Ganga-Meghna
Brahmaputra ||
West Bengal || Bangladesh
||
Middle Ganga Plain, Bihar ||
Uttarpradesh
Jharkhand || North-East Hilly States ||
Rajnandgaon,
Chattisgarh || Behala,
Kolkata, WB || As
toxicity- Homeopathic Treatment
Effectiveness & Reliability - As Field
Testing Kits ||
Utility Of Treatment Plant
Causes, Effects & Remedies - Groundwater As Calamity
|| References
Endangered Generations :Groundwater Arsenic Contamination in West Bengal, India
Arsenic in food chain
|
Though
the arsenic problem is about two decades old and we are deeply
concerned with the arsenic contamination of drinking water, surveys
are yet to be conducted on the amount of the arsenic in irrigation
water and consequent entry of the element through food into the
bodies of humans and animals. We have been studying this problem
for last 3 years and have come to the conclusion that huge amounts
of arsenic are entering the crops through irrigation water. These
crops are in turn causing the element to enter into the bodies
of human being and animals. We have calculated that from the existing
3200 irrigation tube-wells in Deganga Block of North 24-Parganas
are causing 6.4 tons of arsenic to be deposited on the agricultural
fields. Rice, leafy vegetables, spinach, arum and other items
of daily diets have been found to have elevated arsenic concentration
(Photograph 7). |
|
It has been calculated that in Kolsur village 1/3 of the total amount of arsenic entering the body comes from arsenic affected food items. Contrary to the hope that vegetables contain laser amounts of the more harmful and poisonous arsenic compounds (viz. arsenite and arsenate) 85% of the arsenic contained in food items from Kolsur village have been found to be in the form of these two compounds. Vegetables that grow underground contain greater amount of arsenic in them than others do. And average daily intake of arsenic through water and food items among villagers of the Deganga block's Kolsur village during our study is in Table 4.
Table 4: Daily arsenic intake by Kolsur villagers.
| Arsenic intake by | Arsenic intake only from water (µg) | Arsenic intake from rice, edible herb, vegetables, etc. (µg) | From water used in cooking and in preparation of cold rice (µg) | Total daily in take of arsenic (µg) |
| Adult man | 800 | 285.0 | 200 | 1285.0 |
| Adult women | 600 | 285.0 | 200 | 1085.0 |
| Boys / girls below the age of 11 | 400 | 153.2 | 100 | 653.2 |
In addition to human beings domestic animals too are not being spared of arsenic contamination. They too are being forced to take in arsenic through water and food items in affected villages. Cows and buffaloes take in the greatest amount of arsenic in this fashion. These animals generally drink large amount of water (average 40 liters) and about 4 to 5 kgs of hay every day. Our test conducted in 8 hay fields show that on an average 1900 µg of arsenic are present in every kg of hay in Kolsur village. While human being take in 1200 µg of arsenic every day from Kolsur village, cow and buffaloes take about 18000 µg of arsenic daily. Elevated concentration of arsenic has been found in the hair and urine samples from cows and buffaloes in these villages (Photograph 8).
 |
Nowadays whenever villages come to know of the high concentration of arsenic in their tube-wells, they try to drink water from other safer sources. But they can't escape from arsenic intake through food items. Currently groundwater is the main source of irrigation. It is important to note that even villagers of unaffected areas may allow the entry of arsenic into their bodies by eating rice, vegetables etc. grown in arsenic affected areas. Even Kolkata City is not safe from this threat. In the arsenic affected villages, urine samples of people drinking arsenic safe water have been found to contain arsenic in somewhat elevated level than that expected in normal people. Our calculations show that the intake of arsenic through food items is greater than the WHO maximum limit regarding drinking water. The maximum limit of daily intake is 100 µg according to WHO. This figure has been arrived at by considering by 1 liter of water as containing 50 µg of arsenic and an adult human being drinking 2 liters of water a day. |
Arsenic is gradually becoming a part of our daily lives. Its presence is restricted not only to drinking water and vegetables but it has also been found in local ice creams and cold drinks in affected areas. Photograph 9 shows certain local cold drinks that has arsenic content above maximum permissible limit set by WHO for drinking water. The villages of West Bengal are about 95% dependent on groundwater reserves for drinking water. The food processing units and other units manufacturing articles using water of daily use and located in suburban areas are generally using groundwater for production.
 |
Now,
if groundwater in 9 affected districts contains arsenic, and if water
not treated to remove arsenic then the groundwater being used by these
industries may very well contain arsenic. Our research has revealed
that even if the mother is an arsenic patient her breast milk remains
almost free from the element. Similarly cows may eat arsenic contaminated
hay and drink contaminated water, yet their milk will remain quite
free from the element. However, some time we found arsenic in elevated
level in cow milk in the affected villages and that arsenic is due
to contaminated tube-well water added by milkman to increase the volume
of milk. This arsenic contaminated milk also comes to near by city
and used by tea stalls and those making sweets from milk. |