Manganese: biological informationManganese compounds are essential to life. They are essential for the action of some enzymes. Soil deficiencies lead to infertility in mammals and to bone malformation in growing chicks. Levels in humans|Human abundance by weight||200 ppb by weight||Human abundance by atoms||23 atoms relative to C = 1000000|How much manganese is in your body? Find out here. You can use this form to calculate how much manganese your body contains. Enter your weight in either kilograms or pounds and click the "Calculate" button. You must enter a number, not text! Elements for which there are no data will always give a value of zero for the weight, no matter what you put in the weight box. Hazards and RisksHazards and risks associated with manganese: manganese metal powder is a fire hazard. Unless known otherwise, all manganese compounds should be regarded as highly toxic as well as possibly carcinogenic and teratogenic.