Evaluation of lead exposure in workers at secondary lead smelters in South Korea: with focus on activity of erythrocyte pyrimidine 5'-nucleotidase (P5N).
To evaluate lead exposure among secondary lead-smelting workers with a focus on erythrocyte pyrimidine 5'-nucleotidase (P5N) activity, blood lead concentration (PbB), activity of P5N and other biological variables were examined in 88 exposed workers in five secondary lead smelters and in 24 non-exposed workers in Korea. All of the mean values of air lead concentration (PbA) in the three processes, scrap pretreatment, blast furnace smelting, and refining and casting of the secondary lead smelters, markedly exceeded 0.05 mg/m3. In this survey, 29 (97%) of 30 air samples for lead exceeded 0.05 mg/m3. The highest mean PbA and PbB values were found in the section of blast furnace smelting. All of the mean PbB values in all the sections were higher than 30 microg/dl. PbB of 71 (81%) of the 88 exposed workers exceeded 30 microg/dl. In 31 (35%) of the exposed workers, PbB was above 60 microg/dl. Compared with the non-exposed group, zinc protoporphyrin (ZPP) in the exposed group was significantly increased, whereas erythrocyte P5N activity and activity of erythrocyte delta-aminolevulinic acid dehydratase (ALAD) were significantly inhibited. Erythrocyte P5N activity had valid biological correlation with PbB and with other biological variables, such as ALAD activity or ZPP. Lead exposure affected hemoglobin levels via inhibition of P5N activity, as well as the heme biosynthetic pathway, in the high-exposure state.
Kim
Yangho
Y
Department of Occupational and Environmental Medicine, Ulsan University Hospital, South Korea. yanghokm@nuri.net
Lee
Hun
H
Lee
Choong Ryed
CR
Park
Dong Uk
DU
Yang
Jeong Sun
JS
Park
In Jeong
IJ
Lee
Kwang Yong
KY
Lee
MiYoung
M
Kim
Tae-Kyun
TK
Sohn
Nam-Seok
NS
Cho
Young Sook
YS
Lee
NaRoo
N
Chung
Ho Keun
HK
D015720:5'-Nucleotidase / Q000378:metabolism*; D000328:Adult; D015415:Biomarkers / Q000032:analysis; D004912:Erythrocytes / Q000187:drug effects / Q000201:enzymology; D005260:Female; D006418:Heme / Q000096:biosynthesis; D006801:Humans; D007221:Industry; D007723:Korea; D007854:Lead / Q000009:adverse effects* / Q000032:analysis; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D000623:Porphobilinogen Synthase / Q000378:metabolism
D015415:Biomarkers; D007854:Lead; D006418:Heme; D015720:5'-Nucleotidase; D000623:Porphobilinogen Synthase