A new study has suggested that mobile phone radiation may be contributing to declines in bee populations in some areas of the world. Bee populations dropped 17% in the UK last year, according to the British Bee Association, and nearly 30% in the United States says the US Department of Agriculture. Parasitic mites called varroa, agricultural pesticides and the effects of climate change have all been implicated in what has been dubbed 'colony collapse disorder' (CCD). But researchers in India believe mobile phones could also be to blame for some of the losses. In a study at Panjab University in Chandigarh, northern India, researchers fitted mobile phones to a hive and powered them up for two 15-minute periods each day. After three months, they found the bees stopped producing honey, egg production by the queen bee halved, and the size of the hive dramatically reduced. It's not just the honey that will be lost if populations plummet further. Bees are estimated to pollinate 90 commercial crops worldwide. Their economic value in the UK is estimated to be $290 million per year and around $12 billion in the US.