Investigation of oxidative stress enzymes and histological alterations in tilapia exposed to chlorpyrifos

Environmental Science and Pollution Research - Chlorpyrifos (ChF) is an organophosphate pesticide that is widely used in agricultural fields and indoor for controlling pests. Aquatic ecosystems are...     

Chemical and microbiological examination of well and Nile water

The chemical composition and microbiological contamination of well water and Nile River water used for drinking were investigated in localities around Khartoum, Sudan, to present baseline data. The chemical analyses results obtained indicated that public health hazards due to pH, Ca⁺⁺, CO₃^??, HCO₃^?, and NO₃^? are unlikely in all the samples studied, while Na⁺ and Cl^? ions concentrations in well water warrant some attention. Contamination from organic matter and suspended material is also negligible. Microbial contamination with coliform and fecal coliform is high in surface wells and in the Nile River, but negligible in deep bores, tap water, and mineral water. The logarithm of the colony count ranges from zero for mineral water to 6.8 for water from the White Nile. In addition to drawing further attention to the well water and Nile water used for drinking by a wide sector of the population, the microbial count data for water from the Nile disagreed with the generally held belief that the Nile, being one of the largest rivers of the world, carries no detectable fecal contamination. Our data also did not support the belief that the White Nile is more contaminated than the Blue Nile.     

Recovery of nickel oxide from spent catalyst

This study investigates the possibility of recovering nickel from the spent catalyst (NiO/Al2O3) resulting from the steam reforming process to produce water gas (H2/H2O) in many industries. In the extraction process, nickel is recovered as sulfate using sulfuric acid as a solvent. The considered parameters affecting nickel recovery were acid concentration, temperature and time of digestion solid:liquid ratio, particle size and stirring rate. Nickel was to be directly recovered as a sulfate salt by direct crystallization method. The conversion was 99% at 50% sulfuric acid concentration, solid: liquid ratio (1:12) by weight, particle size less than 500 micron for more than 5 h and 800 rpm at 100 degrees C.     

Natural radioactivity in farm soil and phosphate fertilizer and its environmental implications in Qena governorate, Upper Egypt

Samples of phosphate fertilizers and farm soils, taken to a depth of up to 30 cm in cultivated land, were collected over the Qena governorate, Upper Egypt. Activity concentration of background radionuclides such as (226)Ra, (232)Th and (40)K of these samples were determined by gamma-ray spectrometry. The results show that these radionuclides were present in concentrations of 366+/-10.5, 66.7+/-7.3 and 4+/-2.6 Bq/kg for phosphate fertilizers. For farm soil and Nile island's soil the corresponding values were 13.7+/-7, 12.3+/-4.6, 1233+/-646 and 11.9+/-6.7, 10.5+/-6.1, 1636+/-417 Bq/kg, respectively. The radium equivalent activity (Ra(eq)), the representative level index, I(gamma r), and absorbed dose in air for all samples were calculated. The data were discussed and compared with those given in the literature.     

The role of the cement industry in the contamination of air, water, soil and plant with vanadium in Cairo

Levels of vanadium in air, water, soil and plants resulting from the operation of a cement factory in south Cairo were extensively studied. Results obtained were compared with the level of vanadium in a relatively non-polluted residential area. It was concluded that the studied cement factory is the main source of the element to the adjacent environment. This is essentially due to the fact that this cement factory is using fossil fuels and raw materials that both contain high levels of vanadium without adequate control of the release of pollutants. Continuous release of air-borne dust from the cement industry will increase the level of vanadium in the surrounding environment in the long run.     

Respiratory,hepatic, renal,and hematological disorders among adolescent females environmentally exposed to pesticides,Menoufia governorate,Egypt

Environmental Science and Pollution Research - Adolescent females are often environmentally exposed to pesticides by living near agricultural fields, by using pesticides at home, or by having...     

Experimental selection of Marylynnia puncticaudata (Cyatholaimidae,Nematoda) and effects of organic enrichment

Environmental Science and Pollution Research - Meiobenthic nematodes are well-known bioindicators in aquatic ecosystem health programs. However, the explored taxa are still limited and practically...     

Organochlorine insecticide residues in Egyptian mothers’ milk

Two hundred ninety‐two mother's milk samples were collected during 1994 from ten Egyptian governorates representing rural, metropolitan, and newly reclaimed desert areas. The samples were analyzed for 14 organochlorine insecticides and metabolites using electron capture gas chromatography and confirmed by gas chromatography/mass spectrometry (GC/MS). The overall samples average showed that the most abundant organochlorine insecticide residues were p,p'‐DDE, α‐endosulfan, β‐HCH and, p,p’‐DDT. Residues in the range of not detectable to less than 14μg/l whole milk were recorded for α‐HCH, heptachlor, heptachlor epoxide, aldrin, dieldrin, endrin endrin aldehyde and p,p'‐DDD. The percentage of samples exceeding the acceptable daily intake for children (ADIs) set by the FAO/WHO ranged from 19% to 44% in all governorates included in the study except the governorate of Minia in which only 2.6% of the samples exceeded the ADI values. The insecticides exceeding ADI values are mostly heptachlor and heptaclor epoxide (ADI = 3.12 μg/1 whole milk).     

A simple mineral market model: Can it produce super cycles in prices?

This paper develops a stylized supply–demand model for a mineral/nonrenewable commodity. It embodies important distinctions between short-run and long-run mineral supply and the derived demand for minerals as intermediate goods in production sectors with differing intensities of use. This framework is used to address the question: under what conditions might one expect to observe super cycles (i.e. cycles with a period of 20–70 years) in minerals prices? A plausible time path for GDP$GDP$ growth and the structural transformation that accompanies economic development in an emerging region is specified. Using these drivers and reasonable supply and demand parameters, price dynamics are simulated. The result is an asymmetric price cycle with a peak price that is about 250% above trend and an expansion phase that lasts for about 20 years. Thus, this simple model is capable of producing a single cycle with a frequency and amplitude in the range estimated in the empirical literature on super cycles. As other regions reach the development ‘take-off' phase, additional super cycles should emerge.