|Basic Concepts in Environment, Agriculture and Natural Resources Management: An Information Kit (IIRR, 1993, 151 p.)|
Mining operations: environmental effects on soil, water, communities and atmosphere
Mineral Resource - Nonrenewable chemical element or compound in solid form that is used by humans. Mineral resources are classified as metallic (such as iron and tin) or nonmetallic (such as fossil fuels, sand and salt).
Philippine mineral resources include gold, copper, silver, molybdenum, chromite, iron, lead, zinc, pyrite, ore, coal, sulfur, uranium, etc. They are used in the automobile, housing and other heavy industries. It is one of the country's dollar-earning industry.
Most of the mineral resources are located in mountainous areas, near river systems that support lowland communities and coastal areas. The most common type of mining operation used in the country is the open-pit mining. Extraction of gold, copper and ore, among others
MINING OPERATIONS: ENVIRONMENTAL EFFECTS ON LAND/SOIL, WATER, COMMUNITIES AND ATMOSPHERE
Effects on land/soil
· Mining operations necessitate the removal of green vegetation and the dumping of waste soil. Left alone, mountains will lose their natural barriers against heavy rains with cascading flood waters eroding the top soil, making the surrounding lands ill-suited for crops and trees, rendering them unproductive and lowlands will be vulnerable to flash floods.
· Large areas may be destroyed to massive excavations and removal of large volume of rocks and soil materials. Huge pits will be formed, destroying the aesthetic value of the landscape.
· Occurrences of landslides and mudflows due to the weakening of rocks, accumulation of sand and other debris in mine dams or in natural depressions may lead to great loss of life and property.
Effects on water resources
· Intensive drainage or use of surface and groundwater may cause the drying of streams or the groundwater discharge in springs or outlets of underground rivers.
· Many mineral deposits commonly contain pyrites and other sulphuric-bearing minerals which decompose in water and produce acid water.
· Small-scale gold mining operations have been responsible for mercury pollution in rivers, lakes and seas.
· Heat pollution results when hot waters are drawn to the surface, as in geothermal waters, and are then discharged into surrounding water bodies without initial cooling.
Effects on the communities
· Dumping of tailings has affected lowland populations living downstream. Mine tailings fill streams or river systems and riverbanks are periodically eroded and inundated. Settlements in relatively lowerelevations are subject to frequent flooding, large tracts of farm lands are inundated by mine tailings during typhoons or heavy rains. Tailings are devoid of Nitrogen, Potassium and Phosphorous -- soil elements necessary for normal plant growth and development. Mine tailings contain toxic substances directly inimical to sea life and indirectly to humans.
· Mine tailings caused the filling of certain bays and have been responsible for the siltation and consequent death of some coral reefs, adversely affecting the fish catch of fisherfolk.
· The accumulation of waste rocks and tailing occupies large areas formerly used for agriculture and forestry, purposes.
· Mining expansion and pollution have dislocated many people from their farms, forcing them to migrate to other areas.
Effects on air
· Pollution of the air occurs during mining, smelting and refining. Pollution takes the form of dust or total suspended particulates (TSP), carbon monoxide (CO), sulfur dioxide (SO2), nitrogen oxides (NOx) and hydrocarbons (HC). Toxic emissions cover large areas affecting the health of people.
· Acid rain results from the interaction between sulphur dioxide emissions from smelters fed with sulphides of copper, lead, zinc and other metals and rainwater. This type of pollution is responsible for the destruction of some crops and forests, the pollution of lakes and negative effect on the health of people.