Application of Infrared and Near-Infrared Microspectroscopy to Microplastic Human Exposure Measurements

Abundance, characterization, and health risk evaluation of microplastics in borehole water in Birnin Kebbi, Nigeria

Microplastic pollution has become a global menace, and water, being a major "sink" for pollutants, represents a significant source of human exposure. This study aimed to assess the safety of borehole water in Birnin Kebbi, Nigeria, specifically concerning microplastic pollution. Water samples were collected from boreholes in selected areas, including Bayan Kara, Malali, Rafin Atiku, Aliero Quarters, GwadanGaji, FUBK Takeoff Site, Kalgo Market, and Tarasa. Microplastics were extracted from the water samples through filtration using glass fiber filter papers, and were subsequently subjected to spectroscopy and microscopy to determine concentrations, shapes, and polymer types. Health risks associated with the microplastics were also calculated. The results revealed that the samples from Tarasa exhibited the highest concentrations of microplastics (96.967 particles/L), followed by Bayan Kara (92.70 particles/L), Rafin Atiku (92.33 particles/L), GwadanGwaji (92.30 particles/L), FUBK Takeoff Site (91.07 particles/L), Aliero Quarters (90.43 particles/L), Kalgo Market (88.00 particles/L), and Malali (86.40 particles/L). The most dominant shape was fibers (73 %), followed by fragments (16 %), foams (6 %), and filaments (5 %). Polyethylene and polyamide, in that order, were the most dominant polymers, while polystyrene was the least common. The majority of risk scores were classified as III. It can be inferred from the results that microplastic pollution in borehole water poses a health hazard in the city. Consumers of borehole water in the studied areas are advised to treat the water before consumption to mitigate potential health risks.

Effects of Benzo (a) Pyrene and 2,2',4,4'-Tetrabromodiphenyl Ether Exposure on the Thyroid Gland in Rats by Attenuated Total Reflection Fourier-Transform Infrared Spectroscopy

Benzo[a]pyrene (B[a]P) and 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) are widespread environmental pollutants and can destroy thyroid function. We assessed the biochemical changes in the thyroid tissue of rats exposed to B[a]P and BDE-47 using attenuated total reflection Fourier-transform infrared spectroscopy combined with support vector machine(SVM). After B[a]P and BDE-47 treatment in rats, the structure of thyroid follicles was destroyed and epithelial cells were necrotic, indicating that B[a]P and BDE-47 may lead to changes of the thyroid morphology of the rats. These damages are mainly related to C=O stretch vibrations of lipids (1743 cm-1), as well as the secondary structure of proteins [amide I (1645 cm-1) and amide II (1550 cm-1)], and carbohydrates [C-OH (1138 cm-1), C-O (1106 cm-1, 1049 cm-1, 991 cm-1), C-C (1106 cm-1) stretching] and collagen (phosphodiester stretching at 922 cm-1) vibration modes. When SVM was used for classification, there was a substantial separation between the control and the exposure groups (accuracy = 96%; sensitivity = 98%; specificity = 87%), and there was also a major separation between the exposed groups (accuracy = 93%; sensitivity = 94%; and specificity = 92%).