Investigation On Lipid Peroxidation And Antioxidant Level Of Lead Exposed Workers

ObjectivesResearch data on lipid peroxidation of lead exposed work,s is very little. Studies on the relationship between pb load level and lipid peroxidation of lead exposed workers are of great importance to assessing the bio-loading effects.Air lead concentration and urine lead level as the exposure load,malonicdialdehyde(MDA) and hydrogen peroxide(H₂O₂) as indicators of lipid peroxidation injury,catalase (CAT) and GSH-Px as indicators of enzymatic antioxidation,this paper studied how pb load level affects lipid peroxidation products and antioxidation enzyme.Method1.Subjects The study group consists of 126 lead exposed workers in a metal melting enterprise,of which 66 males and 60 females aged 23-46 with working years from 1-4.The control group are made up of 70 administrative staff without exposure to lead,of which 44 males and 26 females aged 20-47 with working years from 1-5.Statistical analysis showed no significant differences between two groups(P＞0.05)2.DSPA-â…¡differential potentiometric stripping analyzer to determine the sample collected by FC-â… dust sampler.3.Using modified graphite furnace atomic absorbtion chromtograpgy to determine urine lead level.4.Lipid peroxidation.indicators:malonicdialdehyde(MDA),peroxide(H₂O₂), catalase(CAT),GSH-Px and all the kits were offered by Nanjing Jiancheng Bioengineering Institute and operational procedures were strictly undertaken according to the instructional manual.5.Statistical analysis with statistical software SPSS 12.0 to analyse the data, (?)±S the standard deviation,by F test and T test as well as linear correlation regression,a=0.05.Results1.Of the 233 samples collected from workshops of metal melting,laminating and assembly,46 were lead dust,177 were lead fume.The lowest lead dust concentration was 0.016mg/m³,below national hygienic standard while the highest was 1.780mg/m³,34.6 times higher than national hygienic standard, averagely 2.99 times higher.The lowest lead fume concentration was 0.013mg/m³, below national hygienic standard but the highest was 1.940mg/m³,63.67 times than national hygienic standard,averagely 7.28 times higher.2.The study group's urine lead level was O.024～2.048μmol/L,0.756±0.449μmol/L on the average(the upper normal limit is 0.34μmol/L according to Diagnostic Standard of Professionally Chronic Lead Poisoning GBZ 37-2002),significantly higher than the control group's O.024±O.039μmol/L,P＜0.05.3.Lipid peroxidation injury indicators:MDA lead exposed group and control group were respectively 19.39±4.58 and 17.25±3.22 nmol/ml;H₂O₂ lead exposed group and control group were respectively 27.97±9.50 and 24.76±6.77 mmol/L,which showed significant difference(P＜0.05).Enzymatic antioxidation indicators:CAT lead exposed group and control group were respectively 2.03±1.62 and 2.49±0.55U;GSH-Px lead exposed group and control group were respectively 215.45±90.86 and 265.69±67.21U,which also showed significant difference(P＜0.05).Correlation regression analysis was undertaken with urine lead loading as the independent variable and MDA,H₂O₂,CAT and GSH-Px level as dependent variable. Urine lead loading and MDA,H2O2,CATå'ŒGSH-Px had no obvious correlation(P＞0.05).4.Lipid peroxidation indicators like MDA and H₂O₂ increased as working years increased;antioxidation indicators like CAT and GSH-PX activity declined as working years increased.There was significant difference between the MDA working years group 2,3 and working years group 1(P＜0.05);significant difference existed between working years group 4 and working years group 1,2 (P＜0.05,P＜0.01);ConclusionExposure to lead may promote lipid peroxidation,reduce antioxidation activities and can be involved in endocrine function impairment as well as histologic injury,which has certain significance in lead exposed workers' health supervision.