Clinical Characteristics And Treatment Of Childhood Lead Poisoning

Part 1 Analysis of Clinical Characteristics of Children with Elevated Blood Lead Level in a Lead Specialty ClinicObjective:This study explored the sources of lead exposure,identified patients’geographic distribution and evaluated the symptoms of children with elevated blood lead levels（BLLs）referred to a lead specialty clinic in China.Methods:Data were collected from 515 consecutive outpatients attending the Pediatric Lead Poisoning Clinic in Xinhua Hospital,Shanghai,China,referred for BLLs≥50μg/L.Atomic absorption spectrometry was used to measure venous BLLs.Results:A total of 515 children were included in the study.The BLLs of all the patients ranged from 50.0 to 1260.0μg/L and the geometric mean and median BLLs were 240.0 and 260.0μg/L,respectively.There’re 44 cases（8.5%）with BLLs between 50 to 99μg/L,125 cases（24.3%）with high level of blood lead,59 cases（11.5%）with mild lead poisoning,227 cases（44.1%）with moderate lead poisoning and 60 cases（11.6%）with severe lead poisoning.43%of the cases（222 children）were related to industrial lead pollution—mainly from Zhejiang,Jiangsu,Hunan,Henan and Anhui provinces;whereas 213 cases were induced by folk medicines widely in use throughout China.Other nonindustrial sources of lead poisoning included lead contamination of tinfoil（12 cases,2.3%）,tin pots（51 cases,9.9%）and some unexpected sources.Only eleven children（BLL:636.0～1260.0μg/L）were diagnosed with symptoms of severe lead poisoning,and the rest discovered to have elevated BLLs through lead screening.Most of the patients exhibited nonspecific symptoms and hyperactivity was the most common symptom.Conclusions:Industrial pollution and folk medicines are major sources of exposure.Children with elevated BLLs often have nonspecific symptoms and are still present in significant numbers in China.Blood lead screening and education are two effective ways to decrease the incidence of children with elevated BLLs.Part 2 Therapeutic Efficiency of Ca Na₂EDTA and Changes of Essential Elements During Chelation TherapyObjective:To evaluate the chelating effect of calcium sodium edetate（Ca Na₂EDTA）after 3 days and 5 days of treatment on chronic childhood lead poisoning and to explore influence of Ca Na₂EDTA on the changes of essential elements in serum and urine,and at last to provide the basis for the optimization of chelation therapy.Methods:14 children with chronic moderate lead poisoning were treated with Ca Na₂EDTA for the following 3 courses.Levels of blood lead,urine lead and essential elements in serum and urine were detected.Compare the effect of the first 3days chelation with the 5 days chelation and compare the levels of serum and urine essential elements before,during and after treatment in each course.Results:The average age of the 14 children were（2.35±1.47）years old and the average blood lead levels（BLLs）before chelation therapy was（360.9±44.8）μg/L.After treatment with Ca Na₂EDTA,children’s BLLs decreased significantly in each course.The average decline of blood lead levels in the first 3 days accounted for75.66%,77.15%,72.25%,respectively,of the decline in 5 days.The decline of blood lead levels per gram of Ca Na₂EDTA in the first 3 days was significantly higher than those in 5 days in each course.The urinary lead excretion of 5 days chelation was significantly higher than that of the first 3 days in each course.The average urinary lead excretion in the first 3 days accounted for 65.08%,70.74%,70.12%respectively in each course of the excretion of 5 days.In each course of treatment,the urinary lead excretion per microgram of medicine in the first 3 days was significantly higher than that in 5 days.During the course of treatment,the highest urinary lead concentration was 13.55 times,9.42 times,and 6.94 times,respectively,the pre-treatment concentration.Serum zinc（Zn）level after 3 days and 5 days chelation were significantly lower than that pre-treatment level.There was no significant difference of serum Zn level between the 3 days treatment and the 5 days treatment.No significant difference was found in the levels of selenium（Se）,magnesium（Mg）,calcium（Ca）and copper（Cu）among pre-treatment,during chelation and post-treatment.Urinary Zn excretion was significantly increased,and the highest concentration of urinary Zn excretion during the first course of treatment was 6.16times before treatment.Conclusion:Ca Na₂EDTA was effective in treating chronic moderate lead poisoning in children.The chelation therapy is more effective in the first 3 days than the total 5days.Optimization of the chelation therapy in childhood lead poisoning is worth to be further studied.The changes of the elements in each course were consistent,and during the chelation Ca Na₂EDTA could cause a great loss of zinc.After the treatment,the supplementation of Zn should be carried on.Part 3 Effects of Lactobacillus plantarum CCFM8661 on Treating Rats with Low-level Lead ExposureObjective:To explore the effect of Lactobacillus plantarum CCFM8661 on decreasing body lead burden in rats with low-level lead exposure.Methods:The model of SD rats with low-level lead exposure model was constructed by drinking lead acetate water.Lactobacillus plantarum CCFM8661 was intragastric administrated after lead exposure.Control groups include blank group（without lead exposure）,non-treatment group and DMSA group.Lead levels of blood,liver,kidney,tibia,hippocampus were detected.Results:The average BLL was（74.66±14.70）μg/L after lead expose,significantly higher than that in the blank group（5.15±2.84）μg/L.Compared with non-treatment group,lead concentration in blood,liver,kidney,tibia,hippocampal in DMSA group were significantly decreased（p<0.05）;No significant difference between the Lactobacillus plantarum group and the non-treatment group about levels of lead in blood,liver,tibia,hippocampus（p<0.05）was found.Compared with the non-treatment group,the kidney lead level was significantly decreased in Lactobacillus plantarum group（p<0.05）.Conclusion:Through this study,Lactobacillus plantarum CCFM8661 did not effectively reduce lead level in rats exposed to low-level lead.It remains to be further studied about the therapeutic efficiency of Lactobacillus plantarum CCFM8661 to low-level lead exposure models.