Pneumonia, diarrhea and malaria are leading killers of young children in low- income settings, accounting for a quarter of child deaths. These and other diseases are associated with environmental risks at the household level: unsafe water, poor sanitation and hygiene, cooking with solid biomass, and disease vectors. In this course, we will explore these risks, the sources of exposure and the associated disease burden. We will also critically examine the principal disease control strategies and evidence of their effectiveness. Throughout the course, we will consider the impact of climate change and the justice issues presented by a disease burden existing only in low-resource settings.