What are the Health Problems with Manganese?

October 20, 2025 •

4 min read

While manganese is an essential mineral for proper bodily function, high levels of exposure are a significant health concern, particularly affecting the nervous system. In fact, the Tolerable Upper Intake Level (UL) for manganese in adults is 11 mg/day, with doses exceeding this potentially causing adverse health effects. This can lead to a range of severe health problems with manganese, including neurological damage and a condition known as manganism.

Quick Summary

Excessive manganese exposure, especially from inhalation or contaminated water, can cause neurotoxic effects resembling Parkinson's disease, along with reproductive and cognitive issues.

Key Points

Manganism is the main health problem: Chronic, high-level manganese exposure can cause a neurological disorder called manganism, which has symptoms similar to Parkinson's disease.
Neurological damage is a primary risk: The brain, specifically the basal ganglia, is the main target of manganese toxicity, leading to tremors, muscle rigidity, slowed movement, and cognitive deficits.
Inhalation is a major pathway: Workers such as welders, miners, and smelters face the highest risk of toxicity due to inhaling manganese dust and fumes, which bypass the body's normal filtering mechanisms.
Certain groups are more vulnerable: Individuals with liver disease, iron-deficiency anemia, infants, and those receiving total parenteral nutrition (TPN) are at a higher risk for manganese accumulation.
Toxicity affects multiple systems: Beyond neurological damage, overexposure can cause respiratory issues, reproductive problems (particularly in males), and further exacerbate liver dysfunction.
Symptoms of toxicity differ from deficiency: While deficiency is rare, toxicity presents with severe neurological symptoms, whereas deficiency involves milder issues like poor growth and altered metabolism.
Prevention is the best treatment: Avoiding sources of excessive exposure is the most effective way to prevent manganese toxicity, as many long-term neurological effects are not easily reversed.

The Dual Nature of Manganese: Essential Nutrient vs. Toxin

Manganese is a trace mineral crucial for numerous bodily functions, including bone formation, metabolism, and acting as an antioxidant. However, the line between beneficial and harmful levels is distinct, with a normal homeostatic balance maintained primarily by the liver and biliary excretion. Most people get sufficient manganese through their diet, which includes sources like grains, nuts, legumes, and tea. However, when this natural regulation is overwhelmed by excessive intake, especially through inhalation, the mineral can become a potent neurotoxin. This dual nature requires careful consideration, particularly for vulnerable populations and those with high exposure risks.

Key Exposure Routes and At-Risk Populations

Manganese toxicity is typically linked to a few key exposure pathways that bypass the body’s normal defense mechanisms. One of the most dangerous routes is inhalation, which is a major occupational hazard for industrial workers.

Common high-risk exposures include:

Occupational Inhalation: Welders, miners, and smelters are routinely exposed to manganese dust and fumes, which are more readily absorbed into the body and transported directly to the brain. Prolonged exposure can lead to severe neurological damage.
Contaminated Drinking Water: In areas where manganese is high in groundwater, contaminated well water can pose a significant health risk, particularly for infants whose systems are more sensitive.
Total Parenteral Nutrition (TPN): Patients receiving long-term TPN, where manganese is given intravenously, can accumulate toxic levels since this route bypasses the gut's regulatory processes.
Pre-existing Medical Conditions: Individuals with chronic liver disease have impaired biliary excretion of manganese, which causes the mineral to build up in the body and brain. People with iron-deficiency anemia may also absorb more manganese, increasing their risk.

The Neurological Impact: Manganism and Beyond

The most feared and well-documented health problem associated with chronic, high-level manganese exposure is manganism, a neurological disorder with symptoms that closely mirror Parkinson's disease. Manganese preferentially accumulates in the basal ganglia of the brain, affecting motor control and cognitive function. However, there are key differences, such as manganism’s typical lack of resting tremor and poor response to levodopa medication.

Symptoms of Manganism

Neurological and psychiatric symptoms can manifest in a few distinct stages:

Early Psychiatric Effects: Symptoms known as "manganese madness" can occur, including mood swings, irritability, anxiety, confusion, and hallucinations.
Progressive Motor Dysfunction: As exposure continues, motor symptoms develop, such as tremors, muscle rigidity, slowed movement (bradykinesia), and an unsteady gait. A distinctive "cock-walk" gait, where the patient walks on their toes, has been described.
Cognitive Impairment: Patients may experience memory loss, attention deficits, and reduced hand-eye coordination.

Beyond the Nervous System: Other Health Complications

The health problems with manganese are not limited to the brain. Overexposure can also damage other vital organ systems.

Reproductive Effects: High-level manganese exposure, particularly inhalation in occupational settings, has been linked to impaired fertility in men, including loss of libido and reduced sperm quality.
Respiratory Effects: The inhalation of manganese dust or fumes can cause irritation and inflammation of the lungs, potentially leading to a flu-like illness called "metal fume fever" or pneumonia.
Liver Damage: Because the liver is crucial for manganese excretion, chronic overexposure or pre-existing liver disease can lead to further hepatic dysfunction.

Comparison of Manganese Deficiency and Toxicity

While toxicity is the primary concern for adverse health effects, a lack of manganese is also problematic, though very rare due to its abundance in food sources.


Feature	Manganese Deficiency (Very Rare)	Manganese Toxicity (Overexposure)
Primary Cause	Insufficient dietary intake, malabsorption issues.	Inhalation (occupational), contaminated water, medical issues.
Neurological Effects	Mood changes, altered glucose tolerance.	Manganism (Parkinson-like symptoms), memory loss, psychiatric issues.
Growth and Development	Stunted growth, poor bone formation.	Impaired neurodevelopment in infants and children.
Reproductive Effects	Potential impact on fertility in both sexes.	Reduced libido, impaired sperm quality in men.
Metabolic Impact	Altered carbohydrate and lipid metabolism.	Oxidative stress and mitochondrial dysfunction.

Protecting Yourself from Manganese Overexposure

Mitigating the health problems with manganese is crucial, particularly for high-risk groups. The most effective strategy is to reduce or eliminate the source of exposure. This involves:

Occupational Safety: For workers like welders, ensuring proper ventilation, using personal protective equipment (respirators), and monitoring workplace air are essential.
Water Testing: If your drinking water comes from a private well, have it tested for manganese contamination. Water filtration systems can effectively reduce manganese levels.
Dietary Considerations: For most people, dietary intake is not a risk factor. However, those with liver disease or iron deficiency should monitor their intake in consultation with a doctor.
Medical Monitoring: Patients on TPN or with liver disease require careful monitoring of blood manganese levels to prevent accumulation.

For more detailed information on protective measures, consult a health and safety authority, such as the Centers for Disease Control and Prevention (CDC).

Conclusion

Manganese is a mineral with a delicate balance in the human body. While essential in small amounts, excess exposure—especially from inhalation or contaminated water—can lead to severe health problems, most notably the neurotoxic syndrome of manganism. Key risk factors include occupational exposure in industries like welding, living near contaminated water sources, and having underlying health conditions such as liver disease. Symptoms can range from psychiatric disturbances and cognitive deficits to severe motor dysfunction mimicking Parkinson's disease. Effective management focuses on preventing overexposure through environmental controls and medical monitoring for at-risk individuals, as the long-term effects of toxicity can be debilitating and often irreversible.

Frequently Asked Questions

Manganism is a neurological disease caused by chronic, excessive exposure to manganese, characterized by a progressive motor disorder that shares symptoms with Parkinson's disease, including tremors, stiffness, and gait abnormalities.

The most significant exposure comes from inhaling manganese fumes in occupational settings like welding or mining. Other sources include contaminated drinking water from wells, certain infant formulas, and long-term intravenous feeding (TPN).

People with chronic liver disease, individuals with iron-deficiency anemia, welders, miners, and infants are considered high-risk groups. Liver disease impairs the body's ability to excrete manganese, and iron deficiency can increase its absorption.

Early symptoms can include psychiatric effects like mood swings, irritability, and hallucinations, sometimes referred to as 'manganese madness.' These can be followed by subtle neurological signs like poor appetite and sleepiness.

While removing the source of exposure and using chelation therapy can help reduce manganese levels in the body, the neurological damage caused by long-term toxicity is often permanent and irreversible.

Yes, children, especially infants, are more susceptible to manganese toxicity. Studies suggest early exposure can impact neurodevelopment, affecting learning, behavior, memory, and motor skills.

For most healthy individuals, dietary manganese is well-regulated and does not pose a toxicity risk. The body's absorption control mechanisms are very effective when manganese is ingested through food.

If you have liver disease, your body's ability to excrete excess manganese is impaired. This can cause the mineral to accumulate in the brain and lead to a specific form of neurotoxicity, potentially leading to symptoms similar to manganism.

If you suspect manganese poisoning, particularly if you are in a high-risk group or have been exposed to a potential source, you should consult a doctor immediately. Treatment often involves eliminating the source of exposure and may include chelation therapy.