Objective To survey the levels of blood lead and zinc protoporphyrin(ZnPP) among the occupationally lead-exposed workers in a lead-smelt factory of Hengyang,Hunan. Methods Totally 859 blood samples of occupationally lead-exposed workers were collected.The samples were detected and judged respectively by Blood-Determination of Lead-Graphite Furnace Atomic Absorption Spectrometric Method(WS/T20-1996),Diagnostic Criteria of Occupational Chronic Lead Poisoning(GBZ37-2002),and Blood-Determination of Zinc Protoporphyrin-Hematofluorometer Method...