What question did this study set out to answer?

This research aims to evaluate the safety and quality of borehole water in a residential area through physicochemical and microbial testing.

February 11, 2026Open Access

Evaluation of Physicochemical Properties, Heavy Metal Contamination and Health Risk Implications, and Microbial Integrity of Borehole Water in Odogunyan-Ikorodu, Lagos, Nigeria

Key Points

This research aims to evaluate the safety and quality of borehole water in a residential area through physicochemical and microbial testing.
Collected water samples from multiple streets in Odogunyan-Ikorodu.
Analyzed samples for physicochemical properties and heavy metal concentrations.
Calculated average daily intake (ADI) and hazard quotient (HQ) for health risk assessment.
Compared results with World Health Organization (WHO) guidelines.
Physicochemical properties were mostly within safe limits, but lead and mercury levels exceeded standards.
Iron concentrations were above permissible limits at several sampling sites.
All samples showed high levels of bacteria and coliform contamination.
The hazard quotient for heavy metals exceeded safe values at all locations, indicating health risks.

Abstract

Background: Contaminated water remains a major cause of disease worldwide, emphasizing the need for regular safety evaluations of water sources in residential areas. This study aimed to assess the physicochemical properties, heavy metal concentrations, and microbial contamination of borehole water in Odogunyan-Ikorodu, Lagos. Methods: The water samples were collected from Ademotu, Three Brothers, Olafiku, Cammy, Leke Silas, Alaba, Opeloyeru, Sakajojo, AOJS, and Omeji streets and analyzed using standard procedures. The results for each parameter were compared with the World Health Organization (WHO) guideline values. Also, the average daily intake (ADI) and hazard quotient (HQ) of the heavy metals were calculated to evaluate potential health risks. Results: Physicochemical analysis indicated that temperature, pH, dissolved oxygen (DO), conductivity, total dissolved solids (TDS), and hardness were within permissible limits. However, concentrations of lead (Pb) and mercury (Hg) exceeded the limits (≤0.01 mg/L for Pb and≤0.006 mg/L for Hg) at all locations. Iron (Fe) levels were also above the permissible limit (≤0.3 mg/L) in samples from Ademotu, Three Brothers, Olafiku, Cammy, and Leke Silas, whereas zinc (Zn) and chromium (Cr) concentrations were within acceptable ranges. Although the ADI values for all heavy metals were within the threshold, the HQ exceeded the acceptable value (≤1) in all sampling sites. Microbiological analysis showed that all samples contained non-permissible levels of bacteria and coliforms. Conclusion: These findings indicate that the borehole water poses potential health risks. Regular monitoring and appropriate treatment are vital to protect public health in the community.

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