Arsenic contamination occurs due to natural causes. The soil contains arsenic minerals. When this mineral comes in contact with the ground water level, it mixes with the water and contaminates the water. Thus arsenic contamination occurs in the water. Arsenic is not a contagious or hereditary disease. Containing more than normal levels of arsenic per liter of water is harmful to human body. It has no color , smell or taste and is extremely harmful to the human body. Arsenic has been found in tubewell water in most parts of our country. Drinking water from tubewells that contain arsenic or using it for cooking increases the chances of contracting various diseases caused by arsenic. Tolerable levels of arsenic According to the World Health Organization, tolerable levels of arsenic per liter of water are 0.01 mg. The Government of Bangladesh has stated that if the tolerable level of arsenic per liter of water is more than 0.05 mg or 0.05 mg of arsenic, then that water cannot be used for drinking or cooking. The cause of arsenic contamination in Bangladesh was initially thought to be due to various fertilizers , use of pesticides , disposal of industrial wastes , poles of rural electrification boards which are treated with arsenic compounds. But later, as a result of various surveys and researches, the researchers came to the conclusion that the pollution of such a vast area is almost impossible to come from all these sources and the reason is geological. Finally, a joint research team from Bangladesh and the United Kingdom came up with an alternative theory that arsenic-rich sediments from different sources accumulate in the delta and alluvial plains. Where the main carrier of arsenic is a monic mineral called iron oxyhydroxide. The subsequent extraction of oxygen by the organic matter stored with the sediment results in degradation of the aquifer , and the degradation process releases arsenic and iron , which are added to the iron oxyhydroxide , in liquid form in groundwater. This is how arsenic is spread in groundwater. Arsenic Affected Areas Arsenic contamination has been found in tube well water in 59 out of 64 districts in Bangladesh and no arsenic contamination has been found in Cox's Bazar , Rangamati , Khagrachhari , Bandarban and Sherpur. More people in Bangladesh are exposed to arsenic contamination than any other country in the world. Symptoms of an Arsenic Patient A person's hair , nails, and skin are usually examined to determine if he or she has been exposed to arsenic. Symptoms of arsenic in a person's body can take from 6 months to 20 years and in many cases even longer. The symptoms of arsenic-infected patients are as follows: In the initial stage, black spots appear on the patient's skin or the skin color becomes black. The palms of the hands and the soles of the feet become rough and may appear as small hard lumps which later turn black. The skin becomes thick and rough. May cause nausea or vomiting. There is loss of appetite , thin stools , bloody diarrhea , sores on the face etc. Sometimes it can turn black on the tongue or inside the skin. Later white , red or black spots appear on different parts of the skin. The hands and feet become swollen and the palms of the hands and feet become cracked. Eventually the kidneys , liver and lungs become enlarged and become tumors. Hands and feet get sore and rot. Cancers of the skin , bladder, and lungs can lead to kidney and liver failure. There may be abdominal pain , headache , vomiting of blood and jaundice. Arsenic-infected patients should drink arsenic-free water. In case of drinking water from rivers , ponds , beels etc. , it can be purified by boiling and boiling for 20 minutes. Rainwater can be collected and drunk during the rainy season. There are no restrictions on the diet of arsenic-infected patients. However, you should eat more vegetables , fruits and nutritious food. As soon as the initial symptoms of arsenic disease appear, the necessary treatment should be taken immediately by seeing a doctor or local health worker. Before installing tubewells to prevent arsenic contamination, the level of arsenic in the ground water must be checked. Arsenic levels in old tube well water and arsenic levels in nearby tubewells should also be tested. Once the tubewell has been installed , the arsenic test should be done again before starting the tubewell. If the level of arsenic in the water of the tubewell is found to be higher than normal, the face of the tubewell should be painted red. And if you find less than usual, you have to color it green. Water from red painted tubewells cannot be used for drinking or cooking. Water containing arsenic cannot be boiled because boiling does not remove the arsenic but by drying the water the concentration of arsenic will increase. Arsenic-free tubewell water should be tested every 6 months to see if the water is arsenic-free. Check whether there is arsenic in the well water. Since rainwater is free of arsenic, it can be collected and used for food and cooking. Water from ponds , rivers or beels can be purified and drunk. In this case , it can be purified by mixing half a teaspoon or 10 mg of alum in 20 liters of water or boiling for 20 minutes. If alum is left for 2 to 3 hours then dirty water mixed with alum will accumulate under the jug. Method of collecting rain water In this method rain water is stored. Complete arsenic-free and safe water is available through rainwater harvesting. The rainwater collected in this method can be used for drinking and cooking. The following is a description of the rainwater harvesting method: First, a large covered pitcher or tank should be prepared next to the house to retain the rainwater. The rest of the rice tin in the tin house needs to be drained. The tank will be connected to this drain. When it rains, the water will flow down the drain and into the water tank. In the case of straw , chaff and golpata houses , the rice should be covered with triple. Then , in the same way, make a drain through which the rain water will flow into the tank. The triple should be tied to the rice and poles of the house in such a way that water collects in the triple. Then , make a hole in the triple through which the water will flow into the tank. Collection in water tank should start 5 minutes after the onset of rain. The tank needs to be thoroughly cleaned 2 to 3 times a year.