Tokyo's tap water has been deemed 'unfit for babies' after radiation from the stricken Japanese nuclear power plant contaminated the Japanese water supply, officials have warned. The warning comes after it emerged last night that radioactive particles have reached Europe and are heading towards Britain in the wake the catastrophe that officials say could cost up to £190billion - making it the costliest natural disaster in history. And fresh safety concerns arose today as black smoke was spotted emerging from Unit 3 of the plant, prompting a temporary evacuation of all workers from the complex, operators Tokyo Electric Power company said. Tokyo Water Bureau officials said levels of radioactive iodine in some city tap water contained 210 becquerels per litre of iodine 131 - two times the recommended limit for infants. They warned parents not to give babies tap water, although they said it is not an immediate health risk for adults. Nearly two weeks after the twin March 11 disasters, nuclear officials were still struggling to stabilise the damaged and overheated Fukushima Dai-Ichi plant, which has been leaking radiation since the disasters knocked out the plant's cooling systems. (Daily Mail)