That is the forecast of the Housing Bureau, that disclosed a study on the matter.
CEM na Mídia

Study measures slum growing rate in counties and shows that in the last decade 464 erratic areas have emerged

City hall and CMS's research expands the concept of slum used in the 2000 IBGE census, that works with the so called "subnormal agglomeration."

A large part of municipal school education has a child per classroom number higher than the maximum allowed by the City Department of Education.