Thanks, Laura, This is very helpful to know. I thought, if algin is a mercury magnet, then it must be so in its home environment also, and must be loaded with mercury if the area it is in is toxic. Therefore, it is good that there is a company testing for this.
Last night, I noticed a post that mentioned that algin is just one part of the seaweed with everything else removed, so I guess the iodine is not an issue.