These solid fuels may be the least costly fuels available.
Indoor smoke from household use of solid fuels.
Some solid fuels, such as wood and coal, are chiefly composed of carbon, hydrogen and oxygen .
Cooking and heating with such solid fuels on open fires or stoves without chimneys leads to indoor air pollution.
Around 3 billion people still cook and heat their homes using solid fuels in open fires and leaky stoves.
Women and girls in rural villages lose time and energy walking around collecting dirty solid fuels, ranging from crop waste to cow dung (better used as fertiliser).
