Blood samples obtained from 200 adults who had visited the $quot;S$quot; general hospital were analyzed to compare the zinc protoporphyrin (ZPP) levels quantified by high performance liquid chromatograph (HPLC) and by hematofluorometer (HF) to investigate the methodological difference if any and the relationship between the levels of blood lead and ZPP among no-lead exposed adults. Also investigated were the distribution of ZPP and protoporphyrin IX (PPIX) concentrations, the establishment of normal levels of blood ZPP and blood lead, and the contribution of age and sex factors to these values. These subjects had no previous occupational exposure to lead.
The results obtained were as follows :
1. The mean values of blood lead for male and female subjects were 9.46±2.44 ㎍/㎗ and 8.09±2.17 ㎍/㎗, respectively. The difference observed in the mean concentrations between male and female subjects was statistically very significant.
2. The mean values of blood ZPP by HPLC for male and female subjects were 15.94 4.55 ㎍/㎗ and 22.26±6.61 ㎍/㎗, respectively. The difference observed in the mean concentrations between male and female subjects was statistically very significant.
The mean values of blood PPIX by HPLC for male and female subjects were 2.51 1.78 ㎍/㎗ and 2.81±1.56 ㎍/㎗, respectively. The difference observed in the mean concentrations between male and female subjects was statistically not significant.
3. The mean values of blood ZPP by HF for male and female subjects were 28.44±7.11 ㎍/㎗ and 37.77±8.04 ㎍/㎗, respectively. The difference observed in the mean concentrations between male and female subjects was statistically very significant.
4. No statistically significant correlation was found between the levels of blood ZPP and blood lead.
5. The ratio of ZPP and protoporphyrin IX (PPIX) concentration to erythrocyte protoporphyrin (EP, EP=ZPP+PPIX) concentration was 87.4% and 12.6%, respectively.
6. A statistically very significant correlation was found between the ZPP concentrations determined by HPLG and the values by HF (r=0.7565). The ZPP concentrations quantified by HF were 1.75 times as high as the values obtained by HPLC.
7. The blood ZPP concentrations quantified by HPLC, HF, and spectrofluorometer (SF) from the blood samples obtained from 14 lead-exposed workers and from 16 no-lead exposed adults showed wide variations. The ZPP concentrations by HF were the highest followed by the levels obtained by SF and by HPLC.
In the exposed group, no statistically significant difference was found among three methods of quantifying blood ZPP levels. In the no-lead exposed group, however, statistically significant difference was observed among these methods. The ZPP concentrations by HF were about twice as high as those of by HPLC or by SF.
Among three methods of quantifying blood ZPP (HPLC, SF and HF), the results revealed significant difference. Therefore it is suggested that objective methods of quantifying blood ZPP and a system of correcting different ZPP levels be developed by the ministry of Labor.
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