During the Apollo missions, astronauts faced challenges from sharp, fine particles of lunar dust that clung to nearly everything, posing potential health risks while causing instrument malfunctions and allergy-like symptoms.
As the space sector prepares for future Mars missions, astronauts and researchers are investigating how Mars dust may impact astronauts and their equipment.
Mars, the Toxic Beach
Justin Wang, a medical student at the University of Southern California, has a background in planetary sciences and aerospace engineering, compares a visit to Mars like one to a sandy beach. When a person leaves the beach, the sand often sticks to their skin, gets tucked into clothing crevices, and may even be deposited in food or drink items.
Except that Mars, a very big and dusty planet, is more like a toxic beach.
Wang is the lead author of a new study published in GeoHealth surveying the minerals and chemicals found in Martian soil. Together, his team examined rover and satellite data, Martian meteorites, and any data on the composition of Mars dust.
“Mars is known as the Red Planet, and the reason for that is that a lot of iron oxides are there, and iron oxide is something that we are concerned about for the health of humans,” says Wang.
In addition to iron oxide, Wang found that Mars dust is made up of many toxic components, including including silica, gypsum, chromium, and arsenic, among others. Although these chemicals and minerals are also found on Earth, people are not often exposed to them in large quantities over extended periods.
But inhalation of these chemicals and minerals can cause adverse, irreversible health problems.
Read More: Adjusting to Earth: How Butch, Suni, and Other Astronauts Readjust After Space Travel
How Particulate Matter Harms Lungs
Glass, for example, is primarily made of silica, and glassblowers have been known to develop a lung disease called silicosis, for which there is no cure.
Gypsum is commonly found in drywall and plaster, and construction workers have reported long-term respiratory ailments like asthma and bronchitis.
Black lung disease, also known as coal workers' pneumoconiosis, occurs when coal dust is inhaled over a prolonged period. These particles lodge in the lungs, causing inflammation and scarring over time, according to the American Lung Association. Similar chemicals found in Mars dust have also been identified in coal dust, which the Interagency for Research on Cancer reports to include silica, phosphates, and arsenic, among others.
Inhalation of coal or Mars dust can lead to irritation and inflammation of the lungs, creating a pathway to severe lung disease.
“With astronauts, they’re working in these small confined spaces without the ability to clean and filter these chemicals out, so they’re exposing themselves — and not just to silica,” says Wang. “Dust particles, including silica, cause irritation and inflammation in the lungs, and as it oxidizes, it reacts with our tissue.”
Highly oxidizing compounds called perchlorates — made of one chlorine and multiple oxygen atoms — also pose a potentially serious threat. Although rare on Earth, perchlorates interfere with the thyroid's ability to absorb iodine, which is vital to thyroid function. Perchlorates also make up a “pretty significant” part of Mars dust.
Even Smaller Particles
Spacesuits are self-contained and act in some ways like scuba equipment. Astronauts use oxygen in tanks in a closed system because there is very little oxygen on Mars and the Moon. Mars dust is very fine and electrostatic, meaning it can get stuck on spacesuit equipment that is carried inside.
In most cases, Mars dust particles are too fine for the body to expel.
“The size of dust particles on Mars is really, really small because its components have been eroded down over billions of years. So when a person inhales Mars dust, it’s too small to attach to our mucus and for the lungs to cough it out,” says Wang.
“Not only is the dust harmful, but it’s going to stay inside the lungs and continue to cause damage, potentially being absorbed into the bloodstream and cause more systemic issues,” Wang adds.
Preparing for Mars
Particulate matter, like dust or smoke, is often measured using a scale of diameter. Fine particles, like those found in wildfires, measure 2.5 µm in diameter or smaller (PM2.5) and can affect the lungs and heart. Larger particles (PM10 and above) are generally of less concern. Mars dust averages roughly PM3, by comparison.
Humans have yet to visit Mars, a transit estimated to take between six and 12 months, that will expose astronauts to other concerns, such as radiation and the effects of microgravity. Still, Wang says Martian dust is not a “game ender” for future Mars exploration.
“I don’t consider this mission ending or the most dangerous part of going to Mars, nor do I consider it the most dangerous medical complications that can be seen when going to Mars,” says Wang. “This is just something we need to address — Martian dust as its own entity.”
Chris Mason, a professor of physiology and biophysics at Cornell Medicine, says that this “prioritized inventory” of Martian dust helps researchers better understand the environmental impacts of Mars on humans, as well as on equipment and tools.
NASA writes that the “surface of Mars is a challenging and inhospitable place,” and the Red Planet’s fine dust presented challenges to rovers. In 2020, scientists developed a specially designed tire tread that could withstand the shape-shifting materials on the Martian surface
Just like the physical properties of Mars dust pose challenges to human-made objects, exposure to the toxic dust can also erode their structure. Exposure to the chemicals is likely okay in the short term, but long-term exposure presents logistical challenges to structural objects in addition to biomedical issues, says Mason.
This means that containment methods need to be “even better than they might be in other environments,” with redundancies put in place across measures. Just like double-bagging groceries protects food if the first bag fails, redundancy helps protect structures and astronauts in the event of deterioration.
“Anything in space is possible,” saysWang. “Preparation is key. Prepare for the worst, but hope for the best.”
Read More: How Long-Term Space Travel Wears Down an Astronaut’s Mind and Body
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
American Lung Association. Coal Worker’s Pneumoconiosis (Black Lung Disease)
NIH. Coal Dust
Madison’s reporting focuses on marine and environmental issues, climate change, and novel scientific discoveries related to health and technology. Raised on an island in southeast Alaska, Madison is now based in western Montana. Her writing has been featured in Time, Snopes, Business Insider, Mountain Journal, EcoWatch, and Alaska Magazine, among others. When not writing, Madison teaches yoga, raises chickens, and fosters adoptable dogs and cats.
