A 9-YEAR CHRONIC TOXICITY STUDY OF CADMIUM INGESTION IN MONKEYS .1. EFFECTS OF DIETARY-CADMIUM ON THE GENERAL HEALTH OF MONKEYS

Thirty-five male rhesus monkeys (Macaca mulatta) 2-5 y-of-age were sep arated into 5 groups and fed 200 g solid food daily which contained 0, 3, 10, 30 or 100 mug cadmium/g (ppm) as cadmium chloride for 462 w (9 y). The control feed (0 ppm) contained 0.27 mug cadmium/g. Dietary zi nc intake was limited to the minimum requirement of 6 mg zinc/day (con trol food concentration was 3 mg zinc/100 g) to avoid impacting cadmiu m toxicity due to excessive zinc intake. Urine was collected at 3-w in tervals. Decreased development (reduced body weight and body length) w as observed in groups that received 10 ppm cadmium or more. The 100 pp m group had glucose in the urine after 48 w, elevated urine protein at 98 w, and markedly increased urine volume after the 102nd week. No ab normalities in renal functions were noted in the 3 or 10 ppm groups. D espite the development of these clinical signs of renal dysfunction, n one of the 100 ppm group had aggravated renal dysfunction or renal fai lure during the 9 y of study.