Evaluation and correlation study of heavy metals load in drinking water and update of water-related disease cases in ebonyi state from 2001 – 2011

Abstract

Spectrophotometric and correlation analysis of heavy metal levels in drinking water was carried out. Samples from various sources of drinking water in different Local Government Areas in Ebonyi State were collected in pre-treated plastic bottles during the rainy and dry seasons and analysed for total Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn. Pearson’s correlation analysis and tTest statistics were used to evaluate the relationship between elevated heavy metal ions in the sample, while Integrated Disease Surveillance and Response System (IDRS) was used in epidemiological studies to evaluate the current status of four water-related disease cases in the area between 2001 to 2011. The result showed that the prevalence of guinea worm, diarrhoea and cholera monitored dropped by a 100 %, 15.3 % and 8.6 % respectively, while typhoid fever escalated by 71.6 % in 2011 compared with the 2001 data. The result also indicated elevated metal concentrations above the WHO guideline limits for drinking water in the order; Pb > Mn > Fe > Cr > Co > Cd > Ni in surface water and Mn > Pb > Cr > Co > Fe > Cd > Ni in groundwater samples. Seasonal variations were not significant (P > 0.05). The correlation analyses showed high degree of metal association in the order: Cu/Zn > Pb/Zn > Fe/Mn > Fe/Pb > Cd/Zn > Cu/Pb > Co/Fe > Cd/Co.