Abstract: Chronic multiple metal exposure is one of the major types of environmental pollutantexposure. However, there is no comprehensive survey on the preschool children’s metalexposure in Taiwan. This three-year study will study on the distributions of blood metallevels of the preschool children, critical factors for exposure to metals, and the potentialadverse health effects. Total 934 preschool children were previously recruited fromkindergartens located in the randomly selected townships or city districts based on astratified sampling strategy. Information on demographics and environmental exposurefactors were collected through questionnaire administration for each study subject. Metallevels in blood samples of the preschool children will be determined with inductive coupledplasma, while polymorphism of the metal metabolism related gene will also be analyzed inthe present study. In the first study year, the norms of lead, mercury, arsenic, zinc, cadmium,manganese, zinc, and copper levels in blood of the preschool children will first beestablished, and the relevant exposure factors will also be elaborated. In addition, theassociation between total immunoglobulin E and the multiple metal levels in blood will beexamined as well. In the second study year, the study will first explore the relationshipsbetween the multiple metal levels in blood of the preschool children and the polymorphismof the metal metabolism related genes. Meanwhile, a structure equation model will beapplied to comprehensively evaluate the effects of chronic multiple metal exposure,polymorphism of the metal metabolism related genes, and environmental exposure factorson the attention deficit of the preschool children. In the third study year, the norms of specialmetals, including gallium, germanium, indium, platinum, rhenium, ruthenium, titanium,thallium and molybdenum, in blood of the preschool children will first be established.Meanwhile, this part of study will also explore the relationship between the levels of theseconcerned special metals in blood of the preschool children and the emission sources amongthe new technology industry and traffic transportation. Research products of the presentstudy will benefit the construction of an appropriate strategy for environmental metalexposure prevention in Taiwan, and provide necessary fundamentals for the continuousacademic research on human susceptibility to metal exposure.