Pollution Assessment and Distribution of Snails’ Genera at a University Community Dam: Implications for Control Strategies

This study was carried out to evaluate the pollution level and distribution of snails’ genera at a dam within a university community in order to develop efficient control strategies. Water samples and sediment samples were collected at twelve sampling points within the dam for eight weeks and analyzed for heavy metals (Manganese [Mn], Zinc [Zn], Iron (Fe), Cadmium [Cd] and Lead [Pb]) while snail genera were identified using standard procedure. Results were compared with the World Health Organization's (WHO) guideline limit (water quality [Mn = 0.4mg/L, Cd = 0.003mg/L, Pb=0.01mg/L]; sediment [Zn = 120mg/kg, Fe = 15mg/kg]). Data were analyzed using descriptive statistics and Spearman rank correlation at p=0.05. Concentrations of Mn (mg/L), Zn (mg/L) in the water sample were 17.5±.01 and 11.3±2.6, respectively. These values were higher than the WHO's recommended limits. Lead and cadmium were not detected. Concentrations of manganese and zinc in the sediment samples were within the recommended limits. Iron concentration (690.3±120.9 mg/kg) exceeded the WHO's recommended limit. The snail genera identified were <i>Bulin</i>us species (65.0%), <i>Biomphalaria</i> species (24%) and <i>Lymnae</i> specie (11%). <i>Bulinus</i> (lunged snail) was the planorbid intermediate host of <i>Schistosoma haematobium</i>.<i> </i>A positive correlation existed between the concentration of manganese in sediment and the number of snail genera available (r = 0.722, p < 0.01). The concentration of metal in the sediment sample was higher than that in the surface water. Water and sediment had high concentration of iron and <i>Bulinus</i> snail species; an intermediate host of <i>Schistosoma haematobium </i>was identified. Continuous assessment of pollution level is highly essential and immediate control measure is encouraged to mitigate health risks associated with contact with this water body.