^1*M. M., Uddin, ²A. K. M., Harun-Ar-Rashid, ³S. M., Hossain, ³M. A., Hafiz, ³K. Nahar and ³S. H. Mubin

¹Department of Physics, Chittagong University of Engineering and Technology, Chittagong, Bangladesh
²Department of Physics, University of Chittagong, Chittagong, Bangladesh
³Institute of Nuclear Science and Technology, Atomic Energy Research Establishment, Dhaka, Bangladesh
*Corresponding author, Email:mohi@cuet.ac.bd Tel.: +88031 714 947; Fax: +88031 714 910

Received 9 March 2006
Accepted 7 September 2006

Code Number: st06054

ABSTRACT: This paper gives impact of Arsenic contaminated water on human health as well as overview of the extent and severity of groundwater arsenic contamination in Bangladesh. Scalp hair is the most important part of the human body to monitor the accumulation of this type of poison. Therefore, an experiment has been carried out by Neutron Activation Analysis (NAA) at Atomic Energy Research Establishment (AERE), Savar, Dhaka, Bangladesh on human hair of corresponding tube well water users of these areas to determine the total accumulation of arsenic to their body. Hair samples collected from the region where the groundwater was found highly contaminated with arsenic. The obtained results of arsenic concentration in the lower age (Hb) categories of users (below 12 years of age users) is in the range of 0.33 to 3.29 µg/g (ppm) and that in the Hu categories (upper 12 years of age users) is 0.47 to 6.64 µg/g (ppm). Where as maximum permissible range is 1 ppm certified from WHO. Results show that the peoples are highly affected where the groundwater is highly contaminated with arsenic and acts as the primary source of arsenic poisoning among the peoples of those areas. The results indicate that human population is affected with arsenic locally using the contaminated water for a long time.

Key words: Arsenic, groundwater, Bangladesh, gamma ray activity, neutron activation analysis, trace elements

INTRODUCTION

Arsenic is one of the most commonly studies trace Toxic, naturally occurring arsenic species elements as it is both toxic and carcinogenic (Nriago,1994). It is reported that 40 % of arsenic in human body comes from food chain (BIAM, 2002). Arsenic has been taken into account as a dangerous environmental pollution and detected as a serious health risk in many countries of the world, reported from Argentina, Mexico, Chile, USA, Taiwan, Mongolia, Thailand, Philippines, China, Japan, India, as well as Bangladesh (Akram, 1997, BGS, 2001 and SOES-DCH, 2000). The arsenic contamination is not only a health hazard for the people; it also affects the environment Metabolic by products of arsenic V and creates social problems (Table 1). There are two main theories (Pyrite oxidation and oxyhydroxide reduction) as to how arsenic is released into the ground water.

Table 2

MATERIALS AND METHODS

Study area

Feni district of Bangladesh is selected for this experiment. It has six upazila. Each upazila comprises of several Unions. Each Union has some ‘blocks’ (wards). In each ‘blocks’ there are some ‘Villages’.

Fig. 1, Fig. 2

Sample collection

Hair samples were collected from the tube well water users. Hair samples of the water users of this district have been categorized into two: below 12 years of ages and upper 12 years and are coded as Hb and Hu, respectively. Before, collecting samples, scissor was cleaned by acetone to avoid the others contamination.

Sample preparation

Hair samples were transferred from polyethylene bag to the Petri dish. In order to clean hair samples properly, samples were washed and dried in the following ways;

i) Acetone and dried naturally
ii) Deionized water and then dried
iii) Again by acetone and dried

The dried clean hairs were cut into small pieces. Four types of standard reference materials were used for the analysis of two sets of hair samples (a total of 30 samples) supplied by National Institute of Standard and Technology (NIST). Whereas the first set was analyzed using the International Atomic Energy Agency (IAEA) certified reference materials Soil-7 and SL-1, the second set was analyzed using coal fly ash and pond sediment. About 100 mg hair was taken into the bullet type irradiation vial. The identification of the sample was put at the outer surface of the vial and heat-sealed.

Calculation of arsenic concentration

For the calculation of concentrations, the peakgr10 software package was used. Concentratrions calculation were also performed manually by the following activation equation

Where, ‘a’ and ‘b’ are the weight of the element in the sample and standard respectively. A_x* is the activityin sample and standard (Laul 1979).Both the program and manual calculations gave the consistent results.

Accuracy of the analysis and the total uncertainty

Quality Assurance (QA) test is performed to investigate the reliability of the analysis by measuring arsenic concentration level in standard reference materialsAs (NIST, USA), coal fly ash, SL-1and Soil-7 (IAEA) relative to primary standard of arsenic. The analytical results for certified reference materials are given in the table below. The experimental results are within 10% deviation, which is a good agreement with the certified value. This deviation was achieved due to poor counting statistics. Uncertainties of the samples were calculated according to the 1993 ISO guide and were added to the uncertainty in the measurement (Kuèera, et al., 1999). Table 3 Shows that Comparison of arsenic concentration determined in the standard reference material As (NIST, USA), Coal FlyAsh, Pond Sediment (NIST, USA), and SL-1, Soil-7, (IAEA) with the certified value.