GC-MS/MS Maps OCP, PCB Levels in Greek Coastal Sediments

It is important to study man-made chlorine chemicals in coastal mud and sediment because they stick around for a very long time, build up in the food chain, and are toxic; even though many were banned decades ago, they are still showing up today. This is because sediment acts like a history book of pollution, storing these chemicals for years. It's not just a passive record, however; over time, these buried pollutants can get stirred back up and released into the water, continuing to affect marine life long after they were first dumped.

A study conducted by researchers at the Hellenic Centre for Marine Research and the National and Kapodistrian University of Athens (both in Greece) have reportedly provided for the first time a comprehensive overview of pollution levels and potential sources of a wide range of banned chlorine-based pesticides (also known as organochlorine pesticides [OCPs]) and polychlorinated biphenyls (PCBs) in Greece's coastal mud. To do this, researchers collected surface sediment samples from 48 spots along the Greek coast in March 2023 and March 2024, then tested them for all these different pesticides and PCBs using using gas chromatography-tandem mass spectrometry (GC-MS/MS). A paper based on this work was published in the Marine Pollution Bulletin.¹

Why Are OCPs and PCBs Harmful, and How Do They End Up Polluting the Environment?

OCPs and PCBs are synthetic persistent organic pollutants (POPs) exhibiting significant persistence in the environment.^2,3The authors of the paper cite myriad sources showing that, because of the way these chemicals are built, they don't dissolve in water; rather, they dissolve in fat instead, which means they build up in the bodies of living things over time and get more concentrated as you move up the food chain, making them a serious risk to both marine life and people.¹ These pesticides and PCBs have been linked to hormone disruption, nerve damage, fertility problems, weakened immune systems, and cancer in both animals and humans.¹ In fact, PCBs are officially classified as cancer-causing by the International Agency for Research on Cancer.¹

These chemicals end up in the environment through activities such as past use of pesticides on farms, waste released from factories, runoff from cities when it rains, and even through the air, which can carry them long distances. Because they can travel so far on wind and water currents, they can end up polluting places that are far away from wherever they were originally used or released.^4-8

What Did the Study Find Regarding Pollution Levels Along the Greek Coast, and Why Do These Findings Matter Going Forward?

The results of the study showed pollution levels varied a lot from place to place, which makes sense given how differently developed or industrialized different parts of the Greek coast are. Levels of the 24 pesticides detected ranged from barely detectable to relatively low amounts, while levels of 25 PCBs detected showed a much wider range (from nearly clean to quite heavily polluted in some spots). The Saronikos Gulf stood out as by far the most polluted area, while sites in the Aegean Sea and southern Crete were the cleanest, likely showing what "normal" background levels look like in areas with little pollution.¹

“Considering the fact that the studied legacy organic contaminants remain detectable in Greek coastal sediments decades after their prohibition,” write the authors of the paper,¹ “the current dataset provides a valuable baseline for monitoring their temporal trends in future sampling surveys, ensuring long-term environmental management, ecosystem quality protection and sustainable coastal development, especially in urbanized and industrialized embayments of Greece and beyond.”

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References

1. Parinos, C.; Skavantzou, T.; Plakidi, E. et al. Mapping Chemical Footprints: A Baseline Assessment for Organochlorine Pesticides and Polychlorinated Biphenyls in Coastal Sediments of Greece (Sastern Mediterranean Sea). Mar Pollut Bull. 2026, 233 (Pt 1), 120115. DOI: 10.1016/j.marpolbul.2026.120115
2. Jones, K. C.; de Voogt, P. Persistent Organic Pollutants (POPs): State of the Science. Environ. Pollut. 1999, 100, 209-221. DOI: 10.1016/S0269-7491(99)00098-6
3. Wania, F.; MacKay, D. Peer Reviewed: Tracking the Distribution of Persistent Organic Pollutants. Environ. Sci. Technol. 1996, 30, 390A-396A. DOI: 10.1021/es962399q
4. Kucuksezgin, F.; Tolga Gonul, J. Distribution and Ecological Risk of Organochlorine Pesticides and Polychlorinated Biphenyls in Surficial Sediments from the Eastern Aegean. Mar. Pollut. Bull.2012, 64, 2549-2555. DOI: 10.1016/j.marpolbul.2012.07.032
5. Gioia, R.; Dachs, J.; Nizzetto, L. et al. Atmospheric Transport, Cycling and Dynamics of Polychlorinated Biphenyls (PCBs) from Source Regions to Remote Oceanic Areas. Occurrence, Fate and Impact of Atmospheric Pollutants on Environmental and Human Health. ACS Symposium Series, American Chemical Society 2013, 3-18. DOI: 10.1021/bk-2013-1149.ch001
6. Iakovides, M.;  Apostolaki, M.; Stephanou, E. G. PAHs, PCBs and Organochlorine Pesticides in the Atmosphere of Eastern Mediterranean: Investigation of Their Occurrence, Sources and Gas-Particle Partitioning in Relation to Air Mass Transport Pathways. Atmos. Environ.2021, 244, 117931. DOI: 10.1016/j.atmosenv.2020.117931
7. Kumar, S.; Kumar, V.; Vir, V. et al. Devastating Impact of Persistent Organic Pollutants on Arctic Environment and Human Health; Xenobiotics in Environment; CRC Press, 2026.
8. Merhaby, D.; Rabodonirina, S.; Net, S. et al. Overview of Sediments Pollution by PAHs and PCBs in Mediterranean Basin: Transport, Fate, Occurrence, and Distribution. Mar. Pollut. Bull. 2019, 149, 110646. DOI: 10.1016/j.marpolbul.2019.110646