Heavy metal concentrations in fish, shellfish and fish products from internal markets of India vis-a-vis international standards

Determination of Selected Heavy Metals and Human Health Risk Assessment in Fishes from Kiri Dam and River Gongola, Northeastern Nigeria

“…This follows from the fact that the concentration of these selected heavy metals are higher in Catfish than Tilapia irrespective of the location. And as stated earlier, this is believed to be due to their difference in eating habit and metabolism [5,19,32]. The relative contributions of the selected heavy metals to the total metal THQ from fish consumptions is shown in Figure 3.…”

“…The mean concentration of Cd in Bare and Mada is 0.0265 and 0.0275 ppm for Catfish and 0.011 and 0.0085 ppm for Tilapia respectively. Cadmium exposure has been reported to enhance kidney damage and hypertension [5,19,22]. None of the sampled fishes was found to contain Cd above the EC limit of 0.1 ppm.…”

“…Working standards of Lead, cadmium, chromium, arsenic and iron were prepared by diluting concentrated stock solutions (Merck, Germany) of 1000 mg/l in ultra-pure water (MilliQ, Millipore-USA) [19].…”

“…Arsenic concentrations as high as 170 mg/kg have been reported in crustaceans and other shellfish [23]. Chronic arsenic poisoning symptoms include pigmented skin lesions, gangrene of the lower extremities (blackfoot disease), along with neuritis and paralysis, anemia and disturbances of the liver and circulatory system [5,19,22,29]. From Figure 2, it is observed that the concentration of these selected heavy metals is higher in Catfish than Tilapia irrespective of the location.…”

“…This is believed to be due to their difference in eating habit and metabolism. As it is well known that one of the most important factors that play a significant role in heavy metal accumulation in aquatic animals is the metabolic activity [5,19,32].…”