IVL Swedish Environmental Research Institute

On behalf of the Swedish Environmental Protection Agency, this study aimed to report and synthesize available environmental monitoring and human exposure data for substances recently listed under the Stockholm Convention on Persistent Organic Pollutants (POPs): PFHxS and its related compounds (listed in 2022), Dechlorane Plus and methoxychlor (2023), and chlorpyrifos, LC-PFCA, MCCP and UV-328 (2025). This report consolidates existing Swedish monitoring data, screening results and published research, report temporal trends where possible, and recommends which substances merit periodic screening or continuous long-term monitoring in different environmental matrices.

Data were collected primarily from Swedish national monitoring databases, supplemented by risk profiles from the POPRC (Persistent Organic Pollutants Review Committee) and scientific literature. International data were used for comparison and to fill gaps. Results showed that data coverage varies considerably. PFHxS and LC-PFCA are the most comprehensively monitored, with clear evidence of long-range transport and bioaccumulation. MCCP, chlorpyrifos and Dechlorane Plus are well covered in air and deposition but more sparsely elsewhere, while data on UV-328 and methoxychlor remain scarce, with most Swedish measurements below detection limits despite confirmed international occurrence.

For all studied substances we recommend a combination of continued monitoring, targeted monitoring and periodic screening to track the effects of these substances' inclusion in the Stockholm Convention. We identified notable data gaps for methoxychlor in all matrices, and also for UV-328 and MCCP in soil, biota and human exposure. Human matrices (for example blood, serum and breast milk) were the least reported for these substances in Swedish databases.