Air pollution is a significant problem in Bor area, due to work of large copper mining and smelting complex, and Pančevo where oil and petrochemical industry is based. Some cities suffer from water supply problems, due to mismanagement and low investments in the past, as well as water pollution (like the pollution of the Ibar River from the Trepča zinc-lead combinate, affecting the city of Kraljevo, or the presence of natural arsenic in underground waters in Zrenjanin).