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.
We use 50% of the Earthâs land area for food production and 50% of the Earthâs available fresh water for drinking. According to http://watersoftenerguide.com the main source of water pollution is not chemical waste but the excrement of farm animals. About 70% of the worldâs marine species are at risk of extinction.