Rapid industrialization since World War II has caused widespread water and air pollution, particularly in Prahova County, an oilrefining region. The nation has 49 cu km of renewable water sources, with about 59% used to support farming and 33% used for industrial purposes. Romania's cities produce on average 3.0 million tons of solid waste per year. Air pollution is heaviest in the nation's cities, where industry produces hazardous levels of sulphur dioxide. In 1992, Romania had the world's 28th highest level of industrial carbon dioxide emissions, which totaled 122.1 million metric tons, a per capita level of 5.24 metric tons. In 1996, the total dropped to 119 million metric tons.
Damage to the nation's soils from erosion and pollution has decreased agricultural production by 50% in some areas. Acid rain originating in Hungary is another environmental problem. Some water conservation programs were initiated in the mid-1980s, but the Environmental Protection Law of 1972 has not been strictly enforced.
Romania's forests and natural steppelands have been encroached on by farmers. Radioactivity from the Chernobyl nuclear site, two floods, and two earthquakes have also contributed to the nation's environmental problems. Moreover, intensive exploitation of forests before, during, and immediately after World War II necessitated a reforestation program that, between 1950 and 1964, resulted in the replanting of 1,159,600 hectares (2,865,400 acres).
As of 2001, 4.6% of Romania's total land area is protected. Sixteen of Romania's mammal species, 11 of its bird species, and 34 plant types are endangered. The Romanian bullhead perch, Atlantic sturgeon, slender-billed curlew, and Mediterranean monk seals are among those listed as endangered.