Metabolism of DDT in different tissues of young rats

The bioconcentration and distribution pattern of p,p'-DDT 1,1,1-1trichloro-2,2-bis(2-chlorophenyl-4-chlorophenyl)-ethane] and its main metabolites (p,p'-DDD [1,1-dichloro-2,2-bis (4-chlorophenyl) ethane] and p,p'-DDE [1,1-dichloro-2,2-bis (4-chlorophenyl) in adipose tissue, liver, brain, kidney, thymus, and testis were examined in young rats after 10 days of intraperitoneal injection of 50 and 100 mg of p,p'-DDT/kg of body weight. Analyses were performed by high-resolution gas chromatography. p,p'-DDT was found to be accumulated in a dose-dependent manner with the highest concentration in adipose tissue. However, in brain, the accumulation of pesticide was low and remained unchanged at the higher dose. This difference may relate to the protective role of the blood-brain barrier, which limits the access of the xenobiotic in the cerebral compartment, and to the differential tissue lipid composition. Although tissues concentration of p,p'-DDE and p,p'-DDD correlated positively to total p,p'-DDT levels, the active role in detoxification of pollutants may explain why p,p'-DDD is more abundant in liver than in the rest of organs. On the contrary, in brain, the concentration of p,p'-DDE is higher than that of p,p'-DDD, suggesting that the metabolism of the parent insecticide proceeds via more than one pathway.     

Laboratory-based assessment on similarities between dynamic behavior of MSW and clay

Journal of Material Cycles and Waste Management - The dynamic response of landfills under seismic loads is greatly dependent on stress–strain cyclic characteristics of municipal solid waste...     

Investigation into effects of work-related quality of life and some related factors on cognitive failures among nurses

Objective. Cognitive failure is one of the factors which can be influenced by personal and professional characteristics. This research was carried out to study the effect of work-related quality of life (WRQoL) and some related factors on cognitive failures (CF) among nurses. Methods. This cross-sectional study was conducted among nurses working in intensive care units, critical care units and emergency units in 2014. Results. In total, 750 nurses participated in the study. The mean?±?SD for the total CF and WRQoL was 40.5?±?12.7 and 75.8?±?13.7 respectively. The results show that CF have a statistically significant difference among the age groups, experience groups and working units. Multiple regression tests show that age, income and WRQoL have a significant effect on CF. Based on the results, for a unit increase in WRQoL we expect a 0.26 unit decrease in CF. Analysis of variance results show that the emergency ward had changed the overall effect of WRQoL on CF, after the effect of WRQoL was controlled. Conclusions. Overall results from the present research indicated that, despite the high level of WRQoL among the studied nurses, the rate of CF was not at an appropriate level. Development of supportive and interventional strategies is highly recommended.     

Sequential fractionation of phosphorus in sediments of El-Fayum lakes—Egypt

The amounts and forms of potentially mobile phosphorus (P) in surface sediments of Qarun and Wadi El-Rayan lakes were evaluated during winter and summer using a sequential chemical extraction. Five sedimentary P fractions were separately quantified: loosely sorbed P (NH₄Cl-P), iron-associated P (BD-P), calcium- bound P (HCl-P), metal oxide bound P (NaOH-P), and residual P (organic and refractory P). The results indicated that the fractional composition of the examined lakes was different while the total P concentrations were approached. The inorganic P in the surface sediment mainly consisted of Ca-P followed by Fe-P in Qarun Lake, while Al-P took the second order in Wadi El-Rayan lakes. The ranks order of the different P extracts were HCl-P > residual-P ≈ NaOH-P > NH₄Cl-P > BD-P and residual-P > NH₄Cl-P > HCl-P > NaOH-P > BD-P for Qarun and Wadi El-Rayan lakes, respectively.     

Trace element contaminants in mineral fertilizers used in Iran

The application of mineral fertilizers which have contaminants of trace elements may impose concern regarding the entry and toxic accumulation of these elements in agro-ecosystems. In this study, 57 mineral fertilizers (nitrogen, potassium, phosphate, and compound fertilizers) distributed in Iran were analyzed for their contents of Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn, and Fe. The results revealed that the contents of these trace elements varied considerably depending on the type of the element and the fertilizer. Among these elements, Fe displayed the highest average content, whereas Cd showed the lowest. Generally, the trace element contents in P-containing fertilizers were higher than those in nitrogen and potassium fertilizers. The mean values of trace elements (mg kg^?1) in P-containing fertilizers were 4.0 (Cd), 5.5 (Co), 35.7 (Cr), 24.4 (Cu), 272 (Mn), 14.3 (Ni), 6.0 (Pb), 226 (Zn), and 2532 (Fe). Comparing trace element contents to limit values set by the German Fertilizer Ordinance showed that the mean contents of potentially toxic trace elements, such as Cd and Pb, were lower than their limit values in all groups of fertilizers. On the other hand, while a number of fertilizers contained a high content of some essential trace elements, particularly Fe, they were not labeled as such.     

Effect of organic and inorganic phosphorus fertilizers on phosphorus availability and its leaching over incubation time

Environmental Science and Pollution Research - The use of organic and inorganic phosphorus (P) fertilizers in agricultural soils is very common, and few studies have been conducted to...     

Hydrogen production from wastewater,storage, economy,governance and applications: a review

Environmental Chemistry Letters - In the context of climate change, most of the actual dihydrogen production is not sustainable with about 96% of the 60 million tons of dihydrogen produced annually...     

The green-agile supplier selection problem for the medical devices: a hybrid fuzzy decision-making approach

Environmental Science and Pollution Research - The supplier selection problem (SSP) is known as one of the major issues in the supply chain management area. In this field, the literature shows that...