Bacteriological and Physicochemical Qualities of Well Water in Imota-Lagos Nigeria and Health Effects Associated with its Usage.

摘要

Well water is a key source of drinking water in rural areas, such as Imota where this study was carried out. Forty wells made of concrete, comprising of 20 (50%) hand-drawn and 20 (50%) operated through mechanical/electrical pumps in Imota were investigated for their physicochemical and bacteriological qualities. Analytes such as total hardness, magnesium hardness, calcium hardness and nitrate levels were within the recommended WHO standard for water quality. The water from the wells with pH values of 4.5 – 5.9 is acidic and falls below the WHO recommended pH range of 6.5-8.5. Ammonium and iron concentrations in the well water were relatively higher as well as very high bacterial loads and coliform counts were obtained. Calcium and magnesium significantly correlates with each other and both with total hardness (p<0.001). Significant positive correlations were obtained between iron concentration and coliform counts (0.039), iron and nitrate (p=0.033), as well as coliform and total bacterial load (p=0.001). Higher bacterial loads were obtained from wells that are hand-drawn using various containers than wells where water is being pumped using devices. The bacteria isolated include Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus equorum, Staphylococcuss carnosus, Kokuria varians, Enterococcus faecalis, Bacillus niacini , Bacillus firmus, Streptococcus pneumoniae, Citrobacter koseri, Enterobacter cloacae, Klebsiella pneumoniae, Enterobacter aerogenes, Acinectobacter baumannii, Pseudomonas sp ., Salmonella enterica , Edwardsiella tarda and Buttiauxella agrestis . The bacterial isolates were highly susceptible to antibiotics except for chloroamphenicol, ampicillin and nitrofurantion which showed 25%, 10% and 28.75% susceptibility respectively.. Symptoms of ill-health commonly reported by participants include fever, chills, headache, weakness/muscle ache, and skin rash, and abdominal pain, diarrhoea, sneezing and coughing. The reported frequencies of ill-health were significantly higher (t=3.200, p=0.013) among residents that drank water from the well than those that do not. The need to treat the water from these wells before drinking is highly recommended. Key words : Antibiotic resistance, bacteria, ill-health, quality, well water.