Assessment Of Effluent Quality At The University Of Ghana Hospital, Legon

Abstract

Hospitals effluent often contain chemical compounds which may have negative impact on the environment and human health if not properly treated. Investigations were conducted to determine the bacteriological and physico-chemical qualities of effluent discharged from University of Ghana hospital into the environment and its effects on agricultural soils and vegetables. Water and soil quality analyses of some physico-chemical and bacteriological variables were carried out on effluent samples using standard methods over a three month period (WHO, 2010). Human health risk assessment was conducted to determine the potential risk on the consumption of vegetables irrigated with the effluent water. The results showed the following variations in physico-chemical parameters; EC (1522-2220 µS/cm), pH (8.2-8.8), TDS (947-1410.7mg/l) BOD (34.8-66.8mg/l) DO (0.8-1.4mg/l) COD (548-775.2mg/l), NO2-_N (0.24-0.45mg/l), NO3-_N (34.5-101.1mg/l), NH3-N,-(15.9-28.8mg/l) PO43-(6.3-9.8mg/l). The TC and E. coli also ranged from 3.120×103 - 4.582×103 cfu/100ml and 1.5×101- 2.9×101 cfu/100ml respectively. Lead and arsenic in water were below the recommended FAO guideline of 0.1 and 0.01mg/l respectively for water used for irrigation of vegetables. Cadmium, Cr, Ni and mercury however, exceeded the guideline. Mercury, nickel and chromium were above the FAO recommended guideline for Agricultural soils whilst Cd, Pb and As fell below the recommended limit. All the heavy metals in cabbage, lettuce and cauliflower in this study were all below recommended limit set by the FAO for vegetables wholesome for human consumption. The human health risk assessment of the vegetables revealed that the hazard index and Hazard quotient for cabbage, lettuce and cauliflower were all less than 1 which indicates that consumers are not at risk to the consumption of these vegetables in the short term. To prevent or reduce environmental effects and health risk associated with hospital effluent, adoption and utilization of decentralized wastewater technologies that are economically viable and efficient such as waste stabilization ponds are recommended to safeguard public health and prevent negative environmental effects.