Abstract：
Microplastics (MPs) are growing and ubiquitous environmental pollutants and represent one of the greatest contemporary challenges caused by human activities. Current research has predominantly examined the singular toxicological effects of individual polymers, neglecting the prevailing reality of organisms confronted with complex contaminant mixtures and potential synergistic effects. To fill this research gap, we investigated the lethal and sublethal effects of two common MPs, polystyrene (PS - 4.8-5.8 μm) and poly(methyl methacrylate) (PMMA - 1-40 μm), and their combination (MIX), on the pollinating insect Apis mellifera. For each treatment, we evaluated the oral toxicity of two ecologically relevant and one higher concentration (0.5, 5 and 50 mg/L) and analysed their effects on the immune system and worker survival. As immune activation can alter the cuticular hydrocarbon profile of honey bees, we used gas chromatography-mass spectrometry (GC-MS) to investigate whether MPs lead to changes in the chemical profile of foragers and behavioural assay to test whether such changes affect behavioural patterns of social recognition, undermining overall colony integrity. The results indicate an additive negative effect of PS and PMMA on bee survival and immune response, even at ecologically relevant concentrations. Furthermore, alterations in cuticle profiles were observed with both MPs at the highest and intermediate concentrations, with PMMA being mainly responsible. Both MPs exposure resulted in a reduction in the abundance of several cuticular compounds. Hive entry guards did not show increased inspection or aggressive behaviour towards exposed foragers, allowing them to enter the colony without being treated differently from uncontaminated foragers. These findings raise concerns not only for the health of individual bees, but also for the entire colony, which could be at risk if contaminated nestmates enter the colony undetected, allowing MPs to spread throughout the hive.
摘要：
微塑料（MPs）是不断增长且无处不在的环境污染物，是人类活动引起的当代最大挑战之一。目前的研究主要研究了单个聚合物的单一毒理学效应，忽略了生物面临复杂污染物混合物和潜在协同效应的普遍现实。为了填补这一研究空白，我们调查了两种常见MPs的致死和亚致死效应，聚苯乙烯（PS-4.8-5.8μm）和聚（甲基丙烯酸甲酯）（PMMA-1-40μm），以及它们的组合(MIX)，授粉昆虫Apismellifera。对于每一种治疗,我们评估了两种生态相关和一种较高浓度（0.5、5和50mg/L）的口服毒性，并分析了它们对免疫系统和工人存活的影响。由于免疫激活可以改变蜜蜂的表皮碳氢化合物分布，我们使用气相色谱-质谱（GC-MS）来调查MPs是否导致觅食者化学概况的变化，并进行行为测定以测试这些变化是否影响社会识别的行为模式。破坏整个殖民地的完整性。结果表明，PS和PMMA对蜜蜂的生存和免疫反应具有累加的负面影响，即使在生态相关的浓度。此外，在最高和中等浓度的MPs中观察到角质层轮廓的改变，主要由PMMA负责。两种MP暴露都导致几种角质层化合物的丰度降低。蜂巢入口警卫没有对暴露的觅食者表现出更多的检查或侵略行为，允许它们进入殖民地，而不会受到与未污染的觅食者不同的待遇。这些发现不仅引起了人们对蜜蜂个体健康的关注，而且对于整个殖民地来说，如果受污染的鸟巢进入殖民地而未被发现，这可能会有风险，允许国会议员在整个蜂巢中传播。
