Urban water disinfection and mortality decline in lower-income countries

Historically, improvements in municipal water quality led to substantial mortality decline in today’s wealthy countries. However, water disinfection has not consistently produced large benefits in lower-income countries. We study this issue by analyzing a large-scale municipal water disinfection program in Mexico that increased water chlorination coverage in urban areas from 58% to over 90% within 18 months. We estimate that the program reduced childhood diarrheal disease mortality rates by 45 to 67%. However, inadequate sanitation infrastructure and age (degradation) of water pipes may have attenuated these benefits substantially