Brent Pautler Coauthored Paper on Passive and Active Sediment Assessment

Brent Pautler, PhD, coauthored "Bioavailability-Informed Sediment Assessment in the Transboundary Begej Canal: A Comparative Evaluation of Active and Passive Methods" in Volume 225 of Marine Pollution Bulletin. 

The article is available now online and will be published in the April 2026 issue. Brent's coauthors are Đorđe Pejin, Slaven Tenodi, Dunja Rađenović Veselić, Kristiana Zrnić Tenodi, Dejan Krčmar, and Dragana Tomašević Pilipović of the University of Novi Sad's Department of Chemistry, and Tijana Stojanović of the University of Novi Sad's Department of Phytomedicine and Environmental Protection. 

In this study, SiREM's SPeeper ™ was used alongside conventional sampling and measured consistently lower freely dissolved concentrations of metals, compared with other testing methods. The study showed that combining active and passive sampling supports balanced sediment management and contributes to EU Water Framework Directive efforts to integrate bioavailability into sediment quality assessment across the Danube Basin. 

Brent is the Chemistry Services Manager at SiREM. He brings more than 10 years of experience in spectroscopy, chromatography, mass spectrometry, passive sampling, and chemistry informatics. Throughout his career, Brent has worked with scientists, engineers, and consultants to help solve unique problems in the laboratory and the field. 

Marine Pollution Bulletin is a peer‑reviewed scientific journal that publishes research on the sources, effects, monitoring, and mitigation of pollution in marine and coastal environments. 

Sediments act as both sinks and potential secondary sources of heavy metals in aquatic systems, playing a key role in ecological risk dynamics and contaminant cycling. This study assessed sediment quality in the Begej Canal (Serbia) by combining conventional (pseudo-total and sequential extraction) and passive sampling with multiple contamination and risk indices. Pseudo-total analyses revealed elevated chromium, cadmium, lead, and zinc. Hakanson's framework indicated a moderate cumulative ecological risk (RI = 270.8), dominated by cadmium (high ERi), while consensus PEC-Q values highlighted chromium, lead, and zinc as principal contributors to biological-effect potential. Sequential extraction confirmed enhanced mobility of cadmium and lead.  

In contrast, SPeeper™ passive samplers measured consistently lower freely dissolved concentrations of metals. The interstitial water criteria toxic unit (IWCTU) index (0.01117) remained well below threshold, and the Single Factor Pollution Index (SFPI) classified sediments as unpolluted based on bioavailable fractions (0.54), versus moderate pollution from pseudo-total content (3.22). These results emphasize that pore-water extraction and bulk analyses can overestimate hazard by disrupting equilibria, whereas equilibrium-based passive methods yield a more ecologically realistic assessment. Overall, although the Begej Canal remains impacted by heavy metals, the continuously bioavailable fraction poses negligible ecological risk. The combined application of active and passive sampling with complementary indices provides a transferable framework for distinguishing between potential mobility and actual exposure. This approach supports balanced sediment management and contributes to EU Water Framework Directive efforts to integrate bioavailability into sediment quality assessment across the Danube Basin. 

Read the article: Bioavailability-Informed Sediment Assessment in the Transboundary Begej Canal: A Comparative Evaluation of Active and Passive Methods 

Learn about the journal: Marine Pollution Bulletin 

Learn more about Brent: Our Team – SiREM LAB