 As a result of all this industrialisation the city's inner suburbs became increasingly polluted and were gradually given over to large, unsightly industrial enterprises.At the same time the extensive development of the city's left bank and western suburbs as new residential areas began.The low-rise tenant houses of the Khrushchev era (Khrushchyovkas) gave way to the construction of high-rise prefabricated apartment blocks (similar to German Plattenbaus).