ANGE ABOA and AARON ROSS THE use of child labour has risen in cocoa farms in Ghana and Ivory Coast over the past decade despite industry promises to reduce it, academics said, largely supporting earlier findings that were questioned by both states. The prevalence of children doing hazardous work, including using sharp tools, has also gone up in the world's top two cocoa producers, according to the study funded by the U.S. government. The levels were higher than in 2010 when companies including Mars, Hershey, Nestle and Cargill agreed to reduce the worst forms of child labour in Ghana and…