1, alum is a traditional food additive, but alum contains aluminum ions, and alum is consumed by people, basically can not be discharged from the body, it will always be deposited in the body, so there are chronic toxic side effects. Its toxic side effects are mainly manifested in alum can kill brain cells, so that people early brain atrophy, dementia and other symptoms, affecting people's intelligence, the impact on life is not significant. At the same time, people in their daily lives if excessive consumption of aluminum will affect the absorption of iron, calcium, etc., leading to osteoporosis, anemia, affecting the development of nerve cells.

2, alum is a traditional water purification agent, has been widely used by people. But in recent years, alum has rarely been used as a purifying agent, mainly because the aluminum contained in alum is harmful to the human body. Long-term consumption of alum-purified water may cause senile dementia. Alum in the production of hair film as an adsorbent, should not be excessive, prolonged overuse, can lead to chronic poisoning.