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The ISS is contaminated with a disturbing amount of harmful chemicals

A startling discovery has revealed that the International Space Station (ISS) has concentrations of potentially harmful chemical compounds surpassing those found in most American homes. These harmful chemicals were found in dust collected from the air filtration systems on the International Space Station (ISS).

This alarming revelation stems from the first study of its kind, led by researchers from the University of Birmingham, UK, along with the NASA Glenn Research Center, USA.

In their investigation, the scientists examined a sample of dust from air filters within the ISS, uncovering levels of harmful chemicals and organic contaminants higher than the median values commonly found in homes in the United States and Western Europe.

This pivotal study, published today in the journal Environmental Science and Technology Letters, highlights the potential consequences of these findings in shaping the design and construction of future spacecraft.

The harmful chemicals found on the ISS

The list of contaminants discovered in the ‘space dust’ is quite extensive and includes polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCDD), ‘novel’ brominated flame retardants (BFRs), organophosphate esters (OPEs), polycyclic aromatic hydrocarbons (PAH), perfluoroalkyl substances (PFAS), and polychlorinated biphenyls (PCBs).

Many of these substances, such as BFRs and OPEs, have various applications on Earth and are used to meet fire safety regulations in consumer products like electronic equipment, building insulation, and furniture fabrics.

Others, like PAH, can be traced to hydrocarbon fuels, while some, such as PCBs and PFAS, have been used in building materials and clothing treatments. The potential health impacts of these substances have resulted in several of them being restricted or banned altogether.

Furthermore, some of these chemicals, including PCBs, specific PFAS, HBCDD, and particular commercial formulations of PBDEs, fall under the category of persistent organic pollutants (POPs) as defined by the UNEP Stockholm Convention.

Certain PAHs are also classified as human carcinogens. Some OPEs are under consideration for restriction by the European Chemicals Agency.

Where did these harmful chemicals come from?

Co-author Professor Stuart Harrad from the University of Birmingham noted the significance of these findings. He stated, “Our findings have implications for future space stations and habitats, where it may be possible to exclude many contaminant sources by careful material choices in the early stages of design and construction. While concentrations of organic contaminants discovered in dust from the ISS often exceeded median values found in homes and other indoor environments across the US and western Europe, levels of these compounds were generally within the range found on earth.”

The researchers point out that the PBDE concentrations in the dust sample may reflect the use of specific flame retardants like ammonium dihydrogen phosphate in fabrics and webbing on the ISS.

Additionally, they identified commercially available ‘off-the-shelf’ items brought aboard for the astronauts’ personal use, such as cameras, MP3 players, tablet computers, medical devices, and clothing, as potential sources of many of these chemicals.

ISS filtration systems not helping

The recirculation of air within the ISS, with 8-10 changes per hour, complicates the situation. Although removal of CO2 and gaseous trace contaminants occurs, the effectiveness of this process in eliminating chemicals like BFRs is still unknown.

Adding to the complexity, the researchers observed that high levels of ionizing radiation could accelerate the aging of materials on the ISS. This might lead to the breakdown of plastic goods into micro and nanoplastics that become airborne in the microgravity environment.

As a result, the concentrations and relative abundance of chemicals like PBDEs, HBCDD, NBFRs, OPEs, PAH, PFAS, and PCBs in ISS dust could differ markedly from those in dust from terrestrial indoor microenvironments.

How the harmful chemicals were measured

In order to measure these harmful chemicals, scientists collected dust samples from the ISS’s microgravity environment, where particles float according to ventilation system flow patterns before settling on surfaces and air intakes.

The ISS HEPA filters, covered with screens that gather this debris, must be vacuumed weekly to maintain efficient filtration. Samples from the vacuum bags, consisting of airborne particles, clothing lint, hair, and other debris, were returned to Earth and subsequently shipped to the University of Birmingham for analysis.

This unique study shines a new light on the hidden challenges of life in space, emphasizing the importance of careful material selection and constant monitoring to safeguard astronauts’ health. It sets the stage for ongoing exploration and provides a roadmap for the safe and responsible design of future space stations and habitats.

More about the International Space Station (ISS)

The International Space Station (ISS) is a space station, or a habitable artificial satellite, orbiting the Earth. It serves as a microgravity and space environment research laboratory in which scientific research is conducted in astrobiology, astronomy, meteorology, physics, and other fields.

A multinational collaborative project involving five participating space agencies, the ISS is one of the most significant achievements in international cooperation for space exploration.

Development and construction

The construction of the ISS began in 1998 and was completed in 2011, although modifications and improvements continue to be made. It involved cooperation from NASA (United States), Roscosmos (Russia), JAXA (Japan), ESA (European Space Agency), and CSA (Canadian Space Agency). These agencies worked together to assemble the station in orbit, using various modules launched from Earth.


The ISS consists of a series of interconnected modules and components that include research laboratories, living quarters, solar arrays, and other support structures. It is divided into two main sections: the Russian Orbital Segment (ROS) and the American Orbital Segment (AOS), shared by many nations.


Astronauts and cosmonauts from around the world live and work on the ISS. They conduct experiments, perform maintenance, and engage in outreach activities with schools and the public. Crew members travel to and from the ISS aboard various spacecraft, and the station is resupplied regularly with cargo missions.


The ISS provides a unique platform for scientific research that cannot be performed on Earth. Scientists utilize the microgravity environment to study biological organisms, human biology, physics, astronomy, and other scientific disciplines. The results of this research contribute to advancements in medicine, technology, and our understanding of the universe.

Life aboard the ISS

Life on the ISS requires adaptation to a microgravity environment. Crew members follow a strict schedule that includes work, exercise, meals, and leisure time. They must also adhere to specific protocols for hygiene and safety.

International collaboration

The ISS represents a significant example of international collaboration. It has fostered partnerships between countries and space agencies, allowing shared access to resources, research opportunities, and the ability to coordinate joint missions.

Challenges and controversies

The ISS has faced technical and logistical challenges, including mechanical failures, resupply issues, and concerns related to aging infrastructure. Additionally, political tensions among participating nations have occasionally impacted cooperation on the project.

Legacy and future

The ISS has served as a symbol of human achievement in space and has paved the way for future missions to the Moon, Mars, and beyond. Its continued operation relies on international agreements, technological advancements, and sustained interest in human space exploration.

The International Space Station stands as a testament to what can be achieved through international cooperation and technological innovation. As a hub for scientific research and a platform for fostering global partnerships, the ISS continues to play a vital role in humanity’s exploration and understanding of space.

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