Platinum in the human diet, blood, hair and excreta

Baseline levels of platinum in the blood, hair and urine of 21 adults from Sydney, Australia, and three adults from the relatively unpolluted area of Lord Howe Island, Australia, were determined by adsorptive voltammetry. The median concentrations of platinum in samples from residents in Sydney were: whole blood, 0.56 microgram Pt l-1; hair, 3.84 micrograms Pt kg-1; urine, 0.18 microgram Pt l-1 (0.23 microgram Pt g creatinine). Samples from residents of Lord Howe Island had platinum levels that were within the range of values of the corresponding samples from Sydney residents. For faeces samples, the median platinum concentration was 10.5 micrograms kg-1 FW. The excretion of platinum over a 4-day period was measured in one adult male. Urinary excretion of platinum was between 0.76 and 1.07 micrograms Pt day-1 and in faeces it was between 0.61 and 0.73 microgram Pt day-1. The concentrations of platinum in a range of foodstuffs from Sydney were between 8.11 micrograms kg-1 FW for liver and 0.13 microgram kg-1 FW for full-cream milk. This information as well as the amounts of these foods in hypothetical diets for Australians was used to calculate the total dietary intake of platinum. The average diet of a Sydney adult contains 1.44 micrograms of platinum per day (adult male, 1.73 micrograms Pt day-1; adult female, 1.15 micrograms Pt day-1). The uptake of dietary platinum from the gut was estimated to be at least 42% and, therefore, diet appears to make a substantial contribution to total platinum intake.