GEOLOGY

Detailed explanation-1: -Fly ash is left behind when coal is burnt. Coal-fired power plants are the biggest sources of fly ash, which contains toxic chemicals such as arsenic, barium, cadmium, nickel and lead, among others. These are known to cause cancer, lung and heart ailments and neurological damage, and contribute to premature mortality.

Detailed explanation-2: -Hexavalent chromium in drinking water has been linked to certain stomach cancers. In December 2010, the Environmental Working Group released a report that found hexavalent chromium in the tap water of 31 of 35 U.S. cities tested.

Detailed explanation-3: -Some of the compounds found in coal ash can cause cancer after continued long-term ingestion and inhalation. When a natural disaster occurs, contamination from coal ash can affect drinking water systems. Public water systems monitor and control for these types of contaminants.

Detailed explanation-4: -Water is another key source of pollution. Water contaminated with high levels of arsenic is a cause of bladder cancer, and it’s also been associated with skin and lung cancers. Drinking water from private wells was found to be a source of arsenic, according to a study in the Journal of the National Cancer Institute.

Detailed explanation-5: -These include naturally-occurring substances, like arsenic, fertilizer by-products like nitrate, as well as disinfection byproducts (DBP), which are compounds formed when chlorine used to disinfect water comes into contact with organic material in water.