International Journal of Environmental Science and Toxicology Research

36-43

Authors: L. A. Margaryan, H. A. Melkonyan, G. P. Pirumyan

Changes in water resources availability, stream flow and in river ecosystems are the major expected impacts of climate changes in river basins. The climate change is expected to influence the quantity as well as the quality of water resources by, for instance, increasing “natural’ pollution. Consequently, it may lead to deterioration of water resources and destruction of ecosystems, along with extinction of endemic species of flora and fauna. In order to investigate the impact of climate changes on the river flow and on the content of salt concentration in river water The River Flow Substance Quantity Transfer Index (RFSQTI) was applied. The index relates the surface water quality and the hydrochemical and hydrological variables, and as a result provides flux of a given chemical substance by tone along the stream flow. The study was conducted in Marmarik River, thought to have no direct anthropogenic influence. The results indicated reduction in river flow and decrease and increase in the concentration of light and heavy ions, respectively, portrayed by the increase in the hardness of river water, suggesting a change in the water river source, with increase in the proportion of the ground water to surface water source. In the absence of major anthropogenic impacts, these changes are attributed to climate change. They attributed these changes to climate changes. The possible implications of the observed changes in the riverine ecosystems, water supply and water demand, as well as in the agriculture in the river basin are further discussed.

19-24

Authors: Russ L Altabtabaee, Oshea Chaudhary, Cassandra Clement, Beth Polidoro

Chlorpyrifos is an organophosphate pesticide used in Costa Rica and other countries around the world for banana and plantain production. In Costa Rica, chlorpyrifos is impregnated into blue plastic bags that are placed around ripening fruit to prevent insect damage to fruit skin. Much is known about chlorpyrifos movement and degradation rates from soils and foliage, but no studies are known on the movement and dissipation of chlorpyrifos from plastic bags. Our objective was to determine the rate of chlorpyrifos loss from plastic bags used in banana production, and to estimate the potential amount chlorpyrifos lost through volatilization or degradation annually in banana production in Costa Rica. Although chlorpyrifos bags were found to be very heterogeneous in chlorpyrifos concentration, approximately 90% of the chlorpyrifos was lost within the first 10 days during 3 replicated experiments, under average daily temperature regimes between 19°C and 30°C. As the vast majority of chlorpyrifos is lost from plastic bags under these conditions, it is estimated than 22.5 metric tonnes of chlorpyrifos and degradation products may lost to the environment, annually during banana and plantain production in Costa Rica.

1-6

Authors: Etim, A. O. Ekpo, F. E. Okeke, A. I.

Studies of heavy metals concentrations in soil samples and edible vegetables (Telfaiferia occientalis and Vernonia amygdalina) were investigated in three core crude oil producing communities (Mkpanak, Ukpenekang and Inuayet Ikot) of Ibeno Local Government Area in Akwa Ibom State during the rainy and dry seasons and the control sites at Etinan L G. Area. Each sample was replicated three times. The levels of heavy metals in the samples collected were determined using Atomic Absorption Spectrophotometer (AAS) Unicam 919 model. The concentrations of heavy metals in soil samples during dry season were higher than those recorded in the rainy season in all the sample locations. The concentrations of heavy metals observed in soil depth (0-15 cm) were significantly higher than those recorded in (16-30cm) soil depth. The concentrations of heavy metals in edible vegetables (Telfaiferia occientalis and Vernonia amygdalina) collected from the three core crude oil producing communities of Ibeno exceeded the maximum permissible limits values of heavy metals for edible vegetable as prescribed by FEPA and WHO. The soils and edible vegetables in the core oil producing communities of Ibeno are contaminated and may pose serious adverse effect to humans and the environment.

144-153

Authors: Mohamed A. El-Sadek

The present work deals with the measurement of concentrations and distributions of natural radionuclide γ-ray activities, produced by 40K, 226Ra, 238U and 232Th, in coastal soils of Koam Mashaal area, Northern Egypt. Besides, the radiation doses that would be delivered to living beings from such soils were calculated. Moreover, external and internal hazard indices, radium equivalents, and annual activities were computed. For this purpose, a total of 57 field samples were collected from the surface till a depth of 50 cm. These samples were analysed using high-purity germanium (HPGe) detector. The concentrations were determined for 40K (range from 114 to 313 Bqkg-1), 226Ra (range from 12 to 234.7 Bqkg-1), 238U (range from 5.5 to 211 Bqkg-1) and 232Th (range from 12.7 to 149.7 Bqkg-1), with their mean values reaching 200.68±4.68Bq/kg, 74.18±6.17Bq/kg, 94.25±6.01Bq/kg and 78.12±4.65Bq/kg respectively. Moreover, gamma–absorbed dose rates and radium equivalent activities were calculated for the analyzed samples to assess their radiation hazards arising from them. The annual effective dose equivalent rates in mSv/y due to natural radioactivity was found to be in the range of 0.03 to 0.21 mSv/y with mean 0.12±0.01 mSv/y. The results of the present work were discussed and compared with international recommended values.

165-172

Authors: Gihan Hosny, Samah Mohamed and Hanan Tayel

Dimethyl nitrosamine (DMN) is a very potent chemical carcinogen which occurs naturally in the environment and in a wide variety of food stuffs, and can be formed in the body by nitrosation of secondary or tertiary amines in the presence of nitrite, nitrate or nitrogen oxides. Soybeans is a powerful antioxidant and has a potent free radical scavenging activity, said to protect cells of breast, liver, brain and other cells in the body from toxins. The objective of this study is to examine the in vivo protective effects of soybeans on the induced oxidative damage in livers of DMN-intoxicated rats histologically and immunohistochemically. The ability of soybeans to protect and detoxify DMN toxicity was examined in rat livers. Dietary pretreatment of rats (body weight 125-135 g) with soybeans for two weeks prior to the intraperitoneal injection of DMN, reversed the hepatotoxic effects of DMN, as examined histologically. DMN in two doses of 15 or 25g/kg were injected. After DMN treatment, the animals were fed with diet with soybeans or without for 72 hours. Rats were sacrificed 72 hours after DMN injection. The immunoreactivity of cells of rats' livers was examined for antibodies of heat shock protein 70 (HSP70) (HSPs are a family of proteins that are triggered to be induced when a cell undergoes environmental stresses including oxidative stress, pathogenic conditions...etc). The histological evaluation revealed prominent changes in groups received DMN in high dose more than low dose. Treatment with soybeans reversed this effect. The immunohistochemical assay for the stress-protective proteins "HSP70" showed that treatment with soybeans triggered more expression of this protein. Soybeans can provide substantial protective effect against DMN-induced hepatic oxidative damage with favorable potential to be enhanced in use in human diet.

122-133

Authors: Ismail, M.T. 1*, El Nadi, M.H.A. 2, Nasr, N.A.H. 3, Wahb, E.S.A.3

Water desalination processes have contributed to a better standard of living in a number of countries during the second half of the 20th century, following an increase in water demand for drinking purposes as well as industrial and agricultural uses. Desalination process produces two streams of water, one is the product fresh water, and the other is concentrate water containing salts and any un-reacted pre-treatment chemicals (Brine). Brine is considered to be one of the main environmental aspects that affect the surrounding environment during disposal. There are a variety of methods that are used for brine disposal / management. The most common methods include (i) Surface water Discharge, (ii) Ground water Discharge, (iii) Evaporation ponds. The availability of the disposal alternative is mostly site-specific. Therefore, the most suitable disposal methods from an environmental and economic perspective have to be evaluated on a site-specific basis. The aim of this study is to develop a mathematical model, named “Brine disposal decision support system” (BDDSS). The model’s main objective is to assist decision makers (Consultants or Government authorities) in the selection of an optimum brine disposal solution applying applicable, environmentally friendly and cost effective methods, through a user friendly interface. The BDDSS model can be applied to any desalination plant to obtain the optimum brine disposal solution, by providing three scenarios for brine disposal, after performing a compilation of all inputs provided by the user, then start comparison among the three alternatives and select the optimum solution / alternative through an evaluation matrix based on the cost / environmental of each disposal alternative. The optimum solution provided is the one achieving lowest cost and lowest negative environmental impact. In order to observe the benefits of applying the BDDSS model on desalination plants, a live run has been conducted on an existing desalination plant in Kuwait bay. The reason for selecting this case is that there is severe impact on the surrounding environment as a result of extensive brine disposal from Doha desalination plants to Kuwait bay. This case study will show results obtained before and after applying the model.