Urinary excretion of chromium in chromeplaters after discontinued exposure

In a previous study [Lindberg and Vesterberg, 1983a], excretion of chromium in urine (U-Cr) in chromeplaters was proposed for biological monitoring of ongoing exposure. Published reports were found about the decline of U-Cr after discontinued exposure in welders working in chromium-alloyed stainless steel, but not in chromeplaters. In this study, half-times (t1/2) were calculated for ten chromeplaters over a weekend, and for 23 chromeplaters over 31 days vacation. The results suggest that the excretion of chromium can be approximated to a two-compartment model. Estimated from the median values, an initial rapid phase with an assumed t1/2 of 2-3 days is followed by a phase with a t1/2 of approximately a month. Differences between the decline of U-Cr in chromeplaters and welders are discussed.