Corcoran Patricia L, Biesinger Mark C, Grifi Meriem
Department of Earth Sciences, University of Western Ontario, London, ON, Canada.
Mar Pollut Bull. 2009 Jan;58(1):80-4. doi: 10.1016/j.marpolbul.2008.08.022. Epub 2008 Oct 2.
Plastic debris in Earth's oceans presents a serious environmental issue because breakdown by chemical weathering and mechanical erosion is minimal at sea. Following deposition on beaches, plastic materials are exposed to UV radiation and physical processes controlled by wind, current, wave and tide action. Plastic particles from Kauai's beaches were sampled to determine relationships between composition, surface textures, and plastics degradation. SEM images indicated that beach plastics feature both mechanically eroded and chemically weathered surface textures. Granular oxidation textures were concentrated along mechanically weakened fractures and along the margins of the more rounded plastic particles. Particles with oxidation textures also produced the most intense peaks in the lower wavenumber region of FTIR spectra. The textural results suggest that plastic debris is particularly conducive to both chemical and mechanical breakdown in beach environments, which cannot be said for plastics in other natural settings on Earth.
地球上海洋中的塑料碎片是一个严重的环境问题，因为在海洋中，化学风化和机械侵蚀造成的分解作用微乎其微。塑料材料沉积在海滩后，会受到紫外线辐射以及由风、洋流、海浪和潮汐作用控制的物理过程的影响。对考艾岛海滩的塑料颗粒进行了采样，以确定其成分、表面纹理和塑料降解之间的关系。扫描电子显微镜图像表明，海滩塑料具有机械侵蚀和化学风化的表面纹理。颗粒状氧化纹理集中在机械弱化的裂缝处以及更圆润的塑料颗粒边缘。具有氧化纹理的颗粒在傅里叶变换红外光谱的低波数区域也产生了最强的峰。纹理结果表明，塑料碎片在海滩环境中特别有利于化学和机械分解，而地球上其他自然环境中的塑料则并非如此。
