Heavy metal (cadmium, lead, and chromium) contamination in farmed fish: a potential risk for consumers' health

To assess heavy metal loads in cultured fish, four farmed carp fish species were sampled from a fish farming cluster at the Head Qadirabad area. Samples were randomly collected from fish farms and a local fish market and analyzed for three nonessential heavy metals, cadmium (Cd), chromium (Cr), and lead (Pb), at Fish Quality Control Labs Manawan, Lahore, Pakistan. All three tested metals were found in all samples of selected fish species. The highest accumulation among heavy metals in farmed carps was recorded for Pb (0.3316 +/- 0.0143 mu g g(-1)), followed by Cr (0.0488 +/- 0.0063 mu g g(-1)) and Cd (0.0094 +/- 0.0011 mu g g(-1)). Mean Pb concentrations found in Labeo rohita (0.3316 +/- 0.0143 mu g g(-1)) and Hypophthalmichthys molitrix (0.3246 +/- 0.0496 mu g g(-1)), collected from the local market, were beyond the permissible limits of the WHO for fish (0.123 mu g g(-1)), while the concentrations of Cr (0.0488 +/- 0.0063 mu g g(-1)) and Cd (0.0094 +/- 0.0011 mu g g(-1)) were found to be below the WHO permissible limits (0.100 mu g g(-1)). Cd was significantly higher in Labeo rohita when compared with other species, while among distribution points Cr was significantly higher in fishes sampled from the local fish market. The correlation matrix showed that concentrations of Cd and Pb were significantly and positively correlated with each other. This study concludes that farmed fish produced in the Head Qadirabad area along the Chenab River are not safe for human consumption due to the presence of Pb, beyond acceptable limits. Eating farmed fish from this area may pose health hazards for humans and thus can create an upsetting situation, not only for the consumers but for the producers as well.