The most significant environmental problems in the Congo are deforestation, increases in urban population, and the protection of its wildlife. The Congo's forests are endangered by fires set to clean the land for agricultural purposes. The forests are also used as a source of fuel. The most accessible forest, that of the Kouilou-Mayombé Mountains, has been overexploited. During 1981-85, deforestation in the Congo proceeded at a rate of 22,000 hectares (54,400 acres) a year. As of 2000, the Congo had nine protected areas, covering some 1.5 million hectares. The two largest, the 7,800-sq-km (3,000-sq-mi) Léfini Reserve and the 2,600-sq-km (1,000-sq-mi) Odzala National Park, were established during the French colonial era. The country has one Wetland of International Importance at the Lake Télé Reserve Altogether, 4.5% of the nation's natural areas were protected as of 2000.
The Congo's urban centers are hampered by air pollution from vehicles and water pollution from sewage. Its water purity problem is most apparent in rural areas where, as of 2000, only 51% of the people have safe drinking water.
Also as of 2000, ten of 200 species of mammals were endangered as were three of 449 species of birds. In addition, two reptile species and two plant types were threatened with extinction.