It just means that there was no mercury in circulation at that time. The urine challenge test is a better way to determine how much mercury is in our body, but even then you could have more buried in layers and it may not show up until after you have chelated the current layer out.

Sorry if this is not what you wanted to hear. <img src="/ubbthreads/images/graemlins/frown.gif" alt="" /> But the good news is, you are on the right track!!! Keep up the good work!!!

Sandi
xoxo