A review in New Scientist for October 23 describes the measurement of radiation levels in seven ancient monuments, with the discovery in three of them of radon in potentially hazardous concentrations. The highest radon level detected, inside the Sakhur Khat pyramid at Saqqara, was 5,809 becquerels per cubic metre. In the nearby Abbis tunnels the concentration reached 1,202 becquerels per cubic metre, and in the Serapeum tomb 816 becquerels per cubic metre.
It is reasonable to expect that radon resulting from uranium decay should be associated with the granite and other rocks utilised in the ancient monument of Egypt. In homes in the United Kingdom the detection of radon in concentrations exceeding 200 becquerels per cubic metre is taken as an indication that special ventilation is called for.
Of course, living inside an Egyptian tomb was never part of the social pattern, but it has been recommended that the ventilation of the temples and tombs should be improved for the protection of visitors and guides. At present guides spend roughly four hours daily inside the monuments, but if their working hours were increased for any reason to double this limit the international safety limit of exposure, 20 millisieverts per annum, would be exceeded. The casual visitor is not at any risk.
It is intriguing to think that, when the tombs were first entered after being sealed for many centuries, there may have been extremely high concentrations of radon present. Some of the early Egyptologists must have encountered these. To associate radon with the traditional curse of the Pharaohs on those who moved their bones would be fantastic in the extreme. The occurrence of the death of the Earl of Carnarvon in 1923, the year after he, with Howard Carter, had explored the tomb of Tutankhamen, was popularly attributed to the celebrated curse of the Pharaoh. But Carter, who did most of the exploration, lived until 1939, and Carnarvon died of pneumonia following severe mosquito bites.
And in the field of archaeological superstition, it is difficult to find any connection with radon of the other cerebrated curse associated with mummy case No 22,542 in the British Museum, belonging to a priestess of Amun, the successive possessors of which unaccountably fell down steps and broke limbs, or otherwise suffered misfortunes. Although the mummy case dates from 1000BC, it is unlikely to have contained radon.
But the Valley of the Kings is an uncanny place at the best of times, radon or no radon.