A hospital department in the UK was shut down when mercury vapour levels exceeded an occupational exposure standard for mercury vapour of 0.025 mg/m3. (This is the suggested level that workers should be subjected to for health and safety reasons over an 8 hour period) I recently had mercury vapour levels tested in my mouth and they were 5 times higher than this and I breath it in 24 hours a day, 7 days a week, 365 days a year. I continue to be shocked.