  Contaminated water is increasingly linked to diseases worldwide,
necessitating the safety evaluation of the sources of domestic and drinking
water in every locality. The present study aimed to assess water safety in
terms of lead (Pb), nickel (Ni), cadmium (Cd), copper (Cu), chromium (Cr), zinc
(Zn), and microorganisms in the borehole and well water in Iwaya, Makoko, and
Ilaje in Lagos, Nigeria. Water samples were subjected to atomic absorption
spectroscopy (AAS) and microbiological examinations using standard protocols
and compared with the World Health Organization (WHO) permissible limits. The
average daily ingestion (ADI) and hazard quotient (HQ) of the selected heavy
metals were also calculated using standard formulas. The AAS indicated that the
borehole and well water of the three locations contained non-permissible levels
of Pb, Ni, and Cd (only the well water in Ilaje), while Zn, Cu, and Cr were
normal. In addition, the microbiological examinations showed that the borehole
and well water of the three locations contained abnormal bacteria and coliform
counts (well water only). The ADI and HQ of the selected heavy metals were less
than one, which is the threshold at which a substance is considered safe for
consumption. Water could pose some health risks, and the consumers in high-risk
areas should consider water treatment before consumption.
