铅作业工人血铅和氧化应激酶变化的研究

目的研究职业性铅接触者的氧化损伤，探讨血铅和氧化应激酶之间的变化关系，以探讨铅中毒的作用机制。方法采用火焰原子吸收分光光度法测定空气中的铅含量，用石墨炉原子吸收分光光度法测定血铅浓度，选择超氧化物歧化酶（SOD）和丙二醛脱氢酶（MDA）作为氧化应激损伤的效应指标，分析血铅与氧化效应指标的变化。结果共采集了车间内5个工作点的空气样品。接触组血铅浓度（244．274±124．59）μg／L，显著高于对照组（P〈0．01）；接触组SOD活性（61．27±6．97）KU／L，与对照组比较无统计学差异（P〉0．05）；接触组MDA含量（9．42±3．89）mmol／L，显著高于对照组（P〈0．01）；血清MDA含量与血铅之间存在正相关关系（r=0．3，P〈0．01）；吸烟、饮酒对SOD活性和MDA含量影响无统计学差异。结论职业性铅接触引起人体血铅升高，作业场所空气中铅浓度与血铅含量变化不一致，血铅是近期铅接触者的敏感内接触指标，且血铅浓度越高，SOD活性代偿性升高；MDA含量越高，氧化损伤越明显。

Changes of Blood Lead and Oxidative Stress Enzymes among the Workers Exposed to Lead

Objective To study oxidative damage for occupational lead exposure, the relationship between serum lead and oxidative stress enzymes, and the mechanism of lead poisoning. Methods The lead content in the air was determined by flame atomic absorption spectrophotometric method, the lead concentration in serum was determined by graphite furnace atomic absorption spectrophotometric method. Superoxide dismutase (SOD) and malondialdehyde (MDA) as the effect indicators of oxidative stress were used to analyze the relationship between blood lead and the indicators. Results Five workplaces were monitored. The lead concentration in exposed group (244.27±124.59ug/L) was significantly higher than that in control group (P<0.01). The SOD activity in exposure group was 61.27±6.97KU/L not significantly different from that in control group (P>0.05), while MDA concetration in exposure group (9.42±3.89mmol/L) was significantly higher than in control group (P< 0.01). There was positive correlation between serum MDA and blood lead concentration (r = 0.3, P < 0.01) . The effects of smoking and drinking on the SOD activity and MDA content were not statistically significant. Conclusion Occupational lead exposure increases the blood lead level. It is inconsistent between the changes of lead concentration in workplace air and in blood lead. Blood lead is a sensitive indicator as the lead internal exposure. The higher blood lead level is, the higher the SOD activity and the MDA concentration, the more seriousthe oxidative damage is.