Air Quality Criteria for Lead Volume II of II - (NEPIS)(EPA) - US ...

AX5-85
Table AX5-6.5. Genotoxic/Carcinogenic Effects of Lead—Genotoxicity Human Cell Cultures Mutagenesis
Compound Dose and Duration Cell Type Co-exposure Effects Reference
Pb acetate,
In vitro
Cytotoxicity–tritium
incorporation (0.1–
100 µM/mL for 2–24 h)
Mutagenesis–HPRT
modified to labeling of
6-thioguanine resistant cells
(0.1–100 µM/mL for
2–24 h)
Pb acetate Cytotoxicity (500–
2,000 µM for 24 h)
Mutagenicity–HPRT assay
(500–2,000 µM for 24 h)
Pb chromate Mutagenicity as 6thioguanine
resistance
(0.25–1 µM for 24 h)
Human Keratinocytes
pooled in MEM and low
calcium MEM + 2% FBS
Human Foreskin
Fibroblasts (Chinese)
in DMEM +10% FCS
Human Foreskin
Fibroblasts
In EMEM +15% FCS
None Decrease in tritium incorporation at 10–100 µM/mL.
6 µM/L was selected as the concentration to study as tritiumincorporation
was highest and greater than control.
Tritium incorporation in the presence of 6-thioguanine (TG)
was optimal after 4 h Pb acetate exposure and 5 days of
expression time. It was concluded that the significant
increase relative to control indicated mutations. The
argument made was that because these cells are TG resistant
they must be mutated. However, this argument was not
proven by sequencing or colony formation in TG.
3-aminotriazole (3-AT)
(80 mM to inhibit
catalase)
Abbreviations
Medium and Components
MEM—Minimal Essential Medium;
DMEM—Dulbecco’s Minimal Essential Medium;
EMEM—Eagle’s Minimal Essential Medium;
FBS—Fetal Bovine Serum
FCS—Fetal Calf Serum
Differences between the serum types are unclear as insufficient details are provided by authors to distinguish.
LC50 = 500 µM. Cytotoxicity not affected by 3-AT.
Pb acetate was not mutagenic.
Mutagenicity not affected by 3-AT.
Ye (1993)
Hwua and Yang
(1998)
None Pb chromate was not mutagenic. Biedermann and
Landolph (1990)