"Cooking with energy from the sun -- a technique featured last month in an episode of "Top Chef" -- could soon put a major dent in what some experts call the world's greatest environmental health issue.
Every day, nearly half the people in the world prepare their meals over burning wood, charcoal or animal dung. And every year, more than 4 million people -- most of them women and children -- die prematurely from the resulting household smoke. The practice also contributes to deforestation and climate change.
"This is a big problem, bigger than outdoor air pollution or dirty water," said Kirk Smith, an expert in health and climate effects of household energy at the University of California, Berkeley, School of Public Health."