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.
Water used from a polluted lake directly contaminates its user. Many of the water creatures are on the verge of extinction due to the dramatic increase in the water pollution. Cause of Water Pollution. Just like air and soil pollution, water pollution is caused by the direct incorporation of hazardous pollutants.