TITLE:
Geological and Geochemical Investigation of Low Grade Basement Rocks: Implication to Human Health in and around Asgeda Tsimbla, Western Tigray, Northern Ethiopia
AUTHORS:
Jemal Ahmed, Kassa Amare
KEYWORDS:
Liver Disease, Environmental Health, Geochemical Survey, Maximum Acceptable Concentration (MAC)
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.4 No.8,
August
25,
2016
ABSTRACT: The increase in the number of liver related disease patients from north western region of Ethiopia has been an environmental health issue of national concern. As the disease is restricted to a specific geographical terrain, particularly to Shire area, northwestern dry zone of the country, detail research studies are required to identify possible etiology and risk factors. The aim of the study is to determine the level of trace element and heavy metal concentrations and distributions in water and stream sediments of the area and identify the possible sources in relation to human health. During the study, geochemical sampling (20 water, 20 stream sediment and 6 rock samples) was carried out in March 2011. The collected samples were analyzed for their major and trace element contents using ICP-MS, ICP-OES, Ion Chromatography (IC), and XRF. Analytical data were organized and treated using Excel, SPSS, ArcGIS and Aquachem softwares. Analytical data results with respect to trace element contents in surface and ground waters are compared with the Maximum Acceptable Concentration or Maximum Allowable Concentration (MAC) of World Health Organization (WHO) and Ethiopian standards for drinking water. The comparison reveals that there are problematic elements that pass over the quality standards set for drinking water. One of these is: Bromine (Br), for which 100% all samples have value above 0.01 mg/l and up to 1.475 mg/l. Other problematic elements including aluminum (Al)—30%, fluorine (F)—20%, arsenic (As)—10%, and nitrate (NO3)—10% are examples of elements which have above WHO-MAC for drinking water. Selenium (Se) deficiency may be the other problematic element in the area for its deficiency is associated with liver damage and heart muscle disorder. The metal contaminations (i.e. heavy metals) were also evaluated by world geochemical background value in average shale and sediment quality guideline proposed by US EPA. The concentration of Co and Cr exceeded average shale value at most sample stations indicated that these stations ware in potential risk. Geochemical factors are mostly considered to explain the etiology of this liver related disease.