This document summarizes existing research on the informal sector and its relationship to the environment in Nigerian towns. It is known that the informal sector provides important employment opportunities for low-income individuals and absorbs migrants from rural areas. However, activities in the informal sector also generate waste and pollution that municipalities struggle to manage effectively. While studies have documented general environmental problems, there are few detailed case studies analyzing the specific environmental impacts of different informal sub-sectors. The document calls for more field research focusing on how particular informal activities affect the local environment in order to develop new policies that balance livelihoods and sustainability.