What major issue does Mumbai face?

Mumbai faces significant challenges related to high levels of pollution, which stem from both industrial activities and the densely populated urban environment. The city is known for its rapid urbanization and the concentration of industries, which contribute to air, water, and soil pollution. The high vehicle density, as well as inadequate waste management practices, exacerbate the situation, leading to poor air quality that affects the health of the residents.

The pollution levels not only result in environmental degradation but also impact the quality of life of the urban population. This issue manifests in various ways, such as increased respiratory diseases, waterborne illnesses, and a general decline in living conditions, making it a critical concern for urban planners and policymakers.

In contrast, the other options do not represent major issues that Mumbai is currently facing. The city does not have extensive agricultural land due to its urban sprawl, urban population growth is typically high, and tourism is a significant sector despite challenges, making pollution the most pressing concern in this context.