Species-specific content of As, Pb, and other elements in pangas (Pangasianodon hypophthalmus) and tilapia (Oreochromis niloticus) from aquaculture ponds in southern Bangladesh.

摘要

Content of arsenic and lead and 10 other potentially toxic elements (Ba, Ce, Cr, Cu, Fe, Mg, Mn, Se, Sr and Zn) was determined in tilapia and pangas from aquaculture ponds in southern Bangladesh. Tilapia had 1.6- to 4.3-fold higher content of Mn, As, Sr, and Ba than pangas, possibly caused by different feeding habits of the two fish. The other elements had similar concentrations in both species. Content of As in tilapia and pangas was 0.37 and 0.11 micro g g-1, respectively, while Pb made up 0.056 and 0.051 micro g g-1, respectively. Water treatment during the farming period (sand filtration and probiotic bacteria) and final depuration in groundwater for up to 48 h had no effect on content of the elements. For As, consumption of 100 g fresh fish per day contained 1.3% (pangas) and 5% (tilapia) of the maximum tolerable daily intake according to FAO recommendations. Relative to whole tilapia from a lake near Dhaka (Begum et al., 2005), muscle tissue in tilapia from the ponds had 3-50 x lower content for Zn, Cu, Mn and Pb, while the remaining elements were similar. Thus, our results suggest that pond-raised fish in Bangladesh may be a healthier choice than wild fish, especially if the fish originate from freshwater receiving untreated wastewater.