Low levels of persistent organic pollutants raise concerns for future generations.

Bans and regulation in many countries have reduced the environmental levels of many persistent organic pollutants (POPs). Despite these declines, there is still evidence of exposures in a range associated with adverse health effects. This seeming paradox is a result of the realisation that levels once presumed safe can cause subtle but important health effects. For example, levels of PCBs now shown to affect human brain development are nearly one million-fold lower than levels previously believed safe. These findings add urgency to efforts to globally eliminate these chemicals, and carry lessons for persistent pollutants that are still in widespread use today, such as the polybrominated diphenyl ethers (PBDEs) and synthetic musks.