Heavy Metal Toxicity

Excerpt

Heavy metals(HMs) are defined differently by different people. In health parlance, they are naturally occurring substances that accumulate and cause damage to the environment and living beings, including humans. They also include substances known as semimetals or metalloids that can have the same deleterious effects.

Humans are exposed to HMs through inhalation, ingestion, or contact with the skin. Environmental pollution with HMs can result in contamination of air, water, sewage, seawater, waterways, and can accumulate in plants, crops, seafood, and meat and indirectly affect humans. Some occupations have increased risk for particular HMs exposure and toxicity.

Some HMs can cause toxicity even at very low concentrations and are known as non-threshold HMs. Factors influencing the risk of toxicity include age, body weight, genetics, route of acquisition, duration of exposure, amount, health, nutritional status, and a combination of HMs. Some preparations used in complementary medicine can result in toxicity.

Symptoms and signs of heavy metal(HM) toxicity vary with the substance and can be due to acute exposure to large amounts, or chronic exposure to repeated small quantities which can result in cumulative toxicity. Many body systems can be affected. Toxic exposure to two or more HMs can lead to more damage than a single HM.

Investigations include tests of urine, blood, skin, nail, and hair. Management includes preventing any further exposure, removal of the offending agent using chelating agents, supportive therapy, and patient education.

Prevention or minimizing exposure is a must, and laws exist to this effect. Public health measures include monitoring air, water, foods, and at-risk individuals, and environmental manipulation of soil, water, and sewage.