Study On The Levels Of Trace Elements In Environment And Children And Their Association With Hand-foot-mouth Disease In Enshi Prefecture

ObjectiveTo investigate the levels and differences of trace elements in the environment and children in different soil selenium levels in Enshi Prefecture,Hubei Province.and to explore the relationship between the levels of various elements in children and hand,foot and mouth disease.MethodsAccording to soil selenium levels,Enshi Prefecture was divided into full selenium area,high selenium area,and extremely high selenium area.Three towns(townships)were selected as survey points for hand-foot-mouth disease in each area.Each place randomly selected a town(township)as a sampling point.The total population and hand,foot and mouth disease data of the three regions were collected from the Enshi Prefecture Population Statistics Bureau and the National Infectious Disease Reporting System.From the three survey points of hand-foot-mouth disease in each area,a town(township)is randomly selected as a sampling point.five natural villages were selected from the selected towns(townships).Six households were randomly selected from each natural village,and collected 90,61,74,70 servings of drinking water,potatoes,corn and soybeans,respectively.Taking township kindergartens as the unit,randomly selected 3 kindergartens in each area,local children aged 3 to 6 years old were taken as the research object,and a total of 443 children's venous blood and 739 hair samples were collected.The content of each element in the samples was determined by inductively coupled plasma mass spectrometry(ICP-MS).In addition,Non-parametric test and principal component analysis were used to compare the correlation between the sample elements and the incidence of hand,foot and mouth disease in different regions.ResultsFrom 2010 to 2014,there were 2002 cases of hand,foot mouth disease in three regional survey sites,including 1191 males,accounting for 59.5%;811 females,accounting for 40.5%.The affected population was mainly concentrated in children under 3 years old(72.6%).The incidence rate was obviously seasonal,with peak incidence in April-June and October-December.The most pathogenic type was EV71 positive,accounting for 79.7%.The average annual incidences of hand,foot and mouth disease in full selenium,high selenium,and extremely high selenium areas are 12.329/100,000,42.206/100,000 and 130.08/100,000.The incidence in the high selenium area was the lowest and the difference was statistically significant(?2=52.888,P<0.001).The results of the rank test showed that the levels of selenium,iron,zinc and molybdenum in drinking water in the full selenium area,high selenium area,and extremely high selenium area were statistically significant(H was 38.043,13.487,6.682,50.591,respectively.P was<0.001,0.001,0.035,<0.001,respectively);The difference between the selenium content of corn and soybeans in the three regions was statistically significant(H=13.081,6.492,P<0.01),and the selenium content was highest in the extremely high selenium area(0.09,0.65?g/g,respectively).Differences in zinc,copper,and antimony levels in potatoes from three regions were statistically significant.The differences in iron,zinc,copper,and antimony levels in soybeans were statistically significant,and the zinc and copper elements were higher in the extremely high selenium regions(43.2,13.3 ?g/g,respectively),and the iron were lower in the extremely high selenium regions(72.4 ?g/g).The differences in the levels of selenium,molybdenum,manganese,and zinc in the three regions of corn were statistically significant.Selenium and zinc were lower in the high selenium regions(0.02,12.2 ?g/g,respectively),and molybdenum was higher in the extremely high selenium regions(0.55 ?g/g),while manganese was the opposite(4.58 ?g/g).Children's blood selenium levels in the three regions were 76.4±14.8,109.8 ±39.2,84.9 ±26.5 ?g/L,hair selenium levels were 0.43 ± 0.11,0.80 ±0.73,0.78 ±0.30?g/g,and the selenium content in the high selenium regions was statistically higher than that in the full selenium area and the extremely high selenium area.Except for manganese in blood,other elements were different in three areas.Correlation analysis results showed that the elements in children's blood and hair were related to the elements of drinking water and crops.The principal component analysis showed that the difference in the incidence of hand,foot and mouth disease was mainly related to iron,copper,manganese,molybdenum in hair and zinc and iron,molybdenum,copper in blood.Conclusions1.The selenium content in drinking water,corn and soybeans in different selenium levels in Enshi Prefecture is different,and it is highest in extremely high selenium areas.The selenium content in children's blood and hair is the highest in the high selenium area,and the zinc,iron,copper and other elements in different samples also differed in different regions.Children's selenium levels are in good condition.2.Boys under the age of three are susceptible to hand,foot and mouth disease.April to June and October to December are the seasons when hand,foot and mouth disease is high.3.There was a correlation between the levels of elements in children and the elements in drinking water and crops.4.Low levels of selenium,zinc,manganese,molybdenum and high levels of copper in children may be associated with the incidence of hand,foot and mouth disease.