Zinc protoporphyrin level in blood determined by a portable hematofluorometer: a screening device for lead poisoning

An inexpensive portable fluorometer has been designed which can be used to determine the concentration of zinc protoporphyrin (ZPP) in a drop of unprocessed blood deposited on a disposable glass slide. No volume measurement of the blood sample need be made. The instrument displays the ZPP level in micrograms per deciliter of blood accurately and reproducibly, automatically calibrating each determination by comparing the blood fluorescence with that of a stable dye. The instrument, which we call a hematofluorometer, is ideally suited for use in primary screening for childhood and occupational lead intoxication. It can be used by public health personnel after a few minutes of instruction. Comparisons of ZPP levels obtained with the use of the hematofluorometer with erythrocyte protoporphyrin levels obtained using accepted extraction methods are presented.