Unregulated mining releases harmful substances into the soil, air and water. Governments are supposed to enforce regulations on companies to reduce the damage from mining-related sources to make mining more sustainable. However, can mining be sustainable? You can look at that post here. Now, I am going to focus on what the environmental damages mining cause.

Of all the ways of mining that are practiced, the most common and the most environmental harmful is the 'open pit mining' (the material is excavated from an open pit). It is particularly damaging because the materials extracted are only available in small concentrations, which increases the amount of ore needed to be mined. Also, in the process, when rocks are crushed, they expose radioactive elements from the liquids used for Separation, can leak into bedrock if not properly contained.

Underground mining, like open pit mining, also involves large-scale movements of rock and Vegetation. Here, Mercury is used to facilitate the recovery of some precious ores. Mercury's improper disposal can lead to contamination of the atmosphere and neighboring bodies of water.

ISL (In Situ Leach) mining has advantages compared to other conventional mining methods. Ir produces a minimal surface disturbance, no waste rocks or tailings and a lower consumption of water is needed. However, the fluids remaining after the leaching process commonly contains high concentrations of metals and radioactive isotopes, posing a great risk to nearby ground and surface water.

Overall, mining has a negative environmental impact for the following reasons:

• The use of heavy metals, which are very harmful for the atmosphere, water and land.
• The Carbon Output generated through mining is the leading cause to the accelerated global warming.
• Land erosion and deforestation leading to the desintegration of biomes. Mining is an invasive process that can cause damage to a landscape much larger that the mine itself, and it can continue even years after the mine has shut down. In Addition to the greenhouse gasses, it includes the death of flora and Fauna, contributing to a loss of biodiversity.
• Water is demanded in mining for: extraction, processing and waste disposal. Wastewaters can pollute water sources nearby and deplete water supplies in the area.

It is a fact that, right now, we cannot live without mining. But it is important to understand what it involves, what is the impact on the environment and think how this environment relates to us. Would you allow a mine to be built in the proximities of your home?

Sources:

http://web.mit.edu/12.000/www/m2016/finalwebsite/problems/mining.html

https://www.elaw.org/files/mining-eia-guidebook/Chapter1.pdf

https://www.environment.co.za/mining-2/effects-of-mining.html

The environmental disaster that has followed the collapse of the dam has caused unprecedent damage in the country and will have irreversible negative effects on the Environment at a bigger scale.

Tonnes of mud made up of iron ore waste and silica, originally estimated to be about 25,000 Olympic Swimming pools in volume, have spread over 800km and reached one of the largest Brazilian rives, the Rio Doce. It is now called by some experts "the dead river".

The contaminated mud, in which the Minas Gerais Institute of Water Management has found toxic substances like Mercury, arsenic, chromioum and manganese at considerably high Levels, has reached the coast of the estate Espírito Santo and it could potentially Impact the wider marine ecosystem. These toxic substances are very likely to end up in the food chain and they could also reach toxic Levels in some organisms.

Changes in the flow of the river in respect to the currents and the new geochemical conditions in the sediments will bring extremely important ecosystem changes, which will also influence the species, leading to a considerable loss of biodiversity. "The biodiversity of the river is completely lost", say experts.

The entire ecosystem is under threat and the Impacts can reach the marine Food chain, possibly affecting the Abrolhos coral reefs, which are really sensitive to sedimentation of inorganic material and could lead to its destruction.

It is impossible to estimate the real Impact of such disaster. Despite some species recoveries are expected through restoration, we cannot calculate now how Long this process will take and how many species will be able to restore.

Sources:

https://www.greenpeace.org/international/en/news/Blogs/makingwaves/Minas-gerais-mining-dam-collapse-mud-flood-rio-doce/blog/54787/

https://www.chemistryworld.com/news/brazilian-mine-disaster-releases-dangerous-metals/9174.article