01 / The world before
Waste disposal contaminated environments and water.
02 / The discovery
Sewer systems, treatment and microbiological monitoring reduced exposure.
03 / The people
Engineers, sanitation workers and public-health authorities.
04 / The obstacles
Many communities still lack safely managed sanitation.
05 / The world after
Infrastructure made prevention part of the built environment.
06 / Why it still matters
Maintenance and equitable access remain essential.