Kinderchick, this is a post TPC made yesterday, referring to a variety of contaminants, to the eggs. I recall there was a fair bit of flame retardant information in a similar thread in a previous year, but I'm not sure how to search the archive files.
Contaminants don't always turn up in the eggshells - DDT and DDE and related contaminants do. Flame retardents don't it appears. Others will be other places. Do we test? No. There is academic research though, the flame retardant stuff is the newest contaminant being looked at - not an eggshell problem so far, but there are some questions as to whether or not they cause behavioural changes. And DDT and DDE was not related to fertility/viability, it caused eggshell thinning which was responsible for embryo/chick mortality.