Assessment of Lead Exposure and Microbial Contamination in Addis Ababa Kindergarten Schools’ Tap Water
No Thumbnail Available
Date
2018-10
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
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 issues 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.
Description
Keywords
Lead contamination, Blood Lead Levels, E.coli, Total coliform, Free chlorine