West Bengal || Bangladesh
Middle Ganga Plain, Bihar ||
A primary school teacher in Calcutta whose permanent address is Semria Ojha Patti village, Bhojpur district, Bihar, India, submitted a water sample to our laboratory because of his concerns over a possible toxic cause of the liver disease and skin lesions of his family in Bihar. The water sample contained 814 µg/L of arsenic. We showed him photographs of arsenical skin lesions and he noted that his family and neighbors have similar lesions, as did his first wife, who had died of cancer. The school teacher, who lived in Calcutta and visited his family every 6 months for 2–3 weeks, had no skin lesions. Preliminary analysis of 159 samples from the village showed such high concentrations of arsenic that a study was initiated. The area studied was the Semria Ojha Patti village of Ara in the Bhojpur district of Bihar. Ara, the district’s headquarter of Bhojpur district is between two important cities, Patna and Buxer, in the Middle Gangetic Plain, Bihar. The river Ganga is 8 km north of the village; the bordering state of Uttar Pradesh is a few kilometers to the west.? Figure 1 shows the position of Upper, Middle and Lower Plains of the Ganges, the groundwater arsenic contaminated area of Chandighar, arsenic affected areas of Terai region, Nepal; arsenic affected areas of West Bengal and Bangladesh in Lower Ganga Plain and the study village and its surroundings in Bhojpur district in the Middle Ganga Plain of Bihar. Semria Ojha Patti, 4 sq. km in area with about 5000 inhabitants, is a remote, agricultural village. There are no factories on the periphery. Many of the adult males work outside Bihar to earn a living for their families. About 20 years ago the large-bore dug wells were abandoned and replaced by hand tube wells as the primary water source. The villagers denied any skin lesions prior to the tube wells. The aged villagers told us that at least 100 villagers who had arsenic skin lesions died during the last 10 years and some of them from cancer. Many died at a very young age. The villagers were unaware of any arsenic problem and believed that God’s wrath was on the affected families.
The 550 subjects examined were
self-selected volunteers, 390 adults and 160 children, 6–11
years old, recruited by loudspeaker announcements at six central
sites. All subjects consented,
and their minor children, to medical evaluation and photography and
provided samples of urine, hair, and nails. There was a low representation
of women who feared stigmatization, of children attending school,
of men working outside the village.
Water, hair, nail, and urine samples were analyzed for arsenic by flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS). For urine samples, only inorganic arsenic and its metabolites together [arsenite, As (III), aresenate, As (V), Monomethyl arsonic acid, MMA (V), and Dimethyl arsinic acid, DMA (V)] were measured with no chemical treatment. Under the experimental conditions of FI-HG-AAS, arsenobetaine and arsenocholine do not produce a signal (Chatterjee et al. 1995). The modes of sample collection, the digestion procedures for hair and nails, analytical procedures, and the details of the instrument and flow injection system were as reported earlier (Chatterjee et al. 1995; Das et al. 1995; Samanta et al. 1999).
1, 10-phenanthroline method with UV-visible spectrophotometer was used for iron analysis of water samples (Fries and Getrost 1975).
Groundwater Arsenic Contamination in Semria Ojha Patti Village The 206 water samples from Semria Ojha Patti represented 95% of the total tube wells of the village. We also analyzed 118 water samples from 5 villages within 3 km of Semria Ojha Patti (Figure 1) but none of the inhabitants were subjects. Figure 2 shows the relatively greater prevalence of highly contaminated hand tube wells compared to the arsenic contaminated areas of West Bengal and Bangladesh. The distribution indicates that, of the 5000 residents of Semria Ojha Patti, 18.4% used safe water (<10 µg/L), 24.7% between 10 and 50 µg/L, 56.8% >50 µg/L, and 19.9% >300 µg/L of arsenic. Our experience in West?Bengal and Bangladesh indicates the probability of skin lesions in a subject drinking water contaminated with >300 µg/L of arsenic. A comparative water analysis data for arsenic presented in Table 1 shows one village from West Bengal, India and one from Bangladesh, which are highly arsenic contaminated with Semria Ojha Patti village of Bihar. Table 1 shows that arsenic contamination of groundwater in Semria Ojha Patti village is comparable with highly arsenic contaminated villages of West Bengal and Bangladesh. The recommended value of arsenic in drinking water in India and Bangladesh is 50 µg/L.