_PollingThread = new Thread(new ThreadStart(ManagerThread));
_PollingThread.IsBackground = true;
_PollingThread.Start();

var sourceName = Thread.GetNamedDataSlot("Source");
var data = Thread.SetData(sourceName, _PipelineName);
...
// starts loop and begins processing things

var sourceName = Thread.GetNamedDataSlot("Source");
var data = Thread.GetData(sourceName);
string sourceTag = String.Empty;

if(data != null)
{
    sourceTag = " [" + data.ToString() + "]";
}