What is the fine-grained topic of the following text: Due to the radioactivity I was warned to take a taxi home and to stay away from people for 48 hours until the Technetium Tc 99m sestamibi reached safer levels.. Andrew and I took the long blue and white taxi home raight to our doorstep and went out shopping today after I came home from respite. Only return the topic.
Dealing with radioactivity and its precautions in everyday life.