The compounds can form PFAS, also known as “forever chemicals,” which have been linked to cancer and birth defects. The E.P.A. approvals came despite the agency’s own concerns about toxicity.
Most plastic persists in the environment. A recently developed polymer degrades in a week and doesn’t leave microplastics behind. Image credit: Larina Marina/ Shutterstock.
Plastic trash chokes shorelines and oceans, in part because plastic polymers do not easily decompose. But a new kind of environmentally degradable plastic could help change that: It breaks down in about a week in sunlight and air, according to a recent study in the Journal of the American Chemical Society (JACS). Chemical characterization using nuclear magnetic resonance (NMR) and mass spectroscopy, among other techniques, revealed that the plastic decomposed rapidly in sunlight from a petroleum-based polymer into succinic acid, a naturally occurring nontoxic small molecule that doesn’t leave microplastic fragments in the environment.
Although a sun-sensitive plastic might not be a good choice for bottles or bags that need to last more than a week on shelves, integrating the environmentally degradable polymer as a minor ingredient, or with other biodegradable polymers, could help speed breakdown of these materials in landfills, says coauthor Liang Luo, an organic materials scientist at Huazhong University of Science and Technology in Wuhan, China. The flexible and degradable material would be potentially useful inside electronics, he says. Sealed inside a cell phone or other flexible electronic device, the polymer could last for years isolated from light and oxygen, Luo notes, while making smartphones easier to dispose of at the end of their service life. And the byproduct succinic acid could be upcycled for commercial uses in the pharmaceutical and food industries, Luo adds.
Data collected can be used to provide new insights into the evolution of the Kuiper Belt, and the larger solar system.
Trans-Neptunian Objects (TNOs), small objects that orbit the sun beyond Neptune, are fossils from the early days of the solar system which can tell us a lot about its formation and evolution.
A new study led by Mohamad Ali-Dib, a research scientist at the NYU Abu Dhabi Center for Astro, Particle, and Planetary Physics, reports the significant discovery that two groups of TNOs with different surface colors also have very different orbital patterns. This new information can be compared to models of the solar system to provide fresh insights into its early chemistry. Additionally, this discovery paves the way for further understanding of the formation of the Kuiper Belt itself, an area beyond Neptune comprised of icy objects, that is also the source of some comets.
Planets which are tilted on their axis, like Earth, are more capable of evolving complex life. This finding will help scientists refine the search for more advanced life on exoplanets. This NASA-funded research is presented at the Goldschmidt Geochemistry Conference.
Since the first discovery of exoplanets (planets orbiting distant stars) in 1992, scientists have been looking for worlds that might support life. It is believed that to sustain even basic life, exoplanets need to be at just the right distance from their stars to allow liquid water to exist; the so-called “Goldilocks zone.” However, for more advanced life, other factors are also important, particularly atmospheric oxygen.
Oxygen plays a critical role in respiration, the chemical process which drives the metabolisms of most complex living things. Some basic life forms produce oxygen in small quantities, but for more complex life forms, such as plants and animals, oxygen is critical. Early Earth had little oxygen even though basic life forms existed.
Ageing is an incredibly complicated process, so much so that we do not yet understand exactly how complicated it is. It is in fact so complicated, that it could actually be incredibly simple. Confused? Well, imagine if you were a structural engineer who was trying to understand why a building collapsed. From an initial inspection of the rubble, it may be extremely difficult to work out exactly what went wrong. Was the building made from inferior materials? Was it built incorrectly? Was its destruction deliberate? Did it just fall apart due to age? All of these are possible, but what was the true cause for its destruction? Well, that is the same mystery we are trying to solve in longevity research. We can see the damage that is caused by ageing, but what is the cause? Is it a general accumulation of damage, or are there single points of failure which have knock on effects that affect the entire body? A cascade failure if you will.
Of the many different changes that occur during the ageing process, one of the most well-known and understood is the decreased capacity for our body to produced chemical energy, which has a knock-on effect throughout the body. This results in a general decrease in our ability to carry out cellular functions and will therefore effective everything from muscle strength to DNA replication and repair. This decrease in energy output has been linked to defects in our mitochondria, but in addition to these physical defects that occur in these small organisms, we now know that they also suffer a decreased capacity to carry out their function due to lacking a critical coenzyme called Nicotinamide adenine dinucleotide (NAD). Anyone who has taken a high school level biology class will probably recognise this enzyme as part of the electron transport chain in respiration.
A unique study of ancient diamonds has shown that the basic chemical composition of the Earth’s atmosphere which makes it suitable for life’s explosion of diversity was laid down at least 2.7 billion years ago. Volatile gases conserved in diamonds found in ancient rocks were present in similar proportions to those found in today’s mantle, which in turn indicates that there has been no fundamental change in the proportions of volatiles in the atmosphere over the last few billion years. This shows that one of the basic conditions necessary to support life, the presence of life-giving elements in sufficient quantity, appeared soon after Earth formed, and has remained fairly constant ever since.
Presenting the work at the Goldschmidt Geochemistry Conference, lead researcher Dr. Michael Broadly said, “The proportion and make-up of volatiles in the atmosphere reflects that found in the mantle, and we have no evidence of a significant change since these diamonds were formed 2.7 billion years ago.”
Volatiles, such as hydrogen, nitrogen, neon, and carbon-bearing species are light chemical elements and compounds, which can be readily vaporized due to heat, or pressure changes. They are necessary for life, especially carbon and nitrogen. Not all planets are rich in volatiles; Earth is volatile-rich, as is Venus, but Mars and the Moon lost most of their volatiles into space. Generally, a planet rich in volatiles has a better chance of sustaining life, which is why much of the search for life on planets surrounding distant stars (exoplanets) has focused on looking for volatiles.
An unknown methane-producing process is likely at work in the hidden ocean beneath the icy shell of Saturn’s moon Enceladus, suggests a new study published in Nature Astronomy by scientists at the University of Arizona and Paris Sciences & Lettres University.
Giant water plumes erupting from Enceladus have long fascinated scientists and the public alike, inspiring research and speculation about the vast ocean that is believed to be sandwiched between the moon’s rocky core and its icy shell. Flying through the plumes and sampling their chemical makeup, the Cassini spacecraft detected a relatively high concentration of certain molecules associated with hydrothermal vents on the bottom of Earth’s oceans, specifically dihydrogen, methane and carbon dioxide. The amount of methane found in the plumes was particularly unexpected.
“We wanted to know: Could Earthlike microbes that ‘eat’ the dihydrogen and produce methane explain the surprisingly large amount of methane detected by Cassini?” said Régis Ferrière, an associate professor in the University of Arizona Department of Ecology and Evolutionary Biology and one of the study’s two lead authors. “Searching for such microbes, known as methanogens, at Enceladus’ seafloor would require extremely challenging deep-dive missions that are not in sight for several decades.”
Physics World
A device that can generate electricity while desalinating seawater has been developed by researchers in Saudi Arabia and China, who claim that their new system is highly efficient at performing both tasks. The device uses waste heat from the solar cell for desalination, thereby cooling the solar cell. It also produces no concentrated brine as waste, cutting its potential environmental impact.
In many parts of the world, climate change and population growth are putting huge demands on freshwater supplies. In some coastal regions, desalination – removing the salt from brackish water or seawater to turn it into fresh water – is increasingly being used to meet demand. Indeed, there are now around 16000 desalination plants around the world producing about 95 million cubic metres of freshwater every day.
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For the first time, an artificial molecular motor has been created that can ‘talk’ to living cells – by gently pulling their surface with enough physical force to elicit a biochemical response. The approach could help scientists decode the language that cells use to communicate with each other in tissues.
‘There is a mechanical language in the form of physical forces applied by the cells themselves, and we want to understand what information is communicated and what the consequences are,’ explains Aránzazu del Campo, who led the study at the Leibniz Institute for New Materials, Germany. ‘Ultimately, we want to be able to provide signals to cells and guide their function when they are not able to do that by themselves in disease cases.’
Usually, studying how cells communicate by sensing mechanical stimuli and producing biochemical responses requires prodding them with pipettes or the tip of an atomic force microscope. However, this doesn’t work at the more complex tissue level.
“I realized that in the middle-dose group, which is the one that mattered for the no-effects level, they had conveniently left out one of the two baseline measurement days,” said Sheppard. “The outrageous thing was that the group they declared as NOEL was only that because they left out data from their analysis.” In a peer-reviewed paper published in October 2020, Sheppard and her colleagues concluded that “the omission of valid data without justification was a form of data falsification.”
In any case, bifenthrin was not the only pesticide that dodged testing to see if it presented dangers. The EPA’s pesticide office granted 972 industry requests to waive toxicity tests between December 2011 and May 2018, 89 percent of all requests made. Among the tests on pesticides that were never performed were 90 percent of tests looking for developmental neurotoxicity, 92 percent of chronic cancer studies, and 97 percent of studies looking at how pesticides harm the immune system.
By law, the companies that submit their products for review pay for these tests, and in a presentation about the waivers last year, Anna Lowit, a senior science adviser in the office, emphasized the savings to these companies: more than $300 million. Lowit also noted that animal lives were saved — a goal that the Trump administration and the chemical industry prioritized within the agency. The EPA developed the guidelines for waiving the tests along with BASF, Corteva, and Syngenta, pesticide manufacturers that all stand to benefit significantly from having their products bypass toxicity testing.
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