The Air Pollution Complex: improved air pollution understanding in China

Researchers have developed a theoretical framework made up of the latest advances in atmospheric and air pollution science to create a more accurate model of China’s air pollution

Peer-Reviewed Publication

INSTITUTE OF ATMOSPHERIC PHYSICS, CHINESE ACADEMY OF SCIENCES

 

IMAGE: SCHEMATIC SHOWING THE THEORETICAL FRAMEWORK OF THE AIR POLLUTION COMPLEX IN CHINA. view more 

CREDIT: TONG ZHU ET AL.

Air pollution in China is generated from many sources and interacts chemically and physically within the atmosphere in ways that can be difficult to predict.  The concept of the Air Pollution Complex was created to address the underlying complexity of air pollution, and scientists have just recently developed a framework to apply the most current research to air pollution prediction and mitigation strategies.  Here, a group of leading scientists have outlined the most significant progress that has been made in the last two to three years in air pollution research in China.    

China has two main sources of air pollution: coal combustion and vehicle exhaust.  These two components of air pollution, coal smoke and photochemical smog, interact both chemically and physically in complex ways in the atmosphere, creating the Air Pollution Complex.  Researchers in China have spent decades researching the formation mechanisms of the Air Pollution Complex by investigating sources, sinks, transport and transformation processes, and effects of air pollution.  These studies have been integrated into a theoretical framework for the Air Pollution Complex to help scientists better understand, predict and mitigate air pollution in China.  A group of the most prominent scientists in the fields of air pollution and atmospheric chemistry in China summarized the most significant progress that has been made in these fields within the past two to three years. 

The team published their review in the journal Advances in Atmospheric Science. It's one of nine review papers of a special issue on the National Report to the 28th International Union of Geodesy and Geophysics General Assembly to be held on July 11-20, 2023, by the Chinese National Committee of International Association of Meteorology and Atmospheric Sciences. 

“Air pollution, especially the air pollution in China we are facing today, is from multiple emission sources and results from complicated chemical and physical processes in the atmosphere. The Air Pollution Complex has been proposed to comprehensively and holistically understand the complicated nature of air pollution,” said Tong Zhu, first author of the review paper and professor in the College of Environmental Sciences and Engineering at Peking University in Beijing, China.  “This review summarizes the most recent advances of air pollution research in China and how … they contribute to the … theoretical framework of the Air Pollution Complex,” said Zhu.

Creating the framework for the Air Pollution Complex helps atmospheric chemists and air pollution scientists predict air quality hazards and shape environmental policies aimed at controlling and mitigating air pollution in China.  “These tremendous advances in air pollution research have helped establish the theoretical framework of the Air Pollution Complex and describe its complicated and nonlinear feedback nature.  The theoretical framework of Air Pollution Complex is essential to better simulating atmospheric physical and chemical processes which lead to the formation of the Air Pollution Complex, to forecast air pollution with much lower uncertainties and to support air pollution control measures and policies with robust science,” said Zhu. 

The review team outlined the most compelling advances in air pollution and atmospheric chemistry research in China, including air pollution sources and emissions; atmospheric chemistry; effects on the climate, meteorology and the weather; effects on the biosphere, or regions of the earth occupied by living organisms; and mathematical models based on experimental observations.  “The advances of atmospheric chemistry research on the mechanism of air pollution formation … in China have provided robust scientific support to the very successful air pollution control policies implemented in China,” said Zhu.  These successful control measures may additionally benefit low-income and developing countries that likely face similar air pollution challenges.

Zhu and his team understand that a cooperative effort is required to make the most significant impact on worldwide air pollution.  “It is a great challenge in China and across the globe to coordinate carbon emission reduction and air quality improvement to achieve the most benefits for human health.  Atmospheric chemistry research in China should be able to and must make important contributions,” said Zhu.  Future research efforts will focus on the mechanism of the Air Pollution Complex formation to control PM2.5, or particulate matter 2.5 micrometers or less in diameter that negatively impacts human health, and ozone (O3), also known as the main pollutant of photochemical smog.

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JOURNAL

Advances in Atmospheric Sciences

DOI

10.1007/s00376-023-2379-0 

ARTICLE TITLE

Recent Progress in Atmospheric Chemistry Research in China: Establishing a Theoretical Framework for the “Air Pollution Complex”

Cleaner air with a cold catalytic converter

New paper in the prestigious journal Science outlines a new catalyst that can purify exhaust gases at room temperature

Peer-Reviewed Publication

EINDHOVEN UNIVERSITY OF TECHNOLOGY

The so-called three-way catalytic converter in the exhaust system of a car consists of expensive materials and only works correctly when the exhaust gases have a temperature that is several hundred degrees Celsius.

As a result, when you start your car, or when you drive a hybrid car in which the petrol engine and electric motor alternate between driving the powertrain, the gases leaving the exhaust still contain toxic carbon monoxide. In a new Science article, scientists led by Emiel Hensen now show that by modifying the carrier material of the catalyst, it is possible to almost completely convert toxic carbon monoxide into carbon dioxide gas even at room temperature.

Noble needs

Automotive catalysts are made by depositing noble metals such as platinum, palladium, and rhodium on a substrate of the material cerium oxide, which is also known as ceria. However, noble metals are both rare and expensive. Researchers around the world are therefore working on methods to achieve the same or even better catalytic activity through the use of less of these materials.

For example, in a previous paper, Hensen’s group at TU/e proved that by dispersing the noble metal in the form of single atoms leads to not only a reduction in material use, but under certain conditions, the catalyst also functions more efficiently.

New size view
In the PhD research project of lead author Valery Muravev, the researchers shifted their attention from the noble metal to the carrier material underneath (ceria in this case) to further improve the catalysts. They produced the ceria in different crystal sizes and deposited the noble metals as single atoms in the same step. Subsequently, they studied how well these combinations of materials managed to bind an extra oxygen atom to carbon monoxide.

Small ceria crystals of 4 nanometers in size turned out to remarkably improve the performance of the noble metal palladium under cold start conditions in the presence of excess carbon monoxide. This improved performance could be explained by a higher reactivity of the oxygen atoms at smaller ceria crystal sizes. Under more conventional conditions, 8 nanometers turned out to be the optimal size of ceria crystals needed to reach a high catalytic activity at temperatures below 100 degrees Celsius.

Wider significance
This research shows for the first time that when developing catalysts, it pays to look not only at the noble metals that have to do the work. In this case, varying the size of the particles that act as the carrier for the active materials offers an interesting new possibility to further improve catalysts and with those, improve the efficiency and specificity of the chemical reactions. This is also of importance for the development of processes to combine carbon dioxide from ambient air with green hydrogen to produce fuels or compounds for the production of sustainable plastics.

Together with the British company Johnson Matthey, which produces catalysts for the automotive industry, the researchers will now further explore how to translate this finding into new products.

Further information on the paper

Valery Muravev, Alexander Parastaev, Yannis van den Bosch, Bianca Ligt, Nathalie Claes, Sara Bals, Nikolay Kosinov, Emiel J.M. Hensen, Size of ceria support nanocrystals dictates reactivity of highly-dispersed palladium catalysts, Science, (2023).

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JOURNAL

Science

DOI

10.1126/science.adf9082 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Size of cerium dioxide support nanocrystals dictates reactivity of highly-dispersed palladium catalysts

ARTICLE PUBLICATION DATE

16-Jun-2023

Disclaimer: AAAS and

Large uncertainty to persist in projected Southern Ocean sequestration of excess heat from greenhouse warming

Peer-Reviewed Publication

SCIENCE CHINA PRESS

 

IMAGE: THE CIRCUMPOLAR SOUTHERN OCEAN LIES BENEATH SEA ICE AND ICE SHELVES AROUND THE ANTARCTIC MARGINS. THE INTERACTIONS BETWEEN THE OCEAN AND SEA ICE AND ICE SHELVES MAKE THE ANTARCTIC CRYOSPHERE VULNERABLE TO A WARMING SOUTHERN OCEAN. view more 

CREDIT: CREDIT: JINGWEI ZHANG, TAKEN AT PLENEAU ISLAND ON 9 JANUARY 2023.

This study is led by Dr. Wenju Cai (Environment, Commonwealth Scientific Industrial Research Organization, Australia) and involves scientists from China, Australia, and United States. The mid-to-high latitude Southern Ocean (30°S southwards) features prevailing westerly winds, the strongest mean sea-surface winds on Earth, which draws up ocean water from below 2–3 km in a wide circumpolar ring. This circulation system exerts a huge influence on climate under greenhouse warming, because the upwelled water was last in contact with the atmosphere hundreds of years earlier and once brought to the surface, absorbs a vast amount of anthropogenic heat and carbon from the atmosphere. However, based on the latest climate models, even under same emission scenario, inter-model differences in simulated amount of heat absorbed by the Southern Ocean are large, with a ratio of the highest over the lowest as high as three times. “The large spread is a concern, and has huge implications, including for melt of Antarctic Sea ice, ice sheets and ice shelves (center image below), radiative budget of the climate system, hemisphere rainfall distribution, and global sea level rise,” says Dr. Cai.

Dr. Cai and his team sought to determine what causes the large inter-model differences by synthesizing recent advances, and through examination of available outputs from latest models participating in the Phase 6 of Coupled Model Intercomparison Project. The team surveyed a large body of literatures and performed extensive analysis of data from some 30 participating models.

The team found that the large inter-model spread is not simply due to differences in the climate sensitivity, which measures the amount of radiative heating required to raise the Earth surface temperature by 1.0 oC. Previous studies suggest sequestration of heat by the Southern Ocean is mainly through mean circulation that facilitates uptake of additional heating, and that circulation changes because of greenhouse warming play a relatively small role. The new analysis instead shows that circulation changes contribute to much of the inter-model differences beyond that are attributable to climate sensitivity. For example, under greenhouse warming, the prevailing Southern Ocean westerly intensifies toward the Antarctic, but the wind changes are vastly different across models.

The wind intensification induces changes in the intensity and distribution of upwelling, with serious consequences. An increase in upwelling accelerates melt of Antarctic ice sheets and ice shelves, and the associated meltwater flux into the ocean leads to a more stratified   upper ocean, which in turn slows heat and carbon uptake by the Southern Ocean. “There are many such complex interactions at work, some of which are poorly understood and not represented in models, contributing to the large uncertainty.” Cai says.

The researchers also found that the uncertainty can arise from a response of remote process to greenhouse warming, such as El Niño, the most consequential climate variability of the Earth climate. An El Niño is known to induce droughts over the western Pacific countries and floods over the eastern Pacific regions. Less known is that El Niño also leads to weakened prevailing Southern Ocean high-latitude westerlies, which over a warming period affecting shelf ocean warming, melt of sea ice, ice shelves and ice sheets. Surprisingly, inert-model differences in the response of El Niño to greenhouse warming systematically influenced the inter-model differences in Southern Ocean warming. But the changes in El Niño under greenhouse warming itself vastly differs across models. “New perspectives like this add to the growing realization that projecting Southern Ocean warming is one of the most complex issues in climate science.” Cai says.

The study suggests that the science of Southern Ocean warming involves appropriately representing interactions of ice shelves and ice sheets with the warming ocean, interactions of changing circulations with carbon cycles that force the circulation changes in the first place, and polar-tropical interactions, to name just a few. Because each of these areas is a challenge, uncertainty likely persists for some time to come. However, identification of such challenges is a start in any effort to move the science forward.

See the article:

Wenju Cai, Libao Gao, Yiyong Luo, Xichen Li, Xiaotong Zheng, Xuebin Zhang, Xuhua Cheng, Fan Jia, Ariaan Purich, Agus Santoso, Yan Du, David M. Holland, Jia-Rui Shi, Baoqiang Xiang, Shang-Ping Xie. Southern Ocean warming and its climatic impacts. Science Bulletin, 2023, 68(13): 946-960

https://doi.org/10.1016/j.scib.2023.03.049

 

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JOURNAL

Science Bulletin

DOI

10.1016/j.scib.2023.03.049 

10-year countdown to sea-ice-free Arctic

Peer-Reviewed Publication

POHANG UNIVERSITY OF SCIENCE & TECHNOLOGY (POSTECH)

 

IMAGE: - BLACK LINE (UNCONSTRAINED): RAW MODEL PROJECTIONS - RED, BLUE, GREEN LINES: MODEL PREDICTIONS CONSTRAINED BY THREE OBSERVED DATASETS. → THE RESULTS PREDICT THAT ALL OF ARCTIC SEA ICE WILL DISAPPEAR IN THE 2030S IF INCREASES IN GREENHOUSE GAS EMISSIONS REMAIN AT CURRENT RATE, AND EVEN WITH EMISSION REDUCTION, IT WILL EVENTUALLY DISAPPEAR DURING THE 2050S. view more 

CREDIT: POSTECH

If the world keeps increasing greenhouse gas emissions at its current speed, all sea ice in the Arctic will disappear in the 2030s, an event that could at best be postponed until the 2050s should emissions be somehow reduced. The prediction is a decade earlier than what the Intergovernmental Panel on Climate Change (IPCC) has projected: an ice-free Arctic by the 2040s.

 

A possible ice-free Arctic in the 2030-2050s was projected regardless of humanity’s efforts to reduce its greenhouse gas emissions by Professor Seung-Ki Min and Research Professor Yeon-Hee Kim from the Division of Environmental Science and Engineering at Pohang University of Science and Technology (POSTECH) and a joint team of researchers from the Environment Climate Change Canada and Universität Hamburg, Germany. The research was published in the international journal, Nature Communications.

 

The term global warming has become a household name since it was first used by a climate scientist at NASA in 1988. The Earth has seen a rapid decline in the Arctic sea ice area as its temperature has increased over the past several decades. This reduction in Arctic sea ice has induced the acceleration of Arctic warming, which is suggested to contribute to the increased frequency of extreme weather events in mid-latitude regions.
 

 

To predict the timing of Arctic sea ice depletion, the research team analyzed 41 years of data from 1979 to 2019.  By comparing the results of multiple model simulations with three satellite observational datasets, it was confirmed that the primary cause of the decline is attributed to 'man-made greenhouse gas emissions’. Greenhouse gas emissions resulting from human fossil fuel combustion and deforestation have been the primary drivers of Arctic sea ice decline over the past 41 years, while the influence of aerosols, solar and volcanic activities has been found to be minimal.  Monthly analysis found that increased greenhouse gas emissions were reducing Arctic sea ice all year round, regardless of season or timing, although September exhibited the smallest extent of sea ice reduction.

 

Furthermore, it was revealed that climate models used in previous IPCC predictions generally underestimated the declining trend of sea ice area, which was taken into account to adjust the simulation values for future predictions. The results showed accelerated decline rates across all scenarios, most importantly confirming that Arctic sea ice could completely disappear by the 2050s even with reductions in greenhouse gas emissions.  This finding highlights for the first time that the extinction of Arctic sea ice is possible irrespective of achieving ‘carbon neutrality.’

 

The accelerated decline of Arctic sea ice, faster than previously anticipated, is expected to have significant impacts not only on the Arctic region but also on human societies and ecosystems worldwide. The reduction of sea ice can result in more frequent occurrences of extreme weather events such as severe cold waves, heat waves, and heavy rainfalls all across the globe, with the thawing of the Siberian permafrost in the Arctic region possibly intensifying global warming further. We may witness terrifying scenarios, which we have seen only in disaster movies, unfold right before our eyes.

 

Professor Seung-Ki Min, who led the study, explained, “We have confirmed an even faster timing of Arctic sea ice depletion than previous IPCC predictions after scaling model simulations based on observational data.” He added, “We need to be vigilant about the potential disappearance of Arctic sea ice, regardless of carbon neutrality policies.” He also expressed the importance of “evaluating the various climate change impacts resulting from the disappearance of Arctic sea ice and developing adaptation measures alongside carbon emission reduction policies.”

 

 The study was funded by the National Research Foundation of Korea (Mid-Career Researcher program).

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JOURNAL

Nature Communications

DOI

10.1038/s41467-023-38511-8 

ARTICLE TITLE

Observationally-constrained projections of an ice-free Arctic even under a low emission scenario

ARTICLE PUBLICATIO

Scientists discover urea in atmosphere revealing profound consequences for climate

Peer-Reviewed Publication

UNIVERSITY OF MANCHESTER

Areas of the ocean that are rich in marine life are having a bigger impact on our ecosystems and the climate than previously thought, new research suggests.  

Observations made by scientists at The University of Manchester found that the primary source of urea – a nitrogen-rich compound, vital for the growth and development of living organisms - comes from the ocean.  

The observations reveal an important but unaccounted for source of reduced nitrogen and offer the first-ever observations of gaseous urea in the air.  

The research, published in the journal Proceedings of the National Academy of Sciences, also reveals that urea can be transported over long distances through the atmosphere to benefit other environments that may be nutrient-deficient. 

The results could have far-reaching consequences for marine productivity and climate stability.   

Emily Matthews, Atmospheric Scientist at The University of Manchester, said: “Our observations provide new insights into the complex interactions between the atmosphere, ocean and ecosystems.  

“Understanding the behaviour and impact of urea in the atmosphere is vital for advancing our knowledge of how chemicals and substances are transferred through our environment and can help us to inform strategies to address climate change.” 

The observations of gas-phase urea in the atmosphere were collected over the North Atlantic Ocean using the FAAM Airborne Laboratory, a UK airborne research facility managed by the National Centre for Atmospheric Science (NCAS) and owned by UK Research and Innovation and the Natural Environmental Research Council. 

Measurements made during these flights provide detailed data on the composition and properties of aerosols and gases in the atmosphere. Scientists from The University of Manchester and NCAS have identified unique species important to the marine reduced nitrogen cycle, including the first observations of gas-phase urea in the atmosphere. 

The researchers say that the findings have significant implications for our understanding of the nitrogen cycle and calls for a revision of current models.  

Emily Matthews added: “The ocean plays an important role in maintaining a stable climate through biological activity occurring near the surface of the water and contributes to oceanic uptake of carbon dioxide.  

“We now know that it is also a significant source of urea in the atmosphere throughout most of the year, which means we need to modify the processes and factors involved in the nitrogen cycle to account for the newfound importance of urea.” 

The nitrogen cycle is the process during which nitrogen moves through both living organisms and physical environments including the atmosphere, soil, water, plants, animals and bacteria. It is central to the composition of the Earth System and changes of the natural environment through interactions such as aerosol formation, ozone production and as a supply of essential nutrients to living organisms.   

The explanation for the observations of gas phase urea remains a mystery and further research is needed to fully understand biogeochemical coupling of nitrogen between the ocean and atmosphere.  

The research findings represent an important pathway for long range transport of nitrogen to fertise nitrogen poor regions of the surface ocean. Revising this knowledge better helps to understand how the ocean biosphere will respond to future changes. 

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JOURNAL

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2218127120 

ARTICLE TITLE

Airborne observations over the North Atlantic Ocean reveal the importance of gas-phase urea in the atmosphere

ARTICLE PUBLICATION DATE

14-Jun-2023

Previously overlooked algae toxin widespread in southern Indian River Lagoon

FAU Harbor Branch study of algae blooms and domoic acid finds potential threat to lagoon’s ecosystem health

Peer-Reviewed Publication

FLORIDA ATLANTIC UNIVERSITY

 

IMAGE: A TRANSMISSION ELECTRON MICROSCOPY IMAGE OF PSEUDO-NITZSCHIA CELLS. view more 

CREDIT: FLORIDA ATLANTIC UNIVERSITY

Spanning about one-third of Florida’s East coast, the Indian River Lagoon has faced frequent harmful algal blooms in recent years. Among them, Pseudo-nitzschia spp., algae that produces the neurotoxin domoic acid.

Domoic acid can bioaccumulate within food webs, causing sickness and death in higher trophic level organisms such as marine mammals and birds, and have been documented in sea turtles in Florida coastal waters and in bull sharks within the Indian River Lagoon system. In humans, consumption of shellfish contaminated with domoic acid can cause harmful symptoms.

Unlike other harmful algal blooms, Pseudo-nitzschia are not bioluminescent and do not cause water discoloration or large fish kills. Because there are no obvious visual cues of these blooms and monitoring them is event based, documenting their presence is challenging.

Researchers from Florida Atlantic University’s Harbor Branch Oceanographic Institute have conducted the first widespread molecular study of domoic acid produced from Pseudo-nitzschia in the Indian River Lagoon. Their results, published in the journal Harmful Algae, suggest domoic acid may be a significant threat to the lagoon’s ecosystem.

To gain a better understanding of the ecology of Pseudo-nitzschia in the central and southern portions of the Indian River Lagoon system where monitoring has been less frequent, researchers collected surface water samples from five locations along the lagoon between October 2018 and May 2020. They analyzed 158 samples for phytoplankton concentrations via cell counts that were collected on 68 different dates. Scanning electron microscopy was conducted on cultured material, which enabled them to morphologically identify six distinct species of Pseudo-nitzschia and compare them with sequencing data.

Results showed Pseudo-nitzschia was present in 87 percent of the samples, which were associated with relatively high salinity waters and cool temperatures. All isolates demonstrated toxicity, and domoic acid was found in 47 percent of surface water samples. Although Pseudo-nitzschia concentrations were more prominent during the first half of the study, cells were often present at lower concentrations throughout the entire study period. Notable differences between the Indian River Lagoon system and other water bodies where Pseudo-nitzschia blooms occur include water temperatures, water clarity, residence times and salinity.

“The frequent presence of Pseudo-nitzschia, including bloom level concentrations, which we observed in our study, could lead to domoic acid integrating into the food web affecting shellfish, finfish, birds, sea turtles, dolphins, sharks, rays and humans,” said Malcolm McFarland, Ph.D., senior author and a research associate at FAU Harbor Branch. “As a nursery for many organisms, and supporting a high amount of biodiversity, the presence of domoic acid could negatively impact the biodiversity of the Indian River Lagoon system.”

In addition to a positive relationship with salinity, researchers also found that Pseudo-nitzschia had an inverse relationship with temperature. This suggests Pseudo-nitzschia in the Indian River Lagoon prefers cooler water temperatures for growth. Cell abundances of Pseudo-nitzschia were highest during the late fall, winter and early spring, when temperatures in the lagoon are cooler. Some of the highest abundances of Pseudo-nitzschia in the southern Indian River Lagoon system occurred at sampling sites with the closest proximities to inlets.

“Given the characteristics of the Indian River Lagoon system, such as warm water temperatures, high nutrients, and shallow depths, we think that Pseudo-nitzschia may be a resident population, that is, present year-round,” said Stephanie Schreiber, first author and a coordinator of research programs and services at FAU Harbor Branch. “Results from our study suggest Pseudo-nitzschia could be considered a key contributor to phytoplankton community composition in the southern Indian River Lagoon system as well.”

As one of multiple toxic harmful algal blooms-forming organisms within the Indian River Lagoon, understanding its distribution and population dynamics is critical to protecting biodiversity as well as human, animal and ecosystem health. 

“Accurate identification methods are critical to determine the presence or absence of toxigenic species of Pseudo-nitzschia and to assess the potential threat posed by blooms of these algae,” said McFarland. “Although domoic acid is not present at all times in the southern Indian River Lagoon system, its frequent occurrence suggests it is an important toxin to monitor in the lagoon. Continuous exposures to domoic acid, even at low levels, may have unknown impacts on the lagoon system over time.”

Study co-authors are Dennis Hanisak, Ph.D., research professor; and Carlie Perricone, a graduate student; FAU Harbor Branch; Andia Chaves Fonnegra, Ph.D., an assistant professor of biology, FAU Harriet L. Wilkes Honors College; and James Sullivan, Ph.D., executive director, FAU Harbor Branch.

This project was funded through the Indian River Lagoon National Estuary Program (Contract Nos. IRL2018-02, IRL2019-24, and IRL2020-15) and the Center for Coastal and Human Health funded by the Harbor Branch Oceanographic Institute Foundation.

- FAU -

About Harbor Branch Oceanographic Institute:
Founded in 1971, Harbor Branch Oceanographic Institute at Florida Atlantic University is a research community of marine scientists, engineers, educators and other professionals focused on Ocean Science for a Better World. The institute drives innovation in ocean engineering, at-sea operations, drug discovery and biotechnology from the oceans, coastal ecology and conservation, marine mammal research and conservation, aquaculture, ocean observing systems and marine education. For more information, visit www.fau.edu/hboi.

 

About Florida Atlantic University:
Florida Atlantic University, established in 1961, officially opened its doors in 1964 as the fifth public university in Florida. Today, the University serves more than 30,000 undergraduate and graduate students across six campuses located along the southeast Florida coast. In recent years, the University has doubled its research expenditures and outpaced its peers in student achievement rates. Through the coexistence of access and excellence, FAU embodies an innovative model where traditional achievement gaps vanish. FAU is designated a Hispanic-serving institution, ranked as a top public university by U.S. News & World Report and a High Research Activity institution by the Carnegie Foundation for the Advancement of Teaching. For more information, visit www.fau.edu.

 

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JOURNAL

Harmful Algae

DOI

10.1016/j.hal.2023.102437 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Cells

ARTICLE TITLE

Pseudo-nitzschia species, toxicity, and dynamics in the southern Indian River Lagoon, FL

Contact lenses shed microplastics

Peer-Reviewed Publication

AMERICAN CHEMICAL SOCIETY

Millions of people around the world wear contact lenses, including reusable ones. But these plastic lenses don’t last forever, and lenses need to be replaced every few days, weeks or months. Now, researchers reporting a pilot study in ACS’ Environmental Science & Technology have developed a method to analyze minute debris in small samples and found that lenses exposed to sunlight over time can shed tiny fragments of plastic, though the health impact is unclear.

Though scientists are still grappling to understand the health and environmental impacts of microplastics, it is important to understand where they can appear and what systems they could impact. When measuring aquatic microplastic pollution, researchers generally filter plastic fragments from large amounts of sampled water. Then, they use a microscope and manually count the fragments, a method that is slow and not very consistent. More automated alternatives have been developed, but the techniques are still time consuming.  So, Bing Wu and colleagues wanted to develop an automated method that could quickly detect and count microplastic particles in small samples, such as contact lenses.

The researchers gathered six kinds of contact lenses from various brands and of different lifespans. To mimic normal wear and care, the lenses were stored in water, kept under a lamp that mimicked sunlight and were rinsed with water three times every 10 hours. After receiving the equivalent of 30 or 90 days of sunlight, the water each lens was stored in was analyzed. To determine the number of microplastics in the small samples, the researchers designed an automated system that took microscopic images of the samples, processed those images, and quantified any microplastics that were present.

In tests with standard amounts of microplastics, the team found that the new system’s analyses were quicker and more accurate than when the samples were analyzed manually. In the absence of any simulated sunlight, no microplastics were detected. However, the researchers observed increasing amounts when the contact lenses were exposed to the equivalent of 90 days of sunlight. Lenses with shorter lifetimes showed the greatest amount of shed microplastics after this exposure. Based on their data in this small-scale study, the researchers estimate that more than 90,000 microplastic particles per year could be shed from some lenses if worn for 10 hours a day. The human health impact of direct exposure of microplastics to eyes is not currently known, but the researchers say their findings indicate that more studies in this area are urgently needed.

The authors acknowledge funding from the National Natural Science Foundation of China, the Fundamental Research Funds for the Central Universities and the Excellent Research Program of Nanjing University.

The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS’ mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.

To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.

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JOURNAL

Environmental Science & Technology

DOI

10.1021/acs.est.3c01601 

ARTICLE TITLE

“High-Content Screening Discovers Microplastics Released by Contact Lenses under Sunlight”

New study reveals willingness of papaya farmers in Kenya to reduce pesticide use

A new study published in the CABI Agriculture and Bioscience journal has revealed a willingness of smallholder papaya farmers in Kenya to reduce their chemical pesticide use to fight the papaya mealybug (Paracoccus marginatus)

Peer-Reviewed Publication

CABI

 

IMAGE: TEACHER AND PAWPAW FARMER WILFRED MUTONDI WITH HIS INFESTED PAWPAW FRUITS (CREDIT: CABI). view more 

CREDIT: CABI

A new study published in the CABI Agriculture and Bioscience journal has revealed a willingness of smallholder papaya farmers in Kenya to reduce their chemical pesticide use to fight the papaya mealybug (Paracoccus marginatus).

Researchers from CABI surveyed 383 farming households in four counties in Kenya alongside key informant interviews with eight extension agents and thirty agro-dealers, and eight focus group discussions.

They found that in a desperate attempt to control invasive alien pests’ farmers often resort to the use of broad-spectrum insecticides even though biological control is a more sustainable method of pest management that is extremely suitable in the smallholder production context found in Sub Saharan Africa (SSA).

Kate Contstanine, Project Scientist at CABI and lead author of the study, said, “In SSA few attempts using biological control for arthropod pests have been successful, with one of the key reasons cited as poor involvement of farming communities and extension in the dissemination of information.

“As a transboundary problem, invasive species present a social dilemma since, for an optimal outcome to be achieved for all affected people, a collective management response is required.”

The scientists sought to determine smallholder farmers’ knowledge, attitudes and practices towards biological control; farmers’ willingness to reduce their chemical pesticide use; and levels of support for a classical biological control (CBC) programme for papaya mealybug in Kenya.

They also found that there were high levels of awareness of the negative impacts and risks associated with chemical pesticides on human health and the environment.

Farmers demonstrated some awareness of the concept of biological control but they lacked knowledge, experience and technical support from extension or agro-dealers. Reasons for not using biological control included inadequate awareness and concerns over efficacy and safety.

Ms Constatine added, “Farmers expressed high levels of interest and willingness to support a classical biological control programme.

“Importantly, most farmers were willing to reduce their chemical pesticide use to conserve the parasitoid biological control agent, Acerophagus papayae, and there were indications of the requirements for collective community action.

“Previously, poor attention has been paid to farmer participation, inclusion and social factors in biological control, which has resulted in limited success in developing countries.

“Both farmers and extension personnel highlighted the importance of engaging with the community at the beginning of any initiative to ensure community ownership as well as long-term sustainability.

“The next steps include targeted awareness-raising, capacity building and effective information dissemination.”

The scientists also say that their research demonstrates significant differences in farmer perceptions between counties and gender which are helpful in focussing resources going forward.

For instance, more men perceived biological control to be useful and necessary than women, suggesting a need to increase women’s awareness and understanding of biological control.

 

Notes to editors

Full paper reference

Kate L. Constantine, Fernadis Makale, Idah Mugambi, Harrison Rware, Duncan Chacha, Aylssa Lowry, Ivan Rwomushana and Frances Williams, ‘Smallholder farmers’ knowledge, attitudes and practices towards biological control of papaya mealybug in Kenya’ CABI Agriculture and Bioscience, 15 June 2023, DOI: 10.1186/s43170-023-00161-7

The paper can be viewed open access here: https://link.springer.com/article/10.1186/s43170-023-00161-7#citeas

About CABI Agriculture and Bioscience

CABI Agriculture and Bioscience (CABI A&B) publishes high quality, rigorously peer-reviewed multi-, inter- and transdisciplinary research focused on agriculture, food security, and the environment.

Global agriculture faces many challenges today. How can we produce more safe, nutritious food in the face of climate change? Can we balance greater efficiencies with the need to reduce greenhouse gas emissions and protect biodiversity?  Can we meet changing market demands and yet develop more equitable economies? Can agriculture provide a livelihood and opportunities for women and young people?

These problems require increasingly complex and urgent solutions from researchers and policymakers. That is why CABI A&B is committed to encouraging an inclusive culture of scientific discussion and rapid information sharing among researchers worldwide. We publish both large and incremental advances in science in both primary and multidisciplinary fields across the biosciences, agriculture, agronomy, microbiology, social sciences, and the environment.

CABI A&B is an open access journal, with rapid peer review, making findings immediately available to all readers worldwide. We believe it will help engender a clearer understanding of facts and findings, and help challenge assumptions.

CABI A&B is the official journal of CABI – an international, inter-governmental, not-for-profit organization that improves people’s lives worldwide by providing information and applying scientific expertise to solve problems in agriculture and the environment. The organization is governed by 49 Member Countries, many of which are low-income and highly dependent on agriculture to feed their population and generate income. CABI A&B’s supports the organization’s aim to help achieve 8 of the Sustainable Development Goals: (1) No Poverty; (2) Zero Hunger; (3) Quality Education; (5) Gender Equality; (12) Responsible Consumption and Production; (13) Climate Action; (15) Life on Land; and (17) Partnerships for the Goals. CABI A&B is integral to delivering on the organization’s mission, and any surplus derived from the journal is reinvested in its international development activities.

https://cabiagbio.biomedcentral.com/

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JOURNAL

CABI Agriculture and Bioscience

DOI

10.1186/s43170-023-00161-7 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Smallholder farmers’ knowledge, attitudes and practices towards biological control of papaya mealybug in Kenya

ARTICLE PUBLICATION DATE

15-Jun-2023