Cookies help us run our site more efficiently.

By clicking “Accept”, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. View our Privacy Policy for more information or to customize your cookie preferences.

Forever chemicals' are known for lingering in the body. Menstruation helps expel them

News Feed
Monday, April 22, 2024

This story is part of a series, “Fighting ‘Forever Chemicals’: Women face pervasive PFAS risks.” Cancer-linked “forever chemicals” got their moniker because of how long they linger without breaking down — in the environment and the human body. Women appear to have a way of shedding at least some of the compounds, however. “Some PFAS bind strongly to proteins in blood, and when women menstruate, they lose those blood proteins linked to PFAS,” Suzanne Fenton, who at the time was a group leader in the Mechanistic Toxicology Branch of the National Toxicology Program at the National Institutes of Health, told The Hill.  “Therefore, this is a unique route of elimination,” added Fenton, who is now the director of North Carolina State University's Center for Human Health and the Environment. Forever chemicals or PFAS, which stands for per- and polyfluoroalkyl substances, are a group of toxic compounds that have been connected to numerous cancers and other illnesses. They are found in many common household items — including waterproof apparel, nonstick pans and cosmetics — and have become pervasive in the air, soil and water due to their use in manufacturing and in certain firefighting foams. The vast majority of Americans have at least some PFAS in their bloodstream. A widely cited study published in 2015 from the Centers for Disease Control and Prevention found that 97 percent of Americans have these substances in their blood.  PFAS tend to bind to proteins like albumin in the blood, according to Erin P. Hines, a researcher in the Environmental Protection Agency’s reproductive toxicology division. But with menstruation and childbirth, she explained, come blood loss. Thanks to their monthly cycle, menstruating adults “typically have a lower body burden” or lower blood concentration of PFAS than non-menstruating peers who live in the same type of community and have a similar socioeconomic status, Hines noted.  A 2022 epidemiological review of studies on the issue also said that “associations have been observed between heavy menstrual bleeding and lower PFAS concentrations.”  Marianthi-Anna ​Kioumourtzoglou, one of the review authors, said the findings show that, at least in theory, some people should be able to “reduce their total body PFAS burden once a month just by menstruating.” A January 2022 Toxicology review published by Fenton’s research team, notes that “menstruation appears to be a crucial route of elimination for many PFAS” and potentially explains up to 30 percent of the discrepancy between male and female PFAS blood levels.  “Since 90–99 percent of PFAS in the blood are bound to serum albumin, menstrual bleeding may prove an important elimination pathway for these persistent substances,” the authors stated.  The authors also cited previous research indicating that PFAS blood concentrations decreased in women who had recently menstruated, relative to individuals who did not experience any such bleeding. Yet another study showed how women who had already undergone menopause — the life stage when menstrual periods cease — had heightened blood levels of four different types of PFAS, in comparison to those who had not yet entered this phase.  Nonetheless, Fenton stressed that “because some PFAS accumulate in tissues, this route is unlikely to rid the body of PFAS.” The impacts of this potential elimination route may also be limited because people are “consistently and constantly exposed” to PFAS, according to ​Kioumourtzoglou, an assistant professor in environmental health sciences at Columbia University. Menstruation’s effectiveness in shedding PFAS is also restricted when periods stop, perhaps as a result of menopause or taking certain hormonal contraceptives. “I think it would be safe to say that a woman who is on an oral contraceptive or an IUD where they're not menstruating would potentially have a higher concentration of the PFAS because they're not menstruating and getting rid of that volume of blood and protein each month,” Hines said.  “Similarly, if you regularly donate blood you can get rid of some of your body burden of the environmental chemicals like the PFAS,” she added. ​Kioumourtzoglou noted that it is important to get a greater understanding of this issue because it could inform health care decisions made by doctors and patients.  “Once we understand this dynamic, if this is an important excretion route then maybe … for some people, we could recommend to go off birth control,” she said. “That could potentially be a recommendation for a certain subset of the population that’s heavily exposed to PFAS and at the same time not in absolute need for birth control, or maybe they can look at different ways of birth control that don’t necessarily reduce blood flow.” But the ability to shed some PFAS through menstruation may be a curse in addition to a blessing — at least when it comes to scientists’ efforts to understand the dangers of PFAS. Kioumourtzoglou’s review notes that because of the substances being excreted in this way, scientists could end up underestimating just how much PFAS people with heavy menstrual bleeding are actually exposed to. “Information on menstrual bleeding may be critical for addressing measurement error to prevent the underestimation of the health impact of PFAS,” the review states.

This story is part of a series, “Fighting ‘Forever Chemicals’: Women face pervasive PFAS risks.” Cancer-linked “forever chemicals” got their moniker because of how long they linger without breaking down — in the environment and the human body. Women appear to have a way of shedding at least some of the compounds, however. “Some PFAS...

This story is part of a series, “Fighting ‘Forever Chemicals’: Women face pervasive PFAS risks.”

Cancer-linked “forever chemicals” got their moniker because of how long they linger without breaking down — in the environment and the human body. Women appear to have a way of shedding at least some of the compounds, however.

“Some PFAS bind strongly to proteins in blood, and when women menstruate, they lose those blood proteins linked to PFAS,” Suzanne Fenton, who at the time was a group leader in the Mechanistic Toxicology Branch of the National Toxicology Program at the National Institutes of Health, told The Hill. 

“Therefore, this is a unique route of elimination,” added Fenton, who is now the director of North Carolina State University's Center for Human Health and the Environment.

Forever chemicals or PFAS, which stands for per- and polyfluoroalkyl substances, are a group of toxic compounds that have been connected to numerous cancers and other illnesses. They are found in many common household items — including waterproof apparel, nonstick pans and cosmetics — and have become pervasive in the air, soil and water due to their use in manufacturing and in certain firefighting foams.

The vast majority of Americans have at least some PFAS in their bloodstream. A widely cited study published in 2015 from the Centers for Disease Control and Prevention found that 97 percent of Americans have these substances in their blood. 

PFAS tend to bind to proteins like albumin in the blood, according to Erin P. Hines, a researcher in the Environmental Protection Agency’s reproductive toxicology division. But with menstruation and childbirth, she explained, come blood loss. Thanks to their monthly cycle, menstruating adults “typically have a lower body burden” or lower blood concentration of PFAS than non-menstruating peers who live in the same type of community and have a similar socioeconomic status, Hines noted. 

A 2022 epidemiological review of studies on the issue also said that “associations have been observed between heavy menstrual bleeding and lower PFAS concentrations.” 

Marianthi-Anna ​Kioumourtzoglou, one of the review authors, said the findings show that, at least in theory, some people should be able to “reduce their total body PFAS burden once a month just by menstruating.”

A January 2022 Toxicology review published by Fenton’s research team, notes that “menstruation appears to be a crucial route of elimination for many PFAS” and potentially explains up to 30 percent of the discrepancy between male and female PFAS blood levels. 

“Since 90–99 percent of PFAS in the blood are bound to serum albumin, menstrual bleeding may prove an important elimination pathway for these persistent substances,” the authors stated. 

The authors also cited previous research indicating that PFAS blood concentrations decreased in women who had recently menstruated, relative to individuals who did not experience any such bleeding. Yet another study showed how women who had already undergone menopause — the life stage when menstrual periods cease — had heightened blood levels of four different types of PFAS, in comparison to those who had not yet entered this phase. 

Nonetheless, Fenton stressed that “because some PFAS accumulate in tissues, this route is unlikely to rid the body of PFAS.”

The impacts of this potential elimination route may also be limited because people are “consistently and constantly exposed” to PFAS, according to ​Kioumourtzoglou, an assistant professor in environmental health sciences at Columbia University.

Menstruation’s effectiveness in shedding PFAS is also restricted when periods stop, perhaps as a result of menopause or taking certain hormonal contraceptives.

“I think it would be safe to say that a woman who is on an oral contraceptive or an IUD where they're not menstruating would potentially have a higher concentration of the PFAS because they're not menstruating and getting rid of that volume of blood and protein each month,” Hines said. 

“Similarly, if you regularly donate blood you can get rid of some of your body burden of the environmental chemicals like the PFAS,” she added.

​Kioumourtzoglou noted that it is important to get a greater understanding of this issue because it could inform health care decisions made by doctors and patients. 

“Once we understand this dynamic, if this is an important excretion route then maybe … for some people, we could recommend to go off birth control,” she said. “That could potentially be a recommendation for a certain subset of the population that’s heavily exposed to PFAS and at the same time not in absolute need for birth control, or maybe they can look at different ways of birth control that don’t necessarily reduce blood flow.”

But the ability to shed some PFAS through menstruation may be a curse in addition to a blessing — at least when it comes to scientists’ efforts to understand the dangers of PFAS. Kioumourtzoglou’s review notes that because of the substances being excreted in this way, scientists could end up underestimating just how much PFAS people with heavy menstrual bleeding are actually exposed to.

“Information on menstrual bleeding may be critical for addressing measurement error to prevent the underestimation of the health impact of PFAS,” the review states.

Read the full story here.
Photos courtesy of

Bills Target Crucitas Gold Mining Mess in Costa Rica

Crucitas ranks among Costa Rica’s most severe environmental setbacks. Illegal gold mining has ravaged the area for years, bringing crime, community unrest, water pollution, and deaths among those risking their lives in unauthorized operations. The once-rich natural zone now shows clear signs of decline, with forests cleared and rivers tainted by chemicals. Recent events highlight […] The post Bills Target Crucitas Gold Mining Mess in Costa Rica appeared first on The Tico Times | Costa Rica News | Travel | Real Estate.

Crucitas ranks among Costa Rica’s most severe environmental setbacks. Illegal gold mining has ravaged the area for years, bringing crime, community unrest, water pollution, and deaths among those risking their lives in unauthorized operations. The once-rich natural zone now shows clear signs of decline, with forests cleared and rivers tainted by chemicals. Recent events highlight the ongoing trouble. Just this month, authorities detained five Nicaraguans for illegal mining, and earlier, two young brothers from Nicaragua died when a tunnel collapsed on them. Rescue teams recovered their bodies after hours of work, a grim reminder of the dangers. These incidents add to a long list of fatalities, as people cross borders chasing gold amid poverty. Lawmakers in the Legislative Assembly are pushing several bills to tackle this mess. The government’s plan stands out—it would permit gold exploration and extraction in Crucitas to curb the chaos from illegal activities. The Alajuela Commission gave it a green light on September 11 with an 8-1 vote, sending it to the full assembly for debate. It awaits scheduling, and motions could still alter it. Supporters argue that regulated mining would bring order, generate jobs, and fund cleanup, but critics question the fit with Costa Rica’s eco-friendly reputation. Open-pit methods, which the bill would allow under strict rules, carry heavy costs. They strip away land, wipe out habitats, and reduce plant and animal diversity. Air gets dusty, water sources shift or get contaminated, and noise drives away wildlife. Communities nearby face health risks from pollutants, as seen already in Crucitas where mercury and cyanide have seeped into streams. Despite bans since 2010, illegal digs persist, often tied to organized groups, making the site a hotspot for violence and smuggling. Another bill, backed by the Frente Amplio party and the Civic Environmental Parliament, takes a different path. It proposes a Sustainable Development Hub for the Huetar Norte region, focusing on recovery without mining. At its core is the Crucitas International Environmental Geopark, covering wooded hills between Fortuna and Botija. A natural and historical museum would join it, highlighting the area’s past and ecology. This approach draws from UNESCO geoparks, with 13 already in Latin America, including one in Nicaragua. Costa Rica’s planning ministry has approved a similar site in Rio Cuarto. The idea is to protect resources while allowing research and low-key recreation. No gold digging permitted—that aligns with the country’s green identity. The hub would put the National System of Conservation Areas in charge of oversight. Locals could run small-scale businesses with support from the Development Bank and rural agencies. Educational programs through the National Learning Institute and universities would train people, creating opportunities on the ground. Tax breaks aim to attract private projects that fit the goals, like eco-tourism or studies. A key part involves cleaning up the damage. Remediation targets the toxins left behind, aiming to restore soil and water. Some still push for mining as the fix, claiming it would stop illegals and boost the economy, but that ignores the added harm to an already battered spot. The debate boils down to priorities: quick cash from gold versus long-term protection. Costa Rica has built its image on sustainability, drawing tourists to parks and beaches. Reopening to mining could shift that, while the hub option builds on strengths in conservation. As bills move forward, locals watch closely, hoping for a solution that heals rather than harms. The post Bills Target Crucitas Gold Mining Mess in Costa Rica appeared first on The Tico Times | Costa Rica News | Travel | Real Estate.

Extraordinary pictures show what a common antibiotic does to E. coli

A commonly used class of antibiotics seems to kill bacteria like E. coli by breaking down their tough armour

The top image shows an untreated E.coli bacterium; the bottom shows a bacterium after 90 minutes of being exposed to the antibiotic polymyxin BCarolina Borrelli, Edward Douglas et al./Nature Microbiology The way antibiotics called polymyxins pierce the armour of bacteria has been revealed in stunning detail by high-resolution microscopy, which could help us develop new treatments for drug-resistant infections. Polymyxins are commonly used as a last-resort treatment against some so-called gram-negative bacteria, which can cause infections such as pneumonia, meningitis and typhoid fever. “The top three World Health Organization priority pathogens are all gram-negative bacteria, and this is largely a reflection of their complex cell envelope,” says Andrew Edwards at Imperial College London. Around their inner cell, these bacteria have an outer surface layer containing molecules called lipopolysaccharides, which act like armour. We knew polymyxins target this outer layer, but how exactly they disrupt it and then kill bacteria wasn’t understood; neither was why the drugs don’t always work. Now, Edwards and his colleagues have used biochemical experiments and atomic force microscopy – in which a needle just a few nanometres wide creates an image of a cell by sensing its shape – to reveal that one of the two types of polymyxin used therapeutically, called polymyxin B, causes strange bulges to break out on the surface of the gram-negative bacterium E. coli. Minutes after the protrusions appear, the bacterium begins to quickly shed its lipopolysaccharides, which the researchers detected in the solution it was in. The researchers say the antibiotic’s presence triggers the bacterium to try to put more and more “bricks” of lipopolysaccharide in its defensive wall. But as it adds bricks, it is also shedding some, temporarily leaving gaps in its defences that allow the antibiotic to enter and kill it. “The antibiotics are a bit like a crowbar that helps these bricks come out of the wall,” says Edwards. “The outer membrane doesn’t disintegrate; it doesn’t fall off. But there are clearly gaps where the antibiotic can then get to the second membrane.” He and his colleagues also uncovered why the antibiotic doesn’t always work: it only affected bacteria that were active and growing. When bacteria were dormant, a state they can enter to survive environmental stress such as nutrient deprivation, the polymyxin B was ineffective, because it wasn’t producing its armour. Images of E. coli exposed to polymyxin B, showing changes to the outer layer of its membrane, from left to right: untreated; bacterium after 15 minutes of antibiotic exposure; after 30 minutes; after 60 minutes; after 90 minutesCarolina Borrelli, Edward Douglas et al. / Nature Microbiology However, the researchers found that providing sugar to the E. coli cells woke them from this dormant state and, within 15 minutes, armour production resumed and the cells were killed. The same is expected to apply to the other polymyxin antibiotic used therapeutically, polymyxin E. Edwards says it might be possible to target dormant bacteria by giving people sugars, but there are dangers to waking these pathogens from their dormant state. “You don’t necessarily want bacteria at an infection site to start multiplying rapidly because that has its own downsides,” he says. Instead, he adds, it might be possible to combine different drugs to bypass the hibernation state without waking the bacteria up.

Cleanup of toxic forever chemicals at Portland base delayed by feds

An Air Force base near Spokane also is among those that will have a longer timeline for cleanup of PFAS.

The U.S. Department of Defense quietly changed its timeline for cleaning up toxic forever chemicals contaminating groundwater at two military bases in Oregon and Washington, delaying the process by six years without public announcement.The Air National Guard base in Portland and the Fairchild Air Force base near Spokane are among nearly 140 military sites nationwide with delayed investigations and remediation for a group of chemicals known as PFAS. The delays come as congressional Republicans are proposing cutting by nearly $200 million the defense agency’s budget for environmental cleanup, including PFAS, an abbreviation for perfluoroalkyl and polyfluoroalkyl substances, and rolling back a 2024 ban on the agency’s use of firefighting foam containing PFAS.Exposure to the human-made chemicals found in flame retardants, nonstick cookware and waterproof clothing can lead to increased risks for cancers, heart damage, high cholesterol and birth defects, among other adverse health effects.Washington was the first state to ban the sale and use of firefighting foam containing PFAS in 2018, and Oregon lawmakers this year voted to phase out the use of PFAS-laden firefighting foam. Such foam was heavily used at military bases for decades, and the Department of Defense has identified at least 600 military sites where PFAS are known to have been released.The delays to PFAS cleanup at military bases were first reported Tuesday by The New York Times. The Times cross-referenced a March list of potentially contaminated military sites — a list not publicly posted on the Defense Department’s website until recently — with a list that had been posted in December by the agency, when it was under the Biden administration.The Capital Chronicle’s own analysis of a Sept. 30, 2024. list found that the Air National Guard site in Portland, then slated to have its PFAS investigation and cleanup planning completed by the end of September 2025, is now slated instead to have that done by September 2031. The remedial investigation and planning for PFAS cleanup previously slated to be complete at Fairchild Air Force base by July 2026 is now expected to be done by June 2032.Michael Loch, a spokesperson for the Oregon Department of Environmental Quality, said in an email that the Air National Guard told Oregon officials at an Aug. 26 meeting that the timeline for cleaning up the base in Portland would be delayed so that money could be directed to other potentially contaminated sites that had not yet undergone investigation. Loch was not able to confirm whether Guard officials told Oregon officials that it would be a full five-year delay.“We are concerned that this shift could mean several years of delay, especially given the high PFAS concentrations already found at the site and its proximity to sensitive water resources like the Columbia Slough,” Loch wrote.The Department of Defense was unable to answer questions from the Capital Chronicle by Tuesday evening about how much information the agency shared with Oregon and Washington state leaders, agencies or impacted communities about the changes.“It will likely take up to a week for our response to be reviewed by general council,” an unidentified Pentagon spokesperson from the Office of the Secretary of Defense said in an email.Stephanie May, a spokesperson for Washington’s Department of Ecology, said in an email she could not confirm by Tuesday whether the Department of Defense told any ecology officials about changes to the clean-up schedule at Fairchild Air Force base, but that they are looking into it.“Our focus in working with the base has been to urge immediate actions that can help nearby residents get safe drinking water and protect their families,” she said.The Environmental Protection Agency officially declared the Fairchild Air Force base a Superfund Site in 1995 for a litany of other contamination issues, and identified in 2017 severe PFAS contamination through well testing. About 100 people who live near the base filed a class action lawsuit in 2018 against 3M — the manufacturer of the firefighting foam used on the base — alleging it has caused them serious health problems.About one-quarter of all military sites with known PFAS releases that are trying to investigate and address contamination now face an average delay of five years, according to the Times’ reporting.In 2024, the U.S. Environmental Protection Agency added several PFAS to the federal list of regulated hazardous substances and mandated states begin testing for them in drinking water systems. In May, the Oregon Department of Environmental Quality added six common PFAS substances to the state’s list of regulated contaminants.Suspected sources of past or ongoing PFAS pollution in Oregon include eight commercial airports that are or were required to maintain PFAS-containing firefighting foam on site, as well as 18 municipal fire training facilities near 20 of the most populous cities in the state, according to rulemaking documents from DEQ.Officials at Portland International Airport began testing for PFAS in 2017 in and around a firefighter training ground there, and found impaired fish and aquatic species in the nearby waters of the Columbia Slough. They have since switched to using PFAS-free firefighting foam and begun initial stages of cleanup.-- Alex Baumhardt, Oregon Capital ChronicleThe Oregon Capital Chronicle, founded in 2021, is a nonprofit news organization that focuses on Oregon state government, politics and policy.If you purchase a product or register for an account through a link on our site, we may receive compensation. By using this site, you consent to our User Agreement and agree that your clicks, interactions, and personal information may be collected, recorded, and/or stored by us and social media and other third-party partners in accordance with our Privacy Policy.

Strange Mars Rocks Could Hold Clues to Ancient Life

NASA’s Perseverance rover has uncovered strange chemical and mineral patterns in Jezero Crater’s Bright Angel formation that may be the strongest hints yet of ancient Martian life. The rocks contain organic carbon, iron, sulfur, and phosphorus arranged in ways eerily similar to microbial processes on Earth. Possible Martian Biosignatures in Jezero Crater A recent study [...]

Rocks in the Bright Angel Formation. NASA’s Mars Perseverance rover acquired this image using its Right Mastcam-Z camera. Mastcam-Z is a pair of cameras located high on the rover’s mast. This image was acquired on May 29, 2024 (Sol 1164) at the local mean solar time of 12:40:40. Credit: NASA/JPL-Caltech/ASUNASA’s Perseverance rover has uncovered strange chemical and mineral patterns in Jezero Crater’s Bright Angel formation that may be the strongest hints yet of ancient Martian life. The rocks contain organic carbon, iron, sulfur, and phosphorus arranged in ways eerily similar to microbial processes on Earth. Possible Martian Biosignatures in Jezero Crater A recent study led in part by Texas A&M University geologist Dr. Michael Tice points to chemical clues in Martian rocks that may signal traces of ancient microbial life. The evidence comes from samples analyzed by NASA’s Perseverance rover. An international group of researchers reported their results after examining a section of Jezero Crater called the Bright Angel formation. The name was inspired by places in Grand Canyon National Park and refers to the pale color of the rocks in that region. Bright Angel lies within the Neretva Vallis channel and contains mudstones packed with oxidized iron (rust), phosphorus, sulfur, and most importantly, organic carbon. While organic carbon has been detected on Mars before, often from sources like meteorites, this particular mix of elements could have provided an energy supply for primitive organisms. Perseverance rover reached the Bright Angel site on Mars by navigating through a dune field, bypassing large boulders. The rover is now investigating this area’s unique geological features to understand Mars’ past environmental conditions and support future human exploration. Credit: NASA/JPL-CaltechStrikingly Different Rocks in Bright Angel Formation “When the rover entered Bright Angel and started measuring the compositions of the local rocks, the team was immediately struck by how different they were from what we had seen before,” said Tice, a geobiologist and astrobiologist in the Department of Geology and Geophysics. “They showed evidence of chemical cycling that organisms on Earth can take advantage of to produce energy. And when we looked even closer, we saw things that are easy to explain with early Martian life but very difficult to explain with only geological processes.” Tice went on to explain that “living things do chemistry that generally occurs in nature anyway given enough time and the right circumstances. To the best of our current knowledge, some of the chemistry that shaped these rocks required either high temperatures or life, and we do not see evidence of high temperatures here. However, these findings require experiments and ultimately laboratory study of the sample here on Earth in order to completely rule out explanations without life.” The team published its findings in Nature. Texas A&M University astrogeologist Dr. Michael Tice. Credit: Texas A&M UniversityAncient Water-Shaped Sediments The Bright Angel formation is composed of sedimentary rocks deposited by water, including mudstones (fine-grained sedimentary rocks made of silt and clay) and layered beds that suggest a dynamic environment of flowing rivers and standing water. Using Perseverance’s suite of instruments, including the SHERLOC and PIXL spectrometers, scientists detected organic molecules and small arrangements of minerals that appear to have formed through “redox reactions,” chemical processes involving the transfer of electrons. On Earth, those processes are often driven by biological activity. Among the most striking features are tiny nodules and “reaction fronts”— nicknamed “poppy seeds” and “leopard spots” by the rover team — enriched in ferrous iron phosphate (likely vivianite) and iron sulfide (likely greigite). These minerals commonly form in low-temperature, water-rich environments and are often associated with microbial metabolisms. “It’s not just the minerals, it’s how they are arranged in these structures that suggests that they formed through the redox cycling of iron and sulfur,” Tice said. “On Earth, things like these sometimes form in sediments where microbes are eating organic matter and ‘breathing’ rust and sulfate. Their presence on Mars raises the question: could similar processes have occurred there?” Organic Carbon in Apollo Temple The SHERLOC instrument detected a Raman spectral feature known as the G-band, a signature of organic carbon, in several Bright Angel rocks. The strongest signals came from a site called “Apollo Temple,” where both vivianite and greigite were most abundant. “This co-location of organic matter and redox-sensitive minerals is very compelling,” said Tice. “It suggests that organic molecules may have played a role in driving the chemical reactions that formed these minerals.” Tice notes it’s important to understand that “organic” does not necessarily mean formed by living things. “It just means having a lot of carbon-carbon bonds,” he explained. “There are other processes that can make those besides life. The kind of organic matter detected here could have been produced by abiotic processes or it could have been produced by living things. If produced by living things, it would have to have been degraded by chemical reactions, radiation or heat to produce the G-band that we observe now.” Life or Geochemistry? Two Competing Scenarios The study outlines two possible scenarios: one in which these reactions occurred abiotically (driven by geochemical processes) and another in which microbial life may have affected the reactions, as it does on Earth. Strikingly, although some features of the nodules and reaction fronts could be produced by abiotic reactions between organic matter and iron, the known geochemical processes that could have produced the features associated with sulfur usually only work at relatively high temperatures. “All the ways we have of examining these rocks on the rover suggest that they were never heated in a way that could produce the leopard spots and poppy seeds,” said Tice. “If that’s the case, we have to seriously consider the possibility that they were made by creatures like bacteria living in the mud in a Martian lake more than three billion years ago.” While the team emphasizes that the evidence is not definitive proof of past life, the findings meet NASA’s criteria for “potential biosignatures” — features that warrant further investigation to determine whether they are biological or abiotic in origin. Rock Sample for Future Return to Earth Perseverance collected a core sample from the Bright Angel formation, named “Sapphire Canyon,” which is now stored in a sealed tube carried by the rover. This sample is among those prioritized for return to Earth in a potential future mission. “Bringing this sample back to Earth would allow us to analyze it with instruments far more sensitive than anything we can send to Mars,” said Tice. “We’ll be able to look at the isotopic composition of the organic matter, the fine-scale mineralogy, and even search for microfossils if they exist. We’d also be able to perform more tests to determine the highest temperatures experienced by these rocks, and whether high temperature geochemical processes might still be the best way to explain the potential biosignatures.” Earth-Mars Parallels in Ancient Microbial Life Tice, who has long studied ancient microbial ecosystems on Earth, said the parallels between Martian and terrestrial processes are striking — with one important difference. “What’s fascinating is how life may have been making use of some of the same processes on Earth and Mars at around the same time,” he said. “We see evidence of microorganisms reacting iron and sulfur with organic matter in the same way in rocks of the same age on Earth, but we’d never be able to see exactly the same features that we see on Mars in the old rocks here. Processing by plate tectonics has heated all our rocks too much to preserve them this way. It’s a special and spectacular thing to be able to see them like this on another planet.” Explore Further: Reference: “Redox-driven mineral and organic associations in Jezero Crater, Mars” by Joel A. Hurowitz, M. M. Tice, A. C. Allwood, M. L. Cable, K. P. Hand, A. E. Murphy, K. Uckert, J. F. Bell III, T. Bosak, A. P. Broz, E. Clavé, A. Cousin, S. Davidoff, E. Dehouck, K. A. Farley, S. Gupta, S.-E. Hamran, K. Hickman-Lewis, J. R. Johnson, A. J. Jones, M. W. M. Jones, P. S. Jørgensen, L. C. Kah, H. Kalucha, T. V. Kizovski, D. A. Klevang, Y. Liu, F. M. McCubbin, E. L. Moreland, G. Paar, D. A. Paige, A. C. Pascuzzo, M. S. Rice, M. E. Schmidt, K. L. Siebach, S. Siljeström, J. I. Simon, K. M. Stack, A. Steele, N. J. Tosca, A. H. Treiman, S. J. VanBommel, L. A. Wade, B. P. Weiss, R. C. Wiens, K. H. Williford, R. Barnes, P. A. Barr, A. Bechtold, P. Beck, K. Benzerara, S. Bernard, O. Beyssac, R. Bhartia, A. J. Brown, G. Caravaca, E. L. Cardarelli, E. A. Cloutis, A. G. Fairén, D. T. Flannery, T. Fornaro, T. Fouchet, B. Garczynski, F. Goméz, E. M. Hausrath, C. M. Heirwegh, C. D. K. Herd, J. E. Huggett, J. L. Jørgensen, S. W. Lee, A. Y. Li, J. N. Maki, L. Mandon, N. Mangold, J. A. Manrique, J. Martínez-Frías, J. I. Núñez, L. P. O’Neil, B. J. Orenstein, N. Phelan, C. Quantin-Nataf, P. Russell, M. D. Schulte, E. Scheller, S. Sharma, D. L. Shuster, A. Srivastava, B. V. Wogsland and Z. U. Wolf, 10 September 2025, Nature.DOI: 10.1038/s41586-025-09413-0 Never miss a breakthrough: Join the SciTechDaily newsletter.

EPA Will Keep Rule Designating PFAS as ‘Hazardous’

September 23, 2025 – Environmental Protection Agency (EPA) Administrator Lee Zeldin announced last week that the agency will keep in place a Biden-era policy change that enables the agency to make companies pay for the cleanup of harmful “forever chemicals.” Per- and polyfluoroalkyl substances, or PFAS, are chemicals that can persist in the environment for […] The post EPA Will Keep Rule Designating PFAS as ‘Hazardous’ appeared first on Civil Eats.

September 23, 2025 – Environmental Protection Agency (EPA) Administrator Lee Zeldin announced last week that the agency will keep in place a Biden-era policy change that enables the agency to make companies pay for the cleanup of harmful “forever chemicals.” Per- and polyfluoroalkyl substances, or PFAS, are chemicals that can persist in the environment for centuries, accumulate in the human body, and are associated with a range of health harms. “EPA’s reaffirmation of this rule is a win for environmental justice, giving communities poisoned without their knowledge a long-overdue path to relief,” Melanie Benesh, vice president of government affairs at the Environmental Working Group (EWG), said in a statement. In April 2024, Biden’s EPA designated the two forever chemicals associated with the most harm and widespread environmental contamination—perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS)—as “hazardous substances” under the Comprehensive Environmental Response, Compensation, and Liability Act, the country’s “Superfund” law. That meant the agency could then prioritize the cleanup of sites contaminated with those chemicals and hold companies responsible for the remediation. Since then, agricultural industry groups, including the National Cattlemen’s Beef Association,  National Pork Producers Council, and American Farm Bureau Federation, have challenged the rule in court, arguing that farmers who spread contaminated fertilizer on their land could be on the hook for the cleanup costs. Last week, a broader coalition of farm groups, among them the National Farmers Union, National Sustainable Agriculture Coalition, and American Farmland Trust, released federal policy recommendations for addressing PFAS contamination on farms. In addition to provisions related to assisting farmers with cleanup and the reduction of future contamination, the groups included a section recommending the EPA further clarify and confirm that farmers will not be held responsible for contamination caused by fertilizers. Zeldin put that issue—referred to as “passive receiver liability”— front and center in the EPA’s Sept. 17 announcement. “When it comes to PFOA and PFOS contamination, holding polluters accountable while providing certainty for passive receivers that did not manufacture or generate those chemicals continues to be an ongoing challenge,” he said. “EPA intends to do what we can based on our existing authority, but we will need new statutory language from Congress to fully address our concerns.” But some experts say those concerns have already been addressed. “The 2024 enforcement discretion policy resolved the situation, clarifying that EPA would focus enforcement only on polluters—not farmers and municipalities that received PFAS chemicals,” said Betsy Southerland, the former director of the EPA’s Office of Science and Technology in the Office of Water, in a statement released by the Environmental Protection Network. Southerland welcomed the announcement that the EPA will keep the designations in place. She also warned it will offer little relief to people worried about forever chemicals in drinking water, because of Zeldin’s earlier decision to roll back limits on four other PFAS. The EPA also recently approved four new pesticides that qualify as PFAS based on an internationally recognized definition the EPA does not use. “Let’s be clear,” Southerland said. “Our drinking water is still at risk because Trump’s EPA is recklessly allowing more toxic chemicals in Americans’ drinking water.” (Link to this post.) The post EPA Will Keep Rule Designating PFAS as ‘Hazardous’ appeared first on Civil Eats.

Suggested Viewing

Join us to forge
a sustainable future

Our team is always growing.
Become a partner, volunteer, sponsor, or intern today.
Let us know how you would like to get involved!

CONTACT US

sign up for our mailing list to stay informed on the latest films and environmental headlines.

Subscribers receive a free day pass for streaming Cinema Verde.
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.