Unions this week sent an urgent warning to schools, urging them to check whether they have warm air cabinet heaters that could contain asbestos. The warning from the Joint Union Asbestos Committee follows the discovery of asbestos in warm air cabinet heaters in Cwmcarn High School in Wales in October 2012, which led to the school's closure. When tests were carried out at the school by HSL, the Health and Safety Executive's laboratory arm, it found asbestos fibres were being released from the school's heaters into the classrooms. JUAC chair Julie Winn said: 'The Cwmcarn High School case clearly demonstrates the confusion around asbestos management and the poor management of it in many schools. Although three separate asbestos consultants reported the potential for asbestos fibre release in the school, as its heaters contained unsealed and damaged asbestos panels and asbestos debris, it has taken six months to reach an agreement to remove the dangerous asbestos so that the school can be safely reopened.' JUAC says more than 140 school teachers have died from the asbestos cancer mesothelioma in the past ten years. It adds that 'an unknown number of cleaners, administrative staff, caretakers, cooks and dinner time supervisors have also died. It is also unknown how many children have been killed by exposure to asbestos at school, but in the US it was estimated that for every one teacher who dies, nine former pupils will die in adulthood from their exposure as a child.'