Assessment of Lead Exposure and Microbial Contamination in Addis Ababa Kindergarten Schools' Tap Water
The objective of this study is to evaluate the quality of water consumed by kindergarten school children in Addis Ababa city, who are highly susceptible to issues associated with heavy metal in water. Through conducting chemical analysis, the level of Lead (Pb) using Micro Plasma Atomic Emission Spectrophotometer (MP-AES), total coliforms & E.coli in the water distribution system were measured at 38 schools. The study can be considered as an unprecedented piece of work as it addresses critical
... ssues and methods to mitigate the problems caused by high concentration of Pb in water supply distribution infrastructure. The samples were taken from 3 water supply sub-systems; Akaki, Legedadi and Gefersa. The results revealed that the average Pb concentration in the city was 62.37μg/L which was higher than the WHO recommended threshold value of 10μg/L. The children's blood lead levels and exposure to Pb was also calculated using integrated exposure uptake bio-kinetic (IEUBK) model as per the USEPA guidelines. In average figure, the model predicted that 20.17% of the children in the city will have their blood lead levels above the WHO recommended 10μg/dL. In the microbial analysis, 7 out of 38 schools were contaminated with total coliform bacteria. However, E. coli was not detected in any of the samples, meaning that all samples were free from fecal contamination. In addition, the free chlorine level of the samples was also tested. The results indicated that 16 out of 38 (42.1%) of the water samples had a free chlorine value below the WHO recommended 0.2mg/L. It is therefore, possible to conclude that regardless of the different water sources, a water supply infrastructure determines the concentration levels of lead and residual chlorine that reaches the end users.