Pollution Research Paper

ENVIRONMENTAL RISK ASSESSMENT OF HOSPITAL WASTEWATER IN ENUGU, NIGERIA

C.T. EZE, O.A. OJE 2 AND I.N.E. ONWURAH

Abstract

The issue of contamination of the environment by hospital and industrial effluent or wastewater has been an issue of concern to the public health of any area where these industries and hospitals are located. This study sets out to determine the level of contamination caused by the discharge of wastewater from different wards at Park Lane General Hospital Enugu, Nigeria. To this end, the microbial load and heavy metal analyses of the hospital wastewater were determined using established procedures. Wastewater samples were collected from three (3) wastewater outlets of the hospital with pre-cleaned sterile and dried containers. The three (3) sampling points were wastewater from Medical Ward-(wws1), wastewater from New Born Baby ward-(wws2) and wastewater from Surgical Ward-(wws3). The isolated pathogenic bacteria include Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi and Bacillus subtilis, while the isolated non-pathogenic organisms were Proteus vulgaris, Klesbsiella pneumonia and Bacteriodes sp. The result of the microbial analyses showed mean total aerobic bacteria counts of 14.40 ± 0.86 x 1010 cfu/mL, 13.70 ± 0.65 × 107 cfu/mL and 22.8 ± 1.14 ×1010 cfu/mL, for wws1, wws2 and wws3 respectively. The mean total anaerobic bacteria counts gave 6.00 ± 1.60 × 103 cfu/mL, 4.00 ± 2.50× 103 cfu/mL and 1.70 ± 0.41 ×104 cfu/mL for wws1, wws2 and wws3 respectively. The result also showed the presence of Candida albican-a pathogenic fungus as the only isolated fungi specie in wws1 and wws3 with a population of 1.70 ± 0.41 x 103 cfu/mL and 2.3 ± 0.16 × 105 cfu/mL respectively. No fungi were isolated from wws2. High level of microbial contamination was observed in wastewater effluent from the surgical ward (wws3) among others as indicated by the obtained mean total aerobic bacteria count, mean total anaerobic bacteria count, mean total fungal count and the frequency of occurrences of the isolated organisms especially the pathogenic ones. The heavy metals analysis showed the presence of Arsenic, Cadmium, Lead, Mercury and Chromium. Most of the heavy metal concentration where found to be within the threshold of the WHO permissible limit of such metal. Therefore, it would be necessary to properly treat all the hospital wastewater before discharging into the environment to avoid the possible environmental health risk that might be associated with the discharge of such contaminated water. Close monitoring of the heavy metal concentration of the discharge water is also suggested.