His research interests span areas of health policy, environmental policy, and environmental epidemiology, with a focus on the impact of air quality and climate change on health.

Previously, Bhargav set up and managed the Centre for Environmental Health at the Public Health Foundation of India (PHFI), where he led work on air quality, climate, and health. In this capacity, he served on Union and State government expert committees on air pollution, biomedical waste, and critically polluted areas. He has also carried out work on health systems and sustainable development across several states.