Energy poverty is even more acute for the three billion people – almost half of the world’s population – who burn dung, cardboard, and twigs indoors to cook and keep warm. The WHO estimates that while outdoor air pollution in developing-country cities may be ten times higher than in advanced-country cities, average indoor air pollution, caused by burning wood and dung, is a hundred times higher.
能源匮乏对三十亿人——也就是几乎一半的世界人口——来说甚至更为严峻，他们在室内烧牲畜粪便，纸板和树枝来做饭和取暖。世界卫生组织估计，在发展中国家城市的室外空气污染可能比发达国家城市高十倍，而通过燃烧木材和粪便造成的平均室内空气污染会高出一百倍。事实上，室内空气污染每年造成350万人死亡，使其成为世界上最严重的环境问题。