Particles of hazardous chemicals are found in dust samples collected from the International Space Station at levels that exceed the typical average.

 

The International Space Station (ISS) operates as a bustling space outpost where astronauts conduct experiments and move equipment. This activity has raised concerns about potential air pollution within the station due to hazardous chemical particles. While astronaut health remains secure for now, NASA must address this issue for prolonged voyages in deep space.

A recent study, featured in the peer-reviewed Environmental Science & Technology Letters journal, unveils that the air on the ISS contains an elevated level of perilous chemical particles compared to Earth's typical readings. Researchers have identified "Persistent Organic Contaminants" in dust samples gathered from the ISS, shedding light on the pathways through which these contaminants infiltrated the highly successful low Earth-orbit platform.

The study pinpoints a higher concentration of flame-retardant compounds like polybrominated diphenyl ethers (PBDEs), novel brominated flame retardant (NBFR), and hexabromocyclododecane (HBCDD) in the ISS air. Additionally, heightened levels of polycyclic aromatic hydrocarbons (PAHs), stemming from hydrocarbon fuel combustion, have been detected.

The investigation also exposes ISS dust contamination with polychlorinated biphenyls (PCBs), a profoundly carcinogenic chemical banned in the US since 1976 by the Toxic Substances Control Act. Elevated quantities of PFAS, PFOA, and other chemicals were also identified, surpassing median values found in residences across the US and several European countries.

The presence of these hazardous chemicals within the ISS prompts the question of how they arrived there. Stuart Harrad, a Professor of Environmental Chemistry at the University of Birmingham and co-author of the study, suggests that many items aboard the ISS are conventional products brought by astronauts. These objects contain organic flame retardants utilized in electrical devices on Earth, leading to their presence in samples returned from the ISS.

Furthermore, the peculiar cleaning practices of ISS inhabitants might contribute to higher chemical concentrations. The space station's vacuum cleaner is frequently employed post-experiments, potentially facilitating the distribution of these chemicals throughout surfaces and the air.

Despite the higher chemical content in ISS samples, Harrad affirms that potential health risks for astronauts remain "within the range" of chemical exposure experienced by the general US population. However, for upcoming Mars and deep space missions, minimizing dangerous contaminants becomes crucial to mitigate heightened health risks for astronauts.