Picture of contaminated water from a mine.

Contaminated water from a mine.

Photo: Pontus Westrin, SGU.

Water, environment and human health

Mining operations can affect water during the discharge of water carrying metals from runoff or mineral processing. The impact of water discharges is regulated by law and can be controlled by well-planned waste management and effective supervision.

Mining activities give rise to the discharge of metals and other elements into water. Metals are elements that occur naturally in all bedrock, soil and water. Rocks are constantly eroded naturally through a process called weathering which result in metals being released into lakes and streams. However, when a given rock is fragmented after being mined out of the ground and processed, weathering can be faster as a larger surface area per mineral grain is exposed to air and water.

Because metals are individual elements, they do not break down and can stay in our environment or in our bodies for a long time. At sufficiently high concentrations, most elements have a negative impact on our health. Concentrations of elements that are toxic for humans depend on the type of elements and is often limited by threshold values recorded in regulations or published guidance. Iron, as an example, is rarely a problem, while even small concentrations of cadmium and uranium can be problematic. Exposure to certain metals can, for example, be carcinogenic, cause harm to the nervous system or affect kidney function.

Read more about metals and health on the Swedish National Food Agency's website (new window)

Mining activities are regulated according to conditions for discharges specified in the environmental permit. The weathering of tailings and other mining waste has an impact on nearby land and water; however this impact can be limited by well-planned waste management. The impact, and whether it can be considered harmful, is often assessed on the basis of environmental quality standards. Environmental quality standards are a legal instrument that explains how much the environment or humans can tolerate, including threshold values for different elements.

Read more about environmental quality standards for surface water on HaV - Swedish Agency for Marine and Water Management's website (new window)

Read more about metals and their different effects on our environment on the Swedish Environmental Protection Agency's website (new window)

Last reviewed 2022-06-17