Power Plays

PETER TURNLEY / CORBIS

Pollution from cooking fires is a major killer of African women and children

In his one-room house in ongata rongai, just outside nairobi, Juma Nyaudo sits on a stool, occasionally stirring the pot of kidney beans slowly bubbling on a small ceramic-lined stove. "I have asthma," he says, "and when I cook with charcoal I have to cough." Not any more. Nyaudo, 62, still cooks with briquettes: it's the only fuel he can afford on his salary of a few dollars a week, earned as a laborer in a stone quarry.

But he's not using ordinary charcoal. Instead, Nyaudo is burning Chardust briquettes, made by compressing the charcoal dust found heaped...