The most toxic form of mercury is methylmercury.
Methylmercury is considered particularly dangerous due to its high absorbability and devastating effects on the body. While mercury exists in several forms, their toxicity is greatly influenced by how readily the human body can absorb and utilize them.
Understanding Methylmercury's Enhanced Toxicity
The primary factor contributing to methylmercury's extreme toxicity is its remarkable absorption rate once ingested. This makes it highly bioavailable, allowing it to rapidly enter the bloodstream and spread throughout the body.
Here's a comparison of how different forms of mercury are absorbed after ingestion:
- Methylmercury: If ingested, approximately 90% of methylmercury is absorbed into the bloodstream from the gastrointestinal tract. This high absorption efficiency means that nearly all ingested methylmercury enters the body's systems, including crossing the blood-brain barrier, leading to severe neurological damage.
- Other Ingested Mercury Forms: For some other ingested forms of mercury, such as certain inorganic compounds, only about 2–10% is absorbed from the gut. Their significantly lower absorption rate reduces their overall systemic toxicity when consumed.
- Elemental Mercury (Ingested): When elemental mercury is ingested, it is not absorbed at all from the gastrointestinal tract. While elemental mercury vapor is highly hazardous when inhaled, its ingestion poses minimal systemic risk because the body cannot take it in effectively.
This stark contrast in absorption efficiency underscores why methylmercury presents the most significant health risk. Once absorbed, methylmercury can accumulate in the body over time, leading to long-term health problems, especially impacting the central nervous system.
