination of impacts from rainstorm and agricultural runoffs. It also revealed that mineral dissolution, sediment load, rainfall events, evaporation, and water-level fluctuation are the major contributors to variations in water quality. The water chemistry of the impounded Al-Wehda Reservoir showed that Na, Ca, Mg, HCO₃, and Cl are the principal ions, reflecting the dominance of carbonate weathering, with some contribution of silicates. The pH values showed a cyclic pattern with highest values observed in the spring seasons. Total dissolved solids (TDS), Ca, Mg, and HCO₃ are primarily related to leaching and evaporation, with elevated levels that occurred in the rainy winter months. In contrast, seasonal patterns in Na, K, Cl, and NH₄–N contents showed decreased values in winter. Peaks in NO₃–N observed in winter are strongly associated with agricultural runoff. Fluctuations in chlorophyll-a level were coincided with low ratio of total nitrogen (TN) to total phosphorus (TP). Seasonal variations in organic matter content were also apparent, with peaks that generally occurred in spring through early fall corresponding with high algal growth. On an annual basis, the vast majority of water quality data have generally declined, particularly, in 2011. However, it is not clear whether these decreases are related to change in management practices within the Yarmouk basin, or protective measures have been implemented. Comparison of in-lake and post-dam water quality from 2009 to 2011 showed variation in concentrations, where Ca, HCO₃, NO₃–N, Mg, and TDS showed relatively greater post-dam values than in-lake water, whereas pH, Na, Cl, K, COD, BOD₅, and chlorophyll-a were consistently lower in post-dam water. This comparison emphasizes the importance of self-purification capacity of Al-Wehda Dam in reducing some contaminants.     

Analysis of multi-temporal landsat satellite images for monitoring land surface temperature of municipal solid waste disposal sites

This studypresents a remote sensing application of using time series Landsat satellite images for monitoring the Trail Road and Nepean municipal solid waste (MSW) disposal sites in Ottawa, Ontario, Canada. Currently, the Trail Road landfill is in operation; however, during the 1960s and 1980s, the city relied heavily on the Nepean landfill. More than 400 Landsat satellite images were acquired from the US Geological Survey (USGS) data archive between 1984 and 2011. Atmospheric correction was conducted on the Landsat images in order to derive the landfill sites’ land surface temperature (LST). The findings unveil that the average LST of the landfill was always higher than the immediate surrounding vegetation and air temperature by 4 to 10 °C and 5 to 11.5 °C, respectively. During the summer, higher differences of LST between the landfill and its immediate surrounding vegetation were apparent, while minima were mostly found in fall. Furthermore, there was no significant temperature difference between the Nepean landfill (closed) and the Trail Road landfill (active) from 1984 to 2007. Nevertheless, the LST of the Trail Road landfill was much higher than the Nepean by 15 to 20 °C after 2007. This is mainly due to the construction and dumping activities (which were found to be active within the past few years) associated with the expansion of the Trail Road landfill. The study demonstrates that the use of the Landsat data archive can provide additional and viable information for the aid of MSW disposal site monitoring.     

Acute toxicities of cadmium and permethrin on the pre-spawning and post-spawning phases of Hexaplex trunculus from Bizerta Lagoon, Tunisia

Marine gastropods, exposed to anthropogenic pollution, accumulate high chemical concentrations in their tissues, especially in the digestive glands. An evaluation of the impacts of cadmium (Cd) and permethrin (Perm), coupled with reproductive events (pre-spawning and post-spawning phase) throughout the year, was attempted by measuring catalase (CAT), a biomarker of defence, on Hexaplex trunculus experimentally exposed for 48 or 96 h. Specimens of gastropods were sampled from Bizerta Lagoon (Tunisia). The results show that CAT activity increased in gastropods exposed to the three cadmium concentrations (C1 Cd, 100 μg L(-1); C2 Cd, 200 μg L(-1); and C3 Cd, 300 μg L(-1)) and to the three permethrin doses (C1 Perm, 100 μg L(-1); C2 Perm, 150 μg L(-1); and C3 Perm, 200 μg L(-1)) tested. A decrease in CAT was noted in the digestive gland of the H. trunculus exposed to permethrin at the concentration of 200 μg L(-1) during the pre-spawning and post-spawning phases. H. trunculus in post-spawning was more sensitive to cadmium and permethrin than in the pre-spawning phase. The biochemical responses to pollutants (cadmium and permethrin) represented by CAT may act as a biomarker of exposure in this species.     

Heavy metal biomonitoring and phytoremediation potentialities of aquatic macrophytes in River Nile

The concentrations of Cd, Cu, Pb, and Zn in sediments, water, and different plant organs of six aquatic vascular plant species, Ceratophyllum demersum L. Echinochloa pyramidalis (Lam.) Hitchc. & Chase; Eichhornia crassipes (Mart.) Solms-Laub; Myriophyllum spicatum L.; Phragmites australis (Cav.) Trin. ex Steud; and Typha domingensis (Pers.) Poir. ex Steud, growing naturally in the Nile system (Sohag Governorate), were investigated. The aim was to define which species and which plant organs exhibit the greatest accumulation and evaluate whether these species could be usefully employed in biomonitoring and phytoremediation programs. The recorded metals in water samples were above the standard levels of both US Environmental Protection Agency and Egyptian Environmental Affairs Agency except for Pb. The concentrations of heavy metals in water, sediments, and plants possess the same trend: Zn > Cu > Pb > Cd which reflects the biomonitoring potentialities of the investigated plant species. Generally, the variation of heavy element concentrations in water and sediments in relation to site and season, as assessed by two-way repeated measured ANOVA, was significant (p < 0.05). However, insignificant variations were observed in the concentrations of Pb and Cd in sediments in relation to season and of Cu and Zn in relation to site. Results also showed that the selectivity of the heavy elements for the investigated plants varied significantly (p < 0.05) with species variation. The accumulation capability of the investigated species could be arranged according to this pattern: C. demersum > E. crassipes > M. spicatum > E. pyramidalis > T. domingensis > P. australis. On the basis of the element concentrations, roots of all the studied species contain higher concentrations of Cu and Zn than shoots while leaves usually acquire the highest concentrations of Pb. Cd concentrations among different plant organs are comparable except in M. spicatum where the highest Cd concentrations were recorded in the leaves. Our results also demonstrated that all the studied species can accumulate more than 1,450-fold the concentration of the investigated heavy elements in water rendering them of interest for use in phytoremediation studies of polluted waters. Given the absence of systematic water quality monitoring, heavy elements in plants, rather than sediments, provide a cost-effective means for assessing heavy element accumulation in aquatic systems during plant organ lifespan.     

Empirical gas emission and oxidation measurement at cover soil of dumping site: example from Malaysia

Methane (CH₄) is one of the most relevant greenhouse gases and it has a global warming potential 25 times greater than that of carbon dioxide (CO₂), risking human health and the environment. Microbial CH₄ oxidation in landfill cover soils may constitute a means of controlling CH₄ emissions. The study was intended to quantify CH₄ and CO₂ emissions rates at the Sungai Sedu open dumping landfill during the dry season, characterize their spatial and temporal variations, and measure the CH₄ oxidation associated with the landfill cover soil using a homemade static flux chamber. Concentrations of the gases were analyzed by a Micro-GC CP-4900. Two methods, kriging values and inverse distance weighting (IDW), were found almost identical. The findings of the proposed method show that the ratio of CH₄ to CO₂ emissions was 25.4 %, indicating higher CO₂ emissions than CH₄ emissions. Also, the average CH₄ oxidation in the landfill cover soil was 52.5 %. The CH₄ and CO₂ emissions did not show fixed-pattern temporal variation based on daytime measurements. Statistically, a negative relationship was found between CH₄ emissions and oxidation (R ²?=?0.46). It can be concluded that the variation in the CH₄ oxidation was mainly attributed to the properties of the landfill cover soil.     

Trace metals in soil and vegetables and associated health risk assessment

The objective of this study was to assess the contamination level of trace metals in soil and vegetables and health risk to the urban population in Bangladesh. The range of Cr, Ni, Cu, As, Cd, and Pb in agricultural soils was 158–1160, 104–443, 157–519, 41–93, 3.9–13, and 84–574 mg/kg, respectively. Sequential extraction tests revealed that the studied metals were predominantly associated with the residual fraction, followed by the organically bound phase. Concerning Cu, Ni, Cd, and Pb in vegetables, more than 50 % samples exceeded the FAO/WHO recommended permissible limits. Considering the transfer of metals from soil to vegetables, Cu and Cd exhibited higher transfer factor (TF) values than the other metals. Target hazard quotient (THQ) for individual metal was below 1, suggesting that people would not experience significant health hazards if they ingest a single metal from vegetables. However, total metal THQ signifies the potential non-carcinogenic health hazard to the highly exposed consumers. The carcinogenic risk (TR) of As (1.9?×?10^?4) and Pb (2.3?×?10^?5) through consumption of vegetables were higher than the USEPA threshold level (10^?6), indicating potential cancer risks.     

Occupational exposure to pesticides and associated health effects among greenhouse farm workers

Environmental Science and Pollution Research - The number and production capacities of greenhouse farms have been increased across the globe, driven by an effort for addressing food security...     

Radical scavenging and antiproliferative effect of novel phenolic derivatives isolated from Nerium indicum against human breast cancer cell line (MCF-7)—an in silico and in vitro approach

Environmental Science and Pollution Research - Multiple drug resistance and increased side effects due to allopathic drugs has warned scientific community with a global alarm to identify molecules...     

Evaluating sewage-associated JCV and BKV polyomaviruses for sourcing human fecal pollution in a coastal river in Southeast Queensland, Australia

In this study, the host-sensitivity and host-specificity of JC virus (JCV) and BK virus (BKV) polyomaviruses were evaluated by testing wastewater and fecal samples from nine host groups in Southeast Queensland, Australia. The JCV and BKV polyomaviruses were detected in 63 human wastewater samples collected from primary and secondary effluent, suggesting high sensitivity of these viruses in human wastewater. In the 81 animal wastewater and fecal samples tested, 80 were polymerase chain reaction (PCR) negative for the JCV and BKV markers. Only one sample (out of 81 animal wastewater and fecal samples) from pig wastewater was positive. Nonetheless, the overall host-specificity of these viruses to differentiate between human and animal wastewater and fecal samples was 0.99. To our knowledge, this is the first study in Australia that reports on the high specificity of JCV and BKV polyomaviruses. To evaluate the field application of these viral markers for detecting human fecal pollution, 20 environmental samples were collected from a coastal river. In the 20 samples tested, 15% (3/20) and 70% (14/20) samples exceeded the regulatory guidelines for Escherichia coli and enterococci levels for marine waters. In all, five (25%) samples were PCR positive for JCV and BKV, indicating the presence of human fecal pollution in the coastal river investigated. The results suggest that JCV and BKV detection using PCR could be a useful tool for identifying human-sourced fecal pollution in coastal waters.