The Environmental Quality Act of 1974 and other environmental laws are administered by the Division of Environment of the Ministry of Science, Technology, and Environment. Discharge of untreated sewage has contaminated the nation's water; the most heavily polluted areas are along the west coast. Malaysia's water pollution problem also extends to its rivers, of which 40% are polluted. The nation has 580 cu km of water with 76% used for farming and 13% used for industrial activity. Malaysia's cities produce an average of 1.5 million tons of solid waste per year.
Clean-air legislation limiting industrial and automobile emissions, was adopted in 1978. However, air pollution from both of these sources is still a problem. In the mid-1990s, Malaysia ranked among 50 nations with the world's highest industrial carbon dioxide emissions, which totaled 70.5 million metric tons per year, a per capita level of 3.74 metric tons per year. Discharge of oil by vessels in Malaysian waters is prohibited.
Of Malaysia's total land area, 59% is tropical rainforest. Malaysia has the world's fifth most extensive mangrove area, which total over a half a million ha (over 1.2 million acres). The country's forests are threatened by commercial interests.
In 2001, 42 of the nation's mammal species and 34 bird species were endangered. Endangered species in Malaysia include the orangutan, tiger, Asian elephant, Malayan tapir, Sumatran rhinoceros, Singapore roundleaf horseshoe bat, four species of turtle (green sea, hawksbill, olive ridley, and leatherback), and two species of crocodile (false gavial and Siamese).