During the Vietnam war, massive bombing raids and defoliation campaigns caused severe destruction of the natural foliage, especially in the Central Highlands in the south. In addition, dioxin, a toxic residue of the herbicide known as Agent Orange, had leached into water supplies. Over 50% of the nation's forests have been eliminated. UN sources estimate that Vietnam loses 160,000 to 200,000 hectares of forest land annually. The nation has 366 cu km of renewable water resources with 86% used for farming activity and 10% used for industrial purposes. As of 2000, only 72% of the rural population had access to safe drinking water. Salinization and alkalinization are a threat to the quality of the soil, as are excessive use of pesticides and fertilizers.
Environmental damage has also been caused by the slash-and-burn agriculture practiced by nomadic tribal peoples in the Central Highlands and in the mountainous regions in the north. The government is engaged in a program to introduce modern farming practices to these populations.
In 2001, 38 of Vietnam's mammal species and 47 bird species were endangered. About 297 types of plants are also endangered. Endangered species include the tiger, elephant, Sumatran rhinoceros, Thailand brow-antlered deer, kouprey, river terrapin, Siamese crocodile (probably extinct), estuarine crocodile, Javan rhinoceros, and the pileated, crowned, and caped gibbons. The Vietnam warty pig has become extinct.