The Blood Lead Levels And Effects Of Lead Exposure On School-Age Children Of Mine Area In Guangxi

Objective To investigate the Blood lead level(BLL) and the lead poisoning epidemic condition and expore the relationships among BLL and blood essential elements levels such as zinc (Zn),Copper (Cu),lron (Fe),Calcium (Ca) and Magnesium (Mg) for 7-12 years old school-age children in GuangXi Province, it can provide a scientific basis for preventing lead poisoning.Materials and Methods A total of 2629 children (1781boys and 848girls) who take a medical in the department of child care in hospital were enrolled in this study. A volume of 1ml fasting venous blood was collected from each child with heparin anticoagulant tubes in early morning to measure blood lead level and test the content of zinc, copper, iron, calcium, magnesium. Whole blood Lead, zinc, Copper, Iron, Calcium and Magnesium were performed by atomic absorption spectroscopy (AAS). Use SPSS 16.0 to analyze BLL, the incidence of child lead poisoning and its distributive features; Use chi-square test to analysis different subgroups’rate of child lead Poisoning; Use Pearson correlation analysis test or Spearman correlation analysis test to expore the relationships among blood lead and the other five essential elementsResults The median level of blood lead in sample children was 54.6μg/L;boys’was 56.9μg/Land girls’was 51.2μg/L, Boys’blood lead level higher than girls’, P< 0.05.9～12 years old boys’blood lead level higher than the same age girls’, P< 0.05; there were no statistical significance among different age groups, P> 0.05. The BLL of the nearly three years was 64.0μg/L,50.1μg/L and 49.5μg/L respectively, the third year group’s BLL lower than other groups,P<0.05.In the three different year groups, boys’ BLL were higher than girls’in some subgroups’, P< 0.05;there were no statistical significance among different age groups, P> 0.05.Children’BLL Mainly occurred in 50μg/L stage and 0μg/L stage, the rates were 50.7% and 41.1 respectively. The rate of Boys’BLL occurred in 0～,50～,100～,150～,≧200μg/L stages were 37.8%,53.1%,7.2%,1.5%,0.4% respectively, girls’were 48%,45.8%,4.5%,0.8% and 0.9% respectively, there were different distribution of BLL (X2=31.534,P=0.000). There were different distribution of BLL between the first year group to other groups, P<0.05.The incidence of child lead poisoning in sample children was 8.2%;boys’ lead poisoning rate (9.1%)was higher than girls’(6.3%) (X2=6.197,P=0.013).9 years old boys’lead poisoning rate was higher than the same age girls’; There were no statistically significant according to sex or age in other subgroups, P> 0.05. The incidence of child lead poisoning in the nearly three years groups was 10.9%,5.2%,8.4% respectively, decreased with the increase of year (X2=3.890, P=0.049); The boy’s lead poisoning rate also decreased with the increase of the year (X2=8.302, P=0.004)Zn, Cu, Fe, Ca and Mg concentrations in whole blood of school-age Children were 6.11±1.29μg/ml,1.36±0.37μg/ml,433.58±69.25μg/ml, 57.77±6.60μg/ml and 35.36±4.52μg/ml respectively. There were no statistically significant according to BLL≥100∴g/L(Lead Poisoning),P>0.05. According to age, There were statistically significant according to BLL≥100μg/L of 9years old age groups’ Fe,Mg concentrations and 10 years old group’s Ca concentrations in whole blood of Childhood Children’s, P<0.05.According to years, two groups’(the first year and the second year)Ca concentrations in whole blood of BLL< 100μg/L group were higher than BLL≥100μg/L group, P< 0.05; there were correlationships between the level of lead poisoning and Fe、Mg concentrations in whole blood in the first year group, the correlation coefficient Rwas -0.245 and -0.224 respectively. P< 0.05.Conclusion BLL and the incidence of child lead poisoning of 7～12years old Childhood Children in GuangXi has a tendency to decline, but the situation is still not optimistic. Boys’susceptibility to Lead Poisoning are higher than girls’; Lead Poisoning happen with low calcium, low iron, low magnesium concentrations in whole blood. So the local government departments should attach great importance to prevent lead poisoning, focus on the content of essential elements of children, take measures to improve the condition of lead poisoning of school-age children.Objective To investigate the lead Poisoning epidemic condition and analysis the effects of lead exposure on thyroid hormone levels, Serum amino acid neurotransmitter levels, intelligence,growth and development level and explore the influence factors of lead poisonning on 7-12 years old school-age children in a lead-zinc mine of the Han nationality in Guangxi, it can provide a reference basis for preventing lead poisoning and further research work.Materials and Methods A total of 255 children who came from a lead-zinc mine school of Han nationality in Guangxi were enrolled in this study. A volume of 1ml fasting venous blood was collected from each child with heParin anticoagulant tubes in early morning to measure blood lead level(BLL) and another 2 ml was isolated to Serum.not until we use them,all samples were stored at -80℃. Whole blood Lead was Performed by graphite furnace atomic absorption spectroscopy (GFAAS); Thyroid hormone such as free triiodothyronine (FT3)、free thyroxine (FT4) and thyroid stimulating hormone (TSH) were tested by Chemiluminescence immunoassay; glutamate (Glu), glutamine (Gln) and y-aminobutyric acid (GABA) were determined using a High Performance Liquid Chromatography (HPLC);A number of 11 rice samples were samPled randomly and the lead level were performed by GFAAS. The morphological indexes such as Height, weight, chest circumference were measured,intelligence was tested by Raven’s Standard Progressive Matrices (SPM) and the influence factors of lead poisoning questionnaire was use to collect information about Family environment, Life habits and Eating preferences for test subjects who agreed to take part in the study. The BLL of lead-zinc mine children was compared to 490 school-age children patient that came from a hospital; The levels of Growth and development were compared to 308 Han school-age children in a Rural primary school of Hepu county. Use SPSS 16.0 statistical software to analysis the data.Results The median lead level of rice was 98.47mg/kg, The rate of over standard was 18.2%. The BLL of children in lead-zinc mine was 84.8μg/L (boys’ was88.4μg/L and girls’ was 83.2μg/L); The control group’s BLLwas 54.25μg/L (boys’ was 58.0μg/L and girls’ was 51.2μg/L),lower than the lead-zinc mine group; In addition to the 12 years old boy’s subgroup,each subgroup’s BLL was higher than the control group, P< 0.05. The incidence of child lead poisoning(when the BLL≥100μg/L) in lead-zinc mine sample children was 31.8%(boys’ was35.7% and girls’ was 27.8%); The incidence of child lead poisoning in control group sample children was 8.2% (boys’ was10.0% and girls’ was 6.3%), the former is greater than the latter, there were statistical significance between the two groups, P=0.000. The incidence of child lead Poisoning in Some subgroups such as 8～10years old boy’s group and 7,10,12years old girl’s group were higher than the control group, there were statistical significance between two groups, P< 0.05.A total of 249 school-age children aged from 7 to 12 years old took part in the tests of Thyroid function and Serum amino acid neurotransmitter levels. TSH concentration of Lead Poisoning group lower than non lead poisoning group, Serum GABA concentrations of girls in Lead poisoning group higher than no Lead poisoning group, P< 0.05. There were correlationship between serum TSH concentration and BLL, The correlation coefficient r was-0.186, P=0.003. there were no correlation with BLLs and the level of serum Glu, Gln and GABA.The internal consistent reliability coefficient of SPM was 0.866.205 school-age children’s intelligence levels mainly belong to level 3(middle) and level 4 (Below average),the rate was 37.6% and 25.9% respectively. The Intelligence quotient (IQ) in samPle children was 92.32±14.68, decreased with the increase of age(P=0.000),7and 8 yeas old children’s IQ higher than other age groups’, P< 0.05. There were no statistically significant according to gender,P > 0.05. The IQ of lead poisoning grouP was 88.7±14.24, less than non lead Poisoning group was 3.59; The IQ of boy s’in lead Poisoning group was 88.69±13.90,lower than boy s’in non lead Poisoning group(94.65±15.13), P< 0.05. there were correlationships between Intelligence levels and BLL (R=0.147, P<0.05)A total of 234 Han nationality school-age children took part in the tests of physical development measure, the levels of height and weight of all subgroups were lower than the control group, P< 0.05. excide 9 years old girls group,other groups’chest level obviously lower than the control group, P< 0.05; only 9 years old boys’group’s chest level was lower than the control group, P< 0.05. growth levels of school-age children’s in Lead-zinc mine were focus on the middle and lower levels,97%children’s Weight focus on these two levels,height and chest reached to 88.5% and 96.1% respectively. The height level ranks, weight level ranks and chest level ranks of school-age children in Lead-zinc mine were worse than the control group, P<0.05. The malnutrition situation of school-age children in Lead-zinc mine was severe,the thin ratio of boys’and girls reached to 21.7% and 22.8% respectively. The height level ranks, weight level ranks and chest level ranks of lead poisoning group school-age children in Lead-zinc mine were equal to the non lead poisoning group, P> 0.05. There were correlationships between BLL and 7years old girl’s height level,8years old girl’s weight level,9years old girl’s chest level, R was-0.432,-0.497and-0.405 respectively, P≤0.05。The internal consistent reliability coefficient of influence factors of Lead Poisoning questionnaire was 0.726.According to the results of non-conditional logistic regression analysis,we knew the five factors can influence the incidence of children lead poisoning, they were Mother occasionally smoking (OR=3.578, P=0.035), Often drink taP water directly (OR=3.716, P=0.003), Often eat fresh fruits and vegetables and often eat Soy products (OR was0.323and 0.181 respectively,P=0.026 and 0.014 respectively) and higher serum TSH concentration (OR=0.775,P=0.003).Conclusion Environmental lead pollution Problem is prominent in the Lead-zinc mine, lead exposure can damage the thyroid hormone levels, Serum amino acid neurotransmitter levels, intelligence,growth and development levels. Lead poisoning affects boys’intelligence much more than girls, but in terms of growth and development was girls’more than boys. Develop good living habits, improve the indoor environment, increase high quality protein and vitamin C supplement can can improve the condition of lead poisoning.