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Abstract
In a period from 1995 to 2000, we had collected and analyzed 33,092 hand tube well water samples from four different/principal geomorphological regions (Hill tract, Table Land, Flood Plain, and Deltaic reason) i.e., from all 64 districts of Bangladesh and found arsenic in 60 districts that were above the WHO recommended value in drinking water (10 μg/L) and 50 districts that were above the maximum permissible limit, 50 μg/L.
In our study for 6 years in Bangladesh, the survey for identification of arsenical patients was conducted by our group with a medical team in 261 villages of 80 police stations under 33 districts out of 50 where contamination of groundwater with arsenic is above 50 μg/L. We could not identify people suffering from arsenical skin lesions who drunk water below 100 μg/L of arsenic.
During this survey, arsenic patients were identified in 222 villages of 69 police stations under 31 out of 33 districts. The number of people we examined including children was 18840, and 3725 people were identified with arsenical skin lesions. We had registered 1885 males, 1542 females, and 298 children out of the total 3725 patients, having arsenical dermal lesions, such as: melanosis, leucomelanosis, keratosis, hyperkeratosis, dorsal, non-petting oedema, gangrene, cancer, etc. If children are included, then 19.77% (n=3725) have arsenical dermal lesions, and for separately adults and children, these are 24.52% and 6.13%, respectively. Buccal mucus membrane melanosis (MMM) on tongue, gums, lips, etc. was also found. Rough dry skin often with palpable nodules (spotted keratosis) on dorsal of hand, feet, and legs are the symptoms seen in severe cases.
Other symptoms are sometimes found (1) conjunctional congestion and (2) non-petting swelling (solid oedema) of feet. Complications like liver enlargement (hepatomegaly), spleen enlargement (splenomegaly) and fluid in abdomen are seen in severe cases. Squamous cell carcinoma, basal cell carcinoma, Bowen's disease, carcinoma affecting lung, uterus, bladder, genitourinary tract, or other sites are often seen in advanced neglected cases suffering for many years. During our preliminary field survey in Bangladesh, we could identify 25 carcinoma /gangrene patients out of 3725 patients. In addition to the above symptoms, we observe some common problems in arsenic patients with arsenical skin lesions such as intolerance to sunlight, burning sensation on whole body, weakness, and respiratory problem.
In children, our last 6 years of field experience in Bangladesh show that normally children under 11 years of age do not show arsenical skin manifestations. However, we have observed a few exceptions when (1) the arsenic content in water consumed by children is very high (1000 μg/L) and (2) the arsenic content is not very high (around 500 μg/L), but the children get poor nutrition. The youngest arsenic patient was a child (age 18 months) with melanosis (+) and keratosis (++) [spotted on palm and sole] who was found in Payerpur village under Madaripur Sadar police station in Madaripur district. While discussing with his mother, I came to know that the child used to drink a very high quantity of water (2-3 liters per day) from childhood.
So far, we had examined 4,864 children, below 11 years of age, drinking arsenic contaminated water from the arsenic affected villages in Bangladesh and out of that arsenical skin lesions registered from 298 children (6.12%) whereas in adults it is 24.47%. Normally, arsenical skin lesions observed in children are diffuse melanosis and spotted melanosis. Keratosis on the palm and sole are not common in children. We have not found children suffering from+++ stage of melanosis and keratosis (we used mild+, moderate to high++, severe+++). Also, we have not found any child patient during last 6 years in Bangladesh, below 11 years of age, with non-pitting oedema, gangrene, Bowens, dorsal, or cancer.
The members of the under-poverty line family versus the rich family: In addition to common arsenical symptoms, we also observed dorsal (15%), chronic bronchitis (30%), and vitamin deficiency among the under-poverty line family members, but such type of symptoms were not observed to the members in rich family. Children at the age around 11 years in that family had no arsenical skin lesions. The arsenic concentration in drinking water of the tube well was 570 μg/L. But six children out of seven, around 11 years of age, were found with arsenical skin lesions in the under-poverty line family. The youngest victim was 8 years old, and the arsenic concentration in drinking water being used by this family was 690 μg/L.
Our field experience in Bangladesh, we have observed that among the adults suffering from diffuse melanosis and light spotted melanosis can recover after drinking safe water, eating nutritious food, and taking vitamins. Normally diffused melanosis disappears easily after drinking safe water, and light keratosis (+) may also disappear. But if keratosis is appreciably visible (++), drinking safe water and eating nutritious food may reduce it, but it may not disappear. In arsenic patients with moderate to severe (++ and +++) keratosis, the appearance of keratosis does not stop even after drinking safe water over a long period of time and even when hair, nail, and skin scales contain safe levels of arsenic.
We have further observed that children recover from diffuse melanosis (blackening of color) and light spotted melanosis (+) quickly if they use safe water, have better nutrition, and eat vitamins. Mild keratosis (+) also disappears, but the children having moderate to high spotted melanosis (++) and spotted keratosis (++), even after drinking safe water and nutritious food, do not recover completely. We had found diffuse melanosis in children disappear, and those who had spotted melanosis (+) and keratosis (+) are no longer showing skin lesions. Those who had ++ spotted melanosis and ++ spotted keratosis could not get rid of their skin lesions, and spotted melanosis is replaced by Leucomelanosis, and keratosis is less. However, the children are still complaining about their weaknesses, breathing problems, and suffering from cough and cold.
Finally, if it is accepted that children are at a higher risk due to arsenic exposure, then the future of the next generation of Bangladesh living in arsenic affected villages may be grim as above 84% and 89% of the children's hair and nail contain arsenic above toxic (hair) or normal level (nail), respectively. Therefore, it is very important to monitor the concentration of arsenic in their drinking water even though they are drinking arsenic free deep tube well water now.
