Toxicology Division, Occupational Health Services Centre, Bokaro Steel Plant, Bokaro, Jharkhand
A cross sectional study was performed to determine the corelation between zinc protoporphyrin (ZPP) and hair lead (PbH) levels of workers in lead prone areas (n=70) and non-lead areas (n=100) in Bokaro Steel Plant. Two categories of ZPP values were stabilized - those below 6.0 microgram/gm of Hb, and those above it. A linear regression analysis was performed to corelate ZPP and Hb, and showed an inverse relationship (p<0.02) between them in both the groups. After chelation therapy however, this inverse relationship did not make any difference in hair lead level (p<0.05).
So ZPP estimation may be used only for screening of lead poisoning cases or iron deficiency anaemia, but for confirmation of lead toxicity, hair lead (PbH) estimation is essential.
