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.