þungmálmar

Þungmálmar is an Icelandic term that translates to "heavy metals." In a scientific context, it refers to a group of metallic elements with relatively high atomic weights and densities. These elements are often toxic or poisonous, even at low concentrations. Common examples of heavy metals include lead, mercury, cadmium, chromium, and arsenic, although arsenic is technically a metalloid.

Heavy metals occur naturally in the Earth's crust. However, human activities such as mining, industrial processes, burning fossil fuels, and improper waste disposal have significantly increased their presence in the environment. This can lead to contamination of soil, water, and air.

Once released into the environment, heavy metals can persist for a long time. They can accumulate in living organisms, a process known as bioaccumulation. As these organisms are consumed by others higher up the food chain, the concentration of heavy metals can increase, leading to biomagnification.

Exposure to heavy metals can have serious adverse health effects on humans and wildlife. The specific effects depend on the type of metal, the dose, and the duration of exposure. Symptoms can range from neurological damage and developmental problems to organ failure and cancer. Due to their persistence and toxicity, the management and reduction of heavy metal pollution are important environmental and public health concerns.