Image Credit: Dmitry Kalinovsky/Shutterstock.com
Glass can be constructed from a myriad of different chemical compositions. These different combinations of chemical components impact the chemical, electrical, mechanical, optical, and thermal properties of the final glass product. Elemental analysis can uncover these chemical compositions, which is useful to a wide range of scientific applications, including helping glass manufacturers establish better methods of conducting quality control, benchmarking, diagnosing production, and material verification. The elemental analysis of glass is also heavily relied upon in research. It is allowing scientists to develop new forensic techniques to enable glass left at crime scenes to act as pieces of key evidence, while it is also furthering our knowledge on the environmental impact of glass production. Here, we discuss the elemental analysis of glass within these research applications.
The Development of New Forensic Methods
For several decades, forensic scientists have understood the value of small fragments of materials that are left behind at crime scenes, particularly in hit-and-run incidents and other violent crimes. Broken glass is often left at a crime scene, and fragment sizes can range from large pieces to tiny, even microscopic-sized shards. These pieces of glass can be transferred to the people and objects involved in the crime, therefore, such evidence can help rule out or rule in suspects. For example, a fragment of glass found on a suspect’s clothes that irrefutably matches a sample left at the scene can place the person at the scene of the crime.
Originally, scientists relied on techniques that analyzed the physical properties of the glass, such as those that quantified its refractive index or density. However, these methods are unable to classify the type of glass. In addition, as the years have gone on, glass producers have improved their methods, resulting in a reduction in the range of physical properties apparent in modern glass samples, making it harder to distinguish unique pieces of glass with these methods.
More recently, elemental analysis has emerged as a reliable method of comparing glass samples in forensic analysis. Research has provided evidence to show that several methodologies, including energy dispersive X-ray fluorescence spectrometry, flameless atomic absorption spectrometry, and inductively coupled plasma atomic emission spectrometry, are reliable techniques of elemental analysis of glass for forensic purposes.
As we collect more data, these methods will no doubt be developed and enhanced for their use in forensic science. The likely outcome of this will be the establishment of more sensitive analytical techniques for the forensic investigation of glass, helping to provide reliable pieces of criminal evidence.
The Environmental Impact of Glass Pollution
Research suggests that glass packaging is potentially more detrimental to the environment and human health than plastic packaging. While this is due in part to the emissions relating to producing glass and transporting it given its relatively heavy weight compared with other packaging, there is also some evidence to show that the dust released into the atmosphere during glass production could be damaging the environment and may be dangerous to breathe in.
When we produce glass, amorphous silica dust is released into the air. While some scientists believe that this dust is not harmful to breathe in, more recent research indicates that it might be. A 2019 study, published in the International Journal of Molecular Science, used elemental analysis to investigate the characteristics of amorphous silica dust and determine its effect on the central nervous system. Elemental analysis helped demonstrate the impact of glass dust on human astrocyte cells, revealing its inflammatory impact and therefore neurological impact.
Results showed that at low levels, exposure to amorphous silica induced a non-significant reduction in cell viability and increased levels of toxicity. Additionally, the analysis revealed that a biomarker of neurodegenerative disease, expression of the amyloid precursor protein (APP) gene, was impacted by exposure to this dust. Finally, over time, the analyses demonstrated that exposure to glass dust reduced cell ability to communicate via gap junctions.
Elemental analysis has helped scientists discover the potential danger of glass dust, which will be vital to establishing safe working practices in places that produce glass products. Right now, the research is in its infancy and much more needs to be studied to fully understand the impact of glass dust in real-world settings. This research also highlights the potential damage to the environment caused by glass dust pollution, which also needs to be explored.
The Future of Elemental Analysis for Glass Research
Various methods of elemental analysis are proving vital to the analysis of glass in research applications. Two areas that are particularly benefiting from this technology is that of forensic science and the investigation of the impact of glass dust on human health and the environment.
In the coming years, we can expect elemental analysis to help uncover vital information regarding the nature of glass so that forensic techniques can be improved on and scientists can devise solutions to protect humans and the environment from glass dust.
References and Further Reading
Arnoldussen, Y., Kringlen Ervik, T., Baarnes Eriksen, M., Kero, I., Skaug, V. and Zienolddiny, S., 2019. Cellular Responses of Industrially Relevant Silica Dust on Human Glial Cells In Vitro. International Journal of Molecular Sciences, 20(2), p.358. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6359019/
Buscaglia, J., 1994. Elemental analysis of small glass fragments in forensic science. Analytica Chimica Acta, 288(1-2), pp.17-24. https://www.sciencedirect.com/science/article/abs/pii/0003267094851123
Hickman, D., 1983. Elemental analysis and the discrimination of sheet glass samples. Forensic Science International, 23(2-3), pp.213-223. https://www.sciencedirect.com/science/article/abs/pii/0379073883901494
Merget, R., Bauer, T., Küpper, H., Philippou, S., Bauer, H., Breitstadt, R. and Bruening, T., 2001. Health hazards due to the inhalation of amorphous silica. Archives of Toxicology, 75(11-12), pp.625-634. https://pubmed.ncbi.nlm.nih.gov/11876495/
Montero, S., Hobbs, A., French, T. and Almirall, J., 2003. Elemental Analysis of Glass Fragments by ICP-MS as Evidence of Association: Analysis of a Case. Journal of Forensic Sciences, 48(5), p.2001413. https://www.researchgate.net/publication/9057604_Elemental_Analysis_of_Glass_Fragments_by_ICP-MS_as_Evidence_of_Association_Analysis_of_a_Case