title: Evaluation of lead exposure in workers at secondary lead smelters in South Korea: with focus on activity of erythrocyte pyrimidine 5'-nucleotidase (P5N).
abstract: 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.
authors.affiliation: Department of Occupational and Environmental Medicine, Ulsan University Hospital, South Korea. yanghokm@nuri.net
authors.forename: Yangho
authors.initials: Y
authors.lastname: Kim
authors.forename: Hun
authors.initials: H
authors.lastname: Lee
authors.forename: Choong Ryed
authors.initials: CR
authors.lastname: Lee
authors.forename: Dong Uk
authors.initials: DU
authors.lastname: Park
authors.forename: Jeong Sun
authors.initials: JS
authors.lastname: Yang
authors.forename: In Jeong
authors.initials: IJ
authors.lastname: Park
authors.forename: Kwang Yong
authors.initials: KY
authors.lastname: Lee
authors.forename: MiYoung
authors.initials: M
authors.lastname: Lee
authors.forename: Tae-Kyun
authors.initials: TK
authors.lastname: Kim
authors.forename: Nam-Seok
authors.initials: NS
authors.lastname: Sohn
authors.forename: Young Sook
authors.initials: YS
authors.lastname: Cho
authors.forename: NaRoo
authors.initials: N
authors.lastname: Lee
authors.forename: Ho Keun
authors.initials: HK
authors.lastname: Chung
mesh_terms: 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
chemical_list: D015415:Biomarkers; D007854:Lead; D006418:Heme; D015720:5'-Nucleotidase; D000623:Porphobilinogen Synthase