What is the “low-dose” theory and how does it relate to endocrine disruptors?
The “low-dose” theory postulates that exposures to very small amounts of certain substances (well below exposure levels considered to have an adverse effect on exposed test animals in toxicological testing aimed at traditional effects) may indeed have adverse effects. Since many natural endocrine hormones are active at extremely low doses — even at picogram levels — it is alleged that some endocrine disruptors also have a “low-dose effect,” i.e., they work at the same low doses that the natural substances work. The theory runs counter to the general axiom that “the dose makes the poison,” i.e., for any given substance, there is an exposure level below which exposure does no harm.
