Abstract

Air quality on board the International Space Station (ISS) is a significant concern for the long-term health of astronauts living on the station. Aerosolized particles are generated from a variety of sources, such as on-board equipment, electronics, and the astronauts themselves. Airborne particles can remain suspended for significant amounts of time due to the absence of gravitational settling. In this work, we examine the particulate matter on board the ISS through scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM/EDX) and single-particle multi-element inductively coupled plasma time-of-flight mass spectrometry (sp-ICP) analysis of two vacuum bag dust samples collected with a handheld vacuum cleaner used to clean surfaces and filter faces inside the ISS. SEM/EDX analysis shows that many large particles were collected. These particles are most commonly clothing fibers or of biological origin, along with smaller numbers of carbonaceous particles that may be from polymer and halopolymer materials. sp-ICP analysis quantitatively determined metal concentrations in particles approximately <10 µm in diameter and was able to identify several distinct particle compositions. Some of these, such as stainless steel (Fe-Cr-Ni-Mn), antiperspirant (Al-Zr), silver (Ag), and titanium oxide (Ti) particles, are consistent with particle types identified through past aerosol and vacuum bag sampling and analyses. Other types, including Fe-Al and other types of Al and Zr particles, do not have a clear origin consistent with past work. SEM/EDX and sp-ICP provide different but complementary information regarding the composition of particles obtained from vacuum bag dust samples. The material analyzed was obtained through the Divert Unwanted Space Trash (DUST) experiment on ISS, which returned vacuum bags to Earth for the purpose of understanding airborne particles in the unique ISS environment.

Copyright © 2021 American Association for Aerosol Research

摘要

国际空间站（ISS）上的空气质量对于居住在该空间站的宇航员的长期健康至关重要。气溶胶颗粒产生于多种来源，例如车载设备，电子设备和宇航员本身。由于没有重力沉降，空气中的颗粒会保持悬浮状态相当长的时间。在这项工作中，我们通过扫描电子显微镜，能量色散X射线光谱仪（SEM / EDX）和单粒子多元素电感耦合等离子体飞行时间质谱仪（sp -ICP）分析用手持式真空吸尘器收集的两个真空袋灰尘样品，这些灰尘用于清洁ISS内部的表面和过滤器表面。SEM / EDX分析表明，收集到许多大颗粒。这些颗粒是最常见的衣物纤维或生物来源，以及少量的碳质颗粒，这些碳质颗粒可能来自聚合物和卤代聚合物材料。sp-ICP分析可定量确定直径约<10 µm的颗粒中的金属浓度，并能够确定几种不同的颗粒组成。其中一些，例如不锈钢（Fe-Cr-Ni-Mn），止汗剂（Al-Zr），银（Ag）和二氧化钛（Ti）颗粒，与通过过去的气雾剂和真空袋鉴定出的颗粒类型一致采样和分析。其他类型，包括铁铝以及其他类型的Al和Zr颗粒，与过去的工作没有明确的起源。SEM / EDX和sp-ICP提供有关从真空袋灰尘样品中获得的颗粒组成的不同但互补的信息。分析的材料是通过在国际空间站进行的无用转移垃圾（DUST）实验获得的，该实验将真空袋返回地球，目的是了解独特的国际环境中的空气传播颗粒。

版权所有©2021美国气溶胶研究协会