Amalgam Vs. Tuna: which is more risky?

Which delivers more mercury, dental amalgam or a tuna fish sandwich? 

Introduction

The debate concerning mercury (Hg) exposure from dental amalgam continues in North America (see, for example: Richardson et al., 2011; Richardson, in press). One response to this debate has been the assertion that one receives more mercury from eating a tuna fish sandwich than from dental amalgam fillings (Greger, 2012). Greger (2012) even suggests that a total of 29 amalgam-filled teeth are required to deliver the same mercury dose as eating 1 tuna fish sandwich per week. Of course, the validity of this assertion requires consideration of a number of factors and assumptions, none of which are defined or described by Greger (2012).