Thursday, August 18, 2022

Living together: how two different species of dolphins coexist in Australia

New study highlights the importance of prey and habitat diversity

Peer-Reviewed Publication

FLINDERS UNIVERSITY

snubfin dolphin 

IMAGE: AN AUSTRALIAN SNUBFIN (ORCAELLA HEINSOHNI) DOLPHIN view more 

CREDIT: PHOTO COURTESY GUIDO PARRA VERGARA

New research by Flinders University scientists sheds new light on the reasons why two species of dolphins coexist in the northern Australian waters.  

Australian snubfin (Orcaella heinsohni) and humpback (Sousa sahulensis) dolphins live in sympatry throughout most of their range, primarily in shallow (less than 30m deep) tropical/subtropical coastal waters from southern New Guinea across northern Australia.

“A major challenge in ecology and conservation is to understand the means by which species coexist as this is the basis of biodiversity,” says Associate Professor Guido Parra Vergara, lead author of the research published in the journal Ecology and Evolution

“If we are to understand the effects of global change on marine mammal biodiversity, and how we can maintain assemblages of coexisting species, we need to understand their patterns of co-occurrence; the biological significance of their interactions, and the mechanisms underlying their coexistence.”  

Ecological niche theory predicts the coexistence of closely related species is promoted by resource partitioning in space and time. Understanding how different species of marine mammals such as dolphins co-exist is particularly challenging due to their size, high mobility, longevity, and the fact that they spend most of their time underwater.  

Ecologically, both species are similar. Each occur in small populations of typically fewer than 150 individuals, show a high degree of overlap in space use, have similar patterns of habitat use and behavioural activities according to space and time, and are recorded frequently in mixed species groups.  

Thus, segregation into exclusive ranges in space and time, and difference in habitat use and behavior patterns, do not seem to fully explain their coexistence. 

To compare stable isotope ratios of carbon and nitrogen in their skin, researchers collected skin samples from live Australian snubfin and humpback dolphins along the east coast of Queensland.  

Differences in carbon isotope ratios are passed up the food web to consumers, providing a quantifiable estimate of habitat and resource use. In contrast, nitrogen isotope ratios increase at each trophic level with top predators having higher nitrogen isotope values compared to lower trophic levels. 

The results of the isotope analysis suggest that while both dolphin species feed at similar trophic levels, have substantial dietary overlap and rely on similar basal food resources, there are subtle differences in their habitat use and prey selection that may promote the coexistence of Australian snubfin and humpback dolphins.  

Snubfin dolphins forage on a wider diversity of prey, while humpback dolphins forage on a wider range of habitats.  

This information elucidates some of the mechanisms of coexistence between these ecologically similar dolphin species and highlights the importance of prey and habitat diversity for the conservation of dolphin communities. 

“Food diversity and abundance and habitat heterogeneity are key factors promoting the coexistence of these two dolphin species, and pressure from overfishing and pollution that could reduce prey abundance and diversity or deteriorate their habitat quality could affect the future of such dolphin co-existence,” says Associate Professor Parra Vergara. 

“Because dolphins play important roles in maintaining the structure and function of marine communities and ecosystems, any pressures on their food and habitat resources need to be considered when planning future multi-species conservation.” 

The research - Isotopic niche overlap between sympatric Australian snubfin and humpback dolphins, by Guido Parra Vergara, Zachary Wojtkowiak, Katharina Peters and Daniele Cagnazzi - has been published in the journal Ecology and Evolution. https://doi.org/10.1002/ece3.8937 

   

CAPTION

Australian humpback (Sousa sahulensis) dolphin

CREDIT

Photo courtesy Guido J Parra Vergara (Flinders University



CAPTION

To compare stable isotope ratios of carbon and nitrogen in dolphins, Flinders University researchers collected skin samples from live Australian snubfin and humpback dolphins along the east coast of Queensland.

CREDIT

Cetacean Ecology, Behaviour and Evolution Lab, Flinders University


FIU researchers discover how DDT exposure contributes to Alzheimer’s disease risk

New finding could help pave the way for early detection and potential therapy for people highly exposed to the pesticide

Peer-Reviewed Publication

FLORIDA INTERNATIONAL UNIVERSITY

FIU researchers discover how DDT exposure contributes to Alzheimer’s disease risk 

VIDEO: JASON RICHARDSON, PROFESSOR AT FLORIDA INTERNATIONAL UNIVERSITY'S ROBERT STEMPEL COLLEGE OF PUBLIC HEALTH & SOCIAL WORK, DISCUSSES A NEW STUDY THAT REVEALS HOW DDT EXPOSURE CONTRIBUTES TO ALZHEIMER’S DISEASE RISK. view more 

CREDIT: FLORIDA INTERNATIONAL UNIVERSITY

MIAMI (Aug. 17, 2022) - A new study led by researchers from Florida International University (FIU) reveals a mechanism linking the pesticide DDT to Alzheimer's disease.

Published in Environmental Health Perspectives, the study shows how the persistent environmental pollutant DDT causes increased amounts of toxic amyloid beta, which form the characteristic amyloid plaques found in the brains of those with Alzheimer’s disease.
 
According to Jason Richardson, professor at FIU’s Robert Stempel College of Public Health & Social Work and corresponding author, the study further demonstrates that DDT is an environmental risk factor for Alzheimer's disease. In 2014, he led a team of scientists at Rutgers University, Emory University, and UT Southwestern Medical School who presented evidence linking DDT to the disease. Now, they have data demonstrating a mechanism that may explain the association.
 
"The vast majority of research on the disease has been on genetics—and genetics are very important—but the genes that actually cause the disease are very rare," Richardson says. “Environmental risk factors like exposure to DDT are modifiable. So, if we understand how DDT affects the brain, then perhaps we could target those mechanisms and help the people who have been highly exposed.”
 
DDT was extensively used between the 1940s and 1970s to combat insect-borne diseases like malaria and treat crop and livestock production. People highly exposed to DDT back then are now beginning or already in the range of ages with a higher risk for developing Alzheimer’s disease. Although banned in the U.S., DDT exposure is likely possible today from legacy contamination or imported foods.
 
The study focused on sodium channels, which the nervous system uses to communicate between brain cells (neurons), as the potential mechanism. DDT causes these channels to remain open, leading to increased firing of neurons and increased release of amyloid-beta peptides. In the study, researchers demonstrate that if neurons are treated with tetrodotoxin, a compound that blocks sodium channels in the brain, the increased production of the amyloid precursor protein and toxic amyloid-beta species is prevented.
 
“This finding could potentially provide a roadmap to future therapies for people highly exposed to DDT,” Richardson says.
 
The study was done in collaboration with Rutgers University.
 
Researchers used cultured cells, transgenic flies, and mice models to demonstrate DDT's effect on the amyloid pathway, a hallmark of Alzheimer’s disease.
 
By exposing all the models to DDT—in the range of what people were exposed to decades ago—researchers observed an increase in the production of the amyloid precursor protein, as well as elevated levels of toxic amyloid species, such as amyloid-beta peptides, and plaques.
 
"We found that if we block sodium channels with the compound tetrodotoxin and then dose neurons with DDT, then they don't increase the amyloid precursor protein and don't secrete excess amyloid-beta," Richardson says.
 
The next step for the researchers will be to test therapeutic drugs using the information they now know. Richardson shares that there already are several drugs that target sodium channels.
“We are in the process of doing those studies to see if we can take an already FDA-approved drug and see if it reduces toxic amyloid accumulation,” he adds.
 
Read the study published in Environmental Health Perspectives

Photo and video assets, including an interview with Richardson, are available here.

Investigation into plastic pollution moves inland

New research highlights the increasing threat of microplastics to global farming and food production

Peer-Reviewed Publication

STAFFORDSHIRE UNIVERSITY

A bundle of anthropogenic fibres found in UK soil 

IMAGE: A BUNDLE OF ANTHROPOGENIC FIBRES FOUND IN UK SOIL view more 

CREDIT: ELLIE HARRISON

New research highlights the increasing threat of microplastics to global farming and food production.

Scientists at Staffordshire University are driving research to understand the scale of plastic pollution in agricultural soils and its impact around the world.

Claire Gwinnett, Professor of Forensic and Environmental Science, explained: “We know a lot about microplastics in oceans and freshwater and we are starting to learn more about microplastics in the air, but we still know very little about microplastics in terrestrial environments.

“With climate change, the pressure of increasing populations on food production and risks to food security, it has become apparent that it is incredibly important that we look into this.”

In recent years, the use of plastics in agriculture has increased significantly. However, microplastics in soil are estimated to take up to 300 years to completely degrade. It is believed that their presence alters soil characteristics such as its structure, water holding capacity, and microbial communities, and that microplastics are, in part, responsible for crop-reducing effects.

The Staffordshire Forensic Fibres and Microplastic Research Group has been undertaking various studies, including an international review into the pressures of plastic pollution in rural regions, which highlights the need for wider analysis of terrestrial microplastics to help reduce environmental and public health threats.

Professor Gwinnett said: “We know that microplastics in agricultural soils are abundant, varied, and are influenced by land use and farming activities. We know from a small number of studies that it can affect organisms living in the soil such as worms and springtails.

“Studies on the effect of microplastics on plants are even rarer but we also know that it impacts crops grown in these environments as well as livestock living there. What we need to know now is how much plastic there is and to better understand what effect this is having.”

Ellie Harrison, a PhD researcher in the Staffordshire Forensic Fibres and Microplastic Research Group, is currently conducting a series of studies on the effects of microplastics on common UK agricultural crops.  She said: “Research into the impacts of microplastics in the agricultural soils conducted at Staffordshire University has shown that this pollutant can cause a decrease in germination rate and changes to seed production which could have negative consequences for food production.”

A recent study, conducted in partnership with Çukurova University, has investigated the amount of plastics derived from disposable greenhouse plastic films and irrigation pipes in agricultural soils in Turkey.

Professor Gwinnett said: “Greenhouse films and irrigation piping are products commonly used in farming and we have the same plastic uses in the UK and across Europe. Instead of being removed, these plastic products are often left in fields where they experience wear and tear and degradation from the sun which breaks these plastics down into secondary microplastics.

“Our results show that from years and years of using these plastics, microplastics are accumulating in the soil and cannot be removed.”

Soil samples were taken from 10 different locations in the Adana/KarataÅŸ region in Turkey. The number of micro-, meso-, macro- and megaplastics that was identified in soil where greenhouse film and irrigation piping was used, was about 47, 78, 17, and 1.2-times higher than in farmlands that did not use plastic, respectively. Findings indicated that residual plastics decreased in the soil where used plastics were removed after usage. The results aim to guide farmers in better management of plastics.

A further study with Çukurova University is investigating farmer practices and perceptions in Turkey to understand what the barriers are to taking up preventative measures or more sustainable approaches.

Staffordshire University has been conducting similar research in the UK in partnership with the National Farmers’ Union (NFU); this study looks into the amount and types of microplastic in UK agricultural soils.  This is the first of its kind in the UK and it aims to get a better understanding of the extent of microplastic pollution in farmland.

Professor Gwinnett added: “Plastic usage in the agricultural sector may have worthy benefits in the short term, but the long-term effects cannot be ignored. We hope that our growing body of research can be used to inform decision makers and kickstart real change to safeguard soil health and the future of the farming.”

Notes to Editors

To request an interview with Professor Claire Gwinnett or a full copy of the publications referenced, please contact Amy Platts on amy.platts@staffs.ac.uk or 07799 341911.

 

 

 

Oil spill cleanup workers more likely to have asthma symptoms

NIH study finds chemicals from Deepwater Horizon disaster associated with more wheeze

Peer-Reviewed Publication

NIH/NATIONAL INSTITUTE OF ENVIRONMENTAL HEALTH SCIENCES

Cleaning up the Gulf oil spill 

IMAGE: OIL SPILL WORKERS MORE LIKELY TO EXPERIENCE ASTHMA SYMPTOMS THAT THOSE WHO DID NOT WORK ON CLEANUP. view more 

CREDIT: NIEHS

Researchers from the Gulf Long-term Follow-up Study (GuLF STUDY) found that workers involved in cleaning up the nation’s largest oil spill were 60% more likely than those who did not work on the cleanup to be diagnosed with asthma or experience asthma symptoms one to three years after the spill.

This ongoing study, led by the National Institute of Environmental Health Sciences (NIEHS), part of the National Institutes of Health, is the largest study to look at the health of workers who responded to the 2010 Deepwater Horizon oil spill in the Gulf of Mexico.   

“This is the first study to ever look at specific chemicals from oil spills and link them to respiratory diseases,” said Dale Sandler, Ph.D., chief of the NIEHS Epidemiology Branch and lead researcher for the GuLF STUDY. “If you were an oil spill cleanup worker in the gulf experiencing wheezing or other asthma-like symptoms, it would be good to let your healthcare provider know you worked on the oil spill.” 

 

The researchers analyzed data from 19,018 oil spill response and cleanup workers and another 5,585 people who had completed required safety training but did not work on cleanup. None of the participants had been diagnosed with asthma before the spill. The non-workers were considered an unexposed comparison group.

The researchers estimated worker’s exposures to specific oil spill chemicals. They then looked at the relationship between doctor diagnosed asthma or asthma-related symptoms and the types of jobs the cleanup workers held and the resulting exposure to total hydrocarbons. Researchers also assessed associations of outcomes with a subgroup of chemicals in crude oil, including benzene, toluene, ethylbenzene, xylene, and n-hexane (collectively known as BTEX-H). These chemicals are classified as hazardous air pollutants according to the U.S. Clean Air Act and are linked to other health effects in the GuLF STUDY.

Researchers found that the relative risk for asthma symptoms increased with increasing levels of exposure to individual BTEX-H chemicals as well as the BTEX-H mixture.

“The more a worker was exposed to these crude oil chemicals, including total hydrocarbons, the individual BTEX-H chemicals, and the BTEX-H mixture, the more likely they were to have asthma symptoms,” said Kaitlyn Lawrence, Ph.D., a staff scientist in the NIEHS Epidemiology Branch and lead author of the study published in Environmental International. She noted, “Exposure levels varied depending on the person’s clean-up jobs and how long they worked.”

Jobs varied from administrative support and environmental water sampling, to mopping up crude oil from aboard a sea vessel or shoreline vessel to decontaminating equipment or wildlife. (A breakdown of all participant jobs is available on GuLF STUDY website).

The paper reports that 983 (5%) of the cleanup workers reported asthma and asthma symptoms, while only 196 (3%) non-workers reported the asthma outcome. Workers that were involved in operating, maintaining, or refueling the heavy cleanup equipment had the highest incidence of asthma. For this study, asthma is defined as reporting a doctor’s diagnosis of asthma or, for never-smokers, self-reporting wheezing or whistling in the chest all or most of the time.

“Because the GuLF STUDY population is socioeconomically vulnerable, with less than half reporting access to medical care, we included non-doctor confirmed asthma cases to minimize any underreporting of true asthma cases in the population that would be missed due to lack of access to health care,” Sandler said.

The definition for asthma used in this study builds off an established definition used successfully as a clinical outcome in other large epidemiological studies.   

The GuLF STUDY continues to follow the nearly 33,000 participants enrolled in the original study to monitor potential health outcomes and answer important public health questions. More information about the GuLF STUDY can be found at https://gulfstudy.nih.gov/en/index.html.

Grants: This research was supported by the Intramural Research Program of the NIH, NIEHS (Z01 ES 102945).

About the National Institute of Environmental Health Sciences (NIEHS): NIEHS supports research to understand the effects of the environment on human health and is part of the National Institutes of Health. For more information on NIEHS or environmental health topics, visit www.niehs.nih.gov or subscribe to a news list.

About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.

NIH...Turning Discovery Into Health®

Reference: Lawrence KG, Niehoff NM, Keil AP, Jackson WB II, Christenbury K, Stewart PA, Stenzel MR, Huynh TB, Groth CP, Ramachandran G, Banerjee S, Pratt GC, Curry MD, Engel LS, Sandler DP. 2022. Associations between airborne crude oil chemicals and symptom-based asthma. Environmental International; Volume 167; (PubMed).

What happens to the waste after an oil spill clean up?


UBC Okanagan researchers develop framework for safe disposal of soiled materials

Peer-Reviewed Publication

UNIVERSITY OF BRITISH COLUMBIA OKANAGAN CAMPUS

Images of damaged coastlines, oily sheens, containment booms and endangered wildlife are part of every offshore oil spill.

And while a response team arrives and the clean up gets underway, UBC Okanagan researchers are now exploring how to effectively handle the waste created from that spill.

As part of a Multi-Partner Research Initiative sponsored by Fisheries and Oceans Canada, UBCO engineers are conducting new research to help the oil spill response industry and its regulators enhance response preparedness and efficiency in Canadian waters. A new research study, published recently in the Journal of Hazardous Materials, conducts a lifecycle assessment of oil spill waste mitigation and how to properly dispose of the refuse.

“We never want to experience any sort of spill, but when it happens we need to be prepared,” explains Dr. Guangji Hu, a School of Engineering postdoctoral fellow and report co-author. “If a spill is on land, contaminated soil can be removed and remediated off-site, but that simply isn’t feasible on the water.”

Using a lifecycle assessment approach, the researchers developed a framework to help decision-makers effectively manage the waste of an offshore oil spill cleanup. The lifecycle assessment quantifies the environmental impacts associated with products and services at different points of their life cycle.

The lifecycle assessment compared various strategies for treating wastes—including its collection, segregation and sorting, initial treatment, secure transportation of waste materials, resource recovery and the final disposal of all soiled materials—as well as the resulting environmental impacts, particularly on scenarios situated in Western Canada.

Addressing maritime oil spills is a complex process with many variables including type of oil, tides and water composition, explains Saba Saleem, an engineering master’s student with UBCO’s Lifecycle Management Lab.

“Every spill is unique, but with this new tool we can identify the barriers, gaps and bottlenecks in oily waste management during an offshore oil spill response and enable decision makers to make more informed choices,” says Saleem, who is also the study’s lead author.

Several techniques such as mechanical containment and recovery, use of chemical dispersants, and in-situ burning are commonly used depending on various factors, such as oil slick characteristics, environmental conditions and the spill location.

“The aspect of oil spill recovery waste is one part of a response, but the management of this waste is the most complex, expensive and time-consuming component of recovery,” says Dr. Hu.

The findings point to a strategy of combining centrifugation and landfilling as the most suitable remediation approach for low-impact offshore oil spill waste management, but also highlight the potential of other strategies based on the severity of the spill.

“Analyzing these challenging situations in a holistic manner through lifecycle assessment allows us to develop a framework that encompasses nearly every possible scenario of offshore oil waste management,” Dr. Hu adds. “As a result, stakeholders have one more tool to address these spills quickly and effectively.”

How do horticultural crops defend themselves against fungal pathogens?

NANJING AGRICULTURAL UNIVERSITY THE ACADEMY OF SCIENCE

Recently, scientists from the Chinese Academy of Sciences summarized recent research progress on defense responses of horticultural crops to fungal pathogens and novel strategies to regulate the induction of plant resistance, as well as problems, challenges, and future research directions.

Phytochemicals with antimicrobial effects are important components of defense systems in plants. Among such phytochemicals, phytoalexins are induced by external factors, whereas phytoanticipins occur naturally or increase after induction. Antimicrobial phytochemicals are classified according to their chemical structures and are primarily phenolics, flavonoids, coumarins, lignins, terpenoids, alkaloids, glucosinolates, and stilbenes. Phenolics and flavonoids are secondary metabolites that constitute one of the most common and extensive groups of phytochemicals. These compounds inhibit pathogens by inducing membrane lipid peroxidation, which disrupts fungal cell membrane permeability and mitochondrial function. Similarly, terpenoids inhibit fungal growth and also induce disease resistance. The other phytochemicals also exhibit strong and stable broad-spectrum antifungal activity, suggesting that they could be developed as alternatives to chemical fungicides.

When fungal pathogens penetrate physical barriers by modifying or degrading host cell walls, pattern recognition receptors (PRRs) may recognize conserved damage-associated molecular patterns (DAMPs) from plants or pathogen-associated molecular patterns (PAMPs) from pathogens and activate pattern-triggered immunity (PTI). Fungal pathogens can secrete effectors or virulence factors, which may be recognized by nucleotide-binding and leucine-rich repeat (NB-LRR or NLR) proteins and other plant resistance (R) proteins. Such recognition may result in further effector-triggered immunity (ETI), which is postulated to be an accelerated and amplified PTI response. A varied number of NB-LRR genes exhibit special evolutionary patterns among plant species. To date, only a few NB-LRR genes have been confirmed to function in response to fungal pathogens. Further in-depth exploration of potential NB-LRRs and their mechanisms of action may substantially enrich our arsenal to counterstrike against fungal pathogens.

To prevent further fungal pathogen invasion, plants have developed a series of responses that include the hypersensitive response (HR), cell wall modification, stomatal closure, callose deposition, phytoalexin production, and toxin degradation. After local defense responses are induced, systemic signaling may activate resistance in other adjacent tissues. Both PTI and ETI can trigger the production and long-distance transport of signaling molecules to induce systemic acquired resistance (SAR) and herbivore-induced resistance (HIR). SAR is mediated primarily by salicylic acid (SA) signaling and to a lesser extent by N-hydroxypipecolic acid (NHP). In contrast to SAR, HIR is modulated by jasmonic acid (JA) and ethylene (ET). Crosstalk among SA, JA, and ET, both synergistic and antagonistic, is common and crucial for defense responses against fungal pathogens.

The overuse of traditional fungicides and antimicrobial agents has increased pathogen resistance to these compounds and also threatens food safety and the environment. Therefore, new strategies must be developed for efficient disease control to meet requirements for the sustainable development of the agricultural industry. The latest studies indicate that the induction of intrinsic resistance in horticultural crops via regulatory elements is both feasible and efficient. The discovery of cross-kingdom RNA trafficking has provided new prospects for crop protection. The necrotrophic fungus B. cinerea can produce small RNAs (sRNAs) that function as effectors to suppress host immunity. In turn, host plants introduce sRNAs into B. cinerea via extracellular vesicles that suppress the expression of genes associated with pathogenicity. Overexpression or knockdown of transferred host sRNAs can either promote or reduce host resistance. Environmental double-stranded RNA (dsRNA) can be taken up by many eukaryotic microbes with varying efficiency, and topical application of dsRNA with high RNA uptake efficiency can markedly inhibit plant disease symptoms.

Translational control of mRNA through the editing of regulatory elements may be another efficient way to induce resistance in horticultural crops. Upstream open reading frames (uORFs) have widespread regulatory roles in modulating mRNA translation in eukaryotes. Moreover, transgene-free lines of plants with improved traits are readily obtained with CRISPR/Cas9, which has broad implications for crop improvement. Because uORFs are found extensively in eukaryotic mRNAs, these regulatory elements could be manipulated to enhance broad-spectrum resistance with minimal adverse effects on normal growth, substantially promoting the genetic improvement of horticultural crops.

“Because of the importance of fungal disease in pre- and postharvest loss of horticultural crops, we focused on plant-pathogen interactions and control technology. Moreover, development and application of omics technologies have provided large data sets at multiple levels, which have further broadened insights into the defense responses against fungal pathogens,” Prof. Tian said. The review paper also examined the limitations of previous studies and proposed future research directions for genetic improvement of resistance in horticultural crops.

 

###

Reference

Authors

Xiaodi Xu1,2,†, Yong Chen1,†, Boqiang Li1, Zhanquan Zhang1, Guozheng Qin1, Tong Chen1,* and Shiping Tian1,2,*

Affiliations

1 Key Laboratory of Plant Resources, Institute of Botany, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100093, China

2 College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China

About Prof. Shiping Tian 

Prof. Shiping Tian received her bachelor's degree from Sichuan Agricultural University in 1982. In 1995, she received her doctoral degree in plant pathology from the University of Bologna in Italy. She returned to China in 1997. Now she is a researcher at the Institute of Botany, Chinese Academy of Sciences. In 2002, she won the National Science Fund for Distinguished Young Scholars. To date, she has published more than 140 SCI papers.

Particles from everyday wall paints can harm living organisms – novel membrane shows high filtering effects

Analyzing two typical dispersion paints, researchers from the University of Bayreuth have discovered a large number of solid particles in them which are only a few micro- or nanometers in size. These particles can harm living organisms

Peer-Reviewed Publication

UNIVERSITÄT BAYREUTH

Dispersion paints are mostly used in households for painting walls and ceilings. An interdisciplinary research team from the University of Bayreuth has now analysed the chemical composition of two typical dispersion paints and discovered a large number of solid particles in them which are only a few micro- or nanometers in size. Studies on biological test systems showed that these particles can harm living organisms. Using a novel membrane developed at the University of Bayreuth, these particles can be filtered out of water before they enter the environment.

Ingredients of dispersion paints

The Bayreuth study on the ingredients of dispersion paints and their possible effects on living organisms has been published in the journal Ecotoxicology and Environmental Safety. It is based on close interdisciplinary networking in Collaborative Research Center 1357 "Microplastics" at the University of Bayreuth. The scientists selected two commercially available dispersion paints that are frequently used in households. These differ primarily in their dripping properties, because they were developed for wall painting on the one hand and ceiling painting on the other. The two paints have a solids content of 49 and 21 percent by weight, respectively, while the organic content is 57 and seven percent by weight. Characteristic solid components in the micro- or nanometer range are particles of silicon dioxide, titanium dioxide and calcium carbonate, as well as particles of various kinds of plastic, especially polyacrylate.

"Many of these tiny particles enter the environment, for example, through abrasion of the paint layers or weathering. Our study now shows that when brushes, rollers, scrapers and buckets used in painting walls and ceilings are cleaned by washing out paint residues, the particles from the dispersion paints can end up in wastewater and thus also in the environment. The impact on the environment needs to be thoroughly investigated, which is all the more urgent given the worldwide spread of dispersion paints and their diverse material compositions. That is why we have not limited ourselves to the chemical analysis of paint components, but have also investigated their effects on living organisms and cells," says Prof. Dr. Andreas Greiner, deputy spokesman of the Collaborative Research Center "Microplastics".

Effects on living organisms

For their inquiries, the Bayreuth scientists selected two test systems which have been well established in research: water fleas of the species Daphnia magna and a line of mouse cells. The water fleas were tested according to OECD guidelines for the testing of chemicals. In this test, the mobility of the organisms is considered. It was found that the mobility of the water fleas was significantly reduced when the water contained a high proportion of dissolved and undissolved inorganic nanoplastic and microplastic particles. In mouse cells, a decrease in cell activity was observed, which was generally caused by particles in the nanometer range. Metabolism in the mouse cells was significantly disrupted by nanoparticles of titanium dioxide and plastics in particular.

"Our research shows that the ingredients of dispersion paints can cause reactions of varying degrees in organisms and cells. Therefore, the possibility that the ingredients could be harmful to the environment cannot be ruled out. Further research in this area is urgently needed, especially since we still know far too little about whether interactions between nanoparticles made of plastic and inorganic nanoparticles can trigger additional damage," explains Prof. Dr. Christian Laforsch, spokesman for the Collaborative Research Center "Microplastics". "It is likewise still a largely unresolved question how the ingredients of dispersion paints interact with other substances in different environmental compartments – for example, in the air, in the soil or in rivers. However, it is already clear that dispersion paints should not be carelessly disposed of in the environment," says Prof. Dr. Ruth Freitag, who is Chair of Process Biotechnology at the University of Bayreuth.

A novel membrane with high filtering effects

Parallel to the studies of dispersion paints and their possible effects, researchers under the direction of Prof. Dr. Andreas Greiner have focussed on a further project: They have developed a new process to remove potentially harmful particles from dispersion wall paints from wastewater by filtration. This involves the use of a membrane made of functionalized fibers produced by the electrospinning process. The membrane retains micro- and nanometer-sized particles in different ways. On the one hand, the pores of the membrane are so fine that microparticles are not allowed to pass through. On the other hand, interactions between the membrane fibers and nanoparticles cause them to stick to the membrane surface even though they would fit into the pores. In both cases, the filtering effect is not associated with rapid and large-scale clogging of the pores. Therefore, water, for example, can easily pass through the membrane and run off.

In the journal Macromolecular Materials and Engineering, the Bayreuth scientists describe the successful application of the membrane. They also tested the two dispersion paints that had proved potentially harmful to living organisms in the study. As it turned out, the membrane is able to retain typical colour components – in particular nanoparticles of titanium dioxide and polyacrylate, and microparticles of calcium carbonate. "In everyday life, all these colour components are discharged together into the wastewater. Here they mix and in some cases even change their structures and properties due to their interactions. Therefore, we specifically tested the filtration performance of our electrospun membrane on such mixtures. The high filtering effects we have achieved show that this process has great potential when it comes to purifying water from particles in the micro and nanometer range, such as those contained in commonly used paints around the world," says Greiner.

POSTMODERN ALCHEMY

How a Japanese herbal medicine protects the gut against inflammatory bowel disease

Peer-Reviewed Publication

RIKEN

Japanese herbal medicine reduces the severity of colitis 

IMAGE: THE CONDITION OF MICE WITH COLITIS IMPROVED AFTER TREATMENT WITH DAIKENCHUTO, A MEDICINE MADE FROM GINGER, GINSENG, AND JAPANESE PEPPER. ANALYSIS SHOWED THAT THIS WAS BECAUSE IT PREVENTS THE LOSS OF KEY BACTERIA IN THE GUT AND FACILITATES THE ACTIVITY OF INNATE IMMUNE CELLS IN THE GUT CALLED ILC3S. view more 

CREDIT: RIKEN

Zhengzheng Shi and colleagues at the RIKEN Center for Integrative Medical Sciences (IMS) in Japan report the effects of a common herbal remedy on colitis, one of two conditions that comprise inflammatory bowel disease (IBD). Published in Frontiers in Immunology, the study shows that DKT—an herbal medicine containing ginger, pepper, ginseng, and maltose—reduced the severity of colitis in lab mice by preventing the loss of important gut bacteria and by increasing levels of immune cells in the colon that fight inflammation.

Colitis is a chronic inflammation of the colon, characterized by an imbalance in gut bacteria and an abnormal immune response. Prevalence has doubled over the last 20 years, and it’s currently a global health concern, particularly in Europe and North America. Although treatments are numerous, they are only partially effective. This has led some researchers to take a closer look at traditional herbal medicines that originated in China, and are now commonly used in Japan and other Asian countries.

Daikenchuto (DKT) is a formula containing specific amounts of ginger, pepper, ginseng, and maltose, and is one of 148 herbal medicines called Kampo, which have been developed in Japan and are often prescribed by doctors to treat a variety of illnesses. Previous research has hinted that DKT might be useful for treating colitis, but evidence, particularly at the molecular level, has been lacking. Thus, Shi and the team of researchers at RIKEN IMS led by Naoko Satoh-Takayama conducted a detailed examination of its effects on a mouse model of colitis.

Colitis was induced in mice using dextran sodium sulfate, which is toxic to the cells that line the colon. When these mice were given DKT, their body weights remained normal, and they had lower clinical scores for colitis. Additional analysis revealed much less damage to the cells lining the colon. Having thus shown that DKT does indeed help protect against colitis, the researchers proceeded to analyze the gut microbiome of the mice and expression levels of anti-inflammatory immune cells.

Gut microbiomes contain numerous bacteria and fungi that aid in digestion and help the immune system. Colitis is associated with an imbalance in these gut microbiota, and analysis showed that a family of lactic acid bacteria were depleted in the colitic mice of this study. Also depleted was one of their metabolites, a short-chain fatty acid called propionate. Treating the model mice with DKT restored much of these missing bacteria—particularly those from the genus Lactobacillus—and levels of propionate were normal.

Colitis is also associated with an abnormal immune response that causes the characteristic intestinal inflammation. When the team looked at innate intestinal immune cells, they found that levels of a type called ILC3 were lower in the untreated colitic mice than in the DKT-treated colonic mice, and that mice engineered to lack ILC3 suffered more and could not benefit from DKT treatment. This means that ILC3s are critical for protecting against colitis and that DKT works by interacting with them. Lastly, qPCR analysis indicated that these important immune cells had receptors for propionate, called GPR43, on their surface.

Daikenchuto is commonly prescribed to prevent and treat gastrointestinal diseases, as well as for reducing intestinal obstruction after colorectal cancer surgery,” says Satoh-Takayama. “Here we have shown that it can also alleviate intestinal diseases like colitis by rebalancing Lactobacillus levels in the gut microbiome. This likely helps reduce inflammatory immune responses by promoting the activity of type 3 innate lymphoid cells.”