Health Risk Assessment of Heavy Metal Pollution in Subsurface Water Quality around Waste Dumpsite of the Upper Benue Floodplain in North-Eastern Nigeria

Abstract

Urbanization presents many challenges for developing countries, such as industrialization and over-population which can lead to indiscriminate dumping of waste. Refuse waste becomes a form of point source pollution if it affects the environment directly and non-point source pollution if it affects the environment indirectly. This leads to contamination of surface and groundwater and adversely impacts public health. Nigeria is a lower middle-income country which is facing a myriad of pollution and environmental health issues. Diseases which may lead to increased mortality are relative to gradual increases in arsenic (As), lead (Pb) and cadmium (Cd) in the environment originating from toxic waste in solid or liquid forms. Indiscriminate dumping of refuse has consequences on the environment, such as flooding due to waste blockage of water run-off channels, and emission of contaminants that leads to slight poisoning. Highly toxic waters (ground and surface) may lead to diseases such as asbestosis, respiratory problems, cancer and eventually death). A geochemical survey of metals in the groundwater around the exposed dumpsite was conducted to determine the impact on the environment. The groundwater in the study area was used for drinking and domestic purposes. The study was carryout at Jimeta along Yola-Mubi road, two samples were chosen at each location for cation and anion analysis, those chosen for cation analysis were acidified with concentrated hydrochloric acid to preserve the elements in the samples, while those chosen for anion analysis were not acidified. Total dissolved solids (TDS), electrical conductivity (Ec), pH and temperature were measured in situ. Analysis of water quality in the study area illustrates the nature of pollutants found in groundwater as a result of continuous random dumping of hazardous waste and discharge of effluents by agriculture and municipal waste in the community and surrounding environment. The results of this study suggest that groundwater close to the study area is no longer potable for drinking due to the moderate-abundant amounts of carbonate, which causes water hardness, and could lead to cosmetic and aesthetic effects on taste, odor and color. There is also an elevated risk for carcinogenic and non-carcinogenic diseases for adults and children in the area due to high occurrence of Pb, As and Cd found in the water. It is therefore recommended that in the municipal, the government should distribute waste disposal bags and establish a waste collection service to reduce indiscriminate dumping of refuse in the area. In addition, a task force should be formed in the community to enforce existing waste disposal and water protection laws. Construction of a centralized, deep, double-cased well is recommended to ensure an uncontaminated water supply for drinking and domestic purposes in the study area.