锌原卟啉作为环境铅污染人群筛查指标的可行性研究

Research of zinc protoporphyrin as screening index for population exposed to environmental lead pollution

目的探讨红细胞锌原卟啉（ZPP）应用于人群接触环境铅污染筛查指标的可行性。方法以紫金县某电池厂附近常住居民为调查对象,采集被调查者静脉血2～3 mL,采用血液锌原卟啉测定仪测定ZPP、石墨炉原子吸收光谱法测定血铅。儿童以血铅含量≥100μg/L、成年人以≥400μg/L为慢性铅中毒判定标准。结果共调查946名居民,其中1～13岁儿童174人、16～87岁成年人772人。儿童血铅含量超标率为14.9%（26/174）,儿童ZPP含量中位数为0.780μmol/L,血铅中位数为47.675μg/L,儿童ZPP含量与血铅含量的相关关系没有统计学意义（P〉0.05）。成人血铅含量超标率为9.5%（73/772）,成人ZPP含量中位数为0.740μmol/L,血铅中位数为69.572μg/L,成人ZPP含量与血铅含量呈弱相关关系（r=0.344,P〈0.05）。儿童血铅高水平组（血铅≥100μg/L）ZPP含量与血铅含量呈较强的相关关系（r=0.530,P〈0.05）,儿童血铅低水平组（血铅〈100μg/L）ZPP含量与血铅含量的相关关系没有统计学意义（P〉0.05）。成人血铅高水平组（血铅≥400μg/L）和低水平组（血铅〈400μg/L）的ZPP含量与血铅含量均具有相关关系（r分别为0.566、0.142,均P〈0.05）。结论成人血铅或儿童血铅水平较高时,ZPP可以作为环境铅污染人群筛查的指标。

Objective To explore the feasibility of applying zinc protoporphyrin （ZPP） as a screening index of exposure to environmental lead pollution. Methods Blood samples （2 - 3 mL） were collected from each residents living nearby a battery factory in Zijin County, Guangdong Province. Lead in blood samples was detected by graphite furnace atomic absorption spectrometer and ZPP in blood, by ZPP hematofluorometer. Blood lead levels （BLLs） ≥100μg/L and≥400μg/L were taken as the diagnostic criteria of chronic lead poisoning for children and adults, respectively. Results A total of 946 residents, 174 children aged 1 - 13 years and 772 adults aged 16 -87, were surveyed. The over standard rate of chil- dreng BLL was 14. 9% （26/174） , and the medians of ZPP and BLL of children were 0. 780 μmol/L and 47. 675μg/L, respectively. ZPP contents in blood of children showed no correlation with their BLLs （P 〉 0. 05 ）. The over standard rate of BLL of adults was 9. 5% , and the medians of ZPP and BLL of adults were 0. 740 μmol/L and 69. 572 μg/L, respectively. ZPP contents in blood of adults showed a weak corre- lation with their BLLs （ r = 0. 344, P 〈 0. 05 ）. ZPP contents of children with high BLL （ ≥100 μg/L） correlated with their BLLs （ r = 0. 530, P 〈 0. 05 ）, while ZPP contents of children with low BLL （ 〈 100 μg/L） showed no correlation with their BLLs （ P 〉 0. 05 ）. ZPP contents of adults with both high BLLs （ 〉1400 μg/L） and low BLLs （ 〈 400 μg/L） showed positive correlations with their BLLs （ r =0. 566 and 0. 142, respectively ; P 〈 O. 05 for both）. Conclusion ZPP could be used as a screening index of exposure to environmental lead population for adults or children with high BLL.