A new HPLC fluorimetric method to monitor urinary delta-aminolevulinic acid (ALA-U) levels in workers exposed to lead

✍ Scribed by Takeo Tabuchi; Akira Okayama; Yasutaka Ogawa; Keiko Miyajima; Mamoru Hirata; Toshiaki Yoshida; Kanji Sugimoto; Kanehisa Morimot

• Publisher: Springer-Verlag
• Year: 1989
• Tongue: English
• Weight: 526 KB
• Volume: 61
• Category: Article
• ISSN: 0340-0131
• DOI: 10.1007/bf00409384

✦ Synopsis

A new sensitive HPLC method for the determination of urinary delta-aminolevulinic acid (ALA-U) was used to evaluate the relationship between blood-lead (Pb-B) and ALA-U levels in male workers exposed to lead The differences between the ALA-U levels determined by this method (ALA-U-HP) and by a colorimetric method (ALA-U-CL) are discussed The HPLC method gave values similar to the ALA-U-CL values at high ALA-U level However, at low blood-lead levels ( 58 ± 22 pg/l, N = 23), the mean ALA-U-HP level corrected by urinary creatinine level was one-third of the corrected ALA-U-CL level ( 0 83 0 14 and 2 4 + O 5 mg/g creatinine, respectively) A significant increase of the mean corrected ALA-U-HP level was observed at 162 ± 22 pg/l Pb-B (P < 0 05, N = 26), while that of ALA-U-CL was observed at 245 + 30 lg/l Pb-B (P < 0 01, N = 37) The regression equation based on the logistic model fitted well to the relationship data between the Pb-B level and the percentage of the subjects with corrected ALA-U-HP above the cut-off point ( 1 12 mg/g creatinine) and the expected Pb-B level for 50 % response was 270 gg/l Pb-B, while it did not fit well to the relationship data between Pb-B level and the percentage of the subjects with corrected ALA-U-CL above the cut-off point ( 3 5 mg/g creatinine).

The maximum responses for the two sets of corrected ALA-U levels were both observed at 625 ± 25 pg/l. The corrected ALA-U level by HPLC method seems to be a useful indicator for biological monitoring of exposure to lead at low levels (< 400 tg/l Pb-B = health-based biological limit, WHO) as well as high ones.