Int. J. Environ. Res. Public Health 2010, 7 1. Introduction 3616 In the past decades, many studies have focused on the potential of a diverse number of persistent organic pollutants (POPs) to cause adverse effects to the environmental and human health [1]. These chemical substances are very stable compounds that resist photolytic, biological and chemical degradation, that thus persist in the environment with long half-lives. Recently, there has been concern about the hormone-like effects on the endocrine and reproductive systems of wildlife and humans of many POPs because of their lipophilicity and tendency to accumulate in food chains and bodies [2]. Today, these chemicals are collectively termed endocrine disrupting chemicals (EDCs), endocrine disruptors or environmental estrogens. Since the 1960s, the risks posed by POPs, especially the organochlorine pesticides (OCPs), have become of increasing concern in international communities. These OCPs are known to be widely used as insecticides, herbicides and fungicides. It should be noted that some of the OCPs also have anti- estrogenic (androgenic) activity. Most OCPs were applied in agriculture and transported to the environment by means of runoff and infiltration. Several regional and global POP treaties and/or initiatives have been negotiated for identifying POPs and developing risk management measures to reduce the exposure of humans and the ecosystem to these toxic substances [3,4]. Among these treaties, the Stockholm Convention on POPs, which came into effect on 17 May 2004, is the most important milestone. Twelve POPs, consisting primarily of OCPs, were initially listed in the Stockholm Convention to be eliminated or their production and use restricted. The OCPs or pesticide-POPs identified in the Convention include aldrin, chlordane, DDT, dieldrin, endrin, heptachlor, hexa- chlorobenzene, mirex, and toxaphene. At the fourth meeting of the Conference of the Parties (COP4), the depositary communicated the adoption of the amendment to Annexes A (elimination), B (restriction) and C (unintentional production) of the Stockholm Convention, that shall enter into force on 26 August 2010. Nine new POPs, including hexachlorocyclohexane, chlordecone, lindane, and pentachlorobenzene were added to the Convention. In Taiwan, soil contamination by OCPs occurred during the 1950s–1970s period due to the widespread use of pesticides in the agricultural sector [5]. As surveyed by Vu Duc et al. [6], the residual levels of OCPs (e.g., DDT and HCH) in soil samples from paddy fields, uplands and urban areas in Taiwan seemed to be higher than those in other Asian countries such as Thailand and Vietnam. It was estimated that over two million kilogram of OCPs was released into the environment annually in that period via volatility, soil erosion and agricultural runoff [7]. From the surveys on the distribution of OCPs residues in river sediments of Taiwan, it was found that residues of some OCPs, such as DDT, dieldrin and hexachlorocyclohexane (HCH), were still detectable in minor amounts in soils and sediments [5,7]. The central competent authorities, including the Council of Agriculture (COA) and the Environmental Protection Administration (EPA), have thus promulgated relevant regulations to ban or restrict toxic and persistent OCPs, and also started investigations to monitor their environmental levels since the 1980s [8]. They were banned for use under the Toxic Chemical Substances Control Act and the Pesticide Management Act. While Taiwan is currently not a party to the Stockholm Convention, it has specially drafted the “National Implementation Plan of the Stockholm Convention on Persistent Organic Pollutants” to serve as a basis for domestic implementation work. This plan was approved by the Executive Yuan on 24 April 2008. Subsequently,