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

点击翻译按钮获取中文摘要

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.