Alterations in Reproductive Indices in Mice Exposed to Contaminated Urban Groundwater From an Automobile Spare Parts Market in Ibadan, South-Western Nigeria

Abstract

Contamination of underground water with pollutants such as spent engine oil from automobile scrap sales and repair activities has health implications on biota and public health. This study investigated the effects of contaminated groundwater within the Araromi spare-parts market, Ibadan on some reproductive indices in male Swiss albino mice. Samples from two wells (CWW1 and CWW7) known to be contaminated with high levels of heavy metals and PAHs concentrations were purposively selected for experimental studies. Four groups of 10 mice each were exposed to graded concentrations (25%, 50%, 75%, and 100%) of the well-water samples, while a control group of 10 mice received distilled water. Semen characteristics, reproductive hormonal levels (LH and FSH) were analysed at days 21, 42 and 84 post-exposure for changes induced by the contaminated well-water. Data were analysed using one-way ANOVA. Sperm count and percentage sperm motility were significantly lower (p<0.05) in exposed mice compared to the control and lower concentration groups (25%) throughout the experiment. Various types of morphological abnormalities including long pin and pin head were observed at day 84 in 75% CWW1 and 100% CWW7 respectively. Significantly elevated (p<0.05) levels of LH and FSH occurred in 100% CWW1 at day 84, while FSH levels were only significantly higher in 100% CWW7 exposed group at day 84. Our findings indicate that the contaminated well-water induced reproductive toxicity in exposed mice and may have negative health implications in orally exposed human populations with prolonged domestic usage of the contaminated water.