Birthweight and environment at Tari.

The weights at birth of 4767 children born in the Tari area between 1979 and 1986 were analyzed after the children had been allocated to seven environmental zones. The environments differ in the quality of land from which the staple food, sweet potato (Ipomoea batatas), is produced. Mean birthweight varies significantly by environment. Women do much of the day-to-day agricultural work. It is argued that women living in the poorer quality environments produce less food, suffer chronic malnourishment and have lighter babies as a result. From time to time, however, El Niño-Southern Oscillation (ENSO) events can result in sharp and severe shortages in food in both favoured and poorer environments. The cause is complex and involves rainfall and women's work rates. These food shortages cause decreases in mean birthweight of up to 285 g for one or more years and an increase in the rate of low-weight births, even in the best environments. The implications for the long-term improvement of health are raised.