1. lack of good quality drinking water: reasons-there are no installations that treat water to the drinking state. In Europe and developed countries, people drink water from taps and water columns. 2. Lack of good sewage treatment facilities. (Special containers, disinfecting sewage.) For all the microbes, viruses, all the dirt from the hospitals, from the factories, etc., flow into the sewerage system. Because of this, people who bathe in the water (within the city) are infected. 3. Discharges of oil products, sewage in the urban water area. Example: in summer the surface of the Golden Horn is covered with oil-oil film. 4. The presence of very old transport in large quantities in our city "Vladivostok", because of this, a large amount of carbon monoxide is released into the air. 5. Illegal cutting of trees in the city. Trees are our lungs, and the air is very dirty. And many more ...