Scientists explore Egyptian mummy bones with X-rays and infrared light
Mummy’s bones are examined by lasers, x-rays and infrared technology which ‘ shine a light on ‘ daily life in ancient Egypt.
A collection of bone specimens from 2,000 to 4,000 years were tested using the Advanced Light Source at the California-based Berkeley Laboratories.
The bones are exposed to a range of wavelengths of clear light that can be used to investigate the composition, structure and other properties of the samples.
‘The bones are acting as an archive,’ said Mohamed Kasem from Cairo University who worked on the study.
The researchers made ‘very thin slices’ of femur bones as part of the study, which they hope will be able to show how people lived, their diet, health and daily lives.
A number of discoveries into the way the people of ancient Egypt lived are already being revealed thanks to the research – although a lot more time is needed to analyse the data, said Dr Kasem.
The team used a chemical-analysis technique, where a short laser pulse blasts away a small volume of material from a sample. The emitted light from the blast is then studied to determine what elements are present.
‘We have found a lead, aluminium, and other elements that give us an indication of the environment and the toxicity of that time. That information is stored right in the bones,’ Dr Kasem said.
For example, while the ancient Egyptians didn’t use aluminium in metal-working, researchers have found that they used potassium alum, a chemical compound containing aluminium, to reduce cloudiness in drinking water.
The team used X-rays to study how the collagen in the bones of the mummies compare to modern humans. When an X-ray is shined through the collagen the X-rays are scattered and the pattern of scattering they make can show researchers how healthy and well preserved the collagen is.
The collagen assemblies generally aren’t as well ordered in the ancient samples as in healthy modern bones, said Eric Schaible, a Berkley scientist.
The samples were brought over from Egypt by scientists from Cairo University and represent four different dynasties in Egypt: the Middle Kingdom, Second Intermediate Period, Late Period and Greco-Roman period. They have also examined soils taken from burial sites of the human remains.
‘So many factors affect preservation. One of them is how long the bone has been buried in soil and also the state of the bone and the different types of soil,’ said Dr Kasem.
Differences in embalming techniques could also affect the preservation of the bone and the chemistry they find in the X-ray studies. ‘There are different qualities in the materials, like the cloth and the resins they used to embalm,’ he said.
The soil samples will help distinguish whether chemical concentrations in the bone samples were related to the individuals’ health, diet, and daily lives, or whether the chemicals in the soil had changed the bones’ chemistry over time.
The samples were recovered from two Egyptian sites – Saqqara, the site of an ancient burial ground and Aswan, the site of an ancient city on the bank of the Nile once known as Swenett.
It’s hoped the research into the way the soil interacts with the bones could help in future projects to preserve mummified remains.
‘It’s very exciting to be involved in this project, and to learn about the journey these mummies have been on, in life and after death,’ Dr Schaible said.