Category Archives: Pollution

These nanobots powered by magnets can successfully remove water pollutants

Surface water, including lakes, canals, rivers, and streams, is a key resource for agriculture, industries, and domestic households. It’s quite literally essential to human activity. However, it’s also very susceptible to pollution, and cleaning it up is rarely easy. But we may have a new ally in this fight: nanobots.

Image credit: Wikipedia Commons.

According to the UN, 90% of sewage in developing countries is dumped untreated into water bodies. Industries are also to blame, as they dispose of between 300 and 400 megatons of polluted water in water bodies every year. Nitrate, used extensively by agriculture, is the most common pollutant currently found in groundwater aquifers.

Once these pollutants enter into surface water, it’s very difficult and costly to remove them through conventional methods, and hence, they tend to remain in the water for a long time. Heavy metals have been detected in fish from rivers, which hold risks to human health. Water pollution can also progress to massive disease outbreaks.

The use of nanotechnology in water treatment has recently gained wide attention and is being actively investigated. In water treatment, nanotechnology has three main applications: remediating and purifying polluted water, detecting pollution, and preventing it. This has led to a big demand lately for nanorobots with high sensitivity

However, there’s a technical challenge. Most nanorobots use catalytic motors, which cause problems during their use. These catalytic motors are easily oxidized, which can restrict the lifespan and efficiency of nanorobots. This is where the new study comes in.

A new type of nanorobot

Martin Pumera, a researcher at the University of Chemistry and Technology in the Czech Republic, and his group of colleagues developed a new type of nanorobots, using a temperature-sensitive polymer material and iron oxide. The polymer acts like small hands that pick up and dispose of the pollutants, while the oxide makes the nanorobots magnetic.

The robots created by Pumera and his team are 200 nanometers wide (300 times thinner than human hair) and are powered by magnetic fields, allowing the researchers to control their movement. Unlike other nanorobots out there, they don’t need any fuel to function and can be used more than one time. This makes them sustainable and cost-effective.

In the study, the researchers showed that the uptake and release of pollutants in the surface water are regulated by temperature. At a low temperature of 5ºC, the robots scattered in the water. But when the temperature was raised to 25ºC they aggregated and trapped any pollutants between them. They can then be removed with the use of a magnet.

The nanorobots could eliminate about 65% of the arsenic in 100 minutes, based on the 10 tests done by the researchers for the study. Pundera told ZME Science that the technology is scalable, which is why with his team he is currently in conversations with wastewater treatment companies, hoping to move the system from bench to proof-of-concept solutions.

The study was published in the journal Nature.

Exposure to air pollution could be a cause of ADHD in children

While genetics play a big role, many other factors have been speculated to cause attention deficit hyperactivity disorder (ADHD) – from eating too much sugar to watching TV. Now, researchers have found that high levels of air pollution and limited access to green areas can also increase the risk of developing the condition.

Image credit: Wikipedia Commons.

ADHD is a common neurodevelopmental condition in children, which sometimes continues in adulthood. It’s a complex condition, difficult to diagnose, and with no cure. If left unchecked, ADHD can impact children’s performance at school and their relationships with parents and peers . It’s more common in boys than girls and it affects 1 in 20 children.

The disorder is generally diagnosed during the first years of school but it can manifest differently from child to child. Its cause, however, has been a subject of debate among researchers. In 2018, a study identified regions of the DNA associated with ADHD, for instance. But scientists have also been studying other factors, with no clear answers on many of them so far.

It seems like a lot of things could be responsible for ADHD, and the latest to blame is air pollution. According to previous research, it may cause ADHD through induced systemic oxidative stress, with disturbs brain development, leading to cognitive deficits. Noise exposure can also increase stress, with is associated with psychological disorders such as hyperactivity. However, results from previous research have so far been inconsistent or limited.

In a new study, researchers at the Barcelona Institute for Global Health (ISGlobal) looked at the links between environmental exposures (greenness, air pollution and noise) in early life and later ADHD incidence – using environmental exposure metrics in combination with a population-based birth cohort linked with administrative data.

“We observed that children living in greener neighborhoods with low air pollution had a substantially decreased risk of ADHD. This is an environmental inequality where, in turn, those children living in areas with higher pollution and less greenness face a disproportionally greater risk”, lead author Matilda van den Bosch said in a statement.

ADHD and air pollution

For the study, the researchers used birth data from the metropolitan area of Vancouver, Canada from 2000 to 2001 and also retrieved data on ADHD cases from hospital records. They estimated the percentage of green spaces in the participants’ neighborhoods as well as the levels of air and noise pollution, using exposure models.

The study identified a total of 1,217 ADHD cases, which represents 4.2% of the sampled population. The participants living in areas with a larger percentage of vegetation had a lower risk of ADHD. More specifically, the study showed that a 12% increase in vegetation was linked with a 10% drop in the risk of having ADHD.

The opposite associated was observed with air pollution. The participants who had higher exposure to PM2.5 (fine particulate matter) had a higher risk of ADHD. Specifically, every 2.1 microgram increase in the levels of PM2.5 meant an 11% increase in the risk of ADHD. No link was found between noise pollution, NO2, and ADHD.

“Our findings also show that the associations between PM2.5 and ADHD were attenuated by residential green space and vice versa as if the beneficial effects of vegetation and the harmful effects of PM2.5 neutralized each other,” Weiran Yuchi, a researcher at the University of British Columbia and first author of the study, said in a statement.

The study was published in the journal Environment International.

These impressive trees can absorb microplastics through their roots

We tend to associate microplastics just with the marine environment, but these small pieces of plastic are also accumulating in soils and at a higher level. Now, a group of researchers has found an unexpected solution. Birch trees, found in the Northern Hemisphere, were found to remediate the soils by absorbing microplastics through their roots.

Image credit: The researchers.

Microplastics are contaminants of growing concern. They originate from the breakdown of larger plastic and from the release of primary materials, which makes them easily transported in water, air, and soil and can accumulate and persist in the environment. Microplastics are everywhere, from the depths of the oceans to the top of Mount Everest.

Most research on the influence of microplastic has focused on how they interact with plants and animals in seas and oceans. While less obvious than in oceans, microplastics also accumulate in soils at levels between four to 23 times higher than in marine ecosystems, either being transported through the atmospheric or by direct deposition.

Microplastics alter the properties of the soil and can also affect plant growth and microbial community. However, not much is known about how microplastics interact with higher-order terrestrial plants such as trees. Recent studies have shown, for example, that microplastics are taken up by agricultural plants such as wheat.

As part of an interdisciplinary project, a group of German researchers has shown that longer-lived woody plants, specifically birch trees (Betula), can absorb and store microplastics in their tissue. The roots of this tree species grow close to the soil surface, where microplastic is the highest, making it a good choice for a study.

“The uptake rate of microplastics and the effects on the short- and long-term health of the trees still need to be studied. But this pilot study suggests birch has real potential for long-term soil remediation solutions – including reducing the number of microplastics in soil and possibly water,” Kat Austen, the lead author, said in a statement.

Birch trees and microplastics

Birch trees are a group of 40 species of ornamental and timber trees and shrubs, generally found in cool regions of the Northern Hemisphere. They have been used to remediate polluted land in the past as they can sequester and store pollutants and heavy metals in their tissues. Plus, they were found in previous studies to be very good at reducing air pollution. So it makes a lot of sense to see if they can help with microplastics.

Longitudinal cross-section showing microplastic particles inside a birch lateral root in a one-year-old birch tree. Image credit: The researchers.

For their study, the researchers added microplastic beads with fluorescent dyes to the soil of potted birch trees, which enabled them to see where the microplastic pieces were going. After five months, they analyzed the root system using fluorescence and confocal laser scanning microscopy, finding microplastics in different sections of the root system in between 5% and 17% in the experimental trees — enough to show that birch trees can be helpful with microplastic bioremediation.

“These results give a strong indication for the uptake and incorporation of soil-derived microplastic into juvenile birch roots and suggest that further investigations addressing the rate of uptake of microplastic and its implications for long term tree health are necessary to determine if birch trees are suitable microplastic remediators.,” the researchers wrote.

However, this doesn’t mean that we suddenly have a solution for microplastics pollution. If we want to truly address this problem, we need to tackle it at its root and think about producing less plastic in the first place.

The study was published in the journal Science of the Total Environment.

A new problem from air pollution: It could be affecting sperm quality

Air pollution doesn’t just kill millions prematurely every year, especially in developing countries, it also affects the human sex ratio at birth and cause birth defects. Now, a new study in China has found yet another problem, finding that chemicals or particles in the air may also target sperm quality — specifically sperm motility, the ability of sperm to move in the right direction.

Image credit: Wikipedia Commons.

Infertility is a big public health problem, affecting about 10% of all couples at reproductive age. Pure male factors, especially poor semen quality, account for 50% of all infertility cases, according to the World Health Organization. Evidence has also suggested recently a downward trend in semen quality, with a decline in sperm motility, and the causes are not entirely clear.

Genetic background plays a big part in poor semen quality, but the marked decline in sperm quality in recent years suggests there’s something else going on, and here’s where environmental factors enter. Studies have reported a link between particulate matter (PM) and semen quality, but so far, the connection has been rather inconsistent.

An international literature review published last year said there’s enough reason to believe that air pollution is affecting fertility in general. Fossil fuels have been found in people’s urine, semen, blood, and breast milk. Many of these pollutants are endocrine disruptors, altering the body’s hormonal systems.

In a new study, researchers from Tongji University in Shanghai explored the data records of almost 34,000 men, aged 34 on average, from 340 Chinese cities, all exposed to a varying degree of air pollution. Their wives got pregnant by using reproductive technology with their sperm between January 2013 and December 2019.

Pollution and sperm

With the data collected, the researchers looked for patterns in semen quality in relation to whether the participants had been exposed to amounts of PM smaller in diameter than 2.5 micrometers, between 2.5 and 10 micrometers and over 10 micrometers. This was done several moments before the patient’s visit to the hospital.

The researchers focused on sperm count, concentration and sperm motility. While they couldn’t find a direct link between air pollution and the first two factors, they did find that the more a patient was exposed to small PM, the lower the sperm total and progressive motility was. Progressive motility is the ability to swim forward and total motility is the ability to swim in general.

Specifically, there was an estimated 3.6% drop of sperm motility when exposed to PM smaller than 2.5 micrometers and a 2.4% decline when exposed to PM of 10 micrometers, the study showed. This means that different sizes of PM could have different effects on semen quality. The smaller the PM, the more likely it is to travel to the human lungs and potentially affect sperm quality.

The study showed that the effects of air pollution on sperm quality are more significant when the exposure occurs in the first part of the 90 days of sperm creation, known as spermatogenesis, instead of the other two phases. This could indicate that PM affects sperm on a genetic level. However, it’s all speculation at this point and further research will be needed to confirm this hypothesis.

“Poor sperm motility has raised global concern as a major cause of male infertility. Our findings add evidence that PM exposure during sperm motility development may contribute to reduced sperm motility. Although the estimated decrease in sperm motility was relatively small, it still resulted in significantly increased odds of asthenozoospermia (the medical term for reduced sperm motility),” the researchers wrote.

The study was published in the journal JAMA.

Black people in the US are more exposed to pollution, regardless of income

When it comes to environmental justice in the US, there’s still a long way to go — things are moving in the right direction, but slowly.

Image credits: Jacek Dylag.

Air pollution is linked to a number of health problems, from lung and cardiovascular diseases to cognitive impairment. But not everyone is exposed to pollution equally. In the US, for instance, previous research has suggested that race plays a significant role in exposure to pollution, with Black people being more exposed to pollution. Now, a new study reinforces that idea.

University of Washington researchers investigated disparities in exposure to six major air pollutants in 1990, 2000, and 2010: carbon monoxide (CO), ozone (O3), sulfur dioxide (SO2), nitrogen dioxide (NO2), and particulate matter (PM10, PM 2.5). They compared models of air pollution with census data that included people’s racial or ethnic background, their address, and income status. Specifically, they used the Center for Air, Climate, and Energy Solutions (CACES) data.

Even when they accounted for income (poorer neighborhoods tend to be associated with more pollution), the researchers found significant racial disparities. There’s been important progress over the past few decades, but the disparities still remain.

“We studied racial-ethnic and income disparities at multiple geographic levels (contiguous US; state; urban/rural areas), using the CACES air pollution models and demographic data from three decadal censuses,” lead author Jiawen Liu, UW doctoral student in civil and environmental engineering, told ZME Science. “This is the first comprehensive and consistent national decades-long study for six criteria pollutants, over time and space. In our study, we found air pollution levels and exposure disparities generally declined during 1990 to 2010. Absolute racial-ethnic exposure disparities decreased more than relative racial-ethnic exposure disparities. In 2010, the most-exposed racial-ethnic group was always a minority group for all pollutants.”

“There have been so many improvements,” the researcher also says. “But we still see these disparities persist, even after two decades.”

Racial-ethnic disparities were found in all US states, for multiple pollutants, and they remain distinct and larger than income disparities.

Credits: Liu et al.

For communities, this is probably a bigger problem than they realize, affecting them in multiple impactful, but subtle ways. This is an environmental justice problem that should be addressed, the researchers say. Environmental justice refers to the fair treatment and meaningful involvement of all people regardless of race, color, national origin, or income, in regards to the implementation and enforcement of environmental laws, regulations, and policies.

“Communities are impacted by air pollution for a long time and we want to make more people realize Environmental Justice is an ongoing issue no matter where they are.  As previous literature has documented, racial/ethnic minority populations and lower-income populations in the US often experience higher-than-average burdens of air pollution and its associated health impacts. The disparities vary by pollutant, location, and time. “

Credits: Liu et al.

It’s not entirely clear why these differences persist. Although there is a lot of previous scientific information about so-called environmental racism and its causes (which include lack of affordable land, lack of political power, lack of mobility, and poverty), this particular study stops short of explaining the causes for the disparities.

“The underlying reasons for exposure disparity is a large and complicated topic. Our study aims on “what”, not “why”. The underlying reasons include where people live and segregation patterns, and where pollution sources are located. Recent studies about systemic racism and racial segregation can help explain exposure disparity we seen in our study.”

However, the fact that the racial disparities aren’t restricted to income suggests a complex interplay of social aspects. This warrants more study policy intervention, Liu concludes — because in the meantime, communities are suffering.

“While these results are new to the scholarly literature, they are not new to communities suffering the disproportionate health risks from air pollution. We hope the information in our study will help motivate positive change, namely, improving air quality while reducing and eliminating exposure disparities. “

The study was published in Environmental Health Perspectives.

Polluted air can reduce cognitive abilities — but improvements in air quality can help

The more researchers look into air pollution, the more problems it seems to cause.

Exposure to pollution has been linked to a number of major health problems, including cardiovascular disease and lung disease. It’s also been linked to dementia before, and some studies have even found that it can even impair cognitive ability. When it comes to other conditions, pollution is a modifiable risk. When the pollution is eliminated, the risk also drops, but for dementia, this hadn’t yet been demonstrated.

So a team of researchers led by Diana Younan, of the University of Southern California, carried out a study on 2,232 older women who were free of dementia when they entered the study. They chose to focus on women because older women are disproportionately affected by Alzheimer’s disease, Younan told ZME Science. The researchers then followed the women for 20 years, giving them two different cognitive tests every year. They also analyzed local changes in air quality for all of the women and used statistical analysis to see if a reduction in air pollution was associated with slower cognitive decline.

It was. Women living in areas with greater improvements in air quality tended to have a much slower decline, as indicated by cognitive tests. Basically, the reduced rate of decline in areas with greater air improvement was equivalent to being 0.9-1.6 years younger, depending on the test.

The findings strengthen the link between pollution and cognitive decline. In order to give context on how much air pollution can affect cognitive ability, the researchers compared the magnitude of their results with other known predictors of cognitive decline, such as age.

We found that reducing air pollution exposure can promote healthier brain aging in older women by slowing cognitive decline. These benefits were seen in older women of all ages, levels of education, geographic regions of residence, and cardiovascular histories,” Younan says.

“Based on our results, we saw that an interquartile range increment of reduced PM2.5 (1.79 ug/m3) and of reduced NO2 (3.92 ppb) was associated with slower decline in cognition,” Younan told ZME Science. “This potential benefit was equivalent to the slower decline rate observed in women who were 1-1.5 years younger at baseline.”  

The good news is that environmental policies can help reduce pollutants, and consequently, help reduce the burden on people’s cognitive abilities.

“The health benefits seen in our study were a result of decreasing levels of both PM2.5 and NO2 across the U.S., which were likely due to national policies and strategies aimed at regulating pollution from stationary (power plants; factories) and mobile (vehicles) sources.”

Cleaner air is already known to improve heart and respiratory health, but in addition to the health component, there’s also an economic component to the study. Dementia is estimated to cost the U.S. economy $159–$215 billion annually, and reducing pollution could be an efficient way of reducing this financial burden.

The researchers were surprised to see that the benefits of reducing pollution levels were seen across older women of all ages — which is all the more reason to take measures to reduce atmospheric pollution, they say.

“Studies have shown that seniors, people with lower levels of education, people living in certain areas across the US, and people with preexisting heart disease are affected more by air pollution,” Younan concludes. “What surprised us and was the most important finding was that these benefits were seen in older women of all ages, levels of education, geographic regions of residence, and cardiovascular histories. The Clean Air Act mandates that the Environmental Protection Agency sets air quality standards to provide a safe margin for sensitive populations and these results suggest that the benefits may be universal in older women. I think these findings show that it is worth the continuing efforts to enforce air quality standards and provide more clear air to all.”

Gas stoves leak methane even when not in use

Methane, a powerful greenhouse gas, is leaking from your stove even when it is not in use. In fact, most of the methane they leak happens while the stoves are not being used. Although individually, each stove doesn’t leak much of the gas, the effect adds up tremendously over the whole USA.

Image via Pixabay.

Leaky troubles

“Simply owning a natural gas stove, and having natural gas pipes and fittings in your home, leads to more emissions over 24 hours than the amount emitted while the burners are on,” says Stanford Professor of Earth Sciences Rob Jackson, co-author of the study.

The team measured the methane released from the cooking stoves in 53 homes in the state of California. They recorded the quantity of methane that leaked whenever the knobs of the stove were turned, in the moments before the gas lit on fire. They also recorded how much methane escaped unburned during cooking. However, the main advantage of this study over comparative ones is that it also measured how much methane was released when the stoves were not in use.

According to the results, a surprising 80% of the methane leaks recorded during the study were observed while the stoves were not in use. These came from loose couplings and fittings between the stove and gas distribution pipes. Eric Lebel, the study’s lead author, says that their results come to address the lack of data on “incomplete combustion from appliances,” offering up a valuable piece of the climate change puzzle.

The stoves and cooktops studied in this study belonged to 18 different brands, and varied in age from between 3 to 30 years old. Stoves using pilot lights leaked more than those equipped with an electronic sparker.

According to the measurements, the team estimates that around 1.3% of the gas used in a stove leaks into the atmosphere — which, individually, is a small quantity. Added up over the more than 40 million gas stoves in the U.S., however, this amounts to a significant quantity of greenhouse gas. Overall, the climate-warming effect of this quantity of methane would be equivalent to the emissions of 500,000 gasoline-powered cars.

Such leaks become important when considering the global push against greenhouse gas emissions. The E.P.A. estimates that buildings account for more than 10% of the greenhouse gas emissions in the USA.

The authors advocate that switching to electric stoves would help slash these emissions. It would also help in the broader sense that making a switch here would make people more comfortable to switching other, larger sources of domestic emissions such as the furnace, water heater, and clothes dryer.

That being said, they are aware that such a switch isn’t viable for many people, such as renters as those who can’t afford to purchase an electric stove. In these cases, there is a simple step everyone can take to limit methane emissions in their home:

“Pull the stove out from the wall and tighten the connectors to the stove and to the nearby pipes,” Jackson says.

In order to remove these emissions completely, however, the team underlines that the only real option is to switch to an electric stove entirely.

The paper “Methane and NOx Emissions from Natural Gas Stoves, Cooktops, and Ovens in Residential Homes” has been published in the journal Energy and Climate.

Snowfall in the Alps is full of plastics particles

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 research site at Sonnblick. Image credits ZAMG / Christian Schober via Flickr.

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.

Plastic snow

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.

Otters in the UK are heavily exposed to toxic ‘forever chemicals’

Toxic, long-lived chemicals have been found in freshwater otters in the UK. The findings point to “widespread pollution” of the country’s waterways with PFASs — perfluoroalkyl and polyfluoroalkyl substances (PFASs).

Image credits Drew Avery / Flickr.

PFASs are known as ‘forever chemicals’ because of their very long lifespan. These compounds are characterized by a strong carbon-fluorine structure which is very chemically stable, making them very hard to degrade in the wild. PFASs have been linked to health problems both in humans and wildlife in the past.

The new study found these substances in all 50 samples recovered from otters across England and Wales; at least 80% of these samples contained 12 or more different kinds of PFASs.

The findings showcase the wide scale of pollution in UK rivers and were published in support of a parliamentary report which held that no English river was free from pollution.

Dirty waterways

“PFASs are a large family of synthetic chemicals used in consumer products for their oil and water-repelling properties, in food packaging, non-stick cookware, waterproof clothing, stain resistant products, paints and fire retardants, amongst other things,” says Emily O’Rourke, a Ph.D. student and lead author of the study.

“They’re known as ‘forever chemicals’ because their strong carbon-fluorine structure means they don’t break down easily in the environment. In recent years there have been efforts to phase these chemicals out, but they remain ubiquitous because of their environmental persistence.”

The team sampled liver tissue from otters that had died between 2007-2009, analyzing these for PFASs content. Records of where the otters were found along with land-use records over that time were used to determine contamination levels at different sites across the UK, and to gauge potential sources of contamination. This time period was selected as it coincided with legislation changes in regards to the use of PFASs; these changes led to the phasing out of the two most common such chemicals, but they were soon replaced by emerging alternatives.

The team sampled 50 otters, finding all of them were contaminated with PFASs. Roughly 8 in every 10 otters showed measurable levels of 12 or more PFASs. These results point to “significant and concerning” contamination sources with such substances into UK rivers, the team explains.

Eurasian otters (Lutra lutra) are apex predators in British waterways and act as reliable indicators of the level of chemical pollution in their environment. Studying them is vital to our understanding of the substances that affect wildlife in the UK’s rivers. The authors note that their findings are validated and supported by similar results obtained by the separate Otter Project, which used more recent samples collected in 2015-2018.

The results point to a few key sources of PFAS pollution. One was a factory on the northwest coast of England that previously used perfluorooctanoic acid (PFOA) in its activity. Other important sources were wastewater treatment sites, which suggests that domestic and industrial wastewater is a significant source of these chemicals in the environment. Samples recovered near agricultural lands also showed high levels of PFASs.

“Our study provides further evidence to support the conclusion of the recent Environmental Audit Committee’s report which highlighted a ‘chemical cocktail’ of contaminants in our waterways,” said Mrs O’Rourke. “The report recommended an independent evaluation of the risks to human health and the environment of spreading sewage sludge—our study provides important evidence that PFASs should be included in that evaluation.”

“Further work is needed to understand where the highest concentrations are now and any current sources of contaminants. It is deeply concerning PFASs were introduced into the environment through industrial and farming practices — policy and management action is vital to address this where it remains an issue,.

The paper “Anthropogenic Drivers of Variation in Concentrations of Perfluoroalkyl Substances in Otters (Lutra lutra) from England and Wales” has been published in the journal Environmental Science & Technology.

Clean clothes, dirty environment: Electric dryers release thousands of microplastic fibers into the air after every use

We know washing machines release thousands of microfibers (a common type of microplastics) into the water. But tumble dryers are also a problem. A new study found that dryers are the main source of microfiber pollution into the atmosphere, with each dryer responsible for releasing up to 120 million microplastic fibers into the air each year.

Image credit: Unsplash / Creative Commons.

Synthetic fibers such as polyester and nylon are widely used to make clothes, with the production of synthetic clothing growing every year. But there’s a catch. During laundering, these can release microfibers into the environment. To date, most studies have focused on washing machines and microfibers, a problem partly solved by treating laundry water in sewage plants. 

But that’s not the case with electric clothes dryers, which release masses of microfiber directly into the environment, with nothing to filter them. In the US and Canada, over 80% of households use a clothes dryer and usage numbers are also growing in developing countries, as more and more people are affording (and wanting) dryers. 

In a new study, researchers at the City University of Hong Kong and the State Key Laboratory of Marine Pollution (SKLMP) explored the role of household driers as sources of microfiber pollution – estimating that between 90 million and 120 million microfibers are produced and released into the atmosphere by each dryer every year. 

“Household tumble dryers can be an important mechanism for releasing textile microfibers to the ambient atmosphere. Because vented air is usually not treated, microfibers are emitted directly through a ventilation pipe connected to the dryer to ambient air, either indoor or outdoor,” the researchers wrote in their paper.

Dryers and microfibers

The team dried clothes made of polyester and cotton in separate 15-minute cycles, using a dryer that had a vent pipe to the outdoors. Then they gathered and counted each airborne particle that escaped the vent. Both cotton and polyester clothes produced microfibers, likely because of the clothes rubbing together in the dryer. 

Image credit: The researchers.

For both fabrics, the dryer released between 1.4 to 40 times more microfibers than what’s generated by washing machines – based on previous studies for the same amount of clothing. The release of polyester microfibers also increased as more clothes were added to the dryer. This wasn’t the case with cotton microfibers, as the fibers tend to clump together and can’t stay airborne. 

As well as highlighting the problem, the researchers explored a possible solution. They designed a filter that could prevent microplastics from being spread from washing machines and are now working on a similar one for clothes dryers. However, they warned that microplastics could still be released into the air if people just put the fibers collected by the filter in the dustbin. 

“Before the realization of better replacements for synthetic fibers such as polyester, it is feasible to minimize the release of microfibers from tumble driers by the installation of a simple, engineered filtration device at the end of the emission pipeline,” the researchers wrote.

The study was published in the journal Environmental Science and Technology Letters. 

The Mediterranean Sea is filled with plastics that come from elsewhere

Almost every country in the Mediterranean Sea has at least one Marine Protected Area (MPA) where over half of its macroplastics originated from another country, according to a new study. The findings highlight that plastic pollution is an international problem and we need international collaboration in order to tackle it, the researchers argue.

Image credit: Joan / Flickr.

Slowly but surely, plastic pollution has become one of the major environmental issues of our times, comparable to the climate crisis and overfishing. While much recent research focused on microplastics, this new effort looked at how macroplastics (plastic bits bigger than five millimeters) affect the marine ecosystem, as organisms ingest or become entangled in plastic litter — often with dramatic consequences. 

Plastic pieces (especially small ones) can travel very long distances and end far from their original sources. They come in unseen for multiple, often distant sources, threatening wildlife and their habitats in marine areas. Previous studies in the Arctic, the Pacific and the Atlantic have shown MPAs are very affected by plastic pollution. 

In the new study, a group of researchers focused on the Mediterranean Sea, one of the most polluted regions globally which also happens to be an important biodiversity hotspot. It’s shared by numerous countries in Europe, Africa, and Asia, which brings big differences in terms of governance, politics, and cultures — which makes it difficult to implement common regulations of marine ecosystems. 

About 229,000 tons of plastic leak every year into the Mediterranean Sea, according to a report by IUCN from 2020, equivalent to 500 shipping containers. Roughly speaking, it’s like dumping a container and a half of plastic straight into the sea. Egypt, Italy, and Turkey were identified as the countries with the highest plastic leakage rates into the Mediterranean, mainly because of mismanaged waste and large coastal cities.

“Our study shows that specific sites, important for the conservation of biodiversity, concentrate high amounts of plastics,” Dr Yannis Hatzonikolkis, lead author of the study, said in a statement. “Although marine protected areas are protected by restrictions from other threats as tourism, plastic acts like an ‘invisible’ enemy.” 

Plastics and the Mediterranean

The researchers carried out a three-year simulation (from 2016 to 2018) of the distribution of plastic particles in the Mediterranean Sea. They used a particle drift model that considers the main dispersion processes such as winds and currents, incorporating three land-based sources of plastic particles – wastewater discharge, rivers, and cities. 

Image credit: The researchers.

The findings showed that coastal zones were the hardest hit, both by macroplastics and microplastics (plastic pieces smaller than five millimeters). As MPAs tend to be closer to coastal zones, they accumulated more plastic waste than sites in offshore waters. Most plastics were traced back to land-based sources, which means the issue has to be tackled at source.

The average concentration of macroplastics in inshore waters was larger than five kilograms per squared kilometer, while offshore waters had over 1.5 kilograms. Meanwhile, average microplastics concentration in inshore waters was higher than 1.5 million particles per squared kilometer, and 0.5 million particles in offshore waters. 

“The most effective way to reduce plastic pollution in protected areas is by reducing marine litter at the sources. A management plan including litter reduction at its sources can occasionally be successfully implemented locally,” the researchers wrote, suggesting the use of a floating barrier installation and a pre-filtering device. 

The study was published in the journal Frontiers. 

The unseen pandemic: Air pollution contributed to 1.8 million excess deaths in 2019

If you’re living in a city, the air you breathe is almost certainly affecting your overall health. A new study found that 86% of the people living in cities worldwide (about 2.5 billion) are exposed to levels of fine particulate matter that largely exceeded the suggested guidelines from the World Health Organization (WHO). Overall, almost air pollution claims almost 2 million lives a year, a figure that may yet increase.

Image credit: Friends of the Earth / Flickr.

More than half (55%) of the world population is currently living in cities, which has massive implications in terms of human health; as urbanization continues in much of the world, the percentage is set to grow. Nevertheless, there’s been limited research comparing urban areas in terms of PM2.5 disease burden – with most studies focusing only on megacities. This is what this new study hopes to address, and the results are sobering.

In the new study, researchers estimate 61 in every 100,000 deaths in urban areas was attributable to PM2.5, a fine particulate matter with a diameter of 2.5 micrometers or less that is especially dangerous to human health due to its small size that allow it to penetrate deep in the lungs. 

“The majority of the world’s urban population still live in areas with unhealthy levels of PM2.5,” Veronica Southerland, lead author of the study, said in a statement. “Avoiding the large public health burden caused by air pollution will require strategies that not only reduce emissions but also improve overall public health to reduce vulnerability.”

The risks of air pollution

Researchers from George Washington University looked at PM2.5 concentrations and associated mortality trends in over 13,000 cities globally from 2000 to 2019. PM2.5 pollutants come from many sources; primary ones, such as power plants, and secondary ones – formed when different chemicals combine and react in the air.

Average PM2.5 concentrations were consistent over the analyzed period, but with big differences by regions. Urban areas in South-East Asia had the biggest regional increases, with a 27% hike in PM2.5 concentrations. Meanwhile, South-East Asian cities also had the largest hike in PM2.5-attributable mortality rates – going from 63 to 84 deaths in 100,000 people. 

The researchers also found that a decrease in PM2.5 concentrations in urban areas across the two decades (for example, in European and North American cities) didn’t match the same level of decreases in deaths. This shows that other demographic factors, such as poor overall health and aging are also big drivers of pollution-related mortality. 

Asthma and air pollution

The same group of researchers simultaneously published a second study looking at nitrogen dioxide gas (NO2), an air pollutant emitted by vehicles, agriculture, and power plants. Previous studies showed NO2 can be liked to asthma exacerbation, especially in children, but without data of its long-term incidence in urban areas. 

The team calculated global NO2 concentrations by combining satellite data with datasets on different types of land use, like roads, and parks. Concentrations were then applied to populations and pediatric asthma rates to calculate pediatric asthma attributable to NO2 between 2000 and 2019 in over 13,000 urban areas in the world. 

The study showed that there were 1,85 million new cases of pediatric asthma associated with NO2 in 2019 – 8.5% of all new cases reported that year. Two in three cases of pediatric asthma attributable to NO2 happened in the urban areas covered by the study. NO2 caused 16% of all new pediatric asthma cases in urban areas in 2019. 

The studies were published in The Lancet Planetary Health and can be accessed here and here. 

A new way to address climate change: cut down on conferences and international events

During the pandemic year of lockdown, most things simply stopped — especially conferences. Large gatherings of people that require traveling are the last thing you can want during a pandemic, so they pretty much stopped. Turns out, that decision had a pretty big impact — the carbon footprint of the global event and convention industry is comparable to the entire emissions of the US. A team of Cornell researchers now says we should learn from that and use video calls and remote conferences when possible, to reduce emissions.

Since the pandemic started, we’ve all had to cut down on some of the things we’d normally do. For millions of people around the world, this meant giving up on conferences or other events that they would have normally attended. Believe it or not, the number of regular, international events of over 50 participants doubles every 10 years, and this growth comes with a big price tag associated — not just financially, but also in terms of greenhouse gas emissions.

“We all go to conferences. We fly, we drive, we check into a hotel, give a talk, meet people – and we’re done,” said senior author Fengqi You, a senior faculty fellow at the Cornell Atkinson Center for Sustainability.

“But we looked at this problem comprehensively and behind the scenes, conventions generate a lot of carbon, consume a lot of energy, print a lot of paper, offer a lot of food – not to mention create municipal solid waste. Yet, video conferencing also requires energy and equipment use. Conference planning means a lot to consider.”

Researchers carried out a complete assessment on the emissions associated with the event industry, and found that the carbon footprint per average participant reaches 3 tons (6,600 pounds) of carbon dioxide equivalent. For comparison, production of a beef burger emits 60 kilograms of CO2, and a return flight from London to Rome is just under 240 kilograms of CO2. In light of this, researchers say we should try implementing a hybrid system of conferences, with both in-person and online meetings.

“There is a lot of interest and attention on climate change, so moving from in-person conferences to hybrid or remote events would be beneficial,” You said. “But we should also be cautious and optimize decisions in terms of selecting hubs and determining participant levels for hybrid meetings.”

Of course, for some events, doing this online versus in person is just not as efficient. With this in mind, researchers also suggest a few ways to reduce the impact of in-person events. For instance, you should focus on conferences closer to home, and avoid stopovers when booking flights, switching to more plant-based dietary options, and selecting conference hubs that are energy-efficient.

Transitioning from in-person to virtual conferencing can substantially reduce the carbon footprint by 94% and energy use by 90%, while a hybrid system with 50% in-person participation can still slash emissions by around two-thirds, researchers say.

The study was published in Nature Communications.

New metal organic framework can produce valuable chemicals out of factory smoke

New technology aims to turn smoke from industry and power generation into useful, commercially-valuable products. The process hinges on a newly-developed metal organic framework (MOF) as a catalyst.

Image via Pixabay.

Smokestacks around the world release a tremendous amount of carbon dioxide gas into the atmosphere. What if, instead of letting it pile up in the atmosphere and heat up the climate, we captured this CO2 and put it to good use, instead? That’s exactly the aim of a scientific collaboration led by researchers at Oregon State University — and, according to a new study they published, one they accomplished.

The team describes a new metal organic framework, a compound material in which metals are used as a base, and interlaced with organic crystals. The compounds inside this MOF act as a catalyst, enabling the production of cyclic carbonates — a useful family of chemicals — from CO2 released in factory flue gases (smokestacks).

Up in smoke

“We’ve taken a big step toward solving a crucial challenge associated with the hoped-for circular carbon economy by developing an effective catalyst,” said chemistry researcher Kyriakos Stylianou of the Oregon State University College of Science, who led the study. “A key to that is understanding the molecular interactions between the active sites in MOFs with potentially reactive molecules.”

The novel MOF is loaded with propylene oxide, a common industrial chemical. This acts as a catalyst, allowing for the quick and easy conversion of CO2 gas into cyclic carbonates. These latter compounds have ring-shaped molecules and are quite useful for a variety of applications — ranging from pharmaceutical precursors to battery electrolytes.

The best part about this is that carbon is scrubbed out of flue gases in the process. Essentially, this MOF can be used to clean greenhouse gases from the smoke. It can also remove carbon from biogas (a mix of CO2, methane, and other gases produced by decaying organic matter).

The MOF is based on lanthanides, a somewhat special (and somewhat rare) family of metals — in fact, they’re often referred to as ‘rare earths’. They are soft, silvery-white, and have a variety of uses. Some examples of lanthanides include cerium, europium, and gadolinium.

Lanthanides were used for the MOF because they provide good chemical stability. This is especially important because the gases the MOF will be exposed to are hot, high in humidity, and quite acidic. The metal acts as a binder, holding the active organic materials in place so they can act as catalysts.

“We observed that within the pores, propylene oxide can directly bind to the cerium centers and activate interactions for the cycloaddition of carbon dioxide,” Stylianou said. “Using our MOFs, stable after multiple cycles of carbon dioxide capture and conversion, we describe the fixation of carbon dioxide into the propylene oxide’s epoxy ring for the production of cyclic carbonates.”

The team says that their findings are “very exciting”. They’re particularly thrilled about the MOF’s ability to use carbon dioxide gas even from impure sources, which saves time, energy, and costs associated with separating it before the process.

The paper “Lanthanide metal–organic frameworks for the fixation of CO2 under aqueous-rich and mixed-gas conditions” has been published in the Journal of Materials Chemistry A.

Danish Prime Minister says country aims to remove fossil fuels from domestic flights by 2030

Denmark aims to make its domestic flights fossil fuel-free by the end of the decade, according to its Prime Minister.

Denmark’s Prime Minister Mette Fredriksen, 2019. Image via Wikimedia.

In her New Year’s address, Denmark’s Prime Minister Mette Fredriksen announced that she aims to “make flying green” inside the country. Although she acknowledges that the solutions are not yet in place in order to reach this goal, the announcement marks a strong — if not fully official — embracing of this goal.

On a larger scale, Denmark aims to slash its overall carbon emissions by 70% compared to 1990 levels by 2030. Fredriksen’s aim to de-couple internal flights from fossil fuel use would help push the country closer to that goal.

Flying green

“To travel is to live and therefore we fly,” said Ms Frederiksen (link in Danish), announcing her plan.”When other countries in the world are too slow, then Denmark must take the lead and raise the bar even more”.

She admits that making domestic flights fully green is no small feat, adding that researchers, as well as transport companies, are working to find solutions.

For example Airbus, a European airplane manufacturer, has announced plans to have hydrogen-fueled planes operational by 2035. If that hydrogen is generated using renewable energy, it could be one avenue through which Denmark could make good on its goal.

However, it’s not yet clear whether said tech will be ready to use on planes, in a cost-efficient manner, by 2030.

That being said, there is growing international interest in this regard — Sweden has also announced plans to make domestic flight fossil fuel-free by 2030, and international flights by 2045. France is also moving to ban domestic flights on routes where trains would take under two-and-a-half hours to make the same journey.

Researchers and manufactures will surely take this interest into account, and it will help to spur development on. For example, there has been some encouraging progress in the field of electric planes, although for now, it remains confined to smaller aircraft.

The air transport sector is a major polluter worldwide. Although domestic flights account for only a small part of its emissions, the smaller distances involved make it a prime area for innovation and development. In time, progress here could make their way on vehicles serving international routes.

Mountain streams aren’t pristine any longer — not when humans move in

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.

Wild microorganisms are evolving to eat plastic pollution

Microorganisms around the world are likely evolving to be able to degrade and consume plastic materials.

Image via Pixabay.

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.

Plastic bacteria

“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.

The microplastics we’re ingesting are likely affecting our cells

We know microplastics are a big environmental problem and that they can now be found almost everywhere, including our food and water — and inside our bodies. But just how harmful are they? Since it’s a problem we’ve only recently started to realize, we don’t know yet — but the data is coming in, and it doesn’t look too good. At least in a petri dish, microplastics have the potential to cause significant damage to human cells in the laboratory, a new study found.

Researchers look for microplastics in a beach. Image credit: Flickr / Laura.

The study is the first to quantify the levels of microplastics (plastic particles measuring less than five millimeters) that may lead to harmful effects in human cells.

“This is the first-time scientists have attempted to quantify the effects of the levels of microplastics on human cells using a statistical analysis of the available published studies,” Evangelos Danopoulos, lead author and PhD student, said in a statement. “We are seeing reactions including cell death and allergic reactions as potential effects.”

Not only are microplastics everywhere already, but the contamination is expected to rise as plastic production and use around the world also increase. Within a century, the ecological risks of microplastics could be widespread in ecosystems across the world. So researchers are trying to understand just how dangerous these microplastics really are.

Exposure and contamination

Humans have two main routes of exposure to microplastics: ingestion and inhalation; we either ingest or inhale microplastics — and concerningly, both seem to be widespread. The presence of microplastics has been verified in human lung tissue, placenta, and colectomy samples.

Danopoulos and his team first reviewed a set of 17 previous studies that looked at the toxicological impact of microplastics on human cell lines. This allowed them to compare the level of microplastics consumed by people through polluted seafood, table salt, and drinking water with the level at which damage is caused to human cells.  

They found that four specific types of harm to human cells (cell death, damage to cell membranes and allergic response) were directly caused by the microplastic that people eat. The study also showed that microplastics with an irregular shape cause more cell death than spherical ones. Most laboratory studies focus on spherical ones. At the levels already found inside human bodies, these particles seem to be causing significant cellular damage.

“Our analysis of the data showed that cell viability depends on the shape of the microplastics. Irregularly shaped microplastics, which are the majority found in the environment, are more hazardous than spherical,” Danopoulos said. “So far, most toxicology studies have been testing spherical microplastics. There needs to be a shift.”

For the researchers, the findings show that we are eating microplastics at levels consistent with harmful effects on our cells, which could then trigger other health effects. Nevertheless, he highlighted the high level of uncertainty regarding how ingested microplastics are excreted from the body – crucial to better understand the true risk that microplastics pose to our health.

The study was published in the Journal of Hazardous Materials. 

China “modified” the weather for a political celebration

If you’re throwing a party in your backyard, you probably wouldn’t want rain or other yucky weather to mess with your plans. But if it happens, there’s not much we can do about it. But that’s not necessarily the case for China, which recently used cloud seeding technology to make sure they don’t have to deal with rain and air pollution ahead of a big political celebration earlier this year.

Image credit: Flickr / Tomislav Domes.

For China, interest to control the weather has quickly escalated over the years, mainly to protect farming areas and have clear skies for big political events. This was the case in the 2008 Beijing Olympics, for example, when the government used cloud seeding to ensure good weather for good events, and has apparently become more and more common in recent years. From 2012 to 2017, China spent over $1.3 billion on weather modification programs. 

Cloud seeding has been around for many years, at least as a concept. It works like this: you inject small amounts of silver iodide into clouds that have a lot of moisture, which condenses around the new particles, become heavier, and eventually fall as rain. A study from 2019 was the first one to definitively confirm that this actually works. After this, there are no more rain-forming clouds around, and you’re guaranteed to have clear weather for some time.

THe other benefit is in terms of air pollution. Beijing, China’s capital, is well known around the world for its high levels of air pollution – caused by the burning of coal to produce electricity and vehicle emissions. In 2019, China was classed as the 11th dirtiest country in the world. But on its 100-year celebration, the Chinese Communist Party would have none of it.

A clear-skied party

The Chinese Communist Party celebrated its centenary on July 1st, with thousands of people gathering at Tiananmen Square. It was a lovely day, but this wasn’t just good fortune. According to a paper from Tsinghua University, first reported by the South China Morning Post, the government used cloud seeding hours to ensure clear skies. 

The celebration in Beijing was due to be a rocky one, as the city faced an increased in air pollutants and an overcast sky back in July, the researchers reported. It was one of the wettest summers on record. Factories had been closed down days ahead of the celebration to prevent high air pollution levels but this apparently wasn’t enough.

In the paper, environmental science researchers Wang Can says a two-hour cloud-seeking operation was carried out before the celebration, with residents seeing rockets launched into the sky on June 30th – carrying silver iodine. The artificial rain was successful, as the level of PM2.5 pollutants was reduced by almost two-thirds.

For the researchers, the drop in pollution was directly related to the artificial rain as this was the single disruptive weather event in that period. According to the China Morning Post, it rained almost every day in the week before the ceremony. And on the day it happened, the participants were given raincoats as part of a souvenir pack. 

Last year, China unveiled a plan to expand its experimental weather modification program to cover an area 1.5 times the total size of India. According to a government statement, China will have a fully functional weather modification system in place by 2025 thanks to new research and technologies and improvements in risk prevention.

Coastal species are setting up shop in the open ocean on the back of islands of plastic waste

Plastic pollution is creating whole environments on the high seas, according to new research.

Coastal podded hydroid (Aglaophenia pluma), an open-ocean crab (Planes genus), and open-ocean gooseneck barnacles (Lepas genus) colonizing a piece of floating debris. Credit: Smithsonian Institution

Coastal species of plants and animals are colonizing the open ocean on the backs of plastic debris, researchers report. This is creating whole new, and previously impossible, communities on the surface of the open ocean. The findings put into perspective just how much of an impact pollution can have on the environments around us, and showcase how the oceans, specifically, are changing due to human activity.

Life in plastic

“The issues of plastic go beyond just ingestion and entanglement,” said Linsey Haram, lead author of the article and former postdoctoral fellow at the Smithsonian Environmental Research Center (SERC). “It’s creating opportunities for coastal species’ biogeography to greatly expand beyond what we previously thought was possible.”

Researchers have termed these communities “neopelagic” — roughly meaning ‘new oceanic’. They develop around patches (or ‘gyres’) of garbage that form in areas where oceanic currents push plastic pollution from coastal regions. Here, veritable islands of plastic float over thousands of square miles of ocean surface. Although they do not lack in large pieces of plastic, a large part of the material that makes up these islands consists of microplastic particles, which are too small to be seen by the naked eye. Other debris like fishing nets, buoys, and bottles help to hold everything together. The single largest such patch today sits in the North Pacific Subtropical Gyre and contains an estimated 79,000 metric tons of trash.

Organisms from the coast seem to hitchhike a ride towards the open seas on these larger pieces of plastic, new research reveals, where they start a whole new life.

Our first clues about neopelagic communities started surfacing in the wake of the 2011 Japanese tsunami when researchers found almost 300 coastal species in the debris this wave brought to the coast from the open ocean. However, direct sightings were extremely rare before now.

For the study, Haram worked together with the Ocean Voyages Institute, a nonprofit organization that works to remove plastic pollution from the ocean using sailing ships. They also enlisted the help of Jan Hafner and Nikolai Maximenko, two oceanographers at the University of Hawai’i at Manoa, who created a model that could predict where plastic was most likely to accumulate in the North Pacific Subtropical Gyre. The organization’s use of sailing ships ensured that the whole expedition would be as environmentally-friendly as possible.

During 2020, the Ocean Voyages Institute team collected 103 tons of plastic and associated debris from the North Pacific Subtropical Gyre. Some of this was sent to SERC’s Marine Invasions Lab, where Haram and her team looked at the species that colonized them. Among these samples, they found several coastal species including anemones, hydroids, and shrimp-like amphipods which were not merely surviving, but seemed to thrive. This represents a very significant shift in the ecology of the open ocean.

“The open ocean has not been habitable for coastal organisms until now,” said SERC senior scientist Greg Ruiz, who heads the Marine Invasions Lab where Haram worked. “Partly because of habitat limitation—there wasn’t plastic there in the past—and partly, we thought, because it was a food desert.”

For now, the findings show that plastic build-up in the ocean is providing a platform for coastal species to use as a habitat, but where exactly they are finding food is still up for debate. Further research will be needed to determine the details of these novel ecosystems. Two possibilities are that ocean gyres already act as hotbeds for biologic activity, and these species are capitalizing on existing food sources, or that the plastic bodies themselves are attracting organisms, which coastal species then consume.

In the long-term, the communities that live on plastic islands could definitely have an impact on the wider environment around them. We don’t even know how common such plastic-borne communities are, at this point. The team plans to understand and quantify this impact in the future. One of their chief concerns is to see whether coastal organisms can act like invasive species in the wider oceanic ecosystem.

The paper “Emergence of a neopelagic community through the establishment of coastal species on the high seas” has been published in the journal Nature Communications.