|
What is manganese?
Manganese is a naturally occurring metal that is found in many types of rocks. Pure manganese is silver-colored, but does not occur naturally. It combines with other substances such as oxygen, sulfur, or chlorine. Manganese can also be combined with carbon to make organic manganese compounds. Common organic manganese compounds include pesticides, such as maneb or mancozeb, and methylcyclopentadienyl manganese tricarbonyl (MMT), a fuel additive in some gasolines.
Manganese is an essential trace element and is necessary for good health. Manganese can be found in several food items, including grains and cereals, and is found in high amounts in other foods, such as tea.
--------------------------------------------------------------------------------
What happens to manganese when it enters the environment?
Manganese can enter the air from iron, steel, and power plants, coke ovens, and from dust from mining operations.
It can enter the water and soil from natural deposits, disposal of wastes, or deposits from airborne sources.
Manganese exists naturally in rivers, lakes, and underground water.
Plants in the water can take up some of the manganese from water and concentrate it.
--------------------------------------------------------------------------------
How might I be exposed to manganese?
Everyone is exposed to small amounts of manganese in air, water, and food.
Individuals who work in occupations that mine or use manganese are likely to be exposed to excess levels in their work environment.
People who improperly use pesticides such as maneb and mancozeb, may be exposed to excess levels.
--------------------------------------------------------------------------------
How can manganese affect my health?
Some individuals exposed to very high levels of manganese for long periods of time in their work developed mental and emotional disturbances and slow and clumsy body movements. This combination of symptoms is a disease called "manganism." Workers usually do not develop symptoms of manganism unless they have been exposed to manganese for many months or years. Manganism occurs because too much manganese injures a part of the brain that helps control body movements.
Exposure to high levels of airborne manganese, such as in a manganese foundry or battery plant, can affect motor skills such as holding one's hand steady, performing fast hand movements, and maintaining balance. Exposure to high levels of the metal may also cause respiratory problems and sexual dysfunction.
--------------------------------------------------------------------------------
How likely is manganese to cause cancer?
There are no human cancer data available for manganese. Exposure to high levels of manganese in food resulted in a slightly increased incidence of pancreatic tumors in male rats and thyroid tumors in male and female mice.
The EPA has determined that manganese is not classifiable as to human carcinogenicity.
--------------------------------------------------------------------------------
How does manganese affect children?
Daily intake of small amounts of manganese is needed for growth and good health in children. Manganese is constantly present in the mother and is available to the developing fetus during pregnancy. Manganese is also transferred from a nursing mother to her infant in breast milk at levels that are appropriate for proper development.
Children, as well as adults, who lose the ability to remove excess manganese from their bodies develop nervous system problems. Because at certain ages children take in more than adults, there is concern that children may be more susceptible to the toxic effects of excess manganese.
Animal studies indicate that exposure to high levels of manganese can cause birth defects in the unborn. There is no information on whether mothers exposed to excess levels of manganese can transfer the excess to their developing fetus during pregnancy or to their nursing infant in breast milk.
--------------------------------------------------------------------------------
How can families reduce the risk of exposure to manganese?
In most situations, there is no need to reduce one's exposure to manganese because it is an essential nutrient for good health.
Excess levels of manganese may be present in soils, especially at or near hazardous waste sites. Therefore, it is important to discourage hand-to-mouth activity in young children, especially near hazardous waste sites or in areas that may have increased manganese levels in the soil.
Manganese is also present in pesticides that may be used around the home. These pesticides should be used in a manner consistent with manufacturer's instructions.
--------------------------------------------------------------------------------
Is there a medical test to show whether I've been exposed to manganese?
Tests are available that show levels of manganese in different body fluids. Measurements of manganese in blood, urine, feces, and scalp hair can be used to determine exposure to excess levels of manganese by testing whether levels of the metal in your body tissues are greater than normal. However, these tests cannot predict how the levels in your tissues will affect your health. Your doctor can take samples and send them to a testing laboratory.
--------------------------------------------------------------------------------
Has the federal government made recommendations to protect human health?
The EPA has set a non-enforceable guideline for the level of manganese in drinking water at 0.05 milligrams per liter (0.05 mg/L).
The Occupational Safety and Health Administration (OSHA) has set a limit of 5 milligrams manganese per cubic meter (5 mg/m³) of workplace air for the average amount of manganese during an 8-hour workday, 40-hour workweek.
The National Research Council has recommended safe and adequate daily intake levels for manganese that range from 0.3 to 1 mg/day for children up to 1 year, 1 to 2 mg/day for children up to age 10, and 2 to 5 mg/day for children 10 and older.
------------------------------------------------------- | 
