US EPA

48326 

Journal Article 

Association of erythrocyte protoporphyrin with blood lead level and iron status in the second National Health and Nutrition Examination Survey, 1976-1980 

Mahaffey, KR; Annest, JL 

1986 

Yes 

Environmental Research
ISSN: 0013-9351
EISSN: 1096-0953 

41 

1 

327-338 

English 

3489614 

10.1016/S0013-9351(86)80194-3 

WOS:A1986E208100033 

Both iron status and body burden of lead influence heme biosynthesis. Measurement of protoporphyrin IX in the circulating erythrocyte (EP) has been used to index the extent of lead exposure and iron deficiency. The association of iron status and blood lead level with the level of EP in whole blood for persons ages 6 months through 74 years in the general U.S. population has been investigated by using data obtained in the second National Health and Nutrition Examination Survey (NHANES II). Iron status was defined as a function of percentage transferrin saturation (%TS) and total iron-binding capacity (TIBC). Both low iron status (%TS 6.0 or TIBC 50 μg/dl serum) and elevated blood lead levels (30 μg/dl) were associated with increased EP concentrations. The analysis of the proportions of persons in the U.S. population with EP levels above the 95th percentile (30 μg EP/dl of whole blood in the NHANES II data) support the concern that iron status has considerable influence on interpretation of EP levels recommended for use in screening programs aimed at identifying children with lead toxicity. With screening techniques based on EP only, currently used in various public health programs, a considerable number of children with blood lead levels of 30 and 50 μg/dl are not referred for further diagnostic evaluation.