Heavy metal profile with health risk peculiarities in Enugu State and their long-term challenges in drinking water

Abstract

Health authorities are particularly concerned about water security in Enugu, southeast Nigeria and heavy metal (HM) pollution. The HM profiles of 51 samples collected from 17 different commercial bottled water brands in Enugu were examined using an flame atomic absorption spectroscopy. Cd, Cr, Cu, Pb, Ni, and Zn had mean values of 0.15 ± 0.03, 0.03 ± 0.02, 0.16 ± 0.03, 0.13 ± 0.02, and 0.02 ± 0.01 mg/L, respectively. The highest levels of Pb2+ were 0.27 mg/L in Exalté, Ni2+ 0.26 mg/L in Jasmine, Cd2+ 0.36 mg/L in Ezbon, Cr3+ 0.07 mg/L in Trinity, Cu2+ 0.04 mg/L in Bigi, and Zn2+ 0.02 mg/L in Aquarapha. The amounts of Cr, Cu, and Zn were below the allowable limits; nevertheless, the Pb content in eight bottled water samples exceeded both the Nigerian and World Health Organization (WHO)/U.S. Environmental Protection Agency (USEPA) permissible limits. The Cd2+ and Ni2+ levels in the 11th and 4th bottled water samples were above the WHO/USEPA-approved limits. Statistical evaluation revealed significant differences in the amounts of HM ions in the samples (p < 0.05). The findings indicated that concentration levels of Cd2+ Ni2+, and Pb2+ pose a public health concern that needs to be addressed due to potential risk to consumer health. HIGHLIGHTS Pb detected in the remaining nine samples and exceeded the allowable limits set by the World Health Organization (WHO) and U.S. Environmental Protection Agency (USEPA).; Cd2+ was found in 11 bottled water samples, all of which were above the WHO and USEPA acceptable limits.; The result (dendrogram) showed five clusters, with Cu being more related to Zn than to Pd, Ni, Cd, and Cr.; The use of nanofiltration and microfiltration is known to remove hexavalent chromium (Cr(VI)).;

Keywords

• drinking water
• heavy metals
• multivariate analyses
• water contamination
• water quality
• water sources