Experiments at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) shed new light on Egyptian soil and ancient mummified bone samples that could provide a better understanding of everyday life and environmental conditions thousands of years ago. Egyptian Mummy Bones
In a two-month research project completed in late August, two researchers from the Egyptian University of Cairo brought 32 bone samples and two soil samples to X-ray and infrared light-based techniques at the Berkeley Lab's Advanced Light Source (ALS). The ALS generates different wavelengths of bright light that can be used to study the microscopic chemistry, structure, and other properties of samples. Egyptian Mummy Bones
The visit was made possible by LAAAMP - the Project "Light Sources for Africa, America, Asia and the Middle East" - a grant-backed program designed to promote international scientific opportunities and collaboration among scientists in this region of the world.
The samples represent four dynasties, two tombs
The samples included bone fragments of mummified human remains, which are 2,000 to 4,000 years old, and soil collected at the sites of human remains. The remains represent four different dynasties in Egypt: the Middle Kingdom, the Second Intermediate Period, the Late Period and the Greco-Roman Period. Egyptian Mummy Bones
Guest researchers, associate professor Ahmed Elnewishy from Cairo University and postdoctoral researcher Mohamed Kasem, wanted to find out if the chemical concentrations in the bone samples are related to the individual's health, diet, and daily lives, or if the chemicals in the soil have changed their values The chemistry of bones over time. Egyptian Mummy Bones
Their work is important for the Egyptian cultural heritage and for a better understanding of the preservation of antiquities and the possible ways to contaminate these remains. The samples were recovered in two places in Egypt - Saqqara, the site of an ancient tomb; and Aswan, the site of an ancient city on the banks of the Nile, once known as Swenett - by archaeologists from the University of Cairo.
"The bones behave like an archive," said Kasem, who has been dealing with old bone chemistry since his doctorate. Studies dating back to the year 2011 He used a chemical analysis technique with laser ablation, in which a short laser pulse bleeds a small volume of material from a sample. Subsequently, the light emitted by this small explosion is analyzed to determine which elements are present.
"We found lead, aluminum and other elements that give us an indication of the environment and the toxicity of that time," he said. "This information is stored directly in the bone." X-Rays And Infrared Light
Distinction between soil and bone chemistry
What is difficult is to find out how the elements got into the bones. "There may be some diffusion of elements from the outside to the inside of the bones and the effects of bacteria, moisture and other effects, and it is difficult to separate them - to know if they are from the surrounding soil we did it. " try different techniques. " X-Rays And Infrared Light
Kasem added, "So many factors affect preservation, one of which is how long the bone is buried in the ground, as well as the condition of the bone and the different types of soil." Differences in embalming technique can also affect bone preservation and chemistry found in X-ray examinations. "The materials have different properties, like the cloth and the resins with which they were embalmed," he said. X-Rays And Infrared Light
While the ancient Egyptians did not use aluminum in metalworking, researchers found that they used potassium alum, a chemical compound that contains aluminum, to reduce the turbidity of drinking water. And lead concentrations were probably due to the lead used by Egyptians to polish ceramics.
Recent studies have focused on specimens, including sections of the femoral head and femoral stems, to determine if one sample type is more susceptible to contaminants from the surrounding soil than the other, for example. Femur bones are the strongest bones in the human body and run from the knees to the hips. The head at the top of the femur has spongier bone material than the stem core.
Together with ALS researchers Hans Bechtel and Eric Schaible, the researchers performed experiments with three different beamlines. Schaible supported the researchers with a technique called small-angle X-ray scattering (SAXS), which they used to analyze the nanoscale structuring of collagen, an abundant human protein. X-Rays And Infrared Light
X-rays show collagen patterns
A single scan of bone cross-sections 3 to 5 centimeters in diameter and about half a millimeter thick took two to six hours and provided a detailed 2D map showing the organization of the collagen in the bone.
These images can be compared to modern bones to better understand if and how the collagen has degraded over time, and can potentially shed light on a person's health.
"Collagen is one of the main building blocks of the body," said Schaible. "It's found in the skin, bones, internal organs, eyes, ears, blood vessels - it's one of the most important things we're made of. When we X-rays radiate through the collagen, the X-rays are scattered and the pattern of scattering, They can tell us a lot about how well preserved and well-organized the collagen is. "
Although much remains to be analyzed to interpret the data from the samples, Schaible said that the collagen assemblies in the old samples are generally not as well ordered as in healthy modern bone.
"It's very exciting to be involved in this project and to learn about the journey these mummies were in life and after death," he said.
Infrared light shows bone chemistry, mineral concentrations
Infrared studies at ALS show the chemical distribution and concentration of minerals and organic matter present in the bones.
"One of the main obstacles was preparing the rehearsals," Elnewishy said. It is difficult to cut thin sections of such sensitive material.
Schaible turned to a specialized laboratory in the Department of Earth and Planetary Sciences at UC Berkeley, which helped with the cutting of the samples. For the thinnest sections and the most fragile samples, the bone was suspended in epoxy resin and then sliced. X-Rays And Infrared Light
Plans for new experiments
Elnewishy said there are plans to conduct similar experiments on SESAME (Synchrotron Light for Experimental Science and Applications in the Middle East), a scientific light source in Jordan opened in 2017 for experiments. SESAME was built by a collaboration of scientists and governments in the region.
He pointed out that what the team is experiencing through its heritage heritage and sample preservation experiments could potentially benefit the collections of the Grand Egyptian Museum in Giza, which is expected to open in 2020 and house more than 100,000 Egyptian artifacts becomes.
The Advanced Light Source is a user facility of the US Department of Energy. LAAAMP is a joint program of the International Union of Pure and Applied Physics and the International Union of Crystallography and is supported by the International Council for Science Grants Program.
DOE/Lawrence Berkeley National Laboratory. "Scientists explore Egyptian mummy bones with X-rays and infrared light." ScienceDaily. ScienceDaily, 12 November 2019. <www.sciencedaily.com/releases/2019/11/191112095754.htm>