Highlights and images for 3 October 2025

How much data is needed for science to be “scientific” enough? How many studies does one draft risk profile need to cite to be considered conclusive? Also, how conclusive does it have to be to pass to the next stage of review, especially in light of the precautionary principle? These were just a few questions experts asked themselves and each other at the last day of the 21st meeting of the Persistent Organic Pollutants Review Committee (POPRC-21). 

In the morning, members swiftly adopted all decisions but one. The draft risk profile for polybrominated and mixed polybrominated/chlorinated dioxins and furans (PBDD/Fs and PBCDD/Fs) turned out to be a tough task to tackle. Members continued working in a contact group until late afternoon on Friday, hoping to reach the agreement. Still, no agreement was reached on whether the substances are prone to long-range environmental transport (LRET), and whether they cause adverse health effects. Most members were eager to move PBDD/Fs and PBCDD/Fs to the next stage of POPCR review, with many agreeing to collect more data during intersessional period. Alas, for very few, the link between LRET and adverse effects was not conclusive, even though many agreed that the criteria were met. 

After protracted discussions, the POPRC agreed to defer the consideration of the draft risk profile for PBDD/Fs and PBCDD/Fs to its next meeting, with intersessional work focusing on collecting more information on the link between LRET and adverse effects, and more information on adverse effects to human health.  

As outgoing POPRC Chair Peter Dawson announced that Magda Frydrych from Poland will serve as the incoming interim Chair of POPRC 22, there were many warm words for Chair Dawson’s leadership, and the work of other 10 outgoing members. The meeting concluded at 9:07 pm on October 3, 2025.