In the 1920s, researchers realized that you can add lead to gasoline to help keep car engines healthy for longer. But while leaded gasoline was good for cars, it was bad for humans.
Leaded gasoline is highly toxic and in addition to causing a number of health problems, it can also cross the blood-brain barrier and accumulate in some parts of the brain, where it can cause a number of problems, including reducing intelligence. According to a new study, exposure to car exhaust from leaded gasoline affected the IQs of over 170 million Americans alive today, costing the country a collective 824 million IQ points.
The findings come from a new study published by Aaron Reuben, a PhD candidate in clinical psychology at Duke University, and Michael McFarland and Mathew Hauer, both professors of sociology at Florida State University. The researchers started from publicly available data on US childhood blood-lead levels and leaded-gasoline use. They then determined the likely lifelong burden of lead exposure of every American alive in 2015. From this, they calculated how much of an intelligence burden this exposure to lead proved to be. While IQ isn’t a perfect proxy to intelligence, it’s still a good population-level indicator.
Previous studies have suggested an association between lead exposure in childhood and a drop in IQ. But when the results came in, even the researchers were surprised.
“I frankly was shocked,” McFarland said. “And when I look at the numbers, I’m still shocked even though I’m prepared for it.”
The results show that over half of all Americans (170 million out of an entire population of 330 million) had clinically significant levels of lead in their blood, resulting in lower IQ levels as adults, as well as a number of potential health problems (such as reduced brain size, greater likelihood of mental illness, and increased cardiovascular disease). The people affected by lead exposure would have each lost, on average, 3 IQ points.
“Lead is able to reach the bloodstream once it’s inhaled as dust, or ingested, or consumed in water,” Reuben said. “In the bloodstream, it’s able to pass into the brain through the blood-brain barrier, which is quite good at keeping a lot of toxicants and pathogens out of the brain, but not all of them.”
Three IQ points may not seem like much, but keep in mind that this is an average for a whopping 170 million people. At its worst, people born in the mid-late 1960s may have lost 6 IQ points on average. At a population level, this is a considerable margin — and even though leaded gasoline was banned in the US in 1996, the effects of the problem are still visible today.
“Millions of us are walking around with a history of lead exposure,” Reuben said. “It’s not like you got into a car accident and had a rotator cuff tear that heals and then you’re fine. It appears to be an insult carried in the body in different ways that we’re still trying to understand but that can have implications for life.”
Thankfully, the era of leaded gasoline is finally over. Most countries banned it two decades ago, but only last year, in 2021, the era of leaded gasoline was finally over as the last stocks were used in Algeria (which had continued to produce leaded gasoline until July 2021).
Leaded gasoline is a good example of an exciting technology that turns out to be very bad for the environment and for human health. But while leaded gasoline has been phased out, there are plenty of other sources of pollution still affecting our brains, lungs, and hearts.
Journal Reference: “Half of US Population Exposed to Adverse Lead Levels in Early Childhood,” Michael J. McFarland, Matt E. Hauer, Aaron Reuben. Proceedings of the National Academy of Sciences, March 7, 2022. DOI: 10.1073/pnas.2118631119
The quantity of plastic on our planet has massively exceeded the safe limits for humans and wildlife, says a new study. Although efforts to recycle have increased substantially over the last few decades, they are falling woefully short of solving the issue; the paper suggests placing limits on plastic production as a necessary solution.
The study was penned by the Stockholm Resilience Centre ahead of a UN meeting in Nairobi at the end of the month. This meeting, the Fifth session of the United Nations Environment Assembly, plans to tackle the issue of plastic pollution “from source to sea”, according to a statement by UN Environment Programme head Inger Andersen said on Monday.
There are an estimated 350,000 different manufactured chemicals on the market today, and large quantities of them end up dumped in the environment in one way or another, the study explains.
“The impacts that we’re starting to see today are large enough to be impacting crucial functions of planet Earth and its systems”, says Bethanie Carney Almroth, co-author of the study. “Some chemicals are interfering with hormone systems, disrupting growth, metabolism and reproduction in wildlife.”
Pesticides and plastics are the main sources of damage to ecosystems and wildlife, the team explains. They impact biodiversity and pile a lot of stress on natural systems that are already crumbling under the pressure of human activity. Pesticides kill living organisms en masse, and plastics hurt wildlife as they are confused for food or entangle various animals.
We as a global society need to put more effort into preventing such substances from reaching the natural environment, the authors conclude. Recycling has, so far, not been sufficient; less than 10% of the world’s plastic is being recycled currently, while production of these materials has doubled to 367 million tons since 2000.
This has led us to an extreme quantity of plastic piling up on our planet. According to previous research cited by the study, the total weight of plastic on Earth today is four times greater than the biomass of living animals.
“What we’re trying to say is that maybe we have to say, ‘Enough is enough’. Maybe we can’t tolerate more,” Almroth adds “Maybe we have to put a cap on production. Maybe we need to say, ‘We can’t produce more than this’.”
The Stockholm Resilience Centre has been researching “planetary boundaries” for several years now. These quantify the Earth’s stability over nine areas and includes elements such as greenhouse gas emissions, freshwater usage, and the integrity of the ozone layer. The aim of this research is to pencil out a “safe operating space” for humanity — how much we can use of the planet across nine dimensions without putting life on Earth at risk.
“Novel entities” — man-made chemical products such as plastics, pesticides, medicine, and non-natural metals — have an impact on the environment. Until now, the team explains, exactly what this impact was remained unclear. This is due to how recent some of them are — most have been developed in the past 70 years — and the fact that data on these materials is often handled as corporate secrets.
Even the most comprehensive databases to date, such as the EU’s REACH inventory, only cover 150,000 of these products; only a third of those have been the subject of detailed toxicity studies, the team adds.
“We are only beginning to understand the large-scale, long-term effects of these exposure. And we’re talking about 350,000 different substances,” Carney Almroth said. “We don’t have knowledge on the vast majority of those, in terms of how much are produced or their stability. Or their fate in the environment or their toxicity.”
“Looking at changes over time and trends in production volumes lost in the environment […] and connecting that to the little bit we do know about impacts, we could say that every arrow is pointing in the wrong direction.”
Although the findings are not encouraging, the team is confident that things can still be set right, if we take “urgent and ambitious actions” at an international level. There’s no easy fix, however, since society as it is today relies on many of these chemicals and materials. What we can do, the team proposes, is to set production caps for these materials, instead.
“This seems very obvious to say but it’s only recently accepted as truth: The more you produce, the more you release,” Carney Almroth concludes.
The paper “Outside the Safe Operating Space of the Planetary Boundary for Novel Entities” has been published in the journal ACS Publications.
New research from the Swiss Federal Laboratories For Materials Science And Technology (EMPA), Utrecht University, and the Austrian Central Institute for Meteorology and Geophysics showcase the scale and huge range of pollution carried through the atmosphere.
The findings suggest that around 3,000 tons of nanoplastic particles are deposited in Switzerland every year, including the most remote Alpine regions. Most are produced in cities around the country, but others are particles from the ocean that get introduced into the atmosphere by waves. Some of these travel as far as 2000 kilometers through the air before settling, the team explains, originating from the Atlantic.
Such results build on a previous body of research showing that plastic pollution has become ubiquitous on Earth, with nano- and microplastics, in particular, being pervasive on the planet.
Although we’re confident that the Earth has a plastic problem, judging by the overall data we have so far, the details of how nanoplastics travel through the air are still poorly understood. The current study gives us the most accurate record of plastic pollution in the air to date, according to the authors.
For the study, the researchers developed a novel chemical method that uses a mass spectrometer to measure the plastic contamination levels of different samples. These samples were obtained from a small area on the Hoher Sonnenblick mountain in the Hohe Tauern National Park, Austria, at an altitude of around 3100 meters from sea level. This area was selected as an observatory of the Central Institute for Meteorology and Geodynamics and has been in operation here since 1886.
The samples were collected on a daily basis, in all types of weather, at 8 AM. They consisted of samples of the top layer of snow, which were harvested and processed taking extreme care not to contaminate them with nanoplastics from the air or the researchers’ clothes. According to their measurements, about 43 trillion miniature plastic particles land in Switzerland every year — equivalent to around 3,000 tons.
In the lab, the team measured nanoplastic content in each sample and then analyzed these particles to try and determine their origin. Wind and weather data from all over Europe were also used in order to help determine the particles’ origins. Most of the particles were likely produced and released into the atmosphere in dense urban areas. Roughly one-third of the particles found in the samples came from within 200 kilometers. However, around 10% of the total (judging from their level of degradation and other characteristics) were blown to the mountain from over 2000 kilometers away, from the Atlantic; these particles were likely formed in the ocean from larger debris and introduced into the atmosphere by the spray of waves.
Plastic nanoparticles are produced by weathering and mechanical abrasion from larger pieces of plastic. These are light enough to be comparable to a gas in behavior. Their effect on human health is not yet known, but we do know that they end up deep into our lungs, where they could enter our bloodstream. What they do there, however, is still a mystery.
The current study doesn’t help us understand their effects any better, but it does put the scale of nanoplastic pollution into perspective. These estimates are very high compared to other studies, and more research is needed to verify them — but for now, they paint a very concerning picture.
The paper “Nanoplastics transport to the remote, high-altitude Alps” has been published in the journal Environmental Pollution.
During the spring of 2020, when the coronavirus pandemic caught everyone with their pants down, governments scrambled to close their borders and impose strict lockdowns in order to curb the spread of a virus that was rife with uncertainty. Human activity slowed to a crawl and, as a result, the air and water became cleaner. Fewer vehicles on the road meant urban spaces became safer for animals and much quieter. There were even viral reports of dolphins in the canals of Venice, Italy, and pumas in the streets in Santiago, Chile, prompting many to triumphantly claim ‘nature is healing’.
The ‘healing’ part is hyperbolic, but what’s clear is that nature went through significant changes as a result of our lockdowns — and it even showed in the sky. At the recent American Geophysical Union meeting in New Orleans, scientists at MIT reported that a drop in atmospheric aerosols due to shuttering of activity coincided with a drop in lightning.
According to a new study, reduced human activity lowered the number of aerosol emissions — microscopic particles in the atmosphere too small to see with the naked eye that can result from pollution due to fossil fuels — affecting the electrical charge of clouds and their ability to form lightning.
Between March 2020 and May 2020, there were 19% fewer intracloud flashes (the most common type of lightning) compared to the same three-month period in 2018, 2019, and 2021.
Earle Williams, a physical meteorologist at the Massachusetts Institute of Technology, and colleagues used three different methods to measure lighting, all of which pointed to the same trend of diminished lightning activity associated with diminished aerosol concentration.
Atmospheric aerosols absorb water vapor thereby helping form cloud droplets. Without any aerosols, we wouldn’t have clouds. When there are more aerosols in the atmosphere, the water vapor becomes more widely distributed across droplets, making them smaller and less likely to coalesce into rain droplets. As a result, clouds grow larger but precipitation is suppressed.
Furthermore, clouds seeded with fewer aerosols have fewer positively charged ice particles in the clouds to react with negatively charged hail in the lower part of the cloud, which explains why we had less lightning that strikes the surface or discharges into the air.
For instance, lightning flashes are more frequent along shipping routes, where freighters emit particulates into the air, compared to the surrounding ocean. And the most intense thunderstorms in the tropics brew up over land, where aerosols are elevated by both natural sources and human activity.
Areas with the strongest reduction of aerosols also experienced the most dramatic drops in lightning events. These include Southeast Asia, Europe, and most of Africa. North and South America also experienced a reduction in lightning, but not as dramatic as in other places. Researchers believe that some of the drop in aerosol pollution due to human activity in the Americas was offset by the catastrophic wide-scale fires experienced in 2020.
Lightning is an important component of the weather system, which is why scientists are so interested in understanding it better. Also, from an ecological perspective, lighting interacts with air molecules to produce nitrogen oxide, a family of poisonous, highly reactive gases.
Mountain spring water isn’t as clean or fresh as we like to assume, according to new research.
Data collected over four decades shows that the quality of water in high-elevation (mountain) streams has been steadily decreasing over time. The issues underlying this decline are both historical and modern, related to man-made developments in hilly and mountainous landscapes.
The main sources of pollutants in mountain streams are sediment from unpaved, rural roads, and agricultural runoff.
No longer pristine
“We had access to studies from 1976 to last year that encompassed both stream and terrestrial studies,” said Rhett Jackson, a professor at UGA’s Warnell School of Forestry and Natural Resources and the paper’s lead author. “Some streams in Macon County have very high sediment concentrations, four times greater than found in forested streams.”
The findings are based on data from the U.S.’ Southern Appalachian area. Streams here still carry the signs of environmental changes caused by European settlers moving into the region during the 1900s, the authors report.
Native Americans, the original inhabitants of the Southern Appalachians, traditionally only farmed the valleys strewn along this mountain chain. They left the hills and mountain slopes undeveloped as woodlands, where they would hunt and gather wild fruits and plants.
When settlers moved in, however, they engaged in heavy logging, to obtain timber for trade and construction, and to clear space for farmland. This process significantly changed the landscape of the area’s hills and mountain slopes. New farmland established on the hills promoted erosion, and the sediment produced by that erosion was gradually cleaned away by rainfall into high-altitude streams.
Even today, the authors explain, streambeds in the Southern Appalachians carry those century-old bodies of sediment, under layers of fresh material that is still making its way into their courses.
High levels of sediment affect the wild animals living in the streams, Jackson explains. For starters, it makes it harder for animals to find food as it makes the waters murky. It also has a direct impact on fish growth and their ability to resist disease.
Sediment builds up downstream as well, making its way into public water supplies. As such, there’s a direct financial cost to communities, as these impurities need to be filtered out before water can be pumped to taps around towns and cities.
The team underscores that these changes in sediment input into high-altitude streams first started manifesting over one century ago, and are the result of environmental changes caused by increased habitation due to settlers moving into the area.
“The landscape you see now isn’t what it was like in 1900—the early settlers logged everything,” said Jackson.
Although the first settlers started this process, their descendants today are carrying the torch. Starting with the 1980s, for example, the area saw a massive rise in interest for the development of the steep (and previously wild) mountain slopes. A large number of vacation residences and villas were built on these slopes, generating significant land disturbance through the buildings themselves and associated infrastructure — the carving out of roads. Such development made the area rife for landslides, and the unpaved roads that reached these buildings produced ample dust.
“Roadside ditches and unpaved roads produce a lot of sediment, [which] increases as roads get steeper and as gravel roads get more use,” said Jackson.
The authors report that while a typical stream in the southern Appalachian forest contains around 8 to 10 milligrams of sediment per liter, in areas with both mountain and hill development, they have found concentrations of sediment between four to six times this value.
Farming also plays a part. Runoff from farms introduces a high level of nitrates into mountain streams. Levels of these compounds are particularly high for streams running past pastures that do not enjoy a buffer of trees to absorb some of the fertilizer. Deforestation further impacts the health of wild communities in these streams as the lack of shade leads to higher average water temperatures, which can be damaging for trout and other local species that are adapted to cold waters. Around 40% of the streams in the study area have lost their buffer of trees, the team reports.
“On small streams, the actions of individual landowners matter a lot,” he said. “Sometimes, we see unusual streamside activities [such as illicit discharge pipes or streams diverted through animal enclosures] with substantial water quality effects.”
“Because the water in streams comes from the whole landscape, everything we see on the land has some effect on streams. But streams are resilient, and as long as we intelligently modify our actions a little bit, we can farm and live near streams while protecting their water quality. Maintaining the quality of our landscape requires a little thought and work on our parts.”
Taking small, simple steps, such as planting rows of trees near an open stream, or making sure to buffer runoff from a gravel road, can help a great deal in improving the water quality of open streams, the team concludes.
The paper “Distinctive Connectivities of Near-Stream and Watershed-Wide Land Uses Differentially Degrade Rural Aquatic Ecosystems” has been published in the journal BioScience.
Microorganisms around the world are likely evolving to be able to degrade and consume plastic materials.
A new global assessment of microorganism genomes, the largest study of its kind, found that wild bacteria and microbes are evolving to be able to consume plastics. Overall, the authors report that an average of one in four of the organisms analyzed in the study carried at least one enzyme that could degrade plastic. Furthermore, the number and types of enzymes matched the amount and type of plastic pollution at the location where samples of different organisms were collected — suggesting that this is a natural, ongoing process, caused by the presence of plastic in the environment.
These results are evidence that plastic pollution is producing “a measurable effect” on the world’s microbes, the authors conclude.
“We found multiple lines of evidence supporting the fact that the global microbiome’s plastic-degrading potential correlates strongly with measurements of environmental plastic pollution — a significant demonstration of how the environment is responding to the pressures we are placing on it,” said Prof Aleksej Zelezniak, at Chalmers University of Technology in Sweden.
Millions of tons of plastic are dumped in the oceans and landfills every year, and plastic pollution has become endemic everywhere on Earth. Addressing this issue will be one of the defining challenges of future generations along with efforts to reduce our reliance on such materials and improve our ability to recycle and cleanly dispose of used plastic. However, plastics are hard to degrade — that hardiness is one of their selling points to begin with.
According to the findings, microbes in soils and oceans across the globe are also hard at work on the same project. The study analyzed over 200 million genes from DNA samples taken from environments all around the world and found 30,000 different enzymes that could degrade 10 different types of plastics. such compounds could serve us well in our efforts to recycle plastics, breaking them down into their building blocks. Having more efficient recycling methods on hand would go a long way towards cutting our need to produce more plastics.
“We did not expect to find such a large number of enzymes across so many different microbes and environmental habitats. This is a surprising discovery that really illustrates the scale of the issue,” says Jan Zrimec, also at Chalmers University, first author of the study.
The team started with a dataset of 95 microbial enzymes already known to degrade plastic; these compounds were identified in species of bacteria found in dumps and similar places rife with plastic.
They then looked at the genes that encode those enzymes and looked for similar genes in environmental DNA samples collected at 236 sites around the world. To rule out any false positives, they compared the enzymes with enzymes from the human gut — all of which are known to be unable to degrade plastic.
Roughly 12,000 new enzymes were identified from ocean samples. Higher levels of degrading enzymes were routinely found in samples taken at deeper points, which is consistent with how plastic pollution levels vary with depth. Some 18,000 suitable genes were identified in soil samples. Here, too, the researchers underscore the effect of environmental factors: soils tend to contain higher levels of plastics with phthalate additives than the ocean, and more enzymes that can attack these substances were identified in soil samples.
Overall, roughly 60% of the enzymes identified in this study did not fit into a previously-known class, suggesting that they act through chemical pathways that were previously unknown to science.
“The next step would be to test the most promising enzyme candidates in the lab to closely investigate their properties and the rate of plastic degradation they can achieve,” said Zelezniak. “From there you could engineer microbial communities with targeted degrading functions for specific polymer types.”
The paper “Plastic-Degrading Potential across the Global Microbiome Correlates with Recent Pollution Trends” has been published in the journal Microbial Ecology.
Sound can help us deal with the growing issue of microplastics plaguing the world’s oceans, according to new research.
Microplastics are building up in all layers of the environment, from soils to waterways, even in the atmosphere. Such particles are produced directly by cosmetics, clothing, or industrial processes, or indirectly through the breakdown of larger pieces of plastic.
They’re becoming a genuine environmental concern risking the health of both humans and wildlife. Considerable effort has been put into developing efficient ways of disposing of microplastics, with varying success. Now, new research from the Institut Teknologi Sepuluh Nopember in Surabaya, Indonesia offers an unusual solution to the problem — filtering them out of the water using sound.
Speakers to the rescue
The approach involves using speakers to generate “bulk acoustic waves” (sound waves that propagate throughout the volume of a substance) in order to force microplastic particles in water to separate from the liquid. This allows for the quick and easy removal of the particles through mechanical means, offering a clean and quick method to scrub waters of microplastics.
During lab testing of their technique, the researchers used two speakers to generate acoustic waves through a sample of water laden with microplastic particles that was circulated through a tube. The force of these waves (sounds propagate through physical motions of a material’s particles) created pressure inside the tube, forcing the plastic microparticles to move towards the center of the tube. This tube eventually split into three channels, with the middle one removing the plastic while the other two carried the cleaner water away.
During the testing, the team’s device scrubbed around 150 liters of polluted water an hour. They tested three types of microplastic particles in pure water and seawater. The effectiveness of the rig depended mostly on the type of water that was flowing through it but also varied with the type of plastic it contained. However, the lowest efficiency ratings of the device were slightly above 56% in pure water and 58% in seawater across all types of microplastics used in the trial.
The team explains that this was only a proof-of-concept run. They’re confident that with further tweaking to the frequency of acoustic waves they generate, of the distance between the speakers and the tube, and the water flow through the tube, higher efficiencies can be attained. How much plastic can be removed throughout a cycle of the device directly depends on how much pressure can be generated in the water using the sound waves, and all those elements would affect this parameter.
One potential issue with the technology that may severely limit its applicability in the wild is that many marine species are highly sensitive to sounds in the audible range of frequency — the same range over which the team blasts their speakers. The authors are hard at work finding potential solutions to this problem. In case this can’t be addressed, the technology still holds promise in scrubbing water before it is dumped in waterways. While this won’t help clean the plastic already floating around the oceans, it can at least limit the influx of new microplastics.
“We believe further development is necessary to improve the cleaning rate, the efficiency, and particularly the safety of marine life,” said Dhany Arifianto, Chair of Vibration and Acoustics at Institut Teknologi Sepuluh Nopember Surabaya, lead researcher on the project.
Could car exhaust be captured and used to grow crops? Researchers at Texas A&M University are saying yes. A new white paper published by three faculty members is proposing that CO2 and water from car exhaust can be captured for this purpose, and outlines a general approach on how to do so. Although such an idea might seem quite exotic, it’s not the first time it’s been proposed, the authors argue.
The current paper doesn’t intend to offer an exact solution to such an approach, or the exact way through which it is to be implemented. Rather, it is a white paper — it outlines the basic issue and the authors’ initial analysis and thoughts on how to best address it. The team hopes that this paper will help to attract the funding needed to perform in-depth, formal research on the topic.
From tailpipe to table
“I started reading the related literature and did simulations of what was possible,” says Maria Barrufet, professor and Baker Hughes Endowed Chair in the Harold Vance Department of Petroleum Engineering at Texas A&M. “This is entirely realistic.”
“Several proposals have already been written for large trucks and marine vehicle applications, but nothing has been implemented yet. And we are the first to think of a passenger car engine.”
Such an approach would help massively reduce humanity’s overall environmental impact by reducing our output of carbon dioxide (CO2), a greenhouse gas, into the atmosphere. At the same time, it would help us increase agricultural productivity without placing any extra strain on natural processes and the ecosystems that provide them.
In broad lines, what the authors propose is to integrate a device into car engines that would capture and compress these waste products. The device in question would operate on the organic Rankine cycle (ORC) system and would be powered by waste heat given off by the engine. Organic Rankine cycle systems operate very similarly to steam engines on a smaller scale, using an organic fluid in lieu of water. This fluid has a lower boiling point than water, meaning that the device requires much lower temperatures to produce physical work than a traditional steam engine.
In turn, this ORC system will power components such as a heat exchange and pumps which will cool down and compress CO2 from a gas into a liquid, to enable storage.
The team explains that the CO2 and water captured from exhaust engines could prove to be very useful for agriculture, especially in high-intensity urban greenhouses. Such greenhouses employ artificial atmospheres that are highly enriched in CO2, generally containing around three times as much of it as the air we breathe. In combination with other systems supplying vital nutrients, this higher concentration of CO2 helps foster plant growth and leads to increased yields, as plants primarily grow using carbon from the air. Farms like these already spend money purchasing CO2, but making the gas widely available for cheap from traffic — maybe even for free — could go a long way towards promoting intensive urban agriculture. The team explains that on average, urban farms purchase roughly 5 pounds (2 kg) of CO2 and nearly six gallons (22 liters) of water for every two pounds (1 kg) of produce they grow.
Another argument in favor of such a scheme is that growing produce locally further reduces costs and environmental impact related to storing, handling, transporting, and refrigerating produce from farms to groceries. It would also help reduce traffic.
Beyond the benefits to agriculture, the sheer environmental benefits such a scheme can produce would be immense. In 2019, there were 1.4 billion private vehicles in operation globally, producing an average of 4.6 tons of CO2 per year each — which adds up to a lot.
“Years ago, we didn’t think we could have air conditioning in a car,” Barrufet said. “This is a similar concept to the air conditioning that we now have. In a simple way, it’s like that device, it will fit in tight spaces.”
For us driving the cars, the ORC system wouldn’t make any noticeable impact. Since it operates using waste heat, the authors are confident that it will not lead to any significant loss of engine power, increase in fuel use, or maintenance needs (although special coatings will be needed to prevent corrosion in the heat exchange systems). As far as emptying the system, the team envisions drivers simply turning in cartridges of water and CO2 in specialized centers, or even at gas stations, in exchange for empty ones. There’s nothing preventing them from using the products in their own greenhouses, however, but the authors stress that this process should be done responsibly to ensure that the CO2 is fully absorbed by plants and does not escape into the atmosphere — which would defeat the purpose of this whole exercise in the first place.
Not everything is settled, however. There is still work to be done determining how large these cartridges should be, how the water produced by the system should be handled (water cannot be compressed like a gas), and technical details, such as determining how the weight of these cartridges would affect the car’s performance and handling across all possible levels of weight.
Realistically, we’re probably looking at roughly 10 years or so of development before such systems are ready to be implemented commercially. We already have all the individual components needed, but we still need to figure out how to put them all together in the most efficient way.
“All of these independent ideas and technologies have no value if they cannot connect,” Barrufet said. “We need people concerned about the future to make this happen soon, energized students in petroleum, mechanical, civil, agricultural and other engineering disciplines who can cross boundaries and work in sync.”
The paper “Capture of CO2 and Water While Driving for Use in the Food and Agricultural Systems” has been published in the journal Circular Economy and Sustainability.
Maryland’s Chesapeake Bay intakes tens of thousands of doses of various drugs every year, according to a new report. This results in persistent (if variable) levels of drugs in the water year-round, at concentrations that affect ecological processes. The source, according to the report, is the city’s leaky sewage system.
The sheer scale of human society means that much of what we do impacts the world around us. Climate change is the most consequential one, but pollution and habitat destruction are arguably the most visible. Sometimes, however, they can happen unnoticed right under our noses, meaning we have a very poor understanding of their scale and effects.
Pharmaceutical or drug pollution in freshwater is one example — it is global in scope and yet, very poorly quantified. A new report, however, comes to fill in at least one piece of this overall story. According to the paper, the sewage infrastructure of Maryland is leaking tens of thousands of human doses of pharmaceutical compounds into the Chesapeake Bay every year. The paper illustrates how outsized an effect old or damaged infrastructure can have on our environment.
Dosing the fish
“Pharmaceuticals enter fresh waters through multiple pathways, including effluent from wastewater treatment and septic systems, as well as agricultural runoff. An important, but often overlooked contributor is aging and faulty wastewater infrastructure, which is common in many older cities,” lead author Megan Fork, a postdoctoral research associate at Cary Institute of Ecosystem Studies, explains.”Because Gwynns Falls streams don’t receive wastewater effluent, we were able to estimate annual loads of pharmaceutical pollution attributed to leaky pipes alone.”
Pharmaceutical pollution in lakes, rivers, and streams can have an immense effect on wildlife communities. Since our drugs are so varied in composition and effect, they can interfere with and disrupt everything from animal biology and behavior to algal growth.
For the study, the team collected water samples from six sites in Baltimore’s Gwynns Falls watershed every week for one year. These sites formed a ‘gradient of development’ according to the authors — they ranged in development levels from suburban to highly urban. These samples were tested for concentrations of 92 pharmaceutical compounds.
The team reports that at 7 of the sites, they identified 37 different compounds among those they were looking for. The most commonly found compound across these sites was the antibiotic trimethoprim. The highest concentration of drugs was identified in samples from a site where Gwynns Falls flows into Baltimore’s Inner Harbor. Overall, however, drug concentrations were higher at sites that were more densely populated than at less-populated ones.
In order to estimate how much of this was leaked from faulty pipes (the annual ‘load’), the team pooled data on drug concentrations detected at the Gwynns Falls outlet with river discharge rates recorded by a USGS monitoring station at the site. Armed with this data, they calculated the annual loads for nine classes of compounds.
They report that faulty pipes fed the Gwynns Falls watershed with an equivalent of 30,000 adult doses of antidepressants, 1,700 doses of antibiotics, and about 30,000 tablets of acetaminophen (a common painkiller). These drug concentrations are environmentally relevant, meaning they have a measurable effect on organisms’ behavior, biology, and on greater ecological processes. While these pharmacological pollutants were persistent throughout the year, they were also variable — meaning the exact mixture of compounds is always changing.
“Establishing the loads of contaminants such as pharmaceuticals is important since low concentrations may mislead regulators and managers into thinking that they are insignificant. In Baltimore we are already seeing that stream-dwelling bacteria are resistant to common antibiotics, suggesting that low chronic exposures can result in significant effects on stream life,” Fork explains.
“We estimate that nearly 1% of raw sewage originating in the Gwynns Falls watershed flows into the environment via leaking infrastructure. If we extrapolate our calculations to the entire Chesapeake Bay watershed, we estimate that approximately 11.7 billion liters of raw sewage may enter the Bay via leaks every year — carrying a range of pharmaceutical compounds that can affect aquatic organisms and disrupt ecosystem processes,” adds Emma Rosi, senior co-author and an aquatic ecologist at Cary Institute.
The paper “Dosing the Coast: Leaking Sewage Infrastructure Delivers Large Annual Doses and Dynamic Mixtures of Pharmaceuticals to Urban Rivers” has been published in the journal Environmental Science & Technology.
Exposure to pollution in all its forms could be making us age faster, according to new research.
Our everyday exposure to UV rays, ozone, cigarette smoke, industrial chemicals, and other pollutants might be even more damaging than we’ve believed. Such factors can lead to the production of free radicals in our bodies, highly reactive chemical molecules that damage tissues or DNA. A new study from West Virginia University, in collaboration with the University of Minnesota, reports that unrepaired DNA damage incurred from these radicals can cause us to age faster.
From their research on aging and cell damage in animals, the team is confident in the effect pollution could have on these factors in humans.
“By the time [a genetically-modified mouse used in the study] is 5 months old, it’s like a 2-year-old mouse,” said Eric Kelley, associate professor and associate chair of research in the School of Medicine’s Department of Physiology and Pharmacology.
“It has all the symptoms and physical characteristics. It has hearing loss, osteoporosis, renal dysfunction, visual impairment, hypertension, as well as other age-related issues. It’s prematurely aged just because it has lost its ability to repair its DNA.”
Kelley and his team used genetically modified mice for their study. These animals had the data encoding a certain protein removed from their hematopoietic stem cells, undifferentiated immune cells that later mature into white blood cells. This protein is a key DNA-repairing component in the mammalian body, and without it, the team could observe what effects their ever-decaying DNA strands would cause to the mice’s cells.
In rough terms, the team explains, a 2-year-old mouse is about as old as a human in their late 70s to early 80s.
These genetically engineered mice showed more markers of senescence (aging), cell damage, and oxidation in their immune cells compared to control mice. However, The damage extended beyond the immune system, with the experimental mice showing aged and damaged cells in organs including the liver and kidneys. This, they note, suggests that unrepaired DNA damage can lead to premature aging throughout an individual’s body.
The oxidation damage observed is largely due to the action of free radicals. There are two main ways that free radicals make their way into our bodies. The first is unavoidable — oxidative phosphorylation. It’s basically what happens after digestion, the step in which food is actually oxidized in our cells to produce energy. Without it, we couldn’t be alive. However, pollution can also introduce these bad chemicals.
Chemical pollutants such as smoke from exhaust or cigarettes can lead to the formation of free radicals inside the body through the interactions they have with chemicals and tissues. Additionally, radiation treatments like those used against cancer can transfer energy to the water molecules in our body, which can break apart into free radicals.
Our bodies do have tools on hand to limit the effects of these free radicals, but nowhere near enough to resist the pollution levels we’re seeing today.
“A cigarette has over 10 to the 16th free radicals per puff, just from combusted carbon materials,” Kelley said. “We have mechanisms in the mitochondria that mop free radicals up for us, but if they become overwhelmed — if we have over-nutrition, if we eat too much junk, if we smoke — the defense mechanism absolutely cannot keep up”.
Furthermore, as we age, these defenses become less and less effective, as our bodies wear out. Eventually, invariably, the oxidants gain the upper hand, the damage they cause starts outweighing our bodies’ repair capacity. Many of the characteristics associated with aging are caused by this. But, the team proposes, if we’re exposed to more pollutants, and accumulate a greater level of free radicals in the body, that aging will take place sooner.
“I come from an Appalachian background,” Kelley said. “And, you know, I’d go to funerals that were in some old house — an in-the-living-room-with-a-casket kind of deal — and I’d look at people in there, and they’d be 39 or 42 and look like they were 80 because of their occupation and their nutrition.”
“The impact is less on lifespan and more on healthspan,” he adds. “If you could get people better access to healthcare, better education, easier ways for them to participate in healthier eating and a healthier lifestyle, then you could improve the overall economic burden on the population of West Virginia and have a much better outcome all the way around.”
Although we have a few pharmaceutical options to deal with free radicals, the team says it’s best to prevent their accumulation in the first place, mainly through lifestyle changes.
The paper “An aged immune system drives senescence and ageing of solid organs” has been published in the journal Nature.
Carbon dioxide levels have hit an all-time high — again. In May (the month scientists use to compare year-to-year CO2 shifts), carbon dioxide in the atmosphere averaged 419 parts per million, according to data from Scripps Institution of Oceanography and the National Oceanic and Atmospheric Administration (NOAA).
Unfortunately, that in itself would hardly even classify as news anymore. But what really is striking is that CO2 levels haven’t been this high since before humans emerged as a species. We’d have to go to the Pliocene Epoch, between 4.1 to 4.5 million years ago, to see similar levels — a period when sea levels were nearly 80 feet higher and temperatures were about 7°F above the preindustrial era.
Not even a pandemic that kept many of us inside could stop the rise of atmospheric carbon dioxide. The long-lived greenhouse gas driving climate change has fluctuated naturally throughout our planet’s history, but scientists are virtually certain that the current accumulation is driven by human activities — especially the burning of fossil fuels. It’s a clear sign that the world is not doing nearly enough to curb emissions.
“The ultimate control knob on atmospheric CO2 is fossil-fuel emissions,” Scripps Oceanography geochemist Ralph Keeling said in a NOAA statement. “We ultimately need cuts that are much larger and sustained longer than the COVID-related shutdowns of 2020.”
It’s not just that CO2 levels are increasing, but the pace at which they are rising is alarming. In 2013, the world first passed a historic mark: 400 parts per million (ppm) of CO2 in the atmosphere. Since then, it took just eight years to climb to 420 ppm, and now, we’re already at 429 ppm.
Initially, there were hopes that the pandemic would at least slow down greenhouse gas emissions — and for the first part of the year, that was true. But by the end of 2020, it was almost as if nothing had changed. Emissions in the last months of the year were already higher than the ones in previous years.
The past year also marked the five-year anniversary of the adoption of the historic Paris climate agreement. Within the plan, countries agreed to take action to reduce their emissions and keep the planet in line with a warming of no more than 2 degrees Celsius over pre-industrial levels (and the ambitious goal of 1.5 Celsius). With temperatures already over 1 degree Celsius over pre-industrial level, the ambitious goal is all but gone now — and even the “normal” goal seems questionable, as few countries have backed up their declared ambitions with action.
CO2 emissions can last for 1,000 years in the atmosphere, and as long as we keep emitting the gas, it will continue to accumulate. Global emissions have likely not peaked, and will continue to drive climate change to uncharted and dangerous territory. Climate change is already costing the world in the trillions, and the cost is only expected to rise as emissions ramp up.
Road salts, applied to sidewalks, streets, and highways to melt out snow and ice, represent a serious and growing global threat to freshwater supplies and public health, a new paper reports.
Cold winters make for dangerous roads, and salt has long been used as a tool to de-ice roads. Since it’s a natural product, it was assumed that such procedures wouldn’t cause harm to the environment. A new paper, however, says they do. Salt used for de-icing can negatively impact public health and freshwater sources, it explains, through the chemicals it leeches into the environment.
Salting the wound
“We used to think about adding salts as not much of a problem,” said Sujay Kaushal, a professor in UMD’s Department of Geology and Earth System Science Interdisciplinary Center and lead author of the study. “We thought we put it on the roads in winter and it gets washed away, but we realized that it stuck around and accumulated.”
“Now we’re looking into both the acute exposure risks and the long-term health, environmental, and infrastructure risks of all these chemical cocktails that result from adding salts to the environment, and we’re saying, ‘This is becoming one of the most serious threats to our freshwater supply.’ And it’s happening in many places we look in the United States and around the world.”
Weather-related car accidents claim thousands of lives globally every year, and the application of salt on roads is an important tool in our arsenal towards saving as many as possible. Salt is sometimes also used as a fertilizer on crop fields, and a host of other purposes.
But this salt eventually finds its way into the environment and accumulates, creating a growing global threat.
Previous work by Kaushal’s team found that salt in the wild can interact with soils and man-made infrastructure, drawing out a cocktail of chemicals including metal and radioactive compounds. They called this cascading process the Freshwater Salinization Syndrome (FSS), and found that it can lead to contaminated drinking water sources, impact public health, agriculture, infrastructure, wildlife health, and ecosystem stability.
The current paper explores how the Freshwater Salinization Syndrome impacts human health and the environment. The findings point to freshwater supplies facing serious threats from this syndrome on a local, regional, and global level. The team calls on officials to improve the management of salt usage, and to better regulate it, in order to protect these sources. The team explains that the effects of the FSS is a threat on par with acid rains or biodiversity loss.
For the study, they compared data from freshwater monitoring stations around the world and reviewed studies on the subject, finding a general increase in chloride levels all across the planet. Chloride is a main component in many types of salt like table salt (sodium chloride) or calcium chloride, which is commonly used for de-icing roads. Judging by data from specific regions of interest, the team says we’re seeing a 30-year trend of growing salinity levels; they note the Passaic River, New Jersey and a 100-mile-plus stretch of the Potomac River, which supplies drinking water to Washington, D.C., as areas affected by this trend.
The most important sources of human-related salt in the Northeastern U.S. is road salts, the team explains. Other important sources include sewage leaks and discharges, water softeners, agricultural fertilizers, and fracking brines. Indirect sources of salt in freshwater include road, bridge, and building weathering — salts leech out of limestone, concrete, or gypsum — and ammonium-based fertilizers used in urban or agricultural settings. Sea-level rise can also lead to saltwater intrusion.
Chemicals released from all these sources harm both anthropic and natural environments. For example, changes in environmental salt levels can allow invasive, salt-tolerant species to take over a stream. These compounds can change the microflora in soil and water, which can lead to even more changes, as bacterial communities underpin the health of whole ecosystems. For built environments, salts can lead to corrosion in roadways and broader infrastructure. This can lead to the leaching of heavy metals in drinking water, as was the case in Flint, Michigan.
“I am greatly surprised by the increasing scope and intensity of these problems as highlighted from our studies,” said study co-author Gene E. Likens, founding president emeritus of the Cary Institute of Ecosystem Studies and a distinguished research professor at the University of Connecticut.
“Increased salinization of surface waters is becoming a major environmental problem in many places in the world.”
For now, the team explains, there are still a lot of unknowns. Exactly how these higher salinity levels will impact the environment is still poorly understood. Furthermore, every body of water presents its own conditions and unique management issues in regards to salt. The best way to go about fixing these issues is to treat salt the same way we do nutrient loads: look at all the different sources on a watershed-ecosystem level and prioritize regulation accordingly, the team explains. Sadly, they also note that work has been done to create technological solutions to nutrient runoff, but similar methods do not exist for salt.
“Ultimately, we need regulation at the higher levels, and we’re still lacking adequate protection of local jurisdictions and water supplies,” Kaushal said. “We have made dramatic improvements to acid rain and air quality, and we’re trying to address climate change this way.”
“What we need here is a much better understanding of the complicated effects of added salts and regulations based on that. This can allow us to avert a really difficult future for freshwater supplies.”
The paper “Freshwater salinization syndrome: from emerging global problem to managing risks” has been published in the journal Biogeochemistry.
If ever there was a time to reconsider how you get to work every day, it’s now.
A study found that those who commute with their car in California are likely exposed to dangerous chemicals that increase the risk for cancer and birth defects — way over the threshold for exposure established by state government legislation.
Bad for you, bad for the planet
US adults spend an average of 6% of their time within an enclosed vehicle, a large amount of which is spent commuting. In the US, a person spends an average of 52.8 min per day commuting to work. This isn’t just bad for the planet (by producing more pollution and greenhouse gas emissions), it’s also bad for you: longer commute times are strongly associated with negative health outcomes such as shorter sleep, obesity, and poor physical/mental health
People who spend a longer amount of time in vehicles are also exposed to higher concentrations of particulate matter, carbon monoxide, VOCs, ozone, and flame retardants. This effect is so pronounced that people experiencing long commutes over years and decades likely represent a sub-population vulnerable to excess exposure to vehicle-borne chemicals. Now, a new study adds even more weight to those concerns.
A group of researchers at the University of California Riverside wanted to better understand the potential risk associated with exposure to vehicle-specific chemicals as a function of commute time. They focused on five Prop 65-listed chemicals detected within vehicle interiors: benzene, formaldehyde, di phthalate, dibutyl phthalate, and trisphosphate.
California’s Proposition 65 (Prop 65) requires businesses to inform people about exposure to chemicals known to cause cancer, birth defects, or other reproductive harm. Prop 65-listed chemicals represent a wide range of naturally occurring and synthetic chemicals that include additives or ingredients in pesticide formulations, common household products, food, drugs, dyes, or solvents. In some cases, Prop 65-listed chemicals that are used in indoor products have the potential to migrate, abrade, or off-gas from end-use products and accumulate in indoor environments. The presence of Prop 65-listed chemicals in indoor air and dust has been well documented, suggesting that people may be exposed to these chemicals through inhalation of air and ingestion of dust.
While several studies have evaluated the potential risk to Prop 65-listed chemicals detected within indoor environments, we don’t know all that much about the risk of these chemicals in regards to exposure within personal vehicles. Due to the small size of a car, chemicals emitted from its interior have the potential to be concentrated.
Chemicals such as phthalates, volatile organic compounds (VOCs), flame retardants, and hydrocarbons — several of which are Prop 65-listed — are commonly detected within interior vehicle dust. Prior studies have demonstrated that the concentration of certain chemicals within vehicle interiors were 2- to 3-fold higher compared to indoor concentrations. In their new study, the researchers at UC Riverside found that the average commuter in California is breathing unsustainably high levels of benzene and formaldehyde, both of which are used in automobile manufacturing. These are highly carcinogenic substances, with benzene carrying the additional risk of reproductive and developmental toxicity. The levels at which these substances are inhaled by many commuters is considered unsafe.
The study calculated the daily dose of benzene and formaldehyde being inhaled by drivers with commutes of at least 20 minutes per day. This showed that up to 90% of the population in Los Angeles, San Diego, Orange, Santa Clara, and Alameda counties have at least a 10% chance of exceeding cancer risk from inhaling the chemicals, based on having 30-minute average commute times.
The presence of these compounds within vehicles can be attributed to extensive use in different vehicle parts. Formaldehyde is used in carpets, leather, and paints within vehicles, resulting in off-gassing and high concentrations within indoor air. Meanwhile, benzene is linked to fuel- and exhaust-related emissions that accumulate in the cabin of operating vehicles. It’s also used to produce styrene, nylon, and phenol
“These chemicals are very volatile, moving easily from plastics and textiles to the air that you breathe,” David Volz, UCR professor of environmental toxicology and co-author of the study, said in a statement. Volz suggested keeping the windows open during car rides if possible so to reduce the concentration of these chemicals thanks to the airflow.
As economies expand, so does air pollution, a product of larger fossil-fuel consumption by vehicles, industries, and homes. But a new study of air quality in Africa has found the exact opposite. Nitrogen oxide (a byproduct of combustion), is declining in the north equatorial part of the continent thanks to fewer people using fires to manage land.
Africa is not a big industrial polluter like the United States or China but it has long been subject to widespread biomass burning during the dry season. This is considered an effective and more importantly cheap method to clear land in preparation for the planting season. It also has the advantage of retaining the mineral nutrients of the soil.
But burning vegetation can also bring potentially serious consequences for human health and global warming. The fires for land management can combine with urban pollution from cars or factories and produce toxic air. Plus, the fires release carbon dioxide (CO2), a greenhouse gas that causes global warming, into the atmosphere.
Thinking of bush fires probably brings to mind images of the out-of-control blazes that happened over the past few years in Australia, which had more than 11 million hectares of bush, forest, and park burned. Nevertheless, north equatorial Africa is actually the region with the most biomass fires in the world, with 70% of the world’s burned land.
The region includes 15 countries from Senegal in the west to South Sudan in the east. An important part of the population lives as nomadic herders amid vast areas of savanna and grassland, traditionally setting fires during the dry season, which goes from November to February. Nevertheless, in recent years, the population has grown and savanna has transformed into villages and plots for crops, bringing social and economic changes to the area.
This has led to fewer people setting up fires to protect the infrastructure and their livelihoods, the new study has shown. Researchers found that from 2005 to 2017 there was a 4.5% overall decline in the region in lower-atmosphere concentrations of nitrogen oxides (NOx) during the dry season, which is the time when fires combine with urban pollution.
“The traditional paradigm is that as middle and low-income countries grow you often see more emissions, and to see a different kind of trajectory is very interesting,” Jonathan Hickman, a researcher at the NASA Goddard Institute for Space Studies who was the lead author on the study, said in a statement. “It’s nice to see a decline occurring when you’d expect to see pollution increasing.”
Scientists usually consider the density of NOx as a proxy for overall air quality. Once they are in the air, these pollutants are involved in chemical reactions that produce an array of other dangerous pollutants, including aerosols that damage crops and human health. The researchers used satellite data to measure gases present in the region’s air and to determine fire trends between 2005 and 2017.
Combining both sets of information, the researchers found that fire trends and the level of gases in the air were closely linked. The decline in NOx actually matched with the areas where population density and economic activity have increased, the study showed, according to economic and demographic data. That said, this could change in the mid-future.
As the population continues to grow and urbanize in the region, more people will be subject to concentrated urban pollution, which could cancel out the benefits of decreased fires, the researchers believe. Up to 80% of the power generated in Africa is from fossil fuels, particularly cars. A growing number of cars is being imported, driving up emissions from transportation.
Noise pollution is a growing issue on land — but the seas are not safe either, apparently.
Marine shipping and construction, along with activity from sonar and seismic sensors are making the ocean a very loud place. While that may sound like just any other day in the big city, these high levels of noise pollution are causing a lot of damage to the health of marine ecosystems. A new paper reports on an “overwhelming body of evidence” that man-made noise is to blame.
Loud and deeply
“We’ve degraded habitats and depleted marine species,” said Prof Carlos Duarte from King Abdullah University, Saudi Arabia, lead author of the study. “So we’ve silenced the soundtrack of the healthy ocean and replaced it with the sound that we create.”
Sound plays a very important part in the lives of marine animals, the team explains, being involved in everything from feeding and navigation to communication and social interactions. A lot of what we know of marine animals such as whales comes from sound recordings.
But this state of affairs could change forever. According to the team, the youngest generations of marine animals are missing out on the “production, transmission, and reception” of key behaviors due to “an increasing cacophony in the marine environment” caused by man-made sound.
Freshly-spawned fish larvae use environmental sound and “follow it”, Duarte explains. But these sounds that helped them navigate and understand their environment are now being drowned out. Beyond noise from vessels, sonars, and acoustic deterrent devices, energy and construction infrastructure are also contributing to the issue.
“[T]here is clear evidence that noise compromises hearing ability and induces physiological and behavioral changes in marine animals,” the authors explain, adding however that currently “there is lower confidence that anthropogenic noise increases the mortality of marine animals and the settlement of their larvae” directly.
While the problems caused by marine sound pollution are pronounced and wide-reaching, the quarantine also showcased how quickly and easily they can be averted. According to the authors, levels of man-made sound in the ocean fell by around 20% last year.
Among some of the effects of this drop, the team notes that large marine mammals have been observed in waterways or coastlines that they’ve abandoned for generations. Such effects show that tackling the issue of marine noise is the “low-hanging fruit” of ocean health.
“If we look at climate change and plastic pollution, it’s a long and painful path to recovery,” Prof Duarte said. “But the moment we turn the volume down, the response of marine life is instantaneous and amazing.”
The paper “The soundscape of the Anthropocene ocean” has been published in the journal Science.
Higher levels of air pollution seem to be damaging to our mental health, reports a new study from the Yale School of Public Health (YSPH).
The findings are based on six years’ worth of mental health outpatient visit data from two major hospitals in Nanjing, China. Nanjing is notorious for its high levels of air pollution, even for China (which has quite a lot of air pollution in general). After comparing the number of visits with records of particulate matter in suspension in the air every day, the authors report that visits were more numerous when air quality was especially poor.
Bad air, bad mindspace
“Here, we show that particulate matter is having these more general effects, not just on symptoms but also on service use,” says Assistant Professor Sarah Lowe, Ph.D., first author of the study.
The findings, says the team, showcase why we need further investments in mental services, especially as air pollution levels around the world are getting worse. More research is needed to understand how and why air quality influences mental health, they add, but now we know that it can influence how much use specialized services see.
Air pollution is the product of many components ranging from carbon monoxide in car exhaust to sulfur dioxide particles from industrial processes. This study focused on particulate matter (PM), tiny pieces of organic materials such as liquids or soil, which are known to pose a threat to human health. The main danger they pose comes down to their size, which allows PM to enter deep into the lungs. Once there, they can cause quite a lot of damage by ripping through lung tissue and entering the bloodstream.
The team believes that these particles can influence mental health after entering the bloodstream and reaching the brain.
“These tiny particles not only have effects on the lungs, the heart and the brain,” said YSPH Assistant Professor Kai Chen, Ph.D., senior author of the paper, “but they also have effects on other organs of your body.”
Levels of PM in Nanjing exceed the safety levels specified in China’s air-quality standards for around one in five days of the year, the team notes. As such, they expected the effect it has on psychological disorders would be reflected in an uptick of mental health visits to the city’s two hospitals.
They did see such an uptick, especially prevalent among men and older residents. This unequal distribution may come down to social and behavioral differences among people in Chinese society, but that’s just a hypothesis at this time; more data is needed to tell for sure.
What they were able to say for sure, however, is that days with worse air pollution saw more demand for outpatient mental health services. Whether one causes the other is still murky. For example, days with high levels of air pollution could limit people’s choices of activities (such as outdoor sporting events becoming unbearable or being postponed), leaving people free to come to their appointments. Alternatively, more air pollution could lead to more physical symptoms such as difficulty breathing, which would coax people into seeking mental health services in order to cope.
“There could be other reasons that we simply couldn’t explore with the data we had,” Lowe explained. “We don’t know that level of detail, and I think that would be a really interesting direction for future research,” she said.
The paper “Particulate matter pollution and risk of outpatient visits for psychological diseases in Nanjing, China” has been published in the journal Environmental Research.
Clean drinking water, like democracy, is one of those things you tend to take for granted until it runs out or becomes polluted. But just like democracy, securing it takes a lot of work and constant oversight.
In Poznań, a city in the western stretches of Poland, this work takes place in a round building with round windows in the middle of the Warta River. This building, the Dębiec Water Treatment Plant, harbors one of the most interesting and wacky takes on the issue of water quality management.
Here, artificial and biological monitoring systems ensure that the water pumped throughout the city’s pipes is safe to drink. The artificial systems take precise measurements of chemical contamination in the water, which is definitely handy. However, as Aquanet.pl explains, it is the plant’s biological systems (or ‘bioindicators’) that allow for a more reliable estimation of the water’s overall toxicity, as they account for a broad range of factors “simultaneously”.
These biological systems are comprised of eight mussels with sensors hot-glued to their shells. They work together with a network of computers and have been given control over the city’s water supply. If the waters are clean, these mussels stay open and happy. But when water quality drops too low, they close off and shut the water supply of millions of people with them.
Enter the mussel
According to a presentation from AquaNES, a project of the European Union that aims to integrate nature-based elements into water management systems, Poznań’s main source of water is the Warta River. The only issue here is that the Warta passes through some of the country’s densest population centers, and some of its oldest industrial areas (where heavy industry has been present since the later parts of the 19th century). This creates an avenue through which pollution can wind up into the city’s drinking water. One particular point of worry is heavy metals such as chromium seeping through the ground and into the river.
Which naturally raises a question — how can Poznań ensure that the drinking water running through its pipes isn’t dangerously contaminated?
“Using an organism as an indicator (bioindicator) cannot be accidental. It requires extensive field research that aims to accurately characterize natural occurrence conditions,” writes Aquanet.
“The best indicator organisms are those that have specific life requirements, i.e. they have a narrow ecological (occurrence) scale. This means that a number of different factors will limit their vital functions or even eliminate them from the environment.”
In essence, these “indicator organisms” allow engineers at the plant to know if the water is safe for human use or consumption, even if they don’t produce hard data on its quality. Organisms such as mussels are good indicators of water quality because they have a low tolerance for pollutants, and they show an obvious response to improper water quality: they clamp shut.
Mussels require clean, well-oxygenated water with low levels of physical or chemical impurities to thrive. They’re less and less common in Polish lakes (and in virtually all coastal waters across the globe) because of pollution, which shows just how sensitive they are to changes in water quality. In Poland’s case, a former communist country, most of the damage is caused by pollutants seeping up from contaminated aquifers (groundwater) into lakes or rivers.
This sensitivity to pollutants made them ideal for monitoring Poznań’s water supply. When waters are nice and clean, mussels open up completely in order to feed — which they do by filtering water and eating any organic matter they find. When water quality drops, they very quickly close their shells, inlet siphon (their ‘mouth’), and slow down their metabolism.
The use of mussels as part of an automated water supply system was tested at the Department of Water Protection at the University of A. Mickiewicz in Poznań and found to be a very reliable indicator of water quality.
Whenever a mussel clamps down, it closes a circuit via a spring that was simply hot-glued to its shell, which alerts a computer that it may be time to turn off the water supply. The computer’s job is to monitor parameters obtained through artificial sensors and produce an alarm if anything seems amiss. This step is meant to account for any possible change in the individual behavior or mussels, of which there are 8; one presumes they may sometimes grow tired and close off for a nap.
If four of the mussels close at the same time, however, the system shuts down automatically. It’s engineering at its best.
Mussels are typically viewed as a nuisance that clogs and damages water supply systems. But the clam-powered system has been running at the Dębiec Water Treatment Plant since September 1994 and might change that view.
Gruba Kaśka (Fat Kathy)
This is one of those stories that you hear and just can’t believe its real. I first ran into it as a meme on Reddit and was convinced it’s just a funny story someone made up for laughs until I started digging around a bit.
But I’m definitely glad I did. The simplicity and creative thought that underpin this system is what I enjoy about it the most. I find it particularly exciting to see engineers cooperating with wildlife in such an important task: to protect public health and the quality of tap water.
Julia Pełka, the director of Gruba Kaska, a documentary film that follows the story of such mussels in Poland’s capital is the one who brought this story out of the plant and into the Internet. Her interest in the topic began when she was little, as Warsaw’s water pumping facility was clearly visible from a bridge she needed to pass over when going to visit her grandparents.
“I read an article about this building called ‘Gruba Kaśka’ which is a water pump and can be accessed through an underground 300-meter tunnel,” Julia Pełka told me. “Inside, 8 clams control the purity of our water.”
“No computer can replace these super-sensitive mussels.”
As an adult, she ran into a story detailing how clams help keep the water supply clean, and thus a documentary film was born. Julia’s documentary follows a clam-based control system similar to the one from Poznan in the city of Warsaw.
“These unassuming creatures take care of the safety of millions of people in Warsaw. I saw a certain metaphor in this, but at the same time a very good subject from a cinematic perspective,” , told me in an email.
She adds that the clams are “paid back after three months of work by releasing them to a place from which they will never be caught again”. While I definitely enjoy the thought of clams earning a comfortable retirement spot, this is done because they eventually become resistant to contamination in the water.
One thing that struck me in my back and forth with Julia (apart from the obvious coolness of the story) is the depth of themes that can be derived from a simple water safety system.
“By making this film I wanted to show man’s dependence on nature. I thought it was brilliant that humans are using mussels to create a warning system against danger. They use the clams’ senses to protect themselves from the dangers of modern civilization.”
“You could say that people use them as protection from themselves.”
Alongside malacologist Piotr Domek, who specializes in finding and selecting appropriate mussels for the Warsaw plant, Julia wanted to offer thanks to the Polish Waterworks, who allowed her to film “inside such a strictly guarded facility”. The documentary premiered late last month as part of the World Showcase Shorts Program 3.
New research found that marine mollusks such as mussels, oysters, and scallops, contain the highest levels of microplastic contamination of all seafood.
The team, led by members from the Hull York Medical School and the University of Hull has analyzed over 50 studies on the topic of microplastic contamination in seafood. These were published between 2014 and 2020 and worked with species ranging from fish to shellfish all around the world.
Food with a little extras
“A critical step in understanding the full impact on human consumption [of plastics] is in first fully establishing what levels of microplastics [MPs] humans are ingesting,” says Evangelos Danopoulos, a postgraduate student at Hull York Medical School and co-author of the paper. “We can start to do this by looking at how much seafood and fish is eaten and measuring the number of MPs in these creatures.”
Microplastics are produced by the breakdown of larger plastic particles as they decompose slowly; some are produced outright, as additives for cleaning or beauty products. Eventually, they make their way into waterways and the ocean through wastewater. Once there, MPs often become ingested by wildlife that confuses it for bits of food. Microplastics resist digestion and build-up in the animals’ bodies.
Whenever we eat seafood, then, we’re also taking in the plastics they ingested over their lifetimes. MP contamination is not limited to seafood, but it is more pronounced here than in any other type of environment. The team found microplastic content ranged between 0-10.5 microplastics per gram (MPs/g) in mollusks, 0.1-8.6 MPs/g in crustaceans, 0-2.9 MPs/g in fish.
“Microplastics have been found in various parts of organisms such as the intestines and the liver,” says Danopoulos. “Seafood species like oysters, mussels, and scallops are consumed whole whereas in larger fish and mammals only parts are consumed. Therefore, understanding the microplastic contamination of specific body parts, and their consumption by humans, is key.”
“No-one yet fully understands the full impact of microplastics on the human body, but early evidence from other studies suggest they do cause harm.”
China, Australia, and Canada are the largest global consumers of mollusks, the team also found, followed by Japan, the US, Europe, and the UK. Those captured off the coasts of Asia tended to see the highest levels of contamination, suggesting these areas are the most heavily polluted with plastics and microplastics.
The findings showcase the sheer extent of the plastic pollution problem facing our planet. Production of such materials is expected to triple by 2060, meaning it will only get worse and worse in the future unless steps are taken soon. For that to happen, however, we need to get a clearer image of the problem, and the team explains that we need standardized methods of measuring microplastic contamination levels, and more on-the-ground data to see how different oceans and waterways are impacted by them.
The paper, “Microplastic contamination of seafood intended for human consumption: a systematic review and meta-analysis” has been published in the journal Environmental Health Perspectives.
A new study sheds light on the potential health costs of 3D printing.
There’s little room for debate around the merits of 3D printing. That’s reflected in their growing use in homes, schools, and other settings where people spend a lot of time. But a new paper comes to warn that the printers aren’t harmless. The printing process can affect air quality and public health through the airborne particles it generates — these are small enough to enter deep into the lungs, the authors warn.
“To date, the general public has little awareness of possible exposures to 3D printer emissions,” states Peter Byrley, Ph.D., EPA, lead author.
“A potential societal benefit of this research is to increase public awareness of 3D printer emissions, and of the possibly higher susceptibility of children”.
Such printers have served an invaluable role during the pandemic, when institutions as well as individuals turned to them for face shields, respirator parts, or other equipment needed (but scarce) in face of COVID-19. However, the authors argue that it’s precisely due this rise in use that we should understand the health effects of 3D printing.
Materials used in the printing process can vary greatly, depending on the model, and include thermoplastics, metals, nanomaterials, polymers, or volatile and semi-volatile organic compounds. Each print can take up to several hours to complete (depending on the printer and the size of the item). During this time, a wide range of chemical by-products and particles can seep into the environment, especially indoors, according to the authors.
The paper provides a meta-analysis of existing literature on the subject. The team reports finding evidence that ABS (acrylonitrile butadiene styrene) emissions generated during the printing process can affect human and rat lung cells it comes into contact with. The same study showed that these particles cause “moderate” toxicity in human lung cells and “minimal” toxicity in rats. Two recent studies from the EPA also showed that emissions from a 3D printer filament extruder (a device used to create printer filaments), both vapor and small particles, are similar to those found in the ABS study. They also report that these emissions can lead to deposition of particles in the lung tissues of individuals aged nine and younger (based on computer simulations).
Another cited study examines the ecological cost of 3D printing. The accessibility, convenience, and scale of 3D printing today is a direct contributor to plastic pollution, it explains. Nanoparticles generated from the breakdown of 3D printed materials were further found to become biologically available when exposed to the environment (meaning an animal or plant can absorb them into their tissues). It establishes a Matrix Release Factor (MRF), describing the percentage of nanoparticles that came out of the plastic when eaten by fish, which can help us gauge how much of them are released when a product breaks down or is consumed.
“This research can help set regulations on how much nanomaterial fillers can be added to particular consumer products, based on their MRF value,” states Sipe. “The data can help determine how much plastic and/or nano-filled products release contaminants into the environment or the human body.”
These risks are manageable, but the only way we can protect ourselves is to know they exist. The authors are confident that 3D printing will continue to enjoy wider popularity in the future, so more in-depth research is needed to uncover all sides of the story in order to make the most of it while keeping people and the environment healthy and safe.
A highly toxic insecticide used on cats and dogs to kill fleas is poisoning rivers and streams across the United States and the United Kingdom, according to two recent studies. The pollution is directly affecting water insects and the fish and birds that depend on them, the researchers warned.
Both studies focused on fipronil, a pesticide commonly used as an anti-flea substance for petsin many parts of the world. It has several properties that make it an attractive pest control agent (including high toxicity towards invertebrates and water solubility) — but those same properties also make it a nasty pollutant.
Despite being banned for agricultural use, fipronil is still commonly used in pets to treat fleas and ticks. In the UK alone, there are 66 licensed veterinary products that contain fipronil, including spot-on solutions, topical sprays, and collars impregnated with the active ingredient. Some require prescription and others don’t.
Researchers in the UK found fipronil in 99% of samples from 20 rivers and the average level of one particularly toxic breakdown product of the pesticide was 38 times above the safety limit. There are about 10 million dogs and 11 million cats in the UK, with an estimated 80% receiving flea treatments.
“Fipronil is one of the most commonly used flea products and recent studies have shown it degrades to compounds that are more toxic to most insects than fipronil itself,” Rosemary Perkins at the University of Sussex, who led the study, told The Guardian. “Our results are extremely concerning.”
This isn’t the first time researchers have sounded the alarm on this type of pollution. A study in 2017 by the conservation group Buglife had already warned over high levels of insecticides in rivers but didn’t include fipronil. Aquatic insects are highly vulnerable to such substances. Previous studies shown chronic waterway pollution led to sharp drops in insect numbers and falls in bird numbers.
With that in mind, Perkins and her team decided to review 4,000 analyses on samples in 20 English rivers. They found fipronil in 99% of the samples as well as a highly toxic breakdown product called fipronil sulfone in 97% of them. Average concentrations were 5 and 38 times higher than their chronic toxicity limits, respectively.
“I couldn’t quite believe the pesticides were so prevalent. Our rivers are routinely and chronically contaminated with these chemicals,” Dave Goulson, part of the study, told The Guardian. “The problem is these chemicals are so potent, even at tiny concentrations. We would expect them to be having significant impacts on insect life in rivers.”
Similar results were found in a recent study in the US. Researchers from Colorado State University. Researchers learned that fipronil and other related compounds were more toxic to stream communities than previous research had suggested, especially in the relatively urbanized Southeast region.
The insecticide is likely affecting stream insects and impairing aquatic ecosystems across the country. To make matters even worse, fipronil degrades into new compounds, some of which the study found to be more toxic than fipronil itself.
The researchers also found delayed or altered timing of when these insects emerged from streams, and the effects of this can cascade across the entire food chain.
“The emerging insects serve as an important food source,” Janet Miller, the lead researcher of the study, said in a statement. “When we see changes, including a drop in emergence rates or delayed emergence, it’s worrisome. The effects can reverberate beyond the banks of the stream.”
Miller said fipronil compounds were detected at unsafe concentrations in 16% of streams sampled across the U.S. and were most prevalent in streams of the Southeast region of the country. Scientists found fipronil compounds much less widespread in other regions, suggesting use patterns of the insecticide differ across the country.