HM concentrations in blood and urine samples (n=450) Concentration HMs TB SD Min - Max N * (n,%) Normal value Blood-Pb (g / dL) 9.06 ± 0.99 6.23 - 11.35 96 (21.33) < 10 Blood-Cd (g / l) KPH (0.0) - Urine-As (g / l) 69.96 ± 23.38 44.65 - 43.32 174 (38.67) < 60 U-ALA (mg / l) 4.50 ± 1.59 2.16 - 11.24 96 (21.33) < 5 U - Cr (g / l) 40.04 ± 6.97 21.38 - 86.56 - - U-Hg (g / l) 1.32 ± 0.51 0.37 - 3.50 (0.0) - N *: Samples exceeded normal level 21.33% of samples had blood Pb, urinary ALA and 38.67% had urinary As higher than the normal threshold.