Chromium (Cr) Contamination of Poultry from Use of Tannery-based Cr-contaminated Feed Ingredients and Public Health and Environmental Risks

Abstract

In Bangladesh, India and Pakistan, protein-concentrates produced from tannery skin-cut solid wastes are used for poultry and fish feeds. These protein-concentrates are highly chromium (Cr)-polluted ingredients into the feeds. Wide use of such protein-concentrates in Bangladesh poses a potential pub lic health threat due to the potential migration of high levels of Cr into food chain. In order to reveal public health risk and the environmental hazards associated with this practice, experiments were conducted simulating the real-world poultry rearing in farms with formulating poultry feeds incorporating such Cr-polluted protein-concentrate. One-day aged commercial broiler chicken line Cobb-500 and duck variety ‘Khaki Campbell’ were obtained from the commercial market for the experiments. The simulated feeds produced as per field-practice have a pollution level of (0.3–0.4) % dry weight basis Cr concentration. One week aged fowls through the experimentation exhibited low Cr accumulation in their body mass, while most of the Cr intake being discarded with excreta. As the age of the fowl increased, with sampling at three weeks and six weeks of age, the proportional Cr concentration inside the body increased, with simultaneous proportional decrease in excreta and gut mass. Compared to daily dietary adequate intakes (AIs) of Cr for humans, the dietary public health exposure from consuming 100 g standard fresh-weight breast meat per day from the contaminated fowls is found to be at least 100 to over 300 times higher than the AIs for any people type and any age group beyond three years, whereas for children under three years such becomes even higher. The environmental hazards are no less severe. Application of one metric ton dry weight excreta produced from the contaminated fowls could pose 2.94 kg environmental Cr load.