Scott, with modern technology's ability to detect substances at the ppq level (that's parts-per-quadrillion, or 10 to the minus 15), we can now detect substances that virtually aren't present. Therefore, I wouldn't be surprised to detect almost anything, everywhere, when using a testing procedure that flags the specific substance.
The fact that a substance does pass through an organism is far better - IMO - than one that doesn't (i.e. one that "accumulates").
