SPECTROSCOPIC EVALUATION AND HEALTH RISK ASSESSMENT OF MICROPLASTICS (MPs) IN BOTTLED WATER SAMPLES SOLD IN ABAKALIKI, NIGERIA

Abstract

The evaluation of microplastics (MPs) in bottled water samples sold in the Abakaliki metropolis was investigated. The absorption peak of the infrared spectroscopy (IR) obtained were 1397, 1636, 1830, 2303, 3261, and 3749 cm-1for sample A1; 1640 cm-1, 2117 cm-1, 3268 cm-1 for A2; while A3, A4 and A5 samples were respectively: 1640 cm-1, 2120 cm-1, 3268 cm-1; 1640 cm-1, 2124 cm-1, 3268 cm-1; 1640 cm-1, 2105 cm- 1 and 3273 cm-1. The functional groups that correspond to the absorption peak of samples A1 to A5 were C=C, C=O, O-H, and an additional C-O for sample A1. Interestingly, all the studied samples were absorbed at 1640 cm-1 while other absorption peaks varied. The particle size of the sample ranged from 17.20 particle/0.75L sample A5 to 44.63 particle/0.75L sample A3. The predominant shape of the microplastic detected was granules. Microplastic pollution load index (MPPLI), micro-plastic contamination factor (MPCF), and the estimated daily intake (EDI) for both children and adults were determined. The MPCF values obtained ranged from 1.00 for sample A1 to 2.59 for sample A3 and followed the profile A5<A1<A4<A2<A3. The result for EDI for adults was less than 1 except in samples A2 and A3 which were slightly greater than 1. The EDI for children ranged from 2.06 samples A5 to 5.36 samples A3. The EDI result showed that children consume more microplastics than adults. The MPPLI was obtained to be 1.58. The microplastic abundance was calculated as 12 % for samples A1 and A5, 21 % for sample A4, 24 % for sample A2, and 31 % abundance for sample A3.