Coastal waters are polluted from sewage outlets, especially in resort areas such as Koror. Industrial wastes are dumped into the Sava, which flows into the Danube. Air pollution is a problem around Belgrade and other industrial cities. Air pollution in the Belgrade area has fallen in recent years, from 605 to 132 micrograms per cu m between 1990 and 1995. Thermal energy plants utilize technology from the 1950s and mostly burn lignite; since combustion is inefficient, air pollution is a major problem in Kosovo. Destructive earthquakes are a natural hazard.
In 2001, Serbia and Montenegro had 104 protected areas, covering about 3.3% of the nation's total land area. There are four Wetlands of International Importance and one World Heritage Site. As of 2001, 12 mammal species, 8 bird species, and 50 plant species are threatened. The endangered list includes Atlantic sturgeon, slender-billed curlew, bald ibis, Danube salmon, and beluga.