Accumulation and transformation of micro- and nano-plastics within the sea surface microlayer

微塑料和纳米塑料颗粒通过消费者个人护理产品直接进入环境，并随着塑料包装等商业产品的老化和降解而在环境中形成。海洋和沿海生态系统是塑料污染的主要汇。已有证据表明，塑料会积聚在海洋生物体内，并对海洋生物的健康产生负面影响，这反过来又增加了生态系统以及依赖这些生态系统健康的海洋产业的压力。这些微小塑料颗粒的最终命运和不利影响取决于它们在自然界中如何相互作用和运输。海洋的一个关键自然成分和最初暴露于塑料污染的点是海洋表面微层，它在全球普遍存在，由天然分子、颗粒物和微生物组成。这些微层起到了“海洋皮肤”的作用，影响了海水和大气之间的质量和热量交换。它们也是微塑料和纳米塑料积累的场所。该项目将研究微塑料和纳米塑料如何与模型海面微层相互作用，这些相互作用如何使它们在海面上积累和转化，以及微塑料和纳米塑料将在多大程度上改变海面微层的性质。其目的是提供对导致微塑料和纳米塑料堆积的界面和胶体性质的基本见解，这可以广泛地有助于确定塑料污染的环境风险并制定补救战略。通过与东北国家科学基金会路易斯·斯托克斯少数族裔参与联盟计划合作，为两名受资助的代表不足的学生提供研究经验，将扩大参与范围。这些学生还将领导一项新的中学外展活动。海面微层厚度从1微米到1000微米不等，在全球海洋和沿海水域普遍存在，调节着这些水域和大气之间的质量和能量交换。海面微层也是重金属、有机污染物和微粒污染物(包括微塑料和纳米塑料)的聚集地。该项目的动机是以下需求：能够进行实验室研究的具有代表性和商业意义的微塑料和纳米塑料；广泛适用并能够取得与命运、迁移和纳米尺度相互作用有关的可行结果的合适的微层系统；以及表征含有颗粒物质的海面微层所需的显微技术。将通过机械和紫外线降解产生表征良好和尺寸分级的微型和纳米塑料模型(目标1)。将在改良的朗缪尔海槽中制备浮游植物海面微层(目标2)，并用于量化微塑料和纳米塑料的积累和转化与其物理性质和组成的关系(目标3)。为了实现该项目对教育、外联以及多样性和包容性的更广泛影响，代表人数不足的学生将参与研究活动，并将创建一个新的中学外联倡议。海洋塑料提供了一个多用途和及时的平台，让学生参与STEM活动。这项工作的变革性方面源于对海面微层在微纳塑料积累中的作用的有限了解，包括查明目前未知的相互作用和转化机制，展示利用复杂领域样本研究微米和纳米颗粒与生物环境界面相互作用的能力，以及创建可广泛应用于不同海洋和沿海区域的新的实验框架。通过与东北国家科学基金会路易斯·斯托克斯少数族裔参与联盟计划合作，为两名受资助的代表不足的学生提供研究经验，将扩大参与范围。这些学生还将领导一项新的中学外展活动。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Microplastic and nano plastic particles enter the environment directly through consumer personal care products and are formed in the environment as commercial products such as plastic packaging weather and degrade. Oceans and coastal ecosystems are major sinks for plastic pollution. Plastics have been shown to accumulate in and negatively impact the health of marine life, which in turn places added stress on ecosystems as well as marine industries reliant on the health of these ecosystems. The ultimate fate and adverse impacts of these small plastic particles depends on how they interact and are transported in nature. A critical natural component of oceans and a point of initial exposure to plastic pollution are sea surface microlayers, which are ubiquitous globally and are comprised of natural molecules, particulate matter, and microorganisms. These microlayers act as an “ocean skin” that influences the exchange of mass and heat between the seawater and the atmosphere. They are also sites for microplastic and nano plastic accumulation. This project will study how microplastics and nano plastics interact with model sea surface microlayers, how these interactions cause them to accumulate and transform at the sea surface, and to what extent microplastics and nano plastics will alter the properties of sea surface microlayers. The goal is to provide fundamental insight into interfacial and colloidal properties leading to microplastic and nano plastic accumulation that can contribute broadly to determining environmental risks of plastic pollution and to devising strategies for remediation. Participation will be broadened by partnering with the Northeast NSF Louis Stokes Alliances for Minority Participation program to provide research experiences to two supported underrepresented students. These students will also lead a new middle school outreach activity. Sea surface microlayers, which range from 1 to 1000 micrometers thick, are ubiquitous globally on ocean and coastal waters, regulating the exchange of mass and energy between these waters and the atmosphere. Sea surface microlayers are also a site of accumulation for heavy metal, organic, and particulate pollutants including micro- and nano-plastics. This project is motivated by the following needs: Representative and commercially relevant micro- and nano-plastics enabling laboratory studies, suitable microlayer systems that are broadly applicable and enable actionable results relating to fate, transport, and nanoscale interactions, and microscopy techniques needed to characterize sea surface microlayers containing particulate matter. Well-characterized and size-fractionated model micro- and nano-plastics will be created by mechanical and UV degradation (Aim 1). Phytoplankton sea surface microlayers will be prepared in a modified Langmuir trough (Aim 2) and used to quantify the accumulation and transformation of micro- and nano-plastics as a function of their physical properties and composition (Aim 3). To realize the broader impact of the project to education, outreach, and diversity and inclusion, underrepresented students will be engaged in research activities and a new middle-school outreach initiative will be created. Marine plastics provide a versatile and timely platform to engage students in STEM activities. The transformative aspects of this work derive from the limited understanding of the role of the sea surface microlayers in micro- and nano-plastic accumulation and include identifying currently unknown mechanisms of interaction and transformation, demonstrating the ability to utilize complex field samples to study micro- and nano-particle interactions with bio-environmental interfaces, and creating a new experimental framework that can be broadly applied to different ocean and coastal regions. Participation will be broadened by partnering with the Northeast NSF Louis Stokes Alliances for Minority Participation program to provide research experiences to two supported underrepresented students. These students will also lead a new middle school outreach activity.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.