It has long been suspected, and in some cases proved, that certain substances disrupt our endocrine systems, including specifically the thyroid. A major problem has been getting sufficient evidence.
Without understanding in some precision and detail, what substances have which effects, we cannot make sensible choices. There might be some substance which is widespread and is known to disrupt, but there could well be other substances that are very much more potent but not yet known.
Good, therefore, to see work going on in this area.
OECD Work Related to Endocrine Disrupters
The protection of human health and the environment from endocrine disrupters is currently a high priority for regulatory authorities in most OECD countries/regions, and it has been proposed by UNEP as a SAICM policy emerging issue. Indeed, the OECD Test Guidelines Programme has spent approximately half of its resources since 1996 to develop Test Guidelines and other tools to support countries’ needs related to testing and assessment of chemicals for endocrine disruption.
A more accessible summary can be found here: