serve as sentinels for indoor exposure to PBDEs for humans who share their houses, said Linda S. Birnbaum, Ph.D., a co-author of the study. No link between human hyperthyrodism and PBDE exposure has been established, Birnbaum noted, adding that some ongoing studies do suggest such a connection. Although several states have banned use of certain PBDEs in commercial products, there are no regulations limiting PBDE content in foods, according to Birnbaum.