Problems of the water pollution are varied. However, the main problem in mission field is parasites. Parasites are small bacteria in the water that may harm people. In poor counties, people drink unpurified water from ground, rivers, and well that may contain parasites. Therefore, they are very vulnerable of getting to get diseases and in extreme case, parasites cause death to many of young children, and even adults. Diseases that people can get from parasites are Amoebiasism, lyme disease, malaria and more.