Microplastics and Per- and Polyfluoroalkyl Substances (PFAS) Analysis in Sea Turtles and Bottlenose Dolphins along Mississippi’s Coast

Article Authors: Sameera R. Gunatilake 4, Gombojav Ariunbold 5, Felio Perez 6, Rooban V. K. G. Thirumalai 7, EI Barbary Hassan 8, Islam Elsayed 8,9, Dinesh Mohan 10, Ashli Brown 11,12, Debra Moore 2,13, Stephen Reichley 2,13, Mark Lawrence 13,14 , Todd E. Mlsna 1,

    • Abstract

    Global plastic production and usage has increased annually for decades and microplastic pollutants (≤5 mm) are a growing concern. Microplastics in surface waters can adsorb and desorb harmful chemicals such as per- and polyfluoroalkyl substances (PFAS). Microplastics can accumulate across all tropic levels in the marine food web. The purpose of this research was to analyze the stomach and intestinal contents of stranded (Mississippi coast) bottlenose dolphins and sea turtles for the presence of microplastics and commonly found PFAS, PFOS, PFOA, and GenX. Gut contents were digested (10% KOH in 50% MeOH) and then analyzed for microplastics using pyrolysis gas chromatography-mass spectrometry (Pyro-GC-MS), Nile red microscopy, X-ray photo electron spectroscopy (XPS), and Raman spectroscopy. Digested sample filtrate was pre-concentrated using solid-phase extraction (SPE) before PFAS liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. The PFOS extraction and analysis had 98.6% recovery when validated with certified pike‒perch fish reference material. The Nile red testing on most samples revealed the presence of microplastics (Table S1). The Pyro-GC-MS results from two samples confirmed the presence of the plasticizer acetamide. The Raman spectroscopy analysis indicated characteristic plastic peaks corresponding to polystyrene in one sample. PFOS (95.5 to 1,934.5 µg/kg) was detected in three dolphin stomach samples. This project is part of a long-term study with the goal of a better understanding of microplastics and PFAS environmental contamination and their impact on bottlenose dolphins and sea turtles.

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    DOI 10.3390/analytica4010003
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    1Department of Chemistry, Mississippi State University, Starkville, MS 39762, USA
    2Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS 39762, USA
    3Department of Biological Sciences, Tougaloo College, Tougaloo, MS 39174, USA
    4College of Chemical Sciences, Institute of Chemistry Ceylon, Rajagiriya 10100, Sri Lanka
    5Department of Physics and Astronomy, Mississippi State University, Starkville, MS 39762, USA
    6Material Science Lab, Integrated Microscopy Center, University of Memphis, Memphis, TN 38152, USA
    7Institute of Imaging and Analytic Technology (I2AT), Mississippi State University, Starkville, MS 39762, USA
    8Department of Sustainable Bioproducts, Mississippi State University, Box 9820, Starkville, MS 39762, USA
    9Department of Chemistry, Faculty of Science, Damietta University, New Damietta 34517, Egypt
    10School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India
    11Department of Biochemistry, Mississippi State University, Starkville, MS 39762, USA
    12Mississippi State Chemical Laboratory, Mississippi State University, Starkville, MS 39762, USA
    13Global Center for Aquatic Health and Food Security, Mississippi State University, Starkville, MS 39762, USA
    14Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS 39762, USA