Chemistry and Forensic Science
On Monday, 26 January 2009 two young members of the Bristol and South West Regional Group Committee, Melanie Sapsford and Becki Scott presented the 2008-2009 School Lecture to 100 girls in Years 10-13 at Westonbirt School. The speakers are PhD Researchers at Cranfield University, at the Centre for Archaeological and Forensic Analysis on the Shrivenham Campus. Their topic was Chemistry and Forensic Science.
Melanie's work concerns the medical and associated uses of salts in the Ancient Near East. She has carried out extensive fieldwork in Egypt. Becki's work concerns the provenancing of glass from forensic and archaeological contexts. Her field work has already taken her to Turkey, the USA and Belgium.
After introducing themselves they gave a review of some of the common analytical techniques used in the forensic sciences such as the analysis of drugs and DNA. Then they asked the girls to work in groups to suggest aspects of forensic science that use chemistry. From this a list was made upon a flip chart and each item was explained.
DNA profiling is now very important but it was not until 1987 that it was first used as evidence in the UK. The four blood groups (A, B, AO & O) enable a group of suspects to be narrowed down, as only 10% of the population are group B and 4% are group AO.
Small bone fragments require tests to determine whether they are human or animal. A skeleton can provide information of height and sex. At this point two skulls (plastic) were passed round for examination! Teeth and dental records are invaluable to exactly identify the remains of one body, among many, so that it can be returned to the family for burial. Mass graves were examined to look for signs of torture and ethnicity. For example in Bosnia, were there people from only one ethnic group or from more than one?
The final topics were the state of decomposition of a dead body, which could indicate the time of death, and the mummification process, to keep the body intact. This led to a lively Question and Answer session and a Vote of Thanks from one of the girls.