Maura Adshead: Nearly half the world’s population eat food cooked indoors on stoves fuelled by wood, coal or animal dung. The World Health Organization estimates that solid-fuel stoves contribute to about 4.3 million deaths a year. In addition to tuberculosis, chronic bronchitis and lung cancer, solid fuel stoves also contribute to air pollution and climate change. It estimated that 40 per cent of India’s air pollution comes from domestic fuel burning.