| Objective:The purpose of this study is to reveal the current situation of Pb exposure of children in mining area by detecting the content of Pb in air,soil,drinking water,diet and other environmental media;The Integrated Exposure Uptake Biokinetic(IEBUK)model for children,which was combined with the environmental parameters of mining area,to build the IEBUK model for local mining area,and compared with the actual detection of children's blood Pb content to explore the practicability of ieubk model for mining area;To provide scientific basis for the management of Pb exposure of children in mining area,the influencing factors of Pb exposure of children in mining area were studied from the aspects of children's behavior,parents'occupation and living environment.Methods:(1)According to the principle of typicality,emphasis and feasibility,a mining area in northern China is selected as the research site.According to the degree of pollution,5 sampling points of ambient air were selected,6 surface water monitoring sections were set up according to the local river trend,30 soil monitoring points were set up in the farmland of the mining area,15 indoor air monitoring points and 15 indoor dust monitoring points were set up in the community of the mining area,30 samples of self-produced corn,30 samples of self-produced vegetables and 36samples of food purchased from the market were randomly collected to determine the content of Pb;Single factor pollution index method and comprehensive pollution index method were used to evaluate Pb pollution;Hazard Quotient(HQ)was used to evaluate the non carcinogenic health risk of Pb,and Incremental Lifetime Cancer Risk(ILCR)was used to evaluate the carcinogenic health risk of Pb.(2)569 children in mining area were selected as the research objects,blood Pb and urine renal function were monitored,and their guardians were investigated by one-to-one question and answer method.(3)The IEUBK model proposed by EPA of the United States and the environmental parameters of the study site were used to build a comprehensive model of Integrated Exposure Uptake Biokinetic for children in the local mining area,and the model was verified and analyzed.The single factor and multi factor analysis of influencing factors of children's Pb exposure were carried out by SAS 9.3,SPSS26.0and other statistical software.Results:(1)The single factor pollution index of Pb in heating period is 3.0 times of that in non heating period,and the concentration of Pb in dry period is 59.04 times of that in wet period;The exceeding standard rates of Pb in vegetable soil and corn soil were 37.50%and 52.94%respectively,and the maximum exceeding multiple was0.8 and 2.50 times,respectively;Pb in indoor air only exceeded the standard in heating period,and the exceeding rate reached 25.45%;The exceeding rate of Pb in indoor dust is 100%,and the maximum exceeding multiple is 17.20 times;The over standard rates of Pb in leafy vegetables,rhizome vegetables and other vegetables of home production were 66.67%,14.29%and 35.0%respectively,which were significantly higher than those in vegetables purchased from the market.There was no over standard phenomenon of Pb in corn of home production.(2)The results showed that the exposure levels of Pb by different exposure routes were:digestive>respiratory>skin,and the exposure amount of digestive tract accounted for 98.21%of the total exposure level;The results showed that the HQ was 3.20×10-3,5.54×10-3and 3.01×10-3respectively in respiratory tract,digestive tract and skin contact,and the ilcr was 4.96×10-7and 5.64×10-6respectively in respiratory tract and digestive tract.(3)The median of blood Pb of children in mining area was 10.61?g/dl,and the interquartile range was 4.33?g/dl-19.32?g/dl.There was a positive correlation between blood Pb and Al,V,Cr,Mn,Ni,Zn,As,and the correlation coefficient with Cr was the highest(rs=0.437),but a negative correlation with Cu.(4)Multiple linear regression and multiple factors showed that:more than 2 hours on the road every day,3-4 times a week of milk powder,Mixed feeding and artificial feeding for more than 9 months were the main factors leading to the increase of blood Pb content of children in mining area.(5)According to the local IEUBK model constructed by using the environmental parameters of mining area,the prediction shows that the blood Pb concentration of children and the probability of exceeding the observed value by 10?g/d L in different age groups are in the follows:the concentration of 0-year-old group is 2.18?g/dl,with a probability of 0.06%;The concentration of 1-year-old group is 4.35?g/dl,with a probability of 3.84%;The concentration of 2-year-old group is 5.3?g/dl,with a probability of 8.84%;The concentration of 3-year-old group is 6.16?g/dl,with a probability of 15.12%;The concentration of 4-year-old group is 6.23?g/dl,with a probability of 15.71%;The concentration of 5-year-old group is 6.38?g/dl,with a probability of 16.93%;The concentration of 6-year-old group is 6.56?g/dl,with a probability of 18.47%.Conclusions:The lead content in the air and drinking water increased during heating period and dry season,and the lead content in agricultural products exceeded the standard at that time,so the environmental control still needs to be strengthened;Children's blood lead level is low,which needs long-term observation;Parents'previous occupational exposure and time of house decoration were associated with children's blood lead;There was a positive correlation between blood lead and vanadium,manganese and nickel in children;More than 2 hours a day on the road is a risk factor for children's blood lead level.Feeding methods in infancy affect children's blood lead level.Dairy products are a protective factor for blood lead level.The prediction effect of IEUBK model is good in 1,2,5 and 6 age groups,and the exposure parameters of IEBUK model need to be optimized in 0,3 and 4 age groups. |
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