"Surface Water Quality Evaluation and Health Implications at In-Stream Sand Mining Sub-Catchment of Abak Local Government Area, Akwa Ibom State, Nigeria"

Abstract

Over the years, incessant sand mining processes demean the quality of surface water in areas of instream mining particularly places where mining is pervasive and irrepressible. Consequently, render the populace vulnerable to gratuitous health risk. In Abak Local Government, Nigeria this study seeks to assess surface water quality of streams where sand mining activities take place and implications on health of catchment communities. Seven active mining streams were delineated within the subcatchment of Cross river basin using stratified random sampling for the study. Surface water samples were collected in all the sites and subjected to standard laboratory methods for physicochemical and nutrient analyses for variables including: pH, temperature, conductivity, dissolved oxygen, total dissolved solid, total suspended solid, acidity, alkalinity, chloride, biochemical oxygen demand, chemical oxygen demand, total hardness, turbidity, calcium, Iron, Zinc, Nickel, Lead, Phosphate, Nitrate and Sulphate. This study found that acidity, Zn, Fe, DO, and turbidity at higher concentration indicate the presence of toxicants in the surface water samples. The results also revealed that values of some water variables deviated from World Health Organization and Minimum Permissible Limit (WHO*MPL). This implies that the least deviations from WHO*MPL mean that the water is risky to health when consumed. Thus, out of 70 responses from the two health centres around the study area, diseases like malaria (24%), typhoid (28%), diarrhea (13%), dysentery (7%), cholera (11%), and guinea worm (16%) were prevalent among the residents and these are diseases that are closely related to poor water quality. Therefore, there is need to regulate mining operations, establish monitoring plans that cover profile changes and sediment transport capacity in order to enable authorities in evaluating long-term and short-term effects of instream mining and reclaiming the terrain to protect the surface water from further contaminations.