Boyd Haley PhD, explains the principles of atomic absorption, which enables one to visualize the shadow of mercury vapor.
One of the reasons this issue has gone on so long is because of the nature of mercury vapor. It is colorless, odorless, invisible and extremely toxic. Thus no one knows when they are being exposed. Boyd Haley PhD, Matt Young, DDS and Alex Hummell from Mercury Instruments USA came together to visually demonstrate the mercury vapor release during the placement, polishing and removal of mercury fillings and the results showed levels of mercury vastly in excess of established safety limits and even higher than levels at which people are evacuated from buildings.