If you add the valences of each atom in the molecular formula for arsenious acid, H 3 AsO 3, you can see that the molecule, which is uncharged, has a total valence state of 0 (3x(+1) for the hydrogen atoms; 1x(+3) for the arsenic(III) atom; 3x(-2) for the oxygen atoms = 3+3-6 = 0).
Eighty percent of sewage in India is untreated and flows directly into the nation's rivers, polluting the main sources of drinking water, a study by an environment watchdog showed Tuesday.
If it comes from many sources, it is called nonpoint-source pollution. Most types of water pollution only affect the immediate area but sometimes the pollution can travel hundreds or thousands of miles and then it is called transboundary pollution.his type of pollution is becoming more and more relevant because it affects our drinking water and the aquifers below the soil. Groundwater pollution is usually caused by highly toxic chemicals and pesticides from farming that leak through the ground to contaminate the wells and aquifers below the surface.