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

AX5-11
Table AX5-2.4 (cont’d). Lead Effects on Hematological Parameters
Dose and Route of
Exposure Duration Species Blood lead Effect Authors
Erythrocytes from
humans of
occupational Pb
exposure and controls
In vivo and in vitro
In vivo; exposure
In vitro assays on
erythrocytes from
exposed populations
— Male Pb workers and
13 normal volunteers
— 1. Workers exposed to
manganese (Mn) and
2. Workers exposed to Pb
without clinical
manifestations of
intoxication
Range 20.6–
71.3 µg/dL
Nicotinamide adenine dinucleotide synthetase activity in the Pb workers
ranged from 0.08 to 1.1 µmol/h per g of hemoglobin. 50% of enzyme
inhibition was observed at 40 µg/dL. Aminolevulinic acid dehydratase
activity decreased rapidly and reached a plateau at Pb-B levels 40-60
µg/dL. 50% of enzyme activity inhibition was observed at 20 µg/dL.
— Erythrocyte concentrations of adenyl nucleotides (ADP and ATP) were
elevated in both groups of workers and that of AMP in Pb-exposed
workers. The ratio of ATP/ADP significantly increased in Pb-exposed
workers.
ALA—Aminolevulinic acid; ALAS—Aminolevulinic acid synthetase; ALAD—Aminolevulinic acid dehydratase, RBC—Red blood cells.
Morita et al. (1997)
Nikolova and
Kavaldzhieva et al.
(1991)