Int. J. Environ. Res. Public Health 2010, 7 3617 other relevant competent authorities, including the Department of Health (DOH), the Council of Agriculture (COA) and the Council of Labor Affairs (CLOA), have also worked together to develop regulatory frameworks to solve pesticide-POP issues. Although the use of OCPs in Taiwan has been banned for many years, the regulatory and non-regulatory approaches for these pesticide-POPs will be expected to offer prevention strategies for other countries. In line with the public concern in recent years about the human health risks of emerging pollutants, this comprehensive paper will focus on the pesticide-POPs, including aldrin, chlordane, chlordecone, DDT, dieldrin, endrin, heptachlor, hexachlorobenzene, α/β- hexachloro-cyclohexanes, lindane, mirex, pentachlorobenzene, and toxaphene. The main subjects addressed by this paper cover the following key elements: ˙Properties and carcinogenity of pesticides-POPs ˙Use and distribution of pesticides-POPs in Taiwan ˙Regulatory system for controlling pesticides-POPs in Taiwan 2. Properties and Carcinogenity of Pesticide-POPs 2.1. Properties of Pesticide-POPs As mentioned above, POPs have been considered to be extremely stable, highly inert and unlikely to be decomposed under e normal environmental conditions. It means that the environmental fate of these pesticide-POPs if released or emitted only involves transportation from a phase to another without changing their identities until equilibrium is approached. Therefore, the properties regarding the environmental distribution among the air, water, and solid phases are very important in understanding their movement between media and evaluating their behavior within a single medium. These environmental properties commonly include octanol-water partition coefficient (Kow), water solubility (Sw), Henry’s law constant (H), and vapor pressure (Vp). Table 1 summarized the identities and environmental properties of these pesticide-POPs, which were mainly compiled from available monographs or books [9,10]. From the molecular structure point of view, these pesticide-POPs comprise C=C (aromatic), C-H, and C-Cl chemical bonds, with lesser numbers of C-C and C-O bonds. This means that the compounds tend to have low polarity, resulting in being lipophilic with high Kow values and having a low solubility in water. As seen in Table 1, it is obvious that these pesticide-POPs, with high log Kow values ranging from 3.6 to 6.5, are hydrophobic compounds and have low solubilities in water which lie between ＜ 10−6 mg/L for endrine to 7.6 mg/L for chlordecone. Therefore, they partition favorably to organic matter and have low mobility, limiting their capacities for spreading in the aqueous phase of soil and sediment [11]. Interface transfer between the gas phase (i.e., atmospheric air) and water bodies is one of the fate processes affecting the transport of many chemical compounds in the environment because the vaporization from aqueous solutions is an important transport pathway from water to air. In this regard, Henry’s law is used to describe the partition of a vapor between two different phases, such as water and air, under equilibrium conditions. Therefore, the Henry’s law constant (H) is usually defined as the ratio of a chemical’s concentration in air to its concentration in water at equilibrium. From the data on the Henry’s law constant (H) and vapor pressure (Vp) in Table 1, it has been suggested that