Study leader Kirk Smith of the University of California, Berkeley, and Linda Birnbaum, director of the National Institute of Environmental Health Sciences, said childhood deaths from pneumonia are relatively uncommon in the United States. However, it kills almost 1.6 million children worldwide -- more than any other disease --- and open fires used for heating and cooking are thought to be a major cause, the researchers said.
The study included a total of 534 households in rural Guatemala with a pregnant woman or young infant.
The study participants were randomly assigned to receive a locally developed cook stove with a chimney or to continue cooking using traditional open wood fires in the home.
Trained field workers visited the homes every week for two years to record the children's health status.
The study, published in The Lancet, found although the study did not significantly reduce the total number of diagnosed childhood pneumonia cases, the reduction in severe pneumonia would likely result in reduced childhood mortality.
In the homes equipped with chimneys, carbon monoxide exposure levels were reduced 50 percent on average, and in these homes the rate of severe pneumonia was reduced by 30 percent in children age 18 months and younger, the study said.