Effects of urinary volume on urinary concentrations of lead, delta-aminolaevulinic acid, coproporphyrin, creatinine, and total solutes.

Urinary volume was related to urinary concentrations of lead, delta-aminolaevulinic acid (ALA), coproporphyrin (COPRO), creatinine, and total solutes in nine lead workers. On a log scale, linear relationships were found between urinary volume and the urinary concentrations. There was a certain difference in the extent of the effects of urinary volume on the urinary concentrations. For example, the concentration of creatinine was more affected by urinary volume than those of lead, ALA, and total solutes among the substances examined: similarly, the concentration of COPRO more than that of ALA. An equation was introduced to eliminate the effects of urinary volume on urinary concentrations. The effects of urinary volume on the concentrations adjusted to urinary specific gravity, osmolality, and creatinine are discussed in the light of these findings.