The impact of particle size and photoaging on the leaching of phthalates from plastic waste

Abstract

Plastic wastes are important sources of phthalates (PAEs), which are a class of endocrine disrupting compounds (EDCs). However, there are still knowledge gap about how environmental weathering processes affect the release of PAEs from plastics wastes. In this study, we investigated the effects of particle size and photoaging on the leaching of PAEs from two kinds of commercial polyethylene plastic express packaging bags with different PAEs contents. Reduction of the size of the plastic from 5 cm to <0.5 mm did not significantly change the leaching of PAEs from the express packaging bags. After photoaging, the sum of all detected PAEs (∑PAEs) leaching amounts from two plastic bags were 1.76–2.91 times and 1.24–2.19 times higher than those of the two original materials, respectively. However, due to the degradation effect of ultraviolet (UV) irradiation on PAEs in plastics, the leaching amount of PAEs decreased at the later stage of the photoaging. The effect of photoaging on the surface properties of polyethylene (PE) plastics, especially on the surface functional groups and hydrophilicity, contributed significantly to the leaching of PAEs. The result of this study indicated that the risk of PAEs release from plastic wastes in the environment could be promoted by photoaging processes. Considering the high leaching ratios of PAEs from plastic packaging materials in this study, these plastic bags may increase the environmental burden and risk of PAEs, even though the PAEs levels of them are low.