American Journal of Epidemiology, Vol 143, Issue 6 608-623, Copyright � 1996
by Oxford University Press Water, waste, and well-being: a multicountry study
SA Esrey United Nations Children's Fund (UNICEF), New York, NY 10017, USA.
Data collected in the late 1980s from eight countries in Sub-Saharan Africa

(Burundi, Ghana, Togo, and Uganda), Asia/North Africa (Sri Lanka and Morocco),

and the Americas (Bolivia and Guatemala) were combined and analyzed to test

whether incremental health effects regarding diarrhea and nutritional status

result from incremental improvements in water and sanitation conditions.

Rural (n = 11,992) and urban (n = 4,888) samples were analyzed separately.

Optimal (i.e., on the premises) and intermediate (improved public water)

water supplies were compared with unimproved water conditions. Optimal

(flush toilets or water-seal-latrines) and intermediate (latrines) sanitation

levels were compared with unimproved sanitation. Nationally representative

(random) samples of ever-married women age 15-49 years, with or without

children, were interviewed in all countries, and children aged 3-36 months

with available weight and height data were included in the analyses. Multiple

linear regression controlled for household, maternal, and child-level

variables; in addition, dummy variables were included for each country.

Improvements in sanitation resulted in less diarrhea and in taller and heavier

children with each of the three levels of water supply. Incremental benefits

in sanitation were associated with less diarrhea and with additional increases

in the weights and heights of children. The effects of improved sanitation

were greater among urban dwellers than among rural dwellers. Health benefits

from improved water were less pronounced than those for sanitation. Benefits

from improved water occurred only when sanitation was improved and only when

optimal water was present. These findings suggest that public health

intervention should balance epidemiologic data with the cost of services and

the demand for water. There should be efforts to develop compatible technologies

so that incremental improvements in service can be made.