Physiochemical characterisation and level of potentially toxic metals in surface water around yauri abattoir, north western Nigeria

Abstract

Physicochemical and potentially toxic metals statuses of surface water samples collected around the Yauri abattoir were examined. Health risk assessment of the toxicant via ingestion was interpreted by calculating the hazard quotient (HQ). The mean concentration values for total dissolved solid (TDS), total suspended solid (TSS), dissolved oxygen (DO), phosphate, and biochemical oxygen demand (BOD) were 1026.78, 565.22, 5.0, 8.89 and 484.64 mg/L respectively. The values are above those obtained for the control water sample as well as those of international safe limits for water. The values of pH (6.6), sulphate (86.91 mg/L), nitrate (41.45 mg/L) and chemical oxygen demand (COD) (903.30 mg/L) fell within world health organization maximum permissible limits for drinking water. The mean concentrations of Co (6.93 mg/L), Cu (14.45 mg/L), Fe (64.16 mg/L), and Zn (37.14 mg/L) were above both the control and WHO, EU and EPA safe limits for metals in water. On the other hand Cd (11.47 mg/L), Ni (35.49 mg/L), and Pb (41.94 mg/L) had a mean concentration values which are higher than the international standard limits and control water sample. The calculated values of HQ show that Cd, Co, Cu and Ni were of high risk, Fe with a medium and Pb and Zn are of low risk. Correlation coefficients revealed general positive and significant correlations between the pairs of metals in water. The results of this study showed some levels of pollution of the stream water indicating that the activities at the abattoir were contributing to the pollution load of water in the area.    Key words: Yauri, abattoir, toxic metals, physicochemical.