It is very relevant. Heavy metals are metals with a specific gravity greater than 5 and a density greater than 4.5g/cm3, such as gold, silver, lead, mercury, cadmium, arsenic and chromium. Chromium can cause bronchial asthma and respiratory cancer. Cadmium poisoning is mainly Symptoms are nausea, vomiting, and diarrhea. The main effects of lead compounds on the human body are the nervous system, kidneys, and blood systems. It can also cause renal failure, affect intellectual development, etc. Arsenic poisoning can cause hair loss, pigmentation, and may also cause cancer. There is acute arsenic poisoning, arsenic trioxide, which is what everyone should know about arsenic poisoning. Mercury is the most harmful to the human body, causing nervous system disorders, liver failure, etc. In addition, many metal ions can also cause protein damage in the human body. Denaturation, such as barium ions, divalent copper ions, etc.