I have a general background in environmental sciences, with a first class undergraduate degree in environmental chemistry. During my thesis I was introduced to the field of environmental radioactivity that would unwittingly form the basis of my career. My subsequent PhD in environmental radioactivity changed my focus more towards the physical/computional sciences and remote detection of radioactive sources. The objective of my PhD was to develop methods to process gamma-ray spectrometry data to estimate the activity and buried depth of radioactive sources. The data processing element relied heavily on Machine Learning techniques. The developed method was used to characterise radioactive contamination at sites contaminated with 226Ra and 137Cs.