Screening the release of chemicals and microplastic particles from diverse plastic consumer products into water under accelerated UV weathering conditions

Abstract

Photodegradation of plastic consumer products is known to accelerate weathering and facilitate the release of chemicals and plastic particles into the aquatic environment. However, these processes are complex. In our presented pilot study, eight plastic consumer products were leached in distilled water under strong ultraviolet (UV) light simulating eight months of Central European climate and compared to their respective dark controls (DCs). The leachates and formed plastic particles were exploratorily characterized using a range of chemical analytical tools to describe degradation and leaching processes. These techniques covered (a) microplastic analysis, showing substantial liberation of plastic particles further increased under UV exposure, (b) non-targeted mass spectrometric characterization of the leachates, revealing several hundreds of chemical features with typically only minor agreement between the UV exposure and the corresponding DCs, (c) target analysis of 71 organic analytes, of which 15 could be detected in at least one sample, and (d) metal(loid) analysis, which revealed substantial release of toxic metal(loid)s further enhanced under UV exposure. A data comparison with the US-EPA’s ToxVal and ToxCast databases showed that the detected metals and organic additives might pose substantial health and environmental concerns, requiring further study and comprehensive impact assessments. Environmental implicationThis pilot study illuminates the complex nature of chemicals and particles liberated from common consumer plastics when subjected to UV irradiation mimicking prolonged sunlight exposure. We use complementary chemical analytical approaches to demonstrate the significant release of complex chemical patterns and microplastics to water upon UV-induced weathering and photodegradation. Understanding these degradation processes is key to mitigating the environmental impact of plastic products during their lifetime and following disposal.