PHYSICOCHEMICAL CHARACTERISTICS OF BOREHOLE WATER IN OLD ILARO TOWNSHIP

Safe drinking water is another problem of severe public health concern in most developing areas, particullaly in Nigeria where the use of borehole water is common. This research assessed physicochemical quality of borehole water, heavy metal content, and related health hazards of Old Ilaro township in Ogun State. Water samples were collected systematically and analyzed with parameters of pH, temperature, electrical conductivity, total dissolved solids (TDS), chloride, sulphate, nitrate, phosphate and selected heavy metals of iron, lead, cadmium, copper, zinc, magnesium and calcium. Findings showed that the majority of the physicochemical parameters such as pH (6.57 ± 0.22) and TDS (298.5 ± 17.67 mg/L) were within the acceptable range of the World Health Organization (WHO). Moreover, lead (0.17 ± 0.04 mg/L) and iron (1.27 ± 0.07 mg/L) were alarming, particularly above guideline levels, and are of great health concern. The level of risk assessment showed a hazard index of 1.09 on adult and 2.76 on children with lead as the major contributor which highlights increased vulnerability of the younger populations. Although the major vitamins required by the human body like calcium, magnesium, and zinc were within acceptable limits, the large amount of lead in the body revealed urgent threats on neurotoxicity and chronic disorders. These results underscore the importance of tightening of the control over the borehole construction, constant monitoring of water quality and mitigation measures that would help to protect the health of the population. Altogether, the research proves that despite the fact that borehole water in Old Ilaro Township can be considered to have passed some of the more basic quality parameters, the contamination of toxic metals, in particular, lead, is a life-threatening issue that needs to be addressed as soon as possible by the policymakers and the community stakeholders.