Mazyr, city in southeastern Belarus, in Homyel' Oblast. Mazyr is located on the Pripyat' River about 210 km (about 130 mi) east of Pinsk and about 100 km (about 60 mi) northwest of Chernobyl'. Mazyr is an important river port and is situated on major north-south railroad and highway routes. It has industries in machine building, metalworking, oil refining, clothes making, and food processing. Significant salt deposits located here are worked. The city also is the site of one of the country's largest oil refineries, with a capacity of 18 million metric tons per year. The Friendship Pipeline carrying crude oil from Russia splits in two at Mazyr, one pipeline continuing into Poland and the other into Ukraine. Educational institutions in Mazyr include a teacher-training institute and a medical school.
Mazyr was founded in about the 12th century and has been a center of trade since the 18th century. In 1986 the city was in the path of the heaviest fallout from the nuclear reactor disaster at the Chernobyl' power plant. The peaty soils near Mazyr are particularly vulnerable to absorption of the radioactive iodine and cesium nuclides that are associated with the greatest health risks, posing an ongoing concern for the local population and food processing industries. Mazyr was a base for strategic nuclear missiles that were installed here as part of the weapons buildup of the Union of Soviet Socialist Republics (USSR) during the Cold War. The last of the nuclear weapons Belarus inherited when the USSR collapsed in 1991 were removed in late 1996 under the terms of the Strategic Arms Reduction Treaty (START) that became fully effective in 1994 as the START I Treaty (Strategic Arms Limitation Talks). Population (1996 estimate) 107,729.