Effects of water restriction and water loading on daily urinary excretion of heavy metals and organic substances in metal workers.

The effects of urinary volume on daily urinary excretion of seven heavy metals and four organic substances were examined in relation to the changes in their plasma and erythrocyte concentrations and urinary creatinine excretion in 19 metal workers. The examination was conducted under the conditions of water restriction and loading for six days. The major findings were as follows: (1) urinary excretion of all heavy metals and organic substances except mercury, together with creatinine excretion, significantly decreased under the water restrictive condition whereas under the water loading condition their excretion significantly increased and (2) daily variations in urinary excretion of lead, cadmium, chromium, copper, hippuric acid, delta-aminolaevulinic acid, and coproporphyrin did not differ significantly from the variation in urinary excretion of creatinine (profile analysis, p greater than 0.05). It is suggested that glomerular filtration is the major factor determining renal excretory mechanisms of the four heavy metals and three organic substances examined.