ISPRS, Vol.34, Part 2W2, “Dynamic and Muiti-Dimensional GIS 1 ', Bangkok, May 23-25, 2001 
CIS AIDED CHARACTERIZATION OF SOIL AND GROUNDWATER ARSENIC CONTAMINATION 
IN SOUTHERN THAILAND 
Jianjun ZHANG \ Xiaoyong CHEN * 2 , Preeda PARKPIAN 3 , Monthip Sriratana TABUCANON 4 
Janewit WONGSANOON 4 Kensuke FUKUSHI 3 , Skorn MONGKOLSUK 5 and N.C.THANH 3 ’ 
Environmental Toxicology Technology and Management/Urban Environmental Engineering and Management Program / 
School of Environment, Resources and Development/Asian Institute of Technology (AIT) 
Mail box: 1201, Asian Institute of Technology P.O. Box: 4, KlongLuang, Pathumthani, 12120, Thailand 
Tel. 66-2-524-5639; Fax: 66-2-516-2126 Email:superchinazii@vahoo.com 
3 Space Technology Applications and Research Program, AIT, Thailand 
4 Urban Environmental Engineering and Management Program, AIT, Thailand 
5 4 The Environmental Research and Training Center (ERTC), Bangkok, Thailand 
Laboratory of Biotechnology, Chulabhorn Research Institute (CRI), Bangkok, Thailand 
KEYWORDS: GIS, Arsenic Contamination, Groundwater, Soil 
ABSTRACT 
As a result of extensive and long term tin mining activities, huge amount of mining waste was dumped along the hillside, riverbank, and 
even buried underground in Ron Phibun district, Na Khon Si Thammarat province, Thailand. More than 1,000 arsenism patients had 
been identified since 1987 due to the consumption of arsenic containing drinking water. In order to understand clearly the current 
situation of arsenic contamination, a large-scale survey was conducted from September 1998 to March 2000 by JICA-ERTC 
(Environmental Research and Training Center) team within an area of 14 km 2 . The patients' distribution, arsenic level of surface water 
(rivers and ponds), groundwater (deep wells and shallow wells), surface soil were integrated with GIS database (ArcView GIS version 
3.1) collected in that locale. With the help of this database, the interpolated arsenic level in ground water, surface soil were made 
possible on the map with emphasis on the highly contaminated hot spots. It was obvious that most part of the area has total arsenic 
level in shallow groundwater higher than the WHO recommended level (0.05mg/L), with mean value of 0.53mg/L, and the highest value 
of 64mg/L (HG-AAS method). Six highly contaminated areas were identified in the studied Ronphibun Basin where the supposed 
mechanism of arsenic release was different respectively. The correlation between arsenic level in soil or groundwater and the distance 
to mining plants and waste sites were analyzed. Comparison of arsenic level in groundwater in dry and rainy season was conducted, so 
as to estimate the dynamic fluctuations of arsenic contamination. The significant correlation between the distribution of arsenism 
patients and the location of high arsenic groundwater was observed. Recommendations including the treatment of groundwater, 
removal of contaminated soil, finding of alternative drinking water sources are proposed. This GIS database provided a feasible 
approach to the further management on the removal of arsenic contaminated soil and the consecutive monitoring of ground water. Also, 
it provided an effective method for the assessment of exposure and potential health consequences as well as the planning and 
implementation of long term sanitation measures for the local government. 
1. INTRODUCTION 
Arsenic is a ubiquitous element present in various compounds 
throughout the earth’s crust. It is widely distributed in the 
environment, and all humans are exposed to low levels of 
arsenic (WHO 1981). However, high level arsenic exposure to 
human being has occurred for decades mainly via drinking 
water due to some natural (geological, volcanic activities) and 
anthropogenic activities (industrial pollution, mining, 
agriculture)(Arrykul 1996, Chanpen, 1998). Among the four 
chemical valence of 0, -3, +3, +5, arsenic (+3) is the most toxic 
species. Arsenism is the result of long-term ingestion of 
arsenic from water, food, or other sources, which has many 
aspects, such as cutaneous manifestations (skin pigmentation 
changes, keratosis), peripheral vascular disease (Blackfoot 
Disease and Roynaud's syndrome), the higher mortality rate 
from cancer of bladder, kidney, the systemic arterial disease 
resulting in myocardial infarction, changes in 
electromyographic patterns, and mutagenic, teratogenic 
effects, etc. WHO has recommended lowering permissible 
concentrations of drinking water standard for arsenic from 50 
pg/L to 10 pg/L, while the USEPA suggests the limit level to 2 
Mg/L (Allan H. Smith, et al 1999), because of the extrapolation 
of skin cancer risks from a population in Chinese Taiwan with 
high levels of arsenic in their drinking water. Unfortunately, 
arsenic contamination has become a problem in many parts of 
the world, from the mine tailings leaching in United States, 
Canada, Mexico, Thailand, Japan, United Kingdom, and 
Australia, also from the arsenic in natural acquifers now or 
recently used for water supply in Bangladesh, India, United 
States, Hungary, Chile, China, Argentina, Chinese Taiwan, 
Ghana, Mexico, Philippines and New Zealand. 
Geographic Information System (GIS) is a valuable scientific 
tool used since 1960s. It's applications now span a wide 
range, from simple inventory and management to 
sophisticated analysis and modeling of spatial data. It is also 
used in environment science, such as the successful models in 
atmospheric, land and subsurface, hydrological, biological and 
ecological; in epidemiology field to disclose the relationship 
between a specific disease and a location. All these 
applications not only facilitate the understanding of the applied 
field, but also provide strong supports for decision-makers to 
take necessary actions. (Goodchild, 1993) 
Recently, GIS was used in an arsenic mitigation program in 
Bangladesh groundwater system (Ahmadul, 1998). It 
completed the many aspects of arsenic problems, including 
analysis of present groundwater conditions, assessment of 
exposure and potential health consequences and planning and 
implementation of emergency and long term sanitation 
measures. The evaluation of public health impact in a public 
health assessment is based on available environmental, 
demographic, health outcome data and community health 
concerns. The application of GIS into this field has showed 
advantages not only on the display of general site information, 
demographic data, environmental data, but also the analysis of 
spatial relationship between public health outcome and 
specific environmental event. Based on this evaluation, public 
health actions are taken or recommended to reduce, eliminate, 
communicate or further evaluate the possibility of health 
impact. In this work, an extensive geological and geochemical 
survey was conducted by Japan International Cooperation 
Agency (JICA) and Environmental Research and Training 
Center (ERTC) in order to understand clearly the current 
situation of arsenic pollution in Ronphibun area of southern 
Thailand from September 1998 to March 2000. The overall 
objective of this study is aimed at developing a GIS database 
so as to depict the arsenic contamination and guide the 
consecutive monitoring and management of arsenic pollution, 
Supported by Visiting Scholar Foundation of Keb Lab. In Wuhan University, P. R China 
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