D. Ronin et F. Strehl, ELEVATION OF ZINC PROTOPORPHYRIN LEVELS IN LEAD WORKERS WITH IRON-SUFFICIENT MICROCYTOSIS, Journal of occupational and environmental medicine, 40(5), 1998, pp. 492-496
Zinc protoporphyrin (ZPP) measurement is a required test under the Occ
upational Safety and Health Administration's lead standard. However, t
here is no mention of the influence of hemoglobinopathy on the ZPP tes
t value. We undertook a retrospective laboratory review of 382 employe
es at the Argonne National Laboratory who had been subjects in a lead
surveillance program since 1982. A total of 321 samples were analyzed,
after female subjects and samples with abnormally high bilirubin leve
ls were excluded. A group with low mean red blood cell volume (MCV; le
ss than 80.0 fL) was compared with a group with normal MCV (greater or
equal to 80.0 fL). A statistically significant difference teas noted
in ZPP (P < 0.007) and total bibirubin (P < 0.0003) values of two grou
ps. There was no statistically significant difference noted in age, le
ad levels, or iron levels between the two groups. Abnormally high ZPP
levels may occur in individuals with hemoglobinopathies. Only a minor
part of this elevation could be explained by the higher bilirubin leve
ls.