In this edition of In Business Peter Day hears some simple ideas about cleanliness which could change the fortunes of poor people around the world, hearing from three projects about the techniques of big business, marketing in particular, they are using to carry their messages. Val Curtis of the London School of Hygiene and Tropical Medicine in London says the single most cost effective intervention to save lives in developing countries is washing hands with soap - one million lives could be saved every year. She's working with producers to make soap available at prices, and sizes, suitable to the pockets of the poor. Linda Scott is a Professor of Marketing at Oxford who discovered millions of girls were missing school in Africa every month once they started having periods. She discovered that they were shunned by family and no longer supported once they were deemed to be women. Now she plans to change that, and economically empower more women, by introducing them to sanitary protection. And there's news of an on the ground initiative using a solid business principles to make sanitary pads made of bamboo available at half the price of imported versions in Rwanda and a solution to eye care in countries where opticians are rare. Producer: Richard Berenger.