Incurred Arsenic Residues in Chicken Eggs

Arsanilic acid and roxarsone were fed to laying hens at elemental arsenic concentrations of 14, 28, 56 or 112 ppm for 10 weeks followed by a 2-week withdrawal period. Arsenic residues in egg components of laying hens that were fed either control or diets treated with organic arsenicals were determined weekly by atomic absorption. Arsenic concentrations in eggs were also determined after either 0, 2 or 4 weeks of refrigerated storage (4°C). Arsenic residues in both yolk and albumen increased in a dose-dependent manner although the amount of arsenic was much higher (95% of total) in yolk. Arsenic concentrations increased within 1 week of treatment, and the highest amounts were obtained between the second and fourth week for yolk samples and by the first week for albumen samples, except in the 14-ppm doses where highest amounts were reached by the middle of the treatment period. Hens treated with 112 ppm arsenic from arsanilic acid produced eggs with arsenic residues exceeding the 500 ppb Food and Drug Administration whole egg tolerance level. Eggs subjected to refrigerated storage did not have increased arsenic concentrations in yolk, although, for a few treatments, residues increased in albumen.