Table 2 Comparison of elemental lead(Pb) and cadmium(Cd) levels in the blood of children age from 0 to 18 in Henan, China, based on gender, age, and year

Gender

 Boys

16142

23.90(15.81,35.50)

28.23±19.63

5.635

<0.001

0.66(0.35,1.06)

0.79±0.60

0.693

0.489

 Girls

9778

22.75(15.11,34.20)

27.17±19.29

0.65(0.35,1.05)

0.79±0.59

Age (years)

 A[0~1)

5745

21.27(14.39,31.82)^a,b,c,d

25.90±20.28

150.006

<0.001

0.66(0.36,1.04)^c,d

0.78±0.57

11.055

0.026

 B[1~3)

8049

23.85(15.74,36.16)^a

28.92±21.99

0.66(0.35,1.08)^g,h

0.80±0.60

 C[3~7)

6811

24.51(15.94,36.04)^b

28.28±17.56

0.65(0.35,1.06)

0.80±0.61

 D[7~13)

4998

24.19(16.19,35.23)^c

27.75±16.78

0.64(0.34,1.04)^c,g

0.78±0.62

 E[13~18]

317

23.63(16.19,32.61)^d

26.42±14.59

0.64(0.31,1.00)^d,h

0.74±0.61

Year

 A(2017)

5843

19.09(13.69,28.62)^a,b,c,d,e

24.10±18.98

689.523

<0.001

0.62(0.34,0.95)^a,b,c,d,e

0.71±0.52

416.896

<0.001

 B(2018)

5099

21.45(13.16,32.80)^a,h,i

26.11±22.60

0.68(0.34,1.12)^a,f,i

0.82±0.66

 C(2019)

4421

21.90(15.01,30.84)^b,k,l

25.56±17.71

0.58(0.29,0.98)^b,f,j,k,l

0.72±0.58

 D(2020)

3659

22.06(15.45,30.41)^c,m,n

24.82±13.96

0.68(0.40,1.04)^c,j,n

0.79±0.54

 E(2021)

3765

31.62(21.53,44.31)^d,h,k,m,o

34.41±18.66

0.68(0.37,1.09)^d,k,o

0.80±0.58

 F(2022)

3133

33.80(23.92,45.72)^e,i,l,n,o

36.37±19.57

0.81(0.46,1.29)^e,i,l,n,o

0.96±0.70

 Total

25920

23.48(15.53,34.98)

27.83±19.51

0.66(0.35,1.05)

0.79±0.60