Cadmium and zinc in kidneys from Danish cattle

This paper describes an investigation on the content of cadmium and zinc in Danish cattles kidneys in relation to animal age and place of rearing. The investigation included kidneys from 176 animals sampled in 1979-81 from 26 slaughterhouses (fig. 1). The investigation shows a statistically significant relationship between kidney cadmium content and age (table I and fig. 2). An age difference of 7 years leads to a 9 fold increase in cadmium concentration. The effect of place of rearing is less marked. The content is highest in kidneys from animals bred in the South-Eastern parts of Denmark and is gradually decreasing when going in a North-Western direction (fig. 3). This geographic pattern parallels earlier Danish studies on atmospheric deposition and of cadmium content in lichens. The zinc concentration shows no relationship with neither age nor place of rearing, and no correlation could be established between renal cadmium and zinc content (fig. 4). Based on the PTWI of 400-500 micrograms it is suggested, that only kidneys from Danish cattles less than two years of age should be used for human consumption. In West Germany a proposal has been made for a maximum tolerable cadmium content of 1 mg/kg kidney for human consumption.