Mercury in the Human Body Why Avoiding Exposure Is Still So Important
Mercury is a heavy metal with well-known toxic potential. Although its use in dental applications especially in amalgam restorations was common for decades, modern science has raised increasing concerns about the systemic effects of mercury on the human body.
In this article, we explore why mercury exposure, even in small amounts, can pose a silent and ongoing risk to health.
What Is Mercury and How Does It Enter the Body?
In dentistry, metallic mercury is used in alloys known as dental amalgams, typically composed of 50% mercury and 50% silver, tin, copper, and other metals. Over time, these restorations can release mercury vapor the most volatile and easily absorbed form of the metal.
Inhaled mercury is rapidly absorbed through the lungs and enters the systemic circulation. It can cross the blood-brain barrier and accumulate in the brain, kidneys, and other vital tissues.
How Mercury Affects the Body
1° Central Nervous System and Cognition
The brain is one of the main targets of mercury toxicity. Chronic exposure is associated with:
- Mood changes and irritability;
- Short-term memory loss;
- Attention and concentration deficits;
- Insomnia and anxiety;
- Advanced cases: tremors and motor impairments.
A study published in the Journal of Neurotoxicology (2006) showed that even low but continuous exposure to metallic mercury can cause neurobehavioral changes in adults.
2° Immune System
Mercury is an immunotoxic agent. It can:
- Increase inflammatory cytokine production;
- Alter adaptive immune responses;
- Be linked to autoimmune diseases such as lupus and multiple sclerosis.
(Shoenfeld et al., Autoimmunity Reviews, 2008)
In predisposed individuals, exposure may act as a silent immune trigger.
3° Kidneys and Excretory System
Mercury is nephrotoxic. Once in the body, it tends to accumulate in the kidneys, impairing glomerular filtration and potentially causing:
- Proteinuria (protein in the urine);
- Tubular damage;
- Decreased glomerular filtration rate (GFR).
Chronic exposure may worsen pre-existing kidney conditions, especially in the elderly or those with metabolic comorbidities.
4° Endocrine System
Mercury interferes with hormonal function by binding to sulfhydryl groups, inhibiting enzymes and blocking hormone receptors. Studies suggest it can:
- Harm thyroid function;
- Be related to menstrual and fertility disorders;
- Disrupt the stress hormone axis (HPA axis).
5° Pregnancy and Fetal Development
Exposure to mercury during pregnancy is especially critical, as it crosses the placenta and may affect fetal neurological development. Reported effects include:
- Cognitive delays;
- Speech disorders;
- Poor motor coordination.
For this reason, institutions like the FDA and WHO recommend avoiding mercury completely in pregnant and breastfeeding women.
Why This Still Matters
Even though the use of dental mercury is declining, millions of people around the world still have amalgam restorations. Over time, these fillings may deteriorate and release vapors silently and continuously, maintaining a chronic, subclinical toxic load in the body.
That’s why the scientific community especially in biological dentistry advocates for a re-evaluation of mercury exposure for both patients and dental professionals.
A Systemic Health Decision
Avoiding or replacing mercury in dental procedures is not merely an aesthetic or environmental issue. It’s about reducing exposure to a proven toxic metal whose cumulative effects can impact various body systems silently, progressively, and often irreversibly affecting quality of life.
Contact the specialists at Clínica Débora Ayala to learn more about how to safely reduce exposure and protect your systemic health.
Scientific References Consulted
- Echeverria D, Aposhian HV, Woods JS, et al. Neurobehavioral effects from exposure to dental amalgam mercury.
https://pubmed.ncbi.nlm.nih.gov/1678210/ - Shoenfeld Y, Agmon-Levin N. ‘ASIA’ – autoimmune/inflammatory syndrome induced by adjuvants.
https://www.sciencedirect.com/science/article/abs/pii/S1568997208000081 - Guzzi G, Grandi M, Cattaneo C, et al. Dental amalgam and mercury levels in autopsy tissues.
https://pubmed.ncbi.nlm.nih.gov/16685322/ - Kobal AB, Horvat M, Drobne D, et al. Mercury-induced endocrine disruption in humans and animals.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4126471/
