A simple protoporphyrin assay-microhematocrit procedure as a screening technique for increased lead absorption in young children

A simple screening technique for measuring protoporphyrin (PROTO) in acidified acetone extracts of capillary blood is described. A statistically significant linear relationship was found between blood lead concentration and log e PROTO concentration. The relationship is sensitive to mild degrees of anemia. The hematocrit may be used to compensate for concurrent anemia when screening for increased lead absorption. When this PROTO assay-microhematocrit procedure was was used prospectively as a screening technique for increased lead absorption, 95 per cent of children with ⪖50 μg Pb were identified, while 90 per cent of those with