Assessment of Heavy Metals and Trace Elements in Eggs and Eggshells of Gallus gallus domesticus, Coturnix coturnix and Anas platyrhynchos from Bangladesh

Abstract

Background: Despite playing an essential role as micronutrients, when exposed to an excess level, heavy metals can augment the risk of potential health diseases among humans and animals. Due to environmental degradation and food adulteration, many people are becoming the victims of those diseases by ingesting heavy metals from those food sources. Eggs are one of the principal sources of proteinaceous food and eggshells are also a good source of calcium, therefore, it is necessary to estimate the frequency of heavy metals as the poultry feeds, nowadays, are contaminated with heavy metals. Materials and Methods: Five types of egg samples were collected from the Jahangirnagar University area including indigenous, white and brown layer chicken eggs, duck eggs, and quail eggs. The concentration of Pb, Cd, Cr, Cu, Fe, and Zn was estimated both for egg contents and eggshells (10 samples) by atomic absorption spectrophotometry compared with the standard curve. Estimated daily intake (EDI), Target hazard quotient (THQ), and Hazard Index (HI) were also calculated to observe whether egg intake possesses any health hazards or not. Results: Among all the trace elements estimated, the highest concentration was 35.36±0.4 (Zn) in white layer chicken eggs, and for eggshells, the highest concentration was 0.69875±0.082 mg/kg (Fe) in Quail eggshell. Except for Fe, Pb was relatively higher compared to other elements in eggs, the amount of Pb was the highest in Quail eggs (0.486±0.09 mg/kg). All the six elements were also within the acceptable range in eggshells where the amount of Pb was the highest in Brown layer eggshells, and Cu and Zn were the highest in indigenous eggshells. Cd and Cr were below the detection limit for all types of eggshells. Estimated daily intake (EDI), Target hazard quotient (THQ) and Hazard Index (HI) values indicated that intake of eggs does not possess any health risk. Conclusion: Interestingly, the heavy metal concentration of our samples belongs within the PTDI and USEPA limit. Therefore, based on our study, all egg samples were safe considering the average egg ingestion in our country. If the average egg consumption rises, people might be at risk for higher Pb consumption through egg intake.