Đang chuẩn bị liên kết để tải về tài liệu:
SIMULATION OF ORGANIC CHEMICAL MOVEMENT IN HAWAII SOILS WITH PRZM

Some of the POPs targeted by the Stockholm Convention are already virtually obsolete. Their toxic effects became obvious early on and they have been banned or severely restricted in many countries for years or even decades. Replacement chemicals and techniques are in place. The remaining challenge is to find any leftover stocks and prevent them from being used. Some developing countries may need financial support to dispose of these stocks and replace them with chemicals whose benefits outweigh their risks | Pacific Science 1989 vol. 43 no. 1 1989 by University of Hawaii Press. All rights reserved Simulation of Organic Chemical Movement in Hawaii Soils with PRZM 1. Preliminary Results for Ethylene Dibromide1 Keith M. Loague 2 Richard E. Green 3 Clark c. K. Liu4 and Tony c. Liang5 ABSTRACT Leaching of agricultural chemicals to groundwater is an environmental issue of major concern in Hawaii. Fumigants used by the pineapple industry are a possible source of this contamination. In this paper we report the results of an initial evaluation of the Pesticide Root Zone Model PRZM for highly structured Hawaiian soils. We use PRZM to predict the transport of the soil fumigant ethylene dibromide EDB for two pineapple fields and compare the simulated concentration profiles with field measurements. Although preliminary our results suggest that PRZM may be useful in the future for pesticide screening and risk assessment in Hawaii. The work reported here is part of a larger ongoing study concerned with development and application of methodology for assessing potential groundwater contamination by pesticides. Groundwater contamination is one of the nation s most important environment concerns Pye and Patrick 1983 Sun 1986 . The public s awareness of groundwater contamination has increased significantly in recent years because of well-publicized case histories such as Love Canal Epstein et al. 1983 . In general groundwater contamination occurs from either point or nonpoint sources. The failure of a waste management facility or a chemical spill are both examples of point sources. Applications of chemicals in agriculture and forestry defoliants herbicides insecticides constitute nonpoint sources. The leaching of toxic chemicals from either Manuscript accepted 18 March 1988. The work reported here was supported by EPA Cooperative Agreement CR811194-02-4 but the contents of this report do not necessarily reflect the views of the Agency and no official endorsement should be inferred. 2 .