A team of scientists from Nanyang Technological University, Singapore (NTU Singapore) has developed a method of 3D printing that can also capture carbon dioxide and store it in concrete.

The process involves injecting carbon dioxide and steam into mixing cement, which is then used in a 3D printer to build structures. For this method, the team sourced both the steam and the carbon dioxide as byproducts of industrial processes. The 3D printer was connected to a steam jet and carbon dioxide pumps in order to incorporate these elements into the mixing concrete.

“The building and construction sector causes a significant portion of global greenhouse gas emissions. Our newly developed 3D concrete printing system offers a carbon reducing alternative by not only improving the mechanical properties of concrete but also contributing to reducing the sector’s environmental impact,” Tan Ming Jen, principal investigator of the study and professor at NTU’s School of Mechanical and Aerospace Engineering, said in a statement. “It demonstrates the possibility of using CO2 produced by power plants or other industries for 3D concrete printing. Since traditional cement emits a lot of carbon, our method offers a way to plough back CO2 through 3D concrete printing.” 

According to the team, the incorporation of carbon dioxide and steam strengthens the resulting concrete when compared to typical 3D-printed concrete, in addition to reducing the carbon footprint of the constructed material. The carbon-injected concrete was able to bear 36.8% more weight and was 45.3% more flexible compared to standard 3D-printed concrete. The scientists published their findings in the journal Carbon Capture Science & Technology.

As for carbon sequestration, this concrete could capture and store 38% more carbon compared to typical 3D-printed concrete, according to the scientists.

Not only was the resulting concrete stronger and better at storing carbon, but it was also easier to print. The study showed this concrete to have 50% more printability, or printing efficiency.

According to the World Economic Forum, cement manufacturing alone makes up about 8% of global carbon emissions. Emissions from the cement manufacturing industry totaled around 1.6 billion metric tonnes in 2022, and that number is expected to grow to 3.8 billion metric tonnes per year based on a business-as-usual scenario.

Using 3D printing can help lower emissions by reducing cement usage and waste, but innovations on the materials used in 3D printing are further reducing emissions in the construction industry. Engineers at Massachusetts Institute of Technology (MIT) have developed a way to use recycled glass in 3D printing, and scientists at University of Virginia School of Engineering and Applied Science are exploring ways of incorporating plant-based cellulose nanofibrils into 3D-printed concrete. 

The study led by NTU further advances the growing research toward more sustainable building materials that will reduce construction-related emissions.

“Our proposed system shows how capturing carbon dioxide and using it in 3D concrete printing could lead to stronger, more eco-friendly buildings, advancing construction technology,” said Daniel Tay, co-author of the study and a research fellow at NTU’s School of Mechanical and Aerospace Engineering.

The scientists at NTU and their collaborators have filed an application for a U.S. patent for their method.

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In a new study, researchers at University of Southern California (USC) have associated certain neighborhood factors — such as food access or proximity to Superfund sites — with higher levels of per- and polyfluoroalkyl substances (PFAS) in human blood.

The researchers examined the levels of certain types of PFAS, including PFOS, PFOA, PFHxS, PFPeS and PFHpS based on a neighborhood’s tap water, level of access to fresh foods and proximity to industrial polluting sites and Superfund sites. As explained by the U.S. Environmental Protection Agency, a Superfund site is an area designated as a hazardous waste dumping ground, such as landfills, mining sites and some types of manufacturing facilities.

The study drew from two previous Southern California-based studies’ data to observe how the defined neighborhood factors affected the PFAS levels in the blood of 446 people, mostly based in Los Angeles County, LAist reported.

The results revealed that each factor on its own was associated with elevated levels of certain types of PFAS in the blood. The team published the results in the journal Environmental Research.

“Instead of placing the burden on individuals to avoid PFAS, we’re looking at neighborhood factors beyond their control,” Shiwen (Sherlock) Li, Ph.D., lead author of the study and postdoctoral researcher at USC’s Keck School of Medicine, said in a statement. “How can we improve our neighborhood environments to reduce PFAS and the associated disease risk?”

The results revealed that places with PFOA, PFOA or PFHxS in the tap water also had residents with higher levels of these compounds in their blood compared to people without these compounds detected in the tap water. The areas with PFAS in the water revealed an increase of around 1.54 nanograms per milliliter (ng/mL) of PFOS, 0.47 ng/mL for PFOA and 116 ng/ML for PFHxS.

The study also reviewed low access to fresh food as a potential link to higher PFAS in blood, because PFAS have been found in food packaging. This neighborhood factor was linked to higher levels of PFOS (an increase of 2.52 ng/mL), PFOA (0.6 ng/mL increase) and PFHpS (0.06 ng/mL) in human blood, with increases by around 40% to 60% and even over 100% for certain PFAS, as LAist reported.

The results found elevated levels of PFOS for people living within a 3-mile radius of an industrial site known for processing PFAS, and it showed higher levels of PFOS, PFHxS, PFHpS and PFPeS for people living within 3 miles of a Superfund site. In August 2024, a separate study revealed that landfills have become major sources of airborne PFAS pollution, although exact measurements of the amounts of PFAS pollution from landfills are still uncertain.

As the Keck School of Medicine reported, the residents in the study were primarily Latino, which highlighted the need for environmental justice efforts to address PFAS in underserved communities.

“We’re adding a different perspective to solving the PFAS problem, because the risk to exposure of PFAS at the neighborhood level is not evenly distributed,” Li said.

Currently, the Keck School of Medicine’s Department of Population and Public Health Sciences has ramped up efforts to educate communities about PFAS contamination in water, although Li emphasized the importance of systemic changes to reduce PFAS pollution.

“In my opinion, it’s harder to change individual behaviors, but if you can create clean environments for everyone, they don’t need any behavioral change in the first place,” Li explained, as reported by LAist.

The EPA is making efforts to regulate PFAS, two of which (PFOA and PFOS) were added to the list of hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).

In April 2024, EPA finalized regulations for six types of PFAS in drinking water, and these rules are set to take effect in 2029.

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A new study has revealed that modern batteries in electric vehicles may last up to 40% longer than expected thanks to stop-and-go driving patterns that help recharge batteries on the go.

According to researchers, the common lab testing methods to determine battery life may not be the most accurate way to estimate how long EV batteries will last. In lab testing, batteries are often discharged at an ongoing rate, then recharged all at once. 

But as the researchers pointed out, EV drivers experience different discharge rates in long spans of driving or stop-and-go traffic. These more frequent cycles of discharging the battery and recharging during braking could help preserve battery life.

Researchers tested 92 commercial lithium-ion batteries for a 24-month period, using both the constant discharge method as well as real-driving scenarios. The batteries tested under real driving methods had a better life expectancy, with about 38% improvement, compared to those tested under common lab testing scenarios. The team published the findings in the journal Nature Energy.

“To our surprise, real driving with frequent acceleration, braking that charges the batteries a bit, stopping to pop into a store, and letting the batteries rest for hours at a time, helps batteries last longer than we had thought based on industry standard lab tests,” Simona Onori, senior author of the study and an associate professor of energy science and engineering at Stanford University’s Doerr School of Sustainability, said in a statement.

According to the National Renewable Energy Laboratory, EV batteries are estimated to last for around 12 to 15 years in mild climates or around 8 to 12 years in extreme climates. But the real battery degradation of EVs is still difficult to determine, since many EVs that are currently on the road were bought within the last few years, Recurrent Auto reported, with many EV batteries lasting well beyond the common 8-year, 100,000 mile warranty.

Although Electrek reported that battery prices just fell by the biggest rate since 2017, with a 20% drop in battery prices for 2024, the prices can still be of concern to consumers considering the switch to an EV over a gas-fueled vehicle. As the study authors pointed out, EV batteries still make up about one-third of the cost of a new electric car. Further, according to NerdWallet, replacing an out-of-warranty electric car battery can cost between $5,000 to $20,000. 

But with an increased longevity for EV batteries, swapping to an EV could be a more economical choice for consumers when compared to paying for more frequent battery replacements, plus fuel, in gas-powered vehicles. As NerdWallet reported, traditional vehicle batteries cost around $60 to $300 each, with replacements necessary every 3 to 5 years, according to AAA.

As Electrek reported, electric batteries are predicted to fall even lower in the coming years, reaching around $69 per kWh by 2030.

The findings could also improve consumer confidence in secondhand EVs, considering a Green Finance Institute survey found that 62% of respondents who didn’t already own an EV said they wouldn’t buy a used electric car due to concerns over battery health.

Although the researchers noted that dynamic cycling can extend the lifespan of an EV battery compared to constant cycling, they explained that time-induced aging will still affect batteries. Proper battery charging practices and vehicle maintenance will still be important for users to consider when maximizing the lifespan of their EV batteries.

“We battery engineers have assumed that cycle aging is much more important than time-induced aging. That’s mostly true for commercial EVs like buses and delivery vans that are almost always either in use or being recharged,” said Alexis Geslin, a lead author of the study and a Ph.D. student in materials science and engineering as well as in computer science at Stanford University’s School of Engineering. “For consumers using their EVs to get to work, pick up their kids, go to the grocery store, but mostly not using them or even charging them, time becomes the predominant cause of aging over cycling.”

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The U.S. Environmental Protection Agency (EPA) has banned two chemicals commonly used in dry cleaning because of their toxicity and cancer risks. 

The EPA announced on Dec. 9 that it finalized the risk management regulations for trichloroethylene (TCE) and perchloroethylene (PCE) under the Toxic Substances Control Act (TSCA).

PCE is commonly used for dry cleaning clothing, and TCE was once used for dry cleaning but has been phased out for that use, according to a 2016 study. Still, both substances are also used in industrial degreasers, consumer adhesive products and paint and stain removing products, the Minnesota Department of Health reported. 

According to the EPA, both chemicals are volatile organic compounds and exposure to each comes with its own elevated risks of certain forms of cancer. 

“It’s simply unacceptable to continue to allow cancer-causing chemicals to be used for things like glue, dry cleaning or stain removers when safer alternatives exist,” Michal Freedhoff, assistant administrator for the Office of Chemical Safety and Pollution Prevention, said in a statement. “These rules are grounded in the best-available science that demonstrates the harmful impacts of PCE and TCE.”

TCE is considered extremely toxic, even in small concentrations, and has been linked to liver cancer, kidney cancer, non-Hodgkin’s lymphoma, fetal heart defects and damage to the central nervous system, kidneys, liver, immune system and reproductive organs, the EPA reported.

Most uses of TCE will be fully banned within the next year, while it will be phased out over a longer timeframe in select industrial uses that will still limit the amount during the phase-out period. The new ban also establishes an inhalation exposure limit that the EPA said would reduce long-term exposure for workers by about 97%.

PCE has been linked to liver cancer, brain cancer, kidney cancer and testicular cancer, along with kidney, liver and immune system damage. It has also been known to cause neurotoxicity and reproductive toxicity, according to the EPA.

The use of PCE in dry cleaning will now be phased out over a 10-year period, except for in new dry-cleaning machines, which will have to stop using PCE within six months. In other industrial and commercial uses, PCE is expected to be phased out within three years, as the EPA determined safer alternatives that are comparably effective to PCE are already available. The finalized PCE rules will be explained in an EPA announcement scheduled for January 15, 2025.

For workplaces that will continue using TCE and/or PCE in limited amounts or during a phase-out timeline, the EPA established a Workplace Chemical Protection Program, which companies have 30 months to implement.

“Despite their dangers, these chemicals could still be found in industries like dry cleaning, automotive repair and manufacturing,” Sen. Ed Markey (Mass.) said in a statement. “With no doubt that these chemicals are deadly, there is no doubt that this final rule will save lives — especially our children’s lives — around the country.”

For small businesses, the Biden administration has proposed funding to assist with the chemical phase-outs and TSCA compliance.

As Chemical and Engineering News reported, the EPA initially announced plans to phase-out PCE in 2023 after identifying related health risks to workers and consumers exposed to the chemical in 2020.

But at the state level, some states have established limits and bans to PCE use several years earlier. California initiated a phase-out of PCE in dry cleaning uses in 2007, with the full phase-out finalized by January 1, 2023, Chemical and Engineering News reported. 

As reported by The Council of State Governments Midwestern Office, Minnesota banned PCE use in 2021, with the full phase-out to be completed by January 1, 2026. The Minnesota legislation also includes funding to help dry cleaning businesses with the transition to alternatives as well as to financially support soil and groundwater cleanup of PCE contamination.

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A new study led by Arizona State University has revealed an association between exposure of glyphosate, one of the most commonly used herbicides in the world, and long-term impacts on brain health in mice.

The study tested the impacts that two different doses of glyphosate exposure had on mice, with a high dose (500 mg per kg) and a lower dose (50 mg per kg), which was similar to the amount that was used to determine the acceptable dose of exposure to humans. The researchers observed how the exposure impacted the brains during a 13-week exposure as well as six months after exposure had ended compared to the control mice, which received no glyphosate exposure.

The team determined that glyphosate exposure led to neuroinflammation as well as behaviors and symptoms similar to anxiety and Alzheimer’s. For some of the animals, the exposure was associated with results as extreme as premature death.

Even the low dose led to negative impacts on the brains that lasted several months after exposure had ended. The scientists published their findings in the journal Journal of Neuroinflammation.

“My hope is that our work drives further investigation into the effects of glyphosate exposure, which may lead to a reexamination of its long-term safety and perhaps spark discussion about other prevalent toxins in our environment that may affect the brain,” Samantha Bartholomew, first author of the paper and a Ph.D. candidate at Arizona State University, said in a statement.

These results have raised concerns over the current standards for glyphosate, which is considered to have no concerning risks to human health when used as directed on the label, according to the U.S. Environmental Protection Agency. 

Further, the researchers warned about the potential impacts to aging populations, which are already experiencing an increase in cognitive decline, according to Ramon Velazquez, a co-author of the study, researcher with the ASU-Banner Neurodegenerative Disease Research Center and assistant professor of life sciences.

But the researchers hope that more investigation is completed to determine if the current acceptable limits of glyphosate are too high, or whether any exposure of glyphosate poses risks.

“Herbicides are used heavily and ubiquitously around the world,” said Patrick Pirrotte, senior author of the study and associate professor at the Early Detection and Prevention Division at Translational Genomics Research Institute (TGen). “These findings highlight that many chemicals we regularly encounter, previously considered safe, may pose potential health risks. However, further research is needed to fully assess the public health impact and identify safer alternatives.”

While the findings brought up the question of what these impacts observed on brains of mice could mean for glyphosate exposure and its potential impacts on human brains, it can also be used as an example to further research alternatives to testing on mice and other animals. Because of the complexity of brains, it is currently still common to use animal testing to observe reactions and impacts in brain research. 

As Cruelty-free International reported, researchers are working on other ways to complete these important types of organ and nervous system studies without the use of animal testing. Scientists are rapidly exploring and advancing alternatives, such as computer modeling, tissue donations, cell cultures and “human-on-a-chip” models for brain research. PETA reported that AI is becoming more suitable as a method for alternative testing. However, more research on non-animal testing is necessary, and once alternatives are more established, they will require regulation to be implemented.

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