Edible clay inclusion in the diet of oysters can reduce tissue residues of polychlorinated biphenyls



Polychlorinated biphenyls (PCBs) are lipophilic and persistent environmental pollutants that are readily absorbed and accumulated in high concentrations in fatty tissues of humans and animals. Invertebrate animals, such as oysters, are vulnerable and sensitive to PCB contamination.


Previously, our in vitro isothermal studies have shown that acid processed montmorillonites (APM) can effectively bind PCBs and Aroclors. Therefore, in a novel application of this work, a dietary strategy for shellfish was developed using APM, and its parent clay to reduce exposures to PCBs in oysters. PCB residues in oysters with clay treatment at different dietary inclusion rates and durations were measured and compared to a washout treatment.


The efficacy and safety of this strategy were supported by a significant reduction of PCB residues with the inclusion of a low level of APM (0.05%) during a 4-day treatment. Moreover, this sorbent strategy reduced PCB residues in oysters in a dose- and time-dependent manner.


Based on our results, it is possible that clay-based sorbents such as APM, can be included in the diet to significantly reduce exposures to PCBs.

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  1. 1.

    Clayton GD, Glayton FE (1981) Halogenated cyclic hydrocarbons. In: Clayton G, Clayton F (eds) Patty’s Industrial Hygiene and Toxicology 2B. Wiley, New York, pp 3645–3669

    Google Scholar 

  2. 2.

    National Technical Information Service (NTIS) (1979) Polychlorinated biphenyls, committee on the assessment of polychlorinated biphenyls in the environment. https://doi.org/10.17226/19865

  3. 3.

    Urban ER Jr, Kirchman DL (1992) Effect of kaolinite clay on the feeding activity of the eastern oyster Crassostrea virginica (Gmelin). J Exp Mar Biol Ecol 160:47–60

    Article  Google Scholar 

  4. 4.

    National Oceanic and Atmospheric Administration (NOAA) (2015) Fisheries of the United States. https://oceanconservancy.org/wp-content/uploads/2017/02/FUS2015-1.pdf. Accessed 11 May 2020

  5. 5.

    Chu FE, Soudant P, Hale RC (2003) Relationship between PCB accumulation and reproductive output in conditioned oysters Crassostrea virginica fed a contaminated algal diet. Aquat Toxicol 65(3):293–307

    CAS  Article  Google Scholar 

  6. 6.

    Jaikanlaya C, Settachan D, Denison MS, Ruchirawat M, Berg MVD (2009) PCBs contamination in seafood species at the Eastern Coast of Thailand. Chemosphere 76(2):239–249

    CAS  Article  Google Scholar 

  7. 7.

    Bjoerk M, Gilek M (1999) Efficiencies of polychlorinated biphenyl assimilation from water and algal food by the blue mussel (Mytilus edulis). Environ Toxicol Chem 18:765–771. https://doi.org/10.1002/etc.5620180424

    Article  Google Scholar 

  8. 8.

    Thompson S, Budzinski H, Garrigues P, Narbonne JF (1999) Comparison of PCB and DDT distribution between water-column and sediment-dwelling bivalves in Arcachon Bay, France. Mar Pollut Bull 38(8):655–662

    CAS  Article  Google Scholar 

  9. 9.

    Vaezzadeh V, Zakaria MP, Bong CW, Masood N, Magam SM, Alkhadher S (2019) Mangrove oyster (Crassostrea belcheri) as a biomonitor species for bioavailability of polycyclic aromatic hydrocarbons (PAHs) from sediment of the west coast of peninsular malaysia. Polycycl Aromat Comp 39(5):470–485

    CAS  Article  Google Scholar 

  10. 10.

    Wang M, Safe SH, Hearon SE, Phillips TD (2019) Strong adsorption of polychlorinated biphenyls by processed montmorillonite clays: potential applications as toxin enterosorbents during disasters and floods. Environ Pollut 255(1):113210

    CAS  Article  Google Scholar 

  11. 11.

    Phillips TD, Wang M, Elmore SE, Hearon S, Wang JS (2019) NovaSil clay for the protection of humans and animals from aflatoxins and other contaminants. Clay Clay Miner 67(1):99–110. https://doi.org/10.1007/s42860-019-0008-x

    CAS  Article  Google Scholar 

  12. 12.

    Chu FL, Soudant P, Cruz-Rodriguez LA, Hale RC (2000) PCB uptake and accumulation by oysters (Crassostrea virginica) exposed via a contaminated algal diet. Mar Environ Res 50(1–5):217–221

    CAS  Article  Google Scholar 

  13. 13.

    U.S. Environmental Protection Agency (EPA) (1990) Guidance on remedial actions for superfund sites with PCB contamination. https://clu-in.org/download/contaminantfocus/pcb/a-guide-quick-93-55401fs-s.pdf. Accessed 11 May 2020

  14. 14.

    Landrum PF, Lydy MJ, Lee H (1992) Toxicokinetics in aquatic system: model comparisons and use in hazard assessment. Environ Toxicol Chem 11(12):1709–1725

    CAS  Article  Google Scholar 

  15. 15.

    Mafra LL Jr, Bricelg VM, Ouellette C, Bates SS (2010) Feeding mechanics as the basis for differential uptake of the neurotoxin domoic acid by oysters, Crassostrea virginica, and mussels, Mytilus edulis. Aquat Toxicol 97:160–171

    CAS  Article  Google Scholar 

  16. 16.

    Fisher WS, Oliver LM, Winstead JT, Long ER (2000) A survey of oysters Crassostrea virginica from Tampa Bay, Florida, associations of internal defense measurements with contaminant burdens. Aquat Toxicol 51:115–138

    CAS  Article  Google Scholar 

  17. 17.

    U.S. Environmental Protection Agency (EPA) (2001) Guidelines for bioremediation of marine shorelines and freshwater wetland. https://www.epa.gov/sites/production/files/2013-07/documents/guidelines_for_the_bioremediation_of_marine_shorelines_and_freshwater_wetlands.pdf. Accessed 11 May 2020

  18. 18.

    Wang M, Orr AA, He S, Dalaijamts C, Chiu WA, Tamamis P, Phillips TD (2019) Montmorillonites can tightly bind glyphosate and paraquat reducing toxin exposures and toxicity. ACS Omega 4(18):17702–17713

    CAS  Article  Google Scholar 

  19. 19.

    Deshpande SA, Yamada R, Mak CM, Hunter B, Obando AS, Hoxha S, Ja WW (2015) Acidc food pH increases palatability and consumption and extends drosophila lifespan. J Nutr 145:2789–2796

    CAS  Article  Google Scholar 

  20. 20.

    U.S. Food & Drug Administration (FDA) Food additive status list. https://www.fda.gov/Food/IngredientsPackagingLabeling/FoodAdditivesIngredients/ucm091048.htm. Accessed 11 May 2020

  21. 21.

    Marketing authorization for food additives that may be used as pH adjusting agents, acid-reacting materials or water correcting agents. https://www.canada.ca/en/health-canada/services/food-nutrition/food-safety/food-additives/lists-permitted/10-adjusting-agents.html. Accessed 11 May 2020

  22. 22.

    Vignier J, Rolton A, Soudant P, Chu FLE, Robert R, Volety AK (2019) Interactions between Crassostrea virginica larvae and Deepwater Horizon oil, Toxic effects via dietary exposure. Environ Pollut 246:544–551

    CAS  Article  Google Scholar 

  23. 23.

    U.S. Environmental Protection Agency (EPA) (1981) Environmental impact guidelines for new source canned and preserved seafood processing facilities. https://nepis.epa.gov/Exe/ZyPDF.cgi/9101E6N0.PDF?Dockey=9101E6N0.PDF. Accessed 11 May 2020

  24. 24.

    Wang M, Hearon SE, Phillips TD (2019) A high capacity bentonite clay for the sorption of aflatoxins. Food Addit Contam Part A 37(2):332–341. https://doi.org/10.1080/19440049.2019.1662493

    CAS  Article  Google Scholar 

  25. 25.

    Wang M, Maki CR, Deng Y, Tian Y, Phillips TD (2017) Development of high capacity enterosorbents for aflatoxin B1 and other hazardous chemicals. Chem Res Toxicol 30(9):1694–1701

    CAS  Article  Google Scholar 

  26. 26.

    Hearon SE, Wang M, Phillips TD (2020) Strong adsorption of dieldrin by parent and processed montmorillonite clays. Environ Toxicol Chem 39(3):517–525

    CAS  Article  Google Scholar 

  27. 27.

    Wang M, Phillips TD (2019) Potential applications of clay-based therapy for the reduction of pesticide exposures in humans and animals. Appl Sci 9(24):5325. https://doi.org/10.3390/app9245325

    CAS  Article  PubMed  Google Scholar 

  28. 28.

    Wang M, Hearon SE, Phillips TD (2019) Development of enterosorbents that can be added to food and water to reduce toxin exposures during disasters. J Environ Sci Health, Part B 54(6):514–524

    CAS  Article  Google Scholar 

  29. 29.

    Lowe JI, Parrish PR, Patrick JM Jr, Forester J (1972) Effects of the polychlorinated biphenyl Aroclor® 1254 on the American oyster Crassostrea virginica. Mar Biol 17(3):209–214

    CAS  Article  Google Scholar 

  30. 30.

    Trevisan R, Flores-Nunes F, Dolores ES, Mattos JJ, Piazza CE, Sasaki ST, Taniguchi S, Montone RC, Bicego MC, Dos Reis IMM, Zacchi FL, Othero BNM, Bastolla CLV, Mello DF, Graga APM, Wendt N, Toledo-Silva G, Razzera G, Dafre AL, Melo CMR, Bianchii A, Marques MRF, Bainy ACD (2017) Thiol oxidation of hemolymph proteins in oysters Crassostrea brasiliana as markers of oxidative damage induced by urban sewage exposure. Environ Toxicol Chem 36(7):1833–1845

    CAS  Article  Google Scholar 

  31. 31.

    Zacchi FL, Flores-Nunes F, Mattos JJ, Lima D, Luchmann KH, Sasaki ST, Bicego MC, Taniguchi S, Montone RC, Almeida EA, Bainy AC (2018) Biochemical and molecular responses in oysters Crassostrea brasiliana collected from estuarine aquaculture areas in Southern Brazil. Mar Pollut Bull 135:110–118

    CAS  Article  Google Scholar 

  32. 32.

    Moukas AI, Thomaidis NS, Calokerinos AC (2014) Determination of polychlorinated biphenyls by liquid chromatography-atmospheric pressure photoionization-mass spectrometry. J Mass Spectrom 49(11):1096–1107

    CAS  Article  Google Scholar 

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This work was supported by the Superfund Hazardous Substance Research and Training Program (National Institutes of Health) (P42 ES0277704); and the United States Department of Agriculture (Hatch 6215).

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Correspondence to Timothy D. Phillips.

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Meichen Wang and Timothy Phillips declare that they have no conflicts of interest.

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This article does not contain any studies with human participants or animals performed by any of the authors.

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Wang, M., Phillips, T.D. Edible clay inclusion in the diet of oysters can reduce tissue residues of polychlorinated biphenyls. Toxicol. Environ. Health Sci. 12, 355–361 (2020). https://doi.org/10.1007/s13530-020-00058-2

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  • Toxicant sorption
  • Oysters
  • Polychlorinated biphenyls (PCBs)
  • Clay