Assessment of zinc and lead concentration in water and muscles of Labeo rohita collected from wild and local fish farms of Pakistan

Reasonable evidences suggest that heavy metal pollutants have been added by factories and other industries to our local water bodies. The present study was conducted to determine the heavy metal (zinc and lead) concentrations in muscle tissues of Labeo rohita inhabiting local water bodies as well as those being raised at farms. Sampling was performed to collect Labeo rohita from two different stations along river Ravi, viz. Lahore Siphon (upstream) and Balloki Headworks (downstream). Additionally, samples were also obtained from the government operated as well as private fish farms located in Lahore District, Pakistan. The fish were dissected; their muscles were digested, filtered, and finally analyzed for concentrations of Zn and Pb. Significant variation of heavy metal ions were observed between two sites along river Ravi as well as government operated and private fish farms. Significantly high mean concentrations of Zn (10.7±1.268) and Pb (0.61±0.082) were observed at Balloki Head-works; whereas, the lowest Zn (1.58±0.235) and Pb (0.16±0.008) heavy metal levels were recorded in the muscle samples collected from private fish farms. It was also observed that the heavy metal concentration in the muscles of Labeo rohita, collected from Balloki Head-works was much higher than the permissible limits laid down by WHO/FAO. Further the recorded highest level of heavy metals in water samples collected from River Ravi indicates that the bioaccumulation of heavy metals is severely affecting the aquatic life of fresh water and industries should not be allowed to release their effluent directly into the river Ravi in their vicinity.