ADJUSTMENT OF CREATININE-ADJUSTED VALUE TO URINE FLOW-RATE IN LEAD WORKERS

Two male lead workers, aged 57 and 51 y, were studied to compare the u rinary flow/creatinine-adjusted values published earlier by Araki et a l. and by Greenberg and Levine. We collected 24-h urine samples once a month for 31 mo and 16 mo for workers 1 and 2, respectively. The work ers' urinary excretions of lead, delta-aminolevulinic acid, and coprop orphyrin were measured. No significant correlations between urine flow rate and urinary flow/creatinine-adjusted values published by Araki e t al. for the three substances were found for these two workers. Howev er, urinary flow/creatinine-adjusted values presented by Greenberg and Levine for lead and delta-aminolevulinic acid were correlated positiv ely with urine flow rate in the two workers, and their adjusted value for coproporphyrin was correlated positively with urine flow rate in o ne of the workers. We concluded that use of the urinary flow/creatinin e-adjusted value by Greenberg and Levine for biological monitoring pos es a problem because of the theoretical fallacy.