Investigation Of Occupational Lead And Cadmium Exposure And Study Of Cytotoxic Effects In Guangx

Objective:The number of new occupational diseases in my country each year is increasing year by year,and the number of occupational lead exposures is also increasing.It is very important to protect against occupational diseases.We investigated and summarized the main occupational hazards in the lead production process;evaluated the effectiveness of occupational disease prevention measures,the effectiveness of occupational health management measures,and occupational worker health examinations,and provided evidence for related companies to prevent and control occupational diseases.Method:The construction projects of 8 lead companies in Guangxi were the research objects,and the basic information of each project,occupational hazard factors,and collect physical examination data;analyze the results;occupational health protection was studied.survey.Excel is used for data entry,SPSS22.0 is used for statistical analysis of the collated data,and the comparison of rates usesc~2 test and Fisher’s exact probability method.Results:According to the project type,the 8 lead construction projects are divided into 4 metal mine projects,2 solid waste treatment projects and 2smelting projects.(1)The main occupational hazards of lead workers are lead and its compounds,total dust,and noise.The detection rate of lead and lead compounds was 24.47%,the detection rate of dust was 21.33%,and the detection rate of noise intensity was 15.85%.(2)There are significant differences in the total dust,noise,lead and its compound exceeding rate among metal mines,solid waste treatment plants and smelters(P<0.05).The total dust(42.11%)and noise(38.89%)of metal mines have the highest over-standard rate,and the highest over-standard rate of lead and its compounds in smelters is60.53%.(3)645 workers in the smelter underwent blood lead inspections,132people exceeded the standard,and the rate of exceeding the standard was20.47%.The urine cadmium of 22 persons was detected,7 persons exceeded the standard,and the abnormal rate was 31.81%.A total of 2736 lead workers underwent dust chest X-ray examinations,14 people were found to be suspected of pneumoconiosis,and the detection rate was 0.51%.(4)The detection rate of abnormal blood pressure among metal mine workers was 0.21%,and the detection rate of abnormal hearing was 0.62%;the detection rate of abnormal blood pressure among workers in solid waste treatment plants was 1.54%;the detection rate of abnormal hearing was 1.54%;the operation of smelters The detection rate of abnormal blood pressure among workers was 0%;the detection rate of abnormal hearing was 0.07%.The detection rates of blood pressure and hearing abnormalities were significantly different among the three item types(P<0.05).Conclusion:(1)The main occupational hazards of lead operation projects are dust,noise,lead and its compounds,and cadmium and its compounds.(2)The detection rate of abnormal concentrations of lead and lead compounds in the air in the smelter’s workplace is high,which is the main factor affecting the blood lead level of workers.(3)The occupational health examination rate of workers has not reached the standard,and the protection capacity of the occupational disease protection facilities of the project company is insufficient.Objective: Combined exposure of lead and cadmium is becoming more common in occupations and the environment.We established a model of damage induced by combined lead and cadmium exposure to SHSY-5Y cells,observed the toxic effects of lead and cadmium alone and combined exposure on SHSY-5Y cells,and explored the effects on amino water.The intervention effect of sodium salicylate(PAS-Na)on SHSY-5Y damage caused by combined lead and cadmium exposure,which provides a basis for PAS-Na treatment of combined lead and cadmium exposure poisoning.Methods: MTT method was used to detect the effect of lead and cadmium single and co-exposure on the viability of SHSY-5Y cells,and to determine the concentration of lead and cadmium co-exposure;The in vitro exposure dose of SHSY-5Y cells was screened by ROS fluorescence and Western blotting.The effect of combined lead and cadmium exposure on the oxidative stress of SHSY-5Y cells was detected by a reactive oxygen species detection kit.Cellular immunofluorescence detect Nrf2 entering the nucleus.In order to verify whether the co-exposure activates the PI3K-Akt/Nrf2-HO-1 signaling pathway,the protein expression levels of PI3 K,Akt,p-Akt,Nrf2 and HO-1 were determined by Western blot.Results:(1)SHSY-5Y cell injury model was established: At the highest exposure dose of 1μmol/L Pb and 0.25μmol/L Cd,the growth trend of SHSY-5Y cells was not significantly inhibited after 24 hours and 48 hours respectively(P>0.05).Therefore,we set the exposure time to 24 h,the lead exposure dose is 1μmol/L,and the cadmium exposure dose is 0.25μmol/L.After 24 hours of exposure to 1μmol/L Pb,0.25μmol/L Cd and 1μmol/L Pb+0.25μmol/L Cd,the growth trend of SHSY-5Y cells was not affected(P>0.05).The viability of SHSY-5Y cells decreased compared with the control group after exposure dose of 10μmol/L Pb+2.5μmol/L Cd for 24 h,the difference was statistically significant(P<0.05).(2)Combined exposure to lead and cadmium induced oxidative stress in SHSY-5Y cells: Compared with the control group,1μmol/L Pb+0.25μmol/L Cd and 10μmol/L Pb+2.5μmol/L Cd after 24 h exposure,ROS expression increased significantly(P<0.05).After pretreatment with N-Acetyl-L-cysteine(NAC),compared with the 10μmol/L Pb+2.5μmol/L Cd group,the ROS expression level was decreased(P<0.05),and the oxidative stress was significantly suppressed.(3)The effect of lead and cadmium single and combined exposure on PI3K/Akt signaling pathway: compared with the control group,the expression levels of PI3 K and p-Akt protein did not change significantly in the 1μmol/L Pb group,0.25μmol/L Cd group,and 1μmol/L Pb+0.25μmol/L Cd for 24 h.The expression of PI3 K and p-Akt protein in the 10 μmol/L Pb+2.5 μmol/L Cd group decreased(P<0.05),and the total Akt protein expression level unchanged.There was a synergistic decrease in joint exposure.(4)Combined exposure to lead and cadmium activates the expression of Nrf2 and HO-1: cell immunofluorescence detected the distribution of Nrf2 in the nucleus after the combined exposure to lead and cadmium.Compared with the control group,Nrf2 in the 10μmol/L Pb+2.5μmol/L Cd group increased in the nucleus,which suggests that Nrf2 from the cytoplasm to the nucleus in SHSY-5Y cells treated with combined lead and cadmium exposure.Increased expression levels of Nrf2 and HO-1(P <0.05).After NAC pretreatment,decreased expression levels of Nrf2 and HO-1(P <0.05).(5)The antagonistic effect of PAS-Na intervention on the neurotoxicity of combined lead and cadmium exposure: Under PAS-Na intervention,the expression of PI3 K and p-Akt protein increased,and the expression of Nrf2 and HO-1 protein decreased(P <0.05).Conclusion:(1)Combined exposure to low-dose lead and cadmium did not have a significant effect on SHSY-5Y cell neural activity.(2)Combined exposure of lead and cadmium(10μmol/L Pb+2.5μmol/L Cd)induces oxidative stress in SHSY-5Y cells,causing cytotoxicity.(3)PAS-Na has a certain antagonistic effect on SHSY-5Y cell damage caused by combined lead and cadmium exposure.