Lack of data showing the present arsenic contamination in Ronphibun has been a matter of public
health concern. Since arsenic contamination of shallow-well water in Amphur Ronphibun, Nakorn si thamarat
Province, had been found in 1985, interventions to reduce the use of the shallow-well water especially for
drinking and cooking have been implemented. However, a large number of shallow wells still exist and the
residents continue to use this water for domestic purposes. The residents are anxious about possible health
problems and the safety of using the water contaminated with arsenic.
Although an AAS is available in Ronphibun Hospital, fast analysis and accurate results of arsenic
analysis cannot be obtained because of problems with the instrument and not enough experience of the
analytical staff. We selected a test kit suitable for use in the field in Ronphibun, tested its accuracy and
investigated the feasibility of further arsenic measurement by Ronphibun people.
The test kit developed by Mahidol University met the criteria concerning cost, availability, ease of
use and interpretation and safety. Accuracy was evaluated using standard arsenic solutions in the laboratory in
Ronphibun Hospital, but the standard color chart of the AAN kit was found to give more accurate values.
A suitable range of measurement was between 100 and 200 ppb arsenic level and optimal reaction time was
20 minutes. Comparing the test kit readings with the AAS values of well water samples, 95 % of test kit
readings were within the range of -61 and +53 ppb around the AAS value. After training, groups of public
health staffs, health volunteers in villages and science teachers of junior high school in Tambon Ronphibun
measured arsenic levels in standard solution of 200 ppb using the kit with acceptable results, with 98 % of the
determinants falling in the range 150 to 250 ppb.
The procedure and results of arsenic analysis using the test kit in the field at Amphur Ronphibun were
shown to the group of the peoples, who well accepted the demonstration of arsenic as a colored result.
Measurement of arsenic levels by the people in Ronphibun using the test kit and with higher precision might
be possible after additional training and sufficient practice, in order to screen for elevated arsenic levels.