Investigating Trophic Exposure to Marine Microplastics and Plasticizers in a Sentinel Species and the Implications for Seafood Safety

项目摘要/摘要 这项拟议的研究将使本科生接触到实践中的严谨研究，探索 海洋、野生动物和人类健康的交叉点。具体地说，学生将参与研究以 了解从受污染的海鲜中接触微塑料和增塑剂(即邻苯二甲酸盐)的风险。 几十年来，宽吻海豚(Tursioptruncatus)一直被用作海洋污染风险的哨兵 依赖海鲜的沿海社区。由于最近在沿海地区检测到普遍存在的邻苯二甲酸盐暴露 对于宽吻海豚，将使用哨兵物种方法来解决三个具体目标：1)评估 营养性接触微塑料的可能性；2)确定邻苯二甲酸盐暴露是否是微塑料的指标 以及3)评估邻苯二甲酸盐暴露的时空差异。这项本科生研究 经验将为学生提供参与联邦保护的创新学习的机会 物种，参与最先进实验室的生态毒物分析，开发适销对路的统计 通过向出版物和演示文稿投稿，加强他们的科学交流。 学生还将接触到广泛的生物医学领域，因为他们将与科学家密切合作 在流行病学、生物统计学、生物学和环境保护、生态毒理学和环境健康方面的专业知识。 海洋中含有数以万亿计的塑料颗粒，主要是微塑料(即直径5毫米的颗粒； 约93%的颗粒物)，已在海洋食物网各级生物体中检测到。 这些发现表明，海鲜安全正受到威胁，公共健康受到威胁，因为 微塑料摄入会导致胃肠道炎症、新陈代谢改变和氧化应激。 塑料还可以渗出干扰内分泌的邻苯二甲酸盐，这与不孕不育有关，异常 生殖器官发育、乳腺癌风险增加和不良妊娠结局。长期的 这项研究的目标是检查被微塑料污染的海鲜是否可能成为人类的另一个来源 接触有害的外来生物物质，以及这种接触在空间和时间上是否不同。研究目标将通过以下途径实现 在佛罗里达州萨拉索塔湾对自由活动的海豚和它们喜欢的猎物进行连续横断面取样。对于目标1， 微塑料的特征将在海豚的胃和粪便样本中，以及鱼肉和 胃肠道组织。在颗粒大小、类型和聚合物组成方面的相似之处将提示营养性暴露。 对于目标2，将对海豚尿液和鱼类代谢组织中的邻苯二甲酸盐代谢物进行量化检测 目标1.目标3的尿邻苯二甲酸酯代谢物与微塑料摄入量的相关性 将对两个不同的海豚种群(佛罗里达州萨拉索塔湾和洛杉矶巴拉塔里亚湾)的浓度进行比较 并跨越时间(2010-2024年)，以了解暴露风险的时空差异。这项研究的发现 将有助于评估受污染的海鲜作为微塑料和邻苯二甲酸盐的额外来源的潜力 对人类的风险暴露，以及关于海鲜安全的信息干预和风险沟通需求。

Project Summary/Abstract This proposed study will expose undergraduate students to hands-on, rigorous research that explores the intersections of oceans, wildlife, and human health. Specifically, students will participate in research to understand the risk of exposure to microplastics and plasticizers (i.e., phthalates) from contaminated seafood. For decades, bottlenose dolphins (Tursiops truncatus) have been used as sentinels of marine pollution risks for coastal communities that rely on seafood. Due to the recent detection of prevalent phthalate exposure in coastal bottlenose dolphins, a sentinel-species approach will be used to address three specific aims: 1) assess the potential for trophic exposure to microplastics; 2) determine if phthalate exposure is an indicator of microplastic exposure; and 3) evaluate spatiotemporal differences in phthalate exposure. This undergraduate research experience will provide an opportunity for students to engage in innovative studies of a federally-protected species, participate in ecotoxicological analyses in state-of-the-art laboratories, develop marketable statistical skills, and enhance their scientific communication through contributions to publications and presentations. Students will also be exposed to a broad range of biomedical fields as they will work closely with scientists with expertise in epidemiology, biostatistics, biology and conservation, ecotoxicology, and environmental health. The oceans contain trillions of plastic particles, mostly microplastics (i.e., particles < 5 mm diameter; approximately 93% of particles), which have been detected in organisms at all levels of the marine food web. These discoveries suggest that seafood safety is being threatened and public health compromised, as microplastic ingestion can lead to gastrointestinal inflammation, altered metabolism, and oxidative stress. Plastics can also leach endocrine-disrupting phthalates, which are associated with infertility, abnormal reproductive organ development, increased breast cancer risk, and poor pregnancy outcomes. The long-term goal of this study is to examine if microplastic-contaminated seafood could be an additional source of human exposure to harmful xenobiotics, and if this exposure varies spatiotemporally. Study aims will be addressed via serial cross-sectional sampling of free-ranging dolphins and their preferred prey in Sarasota Bay, FL. For Aim 1, microplastics will be characterized in dolphin gastric and fecal samples, as well as fish muscle and gastrointestinal tissues. Similarities in particle size, type, and polymer composition will suggest trophic exposure. For Aim 2, phthalate metabolites will be quantified in dolphin urine and fish metabolic tissues to examine correlations with ingested microplastics quantities from Aim 1. For Aim 3, urinary phthalate metabolite concentrations will be compared between two distinct dolphin populations (Sarasota Bay, FL; Barataria Bay, LA) and across time (2010-2024) to understand spatiotemporal differences in exposure risk. Findings from this study will help to evaluate the potential of contaminated seafood as an additional source of microplastic and phthalate exposure for humans, as well as inform intervention and risk communication needs regarding seafood safety.