Accumulation of Heavy Metals in Tilapia Fish (Oreochromis niloticus) from Al-Khadoud Spring, Al-Hassa, Saudi Arabia

Problem statement: Al-Khadoud Spring is one of the largest spring in Al-Hassa governorate (Saudi Arabia). Due to the extended domestic activities and urbanization as well as the continuous industrial and agricultural growth of the region, spring water quality is potentially changing. Approach: This study was conducted to measure toxic heavy metal concentrations in water and fish samples along the spring channel. Filtered spring water and tissues (liver and muscle) of captured fish were analyzed for heavy metals in an Atomic Absorption Spectrophotometer equipped with a Varian Model. Results: The concentrations of metals in water were found in the following order: Fe²⁺>Zn²⁺>Cu²⁺ >Pb²⁺>Mn²⁺>Cd²⁺. The levels of heavy metals recorded in water in this study were generally low, when compared to WHO and USEPA recommended levels in water, except iron which was found to be higher than the recommended levels. In fish samples collected from the polluted spring, metal levels were significantly higher than the levels in water, indicating bioaccumulation. The highest levels of metals were generally reported in fish liver than muscle. Hepatic metal levels were ranked as follow: Zn²⁺>Cu²⁺>Pb²⁺>Cd²⁺. Conclusion: The present results showed that, the fishes, based on the higher levels of metal bioaccumulation, could be unsafe for human consumption. Consequently, very close monitoring of heavy metal loads in Al-Khadoud spring is recommended in view of the possible risks to health of consumers.