Identification of dioxin and dioxin-like polychlorbiphenyls in plant tissues and contaminated soils.

The environmental analysis laboratory (EAL) of the Taiwan environmental protection administration (TEPA) has been monitoring certain sites polluted in southern Taiwan by pentachlorophenol manufacture. The analytical results revealed peculiarities in the concentration distributions in plant tissues. There are no available data on dioxin and dioxin-like polychlorbiphenyls (DL-PCBs), which can be taken up from contaminated soils by plant tissues. Thus, the aims of this study were to identify, understand, and to validate these dioxin and DL-PCBs concentrations in plant tissues of the contaminated soils. This research analyzed ten species of plant tissues, including tappa (Boussonetia papyrifera) and common jasmin orange (Murraya paniculata) from sites in southern Taiwan, with different levels of contamination. Dioxin concentrations in these plant tissues ranged from 12.7 to 2919 ng WHO-TEQ(DF)/kg dry weight (d.w.), with average of 463 ng WHO-TEQ(DF)/kg d.w. (n=16). The DL-PCBs concentrations ranged from 0.236 to 1.75 ng WHO-TEQp/kg d.w., with an average of 0.605 ng WHO-TEQp/kg d.w. (n=8). Tappa is one of the most common and fastest growing plants in Taiwan. It also shows the highest tolerance to environmental contaminants and accumulates dioxin and DL-PCBs. This is one of the best species to take up dioxins and DL-PCBs effectively. It can be recommended as a candidate for dioxin and DL-PCB phyto-remediation. These data are useful to evaluate bioaccumulation of dioxin and DL-PCBs, and to study the capability of phyto-remediation in contaminated soils.

Soil dioxins levels at agriculture sites and natural preserve areas of Taiwan.

In this study, agriculture soil in Taiwan has been sampled and analyzed to determine the background level of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DF) in the agricultural and nature preserve areas. Another objective is to investigate relationship between soil characteristics and air deposition in Taiwan. The results indicate that in nature preserve areas the topsoil shows an extraordinary profile of PCDD/DF compared to that in the air deposition. The PCDD/DF levels of the low-contaminated agricultural soils are compatible with those of the nature preserves soils. However, in the highly-contaminated agricultural soils, there is an abrupt jump in their concentrations, 10-100 times higher. The overall I-TEQ values of the background topsoils range from 0.101 to 15.2 ng I-TEQ/kg. Near industrial/urban areas in Taiwan the PCDD/DF are slightly higher compared to those in the low concentration group. Typically, the PCDD/DF background values found in this survey fall in the 90% confidence interval and can thus, be deemed the background levels in Taiwan. Ninety-five percent of these data are below the European and American soil standard of 10 ng I-TEQ/kg d.w. The PCDD/DF profile with one neighborhood soil sample was shown no significant difference.

Development of a dynamic strategy planning theory and system for sustainable river basin land use management.

Land use management is central to government planning for sustainable development. The main purpose of this study is to develop a novel strategy planning theory and system to assist responsible authorities in obtaining alternatives of sustainable top river basin land use management. The concepts and theory of system analysis, driving force-state-response (DSR) framework, and system dynamics are used to establish the DSR dynamic strategy planning procedure in this work. The integrated management of the land, water, and air resources of a river basin system is considered in the procedure. Two modified land use management procedures combined with the DSR dynamic strategy planning procedure are developed in this work. Based on the DSR dynamic strategy planning procedure, the sustainable river basin land use management DSR dynamic decision support system (SRBLUM-DSRD-DSS) is developed by using the Vensim, MS Excel, ArcView, and Visual Basic software. The concepts of object-orientation are used to develop the system dynamic optimization and simulation models of SRBLUM-DSRD-DSS. Based on the modified land use management procedures, SRBLUM-DSRD-DSS is used to assist decision makers in generating the land use plans of the Nankan river basin in Taoyuan County of Taiwan. Since the decisions of land, water and air resources management are still made at different agencies, the land use management system should be modified based on the innovational procedure to implement the management strategy developed in this work. The results show that the modified land use management procedures can be a guidance for the governments in modifying the systems and regulation of urban and regional plans in Taiwan.