The water you drink may contain many toxic substances.
Fluoride
In soil and air and most water sources have fluoride, they are produced in the process of stone corrosion. Low-grade fluoride can prevent tooth decay by regenerating tooth enamel, so many water treatment plants have added it to drinking water supplies.
Pesticides
Pesticides and herbicides used in farming can be washed away into rivers and reservoirs, seeped into groundwater.
Arsenic
In natural environments, arsenic is present in rocks and soil. Organic arsenic is not toxic but inorganic arsenic can affect health at different levels and increase the risk of cancer in humans.
Currently, water treatment plants are capable of removing arsenic, but water quality needs to be checked periodically.
Lead
Water filtration systems and old metal pipes that are corroded can lead to lead poisoning of water, a dangerous neurotoxin.
This happened in Flint, Michigan, USA. President Obama had to declare a state of emergency when children drank lead-contaminated water, and exposure led to a loss of learning ability due to nerve damage.
The United States used to give a red alert to lead poisoning.
Algae
If you feel a fishy smell, unpleasant mold when drinking water, it is very likely that the drink contains algae.
Hydrogen Sulfide
Hydrogen Sulfide (H2S) smells like rotten eggs. When using Hydrogen Sulfide water, clothing may become dirty when washing and the pipes are corroded.
Copper
Copper is dissolved from the old pipes, if the water containing 1.3mg / l of copper will be green. Copper mainly appears in water at low concentrations and is safe for humans.
Salt
Salt is a common ingredient in water. Sodium sulfate or magnesium sulfate salt exists in water with a certain amount of laxative effect.
Antibiotic
There may be many antibiotics in the urine, such as amoxicillin and Zyrtec, when excreted by the flow of water to rivers, lakes and water supplies. This type of antibiotic only pollutes the water source at extremely low levels.