Heavy Metal Toxicity

Excerpt

Heavy metals 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 heavy metals through inhalation, ingestion, or contact with the skin. Environmental pollution with heavy metals can result in contamination of air, water, sewage, seawater, and waterways and can accumulate in plants, crops, seafood, and meat and indirectly affect humans. Some occupations have an increased risk for particular heavy metals exposure and toxicity. Some heavy metals, known as non-threshold heavy metals, can cause toxicity even at very low concentrations. 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 heavy metals. Some preparations used in complementary medicine can result in toxicity.

Symptoms and signs of heavy metal 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 2 or more heavy metals can lead to more damage than a single heavy metal. Investigations include urine, blood, skin, nail, and hair tests. Management includes preventing any further exposure, removing the offending agent using chelating agents, supportive therapy, and patient education. Prevention or minimizing exposure is necessary, and laws exist to this effect. Public health measures include monitoring air, water, foods, and at-risk individuals, as well as environmental manipulation of soil, water, and sewage.