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Forensic science

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Thesis submitted in Partial Fulfilment of Examination Requirements Leading to the Award BSc (Forensic and Environmental Analysis) Technological University Dublin, 2013. This research was undertaken by Kim Daly in collaboration with the Garda Road Safety Unit, and was supervised by Dr. Claire McDonnell. Kim completed this research as part of her BSc in Forensic and Environmental Analysis.


The aim of this project was to increase student’s awareness of road safety and the relationship between alcohol and driving. This was carried out in conjunction with the Garda Road Safety Unit and the DIT interdisciplinary project known as CARS, College Awareness of Road Safety. This project was carried out last year by another student therefore the aim this year was to build and expand on the work that had been done so far. Increasing the student’s awareness was achieved by speaking to class groups to explain the project and asking them to take part by supplying samples of breath and/or urine the morning after they had consumed alcohol. This was intended to demonstrate to the students that it is possible to be still over the limit the day after they have been drinking. To increase the student’s awareness of the rules of the road, they were asked to take part in a survey and feedback was supplied on their answers both on the day of the student breathalyser event in DIT Kevin Street and by placing the results as well as the correct answers and links to road safety videos on the DIT website. The basis of the work done throughout the project was to analyse urine samples supplied by student volunteers by gas chromatography the day after they had consumed alcohol. The results of these analyses were then compared to the new legal limits that were put in place in 2011. All analyses carried out were performed anonymously however, if requested by the volunteer, feedback was provided on the amount of alcohol that had been detected in their system at the time of giving the sample. Urine samples supplied from members aged 18 to 22 from a local football club, Greenhills Football club on a Sunday morning, were also analysed as a result of a recent Garda press release which stated that a new feature of the implementation of the lower limits was an increase in the number of people detected driving the morning after drinking particularly on Sundays around 11am. In order to analyse the samples supplied by volunteers, ethanol working standards were prepared with the use of a propan-1-ol internal standard and run on the GC to establish a standard calibration curve. This curve was run once a week and the equation of the line obtained was used to calculate the ethanol content of any urine samples analysed that week. In previous years problems had been encountered with the lower concentration ethanol standards however accuracy, precision, linearity and reproducibility were demonstrated throughout the analysis therefore validating the method for these parameters. The coefficient of determination R2, values obtained for the calibration of ethanol standards were 1.000, 0.9994 and 0.9997 respectively. In order to ensure the GC was fit for use each morning, Diasys® check standards and standards provided by the Medical Bureau of Road Safety were analysed. A total of 19 urine samples were analysed, 13 of these were supplied by student volunteers and 6 were supplied by Greenhills Football club. All samples supplied by Greenhills Football club were negative for alcohol suggesting that a recent Garda press release and campaign to target this sex and age group may have had an impact. Of the 13 samples supplied by student volunteers, 5 samples were over the limit for both a specified and full licence driver, 2 samples were over the limit for a specified driver but under the limit for a full licence driver and 1 sample contained alcohol but was under the limit for both a specified and full licence driver. The remaining 5 samples did not contain any alcohol. The legal limits for alcohol in urine can be seen in Chapter 1 Table 1.1. Breath samples supplied by student volunteers were also analysed one morning in DIT Kevin Street using a commercially available breathalyser. A total of 48 student volunteers were breathalysed. Of these 48, 44 student volunteers were negative for alcohol however 4 student volunteers gave positive readings for alcohol. Three of these four volunteers were over the limit for a specified driver but under the limit for a full licence driver and one volunteer had alcohol in their system but was under the limit for both a specified driver and full licence driver. The legal limits for alcohol in breath, urine and blood can be seen in Chapter 1 Table 1.1. During this breath testing event, students were asked to complete a survey which questioned their knowledge of the new legal limits and the units in certain drinks. An online version of this survey was also generated and the survey was also provided in the urine sample packs. Overall, 98 surveys were completed which demonstrates that awareness was raised. Analysis of the surveys demonstrated that students were unsure of the amount of units contained in a bottle of wine and a pint of beer. With regards to the question about the legal limits for specified and full licence drivers, 29% of students answered correctly in both cases. 65% of students also agreed that more could be done to educate students on the relationship between drink and road safety.