To reduce cases of cholera in countries where cholera is widespread, they have found a special and effective system: purifying water with old prizes. The traditional costumes used by women from India and Bangladesh have been at least four times folded and filtered by water have managed to clean the water. The results are evident: cholera cases have been halved.
Cholera is caused by a bacteria that lives in the water, the bacterium Vibrio cholerae, by which many die a year, especially among older people and children. The bacteria are small, so you should have no difficulty passing through the pores of the prize. But in the water there are also crustaceans called copepods, which are thousands of times larger than bacteria and to which the bacteria are attached. Therefore they cannot go through pores of the prize.
Due to the need for a minimum number of bacteria to capture the disease, it is not essential to eliminate all bacteria, so this method is so effective. In addition, the old awards are better than the new ones, since they are usually ready and, having smaller pores, they trap more bacteria.