Synergistic Multi-Spectroscopic Assessment of Photo-Oxidative Degradation and Micro Plastic Leaching in Bottled Water under Extreme Solar Conditions

Abstract

Plastics are being increasingly used in drinking water containers, and this has raised concerns regarding the distribution of micro plastics and other substances into the water, especially during hot weather and exposure to sunlight. Polymer packaging is subject to chemical and structural changes resulting from heat and sunlight over time, which can lead to migration of degradation products into drinking water. The photo-oxidation behavior of polyethylene, commonly called PE, and PET (polyethylene terephthalate) water bottles was investigated in this study during a period of 7 days of simulated sunlight at 45°C. An incorporated analytical approach combining Raman analysis with Fourier transform infrared (FTIR) and attenuated total reflectance (ATR) spectrometers was utilized to monitor molecular-level degradation and polymer transformation processes. The results indicate a significant increase in oxygen-containing functional groups, in particular hydroxyl and carbonyl groups, which is indicative of a faster oxidative degradation of the polymer structure. These chemical modifications suggested the presence of, direct formation of and discharge of microplastics to the aquatic environment. These results highlight the extent to which drinking water bottled in plastic containers is affected by harmful environmental factors, and emphasize the need to improve packaging regulations and periodic monitoring strategies to reduce human exposure to plastic-derived pollutants, while suggesting the use of glass containers as a safer alternative.