Mumbai is one of the most cosmopolitan cities in India with over 50% of its population of non-Maharashtrian ethnicity. There are many large ethnic groups represented such as Gujaratis (in Ghatkopar, Mulund, Borivali, and Kandivali) South Indians (Tamils and Malayalis in Chembur, Marol etc.), Parsis & Sindhis in South-Bombay (south of Dadar), and large communities from UP, Bihar and Punjab scattered around. A large number of people who work as vegetable vendors and shoe-polishers (and other small tradesmen) are migrant labourers from UP and Bihar. Because of a perceived sidelining of Marathi in this large mixture of peoples and cultures, some Maharashtrians (including the elite) emphasize that Marathi should be given due importance, Mumbai being a part of Maharashtra.
Slum population
According to the results of Census of India , 2001, 5,823,510 people lived in the slums of Mumbai or 48.88% of the population of Mumbai. This is by far the largest slum population in any city of India. 72.48% of this slum population was literate. Also, Mumbai, Delhi and Kolkata are the only 3 cities in India where over 1 million people live in slums.
AIDS
With 4.7% of AIDS cases in India from Mumbai, Mumbai is subject to 160% more AIDS than the average prevalence in India.