Scintigraphic assessment of renal function in steel plant workers occupationally exposed to lead.
OBJECTIVE
Occupational exposure to lead may produce kidney damage, but existing data on the dose range associated with nephrotoxicity are inconclusive. We here assessed renal function under conditions of low to moderate lead exposure using renal scintigraphy.


METHODS
Fifty-three male foundrymen (exposed group) and fourty male office workers (control group) from a steel plant were included in the study. Glomerular and tubular renal function were assessed by means of (99m)Tc-DTPA and (99m)Tc-EC clearance, respectively. Urinary markers of glomerular dysfunction (albumin) and tubular damage (α1-microglobulin (α1M), β2-microglobulin (β2M), retinol-binding protein (RBP), N-acetyl-β-glucosaminidase (NAG) activity) were determined using latex beads tests or colorimetry. The lead concentration in blood was measured with atomic absorption spectrometry.


RESULTS
The blood lead concentrations were 145.8 (121.3-175.3) and 39.3 (35.1-44.1) µg/l (geometric mean, 95(th) CI, p<0.001) in the exposed and control groups, respectively. Subjects exposed to lead presented with increased (99m)Tc-DTPA clearance (158.3 (148.4-168.8) vs. 135.9 (127.9-144.4) ml/min; p<0.01) and urinary albumin excretion (7.61 (6.28-9.22) vs. 4.78 (4.05-5.65) mg/g creatinine; p<0.001). (99m)Tc-EC clearance and excretion of α1M, β2M, RBP and NAG were not significantly different between the groups. Significant correlations between (99m)Tc-DTPA clearance and blood lead concentrations (r=0.45; p<0.01) and between urinary albumin excretion and blood lead concentrations (r=0.71; p<0.001) were noted.


CONCLUSIONS
Use of renal scintigraphy in present study revealed measurable alterations of renal function under the conditions of low-level lead exposure and suggest that increased glomerular filtration may be an early indicator of kidney damage in subjects occupationally exposed to lead.
Department of Toxicology and Carcinogenesis, Nofer Institute of Occupational Medicine.
Teresa
T
Wrońska-Nofer
Anna
A
Pisarska
Małgorzata
M
Trzcinka-Ochocka
Tadeusz
T
Hałatek
Jan
J
Stetkiewicz
Janusz
J
Braziewicz
Jerzy-Roch
JR
Nofer
Wojciech
W
Wąsowicz
D000118:Acetylglucosaminidase / Q000652:urine; D000328:Adult; D000419:Albuminuria; D000510:Alpha-Globulins / Q000652:urine; D015415:Biomarkers / Q000652:urine; D016022:Case-Control Studies; D003404:Creatinine / Q000652:urine; D003545:Cysteine / Q000031:analogs & derivatives / Q000493:pharmacokinetics / Q000652:urine; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging* / Q000378:metabolism; D007674:Kidney Diseases / Q000139:chemically induced / Q000000981:diagnostic imaging / Q000378:metabolism; D007854:Lead / Q000097:blood / Q000633:toxicity*; D008297:Male; D008657:Metabolic Clearance Rate; D008669:Metallurgy / Q000706:statistics & numerical data*; D008875:Middle Aged; D009784:Occupational Diseases / Q000139:chemically induced / Q000378:metabolism; D016273:Occupational Exposure / Q000009:adverse effects*; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics / Q000652:urine; D011044:Poland; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics / Q000652:urine; D012177:Retinol-Binding Proteins / Q000652:urine; D013232:Steel; D016284:Technetium Tc 99m Pentetate / Q000493:pharmacokinetics / Q000652:urine; D001613:beta 2-Microglobulin / Q000652:urine
D000510:Alpha-Globulins; D015415:Biomarkers; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D012177:Retinol-Binding Proteins; C016001:alpha-1-microglobulin; D001613:beta 2-Microglobulin; D013232:Steel; C073806:technetium Tc 99m-ethylenedicysteine; D007854:Lead; D003404:Creatinine; D000118:Acetylglucosaminidase; D003545:Cysteine; D016284:Technetium Tc 99m Pentetate