BIOCONCENTRATION OF HEAVY METAL IN CHICKEN EGGS OF DIFFERENT FARMS IN KHULNA, BANGLADESH

Abstract

The concentration of heavy metals (Mn, Ni, Pb, Cr, and Cd) in chicken eggs was studied in Khulna, Bangladesh, using
digestion methods and an Atomic Absorption Spectrophotometer (AAS). The average concentration of heavy metals
in chicken egg white parts and yolk parts from five different farms were: in egg white parts: Mn 1.456±0.102 mg/kg,
Ni 1.061±0.05 mg/kg, Pb 0.584±0.037 mg/kg, Cr 5.05±0.767 mg/kg, and Cd 0.009±0.003 mg/kg; in egg yolk parts:
Mn 1.784±0.132 mg/kg, Ni 1.558±0.059 mg/kg, Pb 0.792±0.064 mg/kg, Cr 6.204±0.582 mg/kg and Cd 0.005±0.002
mg/kg. The ranges of concentration of heavy metals in chicken feeds were recorded as: Mn 112.082±4.252 to
203.147±3.51 mg/kg, Ni 27.823±2.953 to 48.593±2.906 mg/kg, Pb 1.019±0.026 to 1.807±0.21 mg/kg, Cr
8.041±0.115 to 19.363±0.674 mg/kg, and Cd 0.009±0.002 to 0.107±0.01 mg/kg. Among these, the concentrations
of Ni, Pb, and Cr in chicken eggs and Pb and Cr in chicken feeds exceeded the maximum permissible limit set by
FAO and WHO (2002). The highest concentration of Mn, Ni, Pb and Cr was observed in the samples of egg yolk
collected from the farm of Batiaghata (2.329±0.050, 2.475±0.125, 1.205±0.033, and 7.23±1.05 mg/kg respectively);
the highest concentration of Cd was detected in the samples of egg white collected from the farm of Khulna Sadar
(0.014±0.005 mg/kg). Chicken farm dwellers in Khulna frequently use factory feeds that may contain heavy metals;
thus, feed can be a possible source of heavy metals in chicken eggs of different farms in Khulna.