Water Quality

Drinking water needs to be good quality
1. Essential for life, but must be free of poisonous salts(eg. phosphates and nitrates) and harmful micro-organisms - these can cause diseases such as cholera and dysentery
2. Most of our drinking water comes from reservoirs - flows into reservoirs from rivers and groundwater - water companies chose to build reservoirs where theres a good supply of clean water
  1. Government agencies keep a close eye on pollution in reservoirs, rivers and groundwater
3. To monitor water quality, water companies take samples of water - from the water entering the treatment works right through to the taps in consumers' houses
  1. Some people still aren't satisfied - buy filters that contain carbon or silver to remove substances from their tap water. Carbon in the filters removes the chlorine taste and silver is supposed to kill bugs. Can also buy water softeners
    1. Totally pure water with nothing dissolved in it can be produced by distillation - boiling water to make steam and condensing the steam
Adding Fluoride and chlorine to water has disadvantages
1. Fluorine is added to drinking water in some parts of the country - reduces tooth decay, chlorine prevents disease
  1. Some studies have linked adding chlorine to water with an increase in some cancers - chlorine can react with some natural substances and produce toxic by-products - some think these may cause cancer
2. In high doses fluoride can cause cancer and bone problems in humans - some think it shouldn't be added to drinking water - 'mass medicating' - choose whether to have fluoride toothpaste but not about tap water
3. Levels of chemicals added need to be carefully monitored as too much could be harmful

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	Creado por jadepalmer98 hace casi 11 años