Why the melting point of Mn is high


Health effects of manganese

Manganese is a very common substance that occurs almost everywhere. It is one of the three essential trace elements that are toxic in high concentrations. If people take in too little manganese every day, their state of health deteriorates, but if the daily intake is too high, health problems also arise.
Humans ingest manganese through foods such as spinach, tea and herbs. The foods that contain the highest levels of manganese are grains and rice, soybeans, eggs, nuts, olive oil, green beans and oysters. The ingested manganese is transported via the blood to the liver, kidneys, pancreas and endocrine glands.
Excessive manganese intake has negative effects on the respiratory tract and the brain in particular. Symptoms of manganese poisoning are hallucinations, forgetfulness and nerve damage, but Parkinson's, pulmonary embolism and bronchitis can also develop. In men, excessive manganese intake can lead to impotence. Typical symptoms are also schizophrenia, stupidity, muscle weakness, headaches and insomnia.

A lack of manganese manifests itself in the following symptoms:

- obesity
- Glucose intolerance
- blood clots
- skin problems
- Increased cholesterol level
- skeletal malformations
- freaks
- changes in hair color
- Effects on the nervous system

Environmental effects of manganese

Manganese compounds occur as solids in soil and water. In the air they appear as dust compounds that settle within a few days.
Burning fossil fuels increases the concentration of manganese in the air. Through human activity, manganese also finds its way into surface water, groundwater and wastewater, as well as into the soil when pesticides containing manganese are used.
Manganese plays a crucial role in the production of more than 36 enzymes that are important for carbohydrate, protein and fat metabolism. Animals that ingest too little manganese can show abnormal growth, bone deformities, and reproductive disorders. Some animal species tolerate very low doses of manganese and die if they are exceeded. Symptoms that show up in these animals are: lung, liver and vascular diseases, drop in blood pressure, developmental disorders in fetuses and brain damage.
Skin contact with manganese can cause tremors and incoordination. Animal experiments have shown that serious manganese poisoning also contributes to tumor formation.
Plants absorb manganese from the soil and transport it to their leaves. If the manganese supply is too low, it affects photosynthesis, i. H. in particular that the splitting of water into oxygen and hydrogen, for which manganese is very important, is disturbed. Manganese deficiency is generally more likely to be found in soils that have a low pH.
Extremely high manganese concentrations cause the cell walls to swell, the leaves to wither and brown spots to form on the leaves. However, these symptoms can also be caused by a lack of manganese. Overall, this means that there is only a relatively low tolerance range for the manganese concentration for each plant.

Manganese and water

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