Heavy Metals Concentration in Effluents of Textile Industry, Tikur Wuha River and Milk of Cows Watering on this Water Source, Hawassa, Southern Ethiopia

Abstract

Textile industries contribute immensely to surface water deterioration and are categorized among the most polluting in all industrial sectors. For this reason, the heavy metals profiles of Hawassa Textile effluent along with Tikur Wuha River and their accumulation in milk samples collected from cows watered in this water source was assessed in Chafe and Dato Villages, Southern Ethiopia. In the present study, water samples were collected from the textile factory treatment ponds and Tikur Wuha River at different sampling site. Similarly, fresh milk samples were collected from 15 cows watered in textile treatment pond water and Tikur Wuha River, Chafe and 15 cows from Dato, relatively far from textile industry. Metal levels in both water and milk samples were determined using Atomic Absorption Spectrophotometer after wet digestion. The result shows the mean concentrations in water samples collected from site S1, S2, S3 and S4 to be 0.72, 0.652, 0.121 and 0.12mg/L respectively for lead metal, 0.135, 0.05, 0.124 and 0.132mg/L for nickel, 0.023, 0.01, 0.014 and 0.02mg/L for cadmium. The results further indicated that the mean concentrations of Pb, Ni, Cd and Cr in milk samples collected from Chafe were 0.8, 1.6, 0.2 and 0.2mg/L respectively while in samples from Dato village to be 0.4, 1.4, 0.1 and 0.8mg/L in the same order. It was therefore implicated that textile effluent entering Tikur Wuha River could cause toxic effects on consumers through food chain like via milk consumption and decreases livestock productivity consuming this water source and grazed around this area. It could also cause toxic effects on aquatic species of the river. It was emphasized that using the water for irrigation and water source for livestock in its present state is unsafe.

Keywords: Heavy metals, milk, water, permissible limits