Plastic Bottle Tops—A Major Source of Plastic in the Terrestrial Environment of the United Arab Emirates

Bottle tops made of polythene (PE) and polypropylene (PP) are a major source of terrestrial plastic pollution in the United Arab Emirates (UAE). This study looks at the occurrence, distribution and fate of plastics derived from bottle tops in the area of Al Ain, Eastern region of Abu Dhabi, UAE. Photo-oxidative degradation of the plastics in the hot, arid environment of Al Ain can be followed by infrared spectroscopy and quantified by the oxidation index (OxI). The oxidation index can be used to estimate the residence time of the plastic in the open environment. Oxidation of plastic bottle tops in the open environment over a period of 15 months leads to brittleness. Easy fragmentation of the tops can occur upon impact with another body, resulting in meso- and microplastics. This was demonstrated by the effect that a hailstorm as a single weather event had on an experimental “field” of plastic bottle tops set out in the open. Here, the oxidation index was a good indicator of whether the plastic fragmented or stayed intact. To reduce the contamination of the environment with plastic bottle tops, it is suggested that legislation be developed similar to the EU’s Single-Use Plastics Directive requiring that plastic bottle tops remain attached to their bottles. This also aligns with the principles of a more circular economy.