In addition, among surveyed dentists, 40% (96 respondents) did not have traps or filters for amalgam separation meaning that amalgam waste ends up in the waste water. An average of 9.1 newly placed amalgam fillingsper week per clinic is reported in this study.
One unit of amalgam filling (equivalent of one small filling) is estimated to release around 0.55 g of mercury (Al-Khatib and Darwish 2004); therefore,the weekly total amount of mercury released can be estimated in this study at 9.57 g/clinic.