As plastic has become an integral component of daily life, microplastic has become a ubiquitous, unavoidable constituent of nearly all ecosystems. Besides monitoring the amount and distribution of microplastic in the environment, it is necessary to understand the possible direct effects, especially toxicity and how it is affected by environmental factors where it is discarded. The present study investigated how microplastic derived from high-density polyethylene bottle caps collected in two climatically different cities, i.e., Singapore (tropical rainforest climate) and Lahti, Finland (continental climate), affected the essential agricultural grain crop, Triticum aestivum (L.). Wheat seedlings were exposed to microplastic derived from these collected bottle caps, as well as new and artificially aged caps, for seven days. Morphological parameters, such as root and shoot length and oxidative stress development, were measured. Exposure to microplastic derived from the caps resulted in reduced seedling root and shoot lengths compared to the controls, as well as enhanced lipid peroxidation and catalase activity. With all parameters tested, microplastic derived from Lahti bottle caps exhibited more severe effects than Singapore, which was similar to that elicited by new microplastic. The Singapore microplastic had possibly leached its toxic substances before collection due to accelerated degradation promoted by the prevailing warmer climate conditions.

中文翻译：

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案例研究比较两个城市收集的瓶盖微塑料对普通小麦（小麦）的影响

随着塑料已成为日常生活不可或缺的组成部分，微塑料已成为几乎所有生态系统中无处不在、不可避免的组成部分。除了监测微塑料在环境中的数量和分布外，还需要了解可能的直接影响，尤其是毒性，以及它如何受到丢弃的环境因素的影响。本研究调查了在两个气候不同的城市，即新加坡（热带雨林气候）和芬兰拉赫蒂（大陆气候）收集的高密度聚乙烯瓶盖中提取的微塑料如何影响必需的农作物小麦。(L.)。小麦幼苗暴露于来自这些收集的瓶盖以及新的和人工老化的瓶盖的微塑料中 7 天。测量形态参数，例如根和枝条长度以及氧化应激发育。与对照相比，暴露于来自帽的微塑料导致幼苗根和芽长度减少，以及脂质过氧化和过氧化氢酶活性增强。在测试所有参数后，来自 Lahti 瓶盖的微塑料表现出比新加坡更严重的影响，这与新微塑料引起的影响相似。由于普遍变暖的气候条件促进了加速降解，新加坡微塑料可能在收集之前浸出其有毒物质。