Only a quarter - 24% - of school-age children drink the amount of water recommended by experts, with a fifth saying they never drink it, according to a new report. Health and nutrition experts are concerned about dehydration in children as they may risk such symptoms as headaches, lethargy and an inability to concentrate at school and at home.The comprehensive report, "Water: the source of life", was commissioned by Brita Water Filters and also covers water quality, health and beauty benefits of water, water costs and the environmental impact of bottled water.