Portfolio 21 does not invest in metals and mining companies. By nature, the mining industry has enormous ecological impacts. Mining requires access to large volumes of water and generates large volumes of waste. Proper management of waste is often difficult, creating numerous liabilities in the form of spills and releases, surface water runoff, and contamination. Mining is also labor intensive and takes place in challenging environments, often in countries with varying safety standards, in areas that infringe on culturally significant land. Mining companies are also increasingly operating in politically unstable regions where risks of corruption are high. The ecological, social, and governance risks associated with this sector are perceived by Portfolio 21 to be excessively high.