Publisher Health

A nationwide study from the U.S. Centers for Disease Control and Prevention (CDC) is the first to show that immunity against severe COVID-19 disease begins to wane 4 months after receipt of the third dose of an mRNA vaccine (Pfizer or Moderna). Waning immunity was observed during both the Delta and Omicron variant waves in similar fashion to how mRNA vaccine effectiveness wanes after a second dose. Although protection decreased with time, a third dose was still highly effective at preventing severe illness with COVID-19.
Until this study, little was known about durability of protection following three doses, especially during periods of Delta or Omicron predominance in the U.S.
“The mRNA vaccines, including the booster shot, are very effective, but effectiveness declines over time. Our findings suggest that additional doses may be necessary to maintain protection against COVID-19, especially for high-risk populations,” said study co-author Brian Dixon, PhD, MPA, Regenstrief Institute and Indiana University Richard M. Fairbanks School of Public Health director of public health informatics. “We also found that people who are Hispanic or Black are half as likely to have a third vaccine dose than people who are white, making people who are Hispanic or Black more vulnerable to severe COVID and highlighting the need for public health officials to double down on efforts to protect these vulnerable populations.”
According to a CDC dashboard, as of February 8, 2022, among Americans 65 years or older who received a booster dose: 72.3 percent were people who are white, 8.9 percent were people who are Hispanic, and 7.6 percent were people who are Black. The rates among people who are Black or Hispanic are lower than the proportion of those groups with two doses, and these proportions are lower than the percentage of the U.S. population composed of people from those groups, indicating disparities in who has received third doses in the U.S. In the last two weeks, however, higher rates of vaccination have been observed among these minority groups (16.9 percent of recent boosters are among people who are Hispanic; 12.7 percent of recent boosters are among people who are Black). In the study, among patients who are white in the ED/UC, 12 percent had received a third dose compared to 7 percent of patients who are Hispanic and 6 percent of patients who are Black. Similar disparities in third dose administration were observed among those patients hospitalized for severe COVID-19.
Overall, the study reported that individuals with second and third doses of an mRNA vaccine had greater protection against hospitalizations (severe disease) than against emergency department/urgent care (ED/UC) visits (symptoms which may not require hospitalization). Vaccine effectiveness was also lower overall during the Omicron period than during the Delta period.
Vaccine effectiveness against ED/UC visits declined from 97 percent within the first two months of receipt of a booster to 89 percent effectiveness at four months or more during the Delta-predominant period (summer/early fall 2021). During the Omicron-predominant period (late fall 2021/winter 2021-22), vaccine effectiveness against ED/UC visits was 87 percent during the first two months after a third dose, decreasing to 66 percent at four months after a third dose.
After the third dose, protection against Delta variant-associated hospitalization declined from 96 percent within two months to 76 percent after four months or longer. Vaccine effectiveness against Omicron variant-associated hospitalizations was 91 percent during the first two months declining to 78 percent at four months.
“Our findings confirm the importance of receiving a third dose of mRNA COVID-19 vaccine to prevent moderate-to-severe COVID-19 illness, especially among those with comorbidities,” said study co-author Shaun Grannis, M.D., M.S., vice president for data and analytics at Regenstrief Institute and professor of family medicine at Indiana University School of Medicine. “That protection conferred by mRNA vaccines waned in the months following a third vaccine dose supports further consideration of booster doses to sustain protection against moderate-to-severe COVID-19 illness.”
“Waning Effectiveness 2-dose and 3-dose mRNA Vaccines Against COVID-19-Associated Emergency Department and Urgent Care Encounters and Hospitalizations Among Adults During Periods of Delta and Omicron Variant Predominance — VISION Network, 10 States, August 2021-January 2022” is published in the CDC’s Morbidity and Mortality Weekly Report.
The CDC collaborated with six U.S. healthcare systems plus the Regenstrief Institute, to create the VISION network to assess COVID-19 vaccine effectiveness. In addition to Regenstrief Institute, other members are Columbia University Irving Medical Center, HealthPartners, Intermountain Healthcare, Kaiser Permanente Northern California, Kaiser Permanente Northwest and University of Colorado. Regenstrief contributes data and expertise to the VISION Network.
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A study in mice — led by researchers at Washington University School of Medicine in St. Louis — shows that a new class of compounds the scientists developed can improve multiple aspects of metabolic syndrome. An increasingly common group of conditions that often occur together, metabolic syndrome includes type 2 diabetes, high cholesterol, fat buildup in the liver, and excess body fat, especially around the waist. This syndrome often leads to cardiovascular disease, the leading cause of death worldwide.
The study is published in the journal Nature Communications.
Testing one of the compounds referred to as SN-401, the researchers found it treats diabetes by improving the ability of the pancreas to secrete insulin and boosting the ability of other tissues to utilize that insulin to more effectively remove sugar from the bloodstream. In an effort to optimize the treatment, the researchers fine-tuned the compound — creating a class of related compounds — based on their studies of a key protein called SWELL1 (also LRRC8a). The gradual decline of this protein may have a central role in the development of diabetes and other aspects of metabolic syndrome.
“Our goal is to develop better therapies for cardiovascular disease, including diabetes and metabolic syndrome, which are major risk factors for worsening heart and vascular problems,” said senior author Rajan Sah, MD, PhD, an associate professor of medicine. “We have many treatments for diabetes, but even with those therapies, cardiovascular disease remains a leading cause of death among patients with type 2 diabetes. There is a need for new treatments that work differently from the current standard-of-care therapies.”
The protein Sah and his colleagues studied is called SWELL1 because of its role in sensing the size or volume of cells. Their new research reveals that the protein also helps to control insulin secretion from the pancreas and improve insulin sensitivity, including in skeletal muscle and adipose tissue, the body’s fat stores.
Surprisingly, the researchers showed that SWELL1 does both of these seemingly independent tasks because the protein has a previously unknown double life. It acts as a signaling molecule, turning on cellular tasks that govern how well cells use insulin and also facilitates the pancreas’ secretion of insulin into the bloodstream.
“This protein, SWELL1, has a sort of dual personality,” Sah said. “The compound binds to SWELL1 in a manner that stabilizes the protein complex so as to enhance expression and signaling across multiple tissues, including adipose, skeletal muscle, liver, the inner lining of blood vessels, and pancreatic islet cells. This restores both insulin sensitivity across tissue types and insulin secretion in the pancreas.”
Sah and his colleagues showed that the SN-401 compound improved multiple aspects of metabolic syndrome in two groups of mice that each developed diabetes from different causes, one because of a genetic predisposition and the other due to a high-fat diet. In addition to improving insulin sensitivity and secretion, treatment with the compound also improved blood sugar levels and reduced fat buildup in the liver. Most of these studies were conducted with an injected form of the compound, but the researchers showed evidence that it also could be effective if taken by mouth.
The researchers further showed that the compound does not have a big impact on blood sugar in healthy mice, which is important for its potential as a future possible therapy. Current medications for diabetes can result in blood sugar levels that are too low. The evidence suggests that this compound does not lower blood sugar in situations when it doesn’t need to.
Sah worked with Washington University’s Office of Technology Management to patent the class of compounds and co-found a startup company called Senseion Therapeutics Inc., which is developing small molecule drugs that act on SWELL1. The company was first supported through funding from the university’s Leadership Entrepreneurship Acceleration Program (LEAP), and also recently received three Small Business Innovation Research (SBIR) grants totaling $4.5 million. SBIR grants are supported by the small business seed fund of the National Institutes of Health (NIH).
This work was supported by the National Institutes of Health (NIH), grant numbers P30CA086862, P30DK020579, T32GM008365, GM123496, GM128263, P30 DK056341, UL1 TR000448, T32 HL130357, R01DK115791, R01DK106009, R01DK126068, R01DK127080, R43 DK121598 and R44 DK126600; the John L. & Carol E. Lach Chair in Drug Delivery Technology; grants from the New York Stem Cell Foundation; a McKnight Foundation Scholar Award; a Rose Hill Innovator Award; a Sloan Research Fellowship; the Leadership Entrepreneurship Acceleration Program (LEAP) from the Skandalaris Center for Interdisciplinary Innovation and Entrepreneurship at Washington University in St. Louis; and the Roy J. Carver Trust, University of Iowa.

Kessler Foundation experts in stroke rehabilitation proposed a new paradigm for improving treatment of spatial neglect, a disabling condition that hinders recovery for at least 30 percent of stroke survivors. They outlined their approach in their recent article, “Immersive virtual reality treatment for spatial neglect: An agile user-centered development process,” published online on November 15, 2021, by the Annals of Physical Medicine & Rehabilitation. Authors are Peii Chen, PhD, senior research scientist in the Center for Stroke Rehabilitation Research, and Denise Krch, PhD, senior research scientist in the Center for Traumatic Brain Injury Research.
Spatial neglect impairs the neural networks supporting spatial attention and related cognitive and motor functions. People experience altered spatial orientation, which can cause problems with balance and navigation, as well as with memory, reading, and other cognitive processes. While progress has been made in detecting post-stroke spatial neglect, treatment strategies have lagged. To address the need for effective neurorehabilitation, the authors developed a treatment approach based on immersive virtual reality (VR), which allows standardized delivery of intensive, repetitive therapy in a flexible, engaging environment.
To develop the Kessler Foundation Spatial Re-Training Therapy (KF-SRT™), which employs a head-mounted display and hand-tracking technology, the Foundation team worked closely with Virtualware, an award-winning VR technology company based in Spain. “During user testing, we were able to communicate the need for revisions to Virtualware and adapt the software according to feedback from therapists and patients,” said Dr. Chen. “The resultant system has a user interface that accommodates creation of a patient profile, a calibration module, a choice of four game-like treatment modules, and a spreadsheet for data collection and export, enabling therapists to review progress across sessions.”
In the virtual treatment environments, patients wear a head-mounted display and hand-tracking technology to engage in a variety of challenging motor tasks. “The scoring algorithm rewards correct responses, with higher scores awarded for tasks completed successfully in the neglected space,” explained Dr. Krch.
The team reported that therapists were unanimously satisfied with the KF-SRT user interface, and patients preferred the VR experience to conventional therapy. “The next step is to conduct pilot studies of feasibility, limitations, and preliminary efficacy,” they concluded, “while continuing to update the system’s software and technology. This will position VR technology in the forefront of options for rehabilitating individuals with spatial neglect.”
Funding sources: National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR; grant number no. 90IFDV0001).
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Empowering small, humanoid-sensing robots to take a patient’s blood pressure — using only a simple touch — is Simon Fraser University researcher Woo Soo Kim’s latest health care technology development.
Based on the intricacies of origami — and inspired by the movements of nature’s leeches — his research is advancing how robots could carry out basic health care tasks in certain conditions, including in remote regions, or where minimal personal contact is needed, such as during pandemics. The research is published in the journal npj Flexible Electronics from Nature Publishing Group.
Together with PhD student Tae-Ho Kim and a team in SFU’s Additive Manufacturing Lab, Kim and researchers have replaced the traditional blood pressure procedure by replicated the folding mechanisms of the leech in their design of 3-D printable origami sensors. The leech-inspired origami (LIO) sensors can be integrated onto the fingertips of a humanoid-sensing robot.
“Our origami-inspired dry electrode has unique characteristics such as suction for grasping and foldability inspired by nature,” says Kim, a professor and associate director of SFU’s School of Mechatronic Systems Engineering. “In keeping with nature, we saw that in addition to the complex mechanisms of a leech’s adhesive feature, these creatures have an expandable posterior sucker and body, while its organs expand and shrink appropriately to maintain better adhesion to its victim. Incorporating this point of view, we found that origami can achieve similar motions and also be customized.”
How It Works
The LIO sensors integrated onto the robot’s fingertips can be positioned on the patient’s chest. Blood pressure is monitored and estimated by combining data from electrocardiogram (ECG)and photoplethysmogram (PPG) readings, as recorded by sensors on the fingers of each hand respectively.
Using predetermined algorithms, the signals from the paired sensors can generate a patient’s systolic and diastolic blood pressure without using the traditional cuff-based digital sphygmomanometer.
Kim’s earlier work involved programming sensing robots to measure other human physiological signals, such as those from an electrocardiogram (which monitors heart rate), temperature and respiration rate.
“Robotics offers a promising method to mitigate risk and improve patient care effectiveness and quality as focused remote healthcare technology,” says Kim. The researchers plan further trials of their new process and are developing the next generation of sensors, which they hope will lead to its biomedically meaningful implementation.
“Blood pressure monitoring is an essential medical diagnostic tool for many chronic diseases and overall good health. The use of sensing robots in medical healthcare systems has substantial advantages because they can assist health care workers in monitoring patient vital signs while creating a friendly environment for those patients who may need to be isolated.”
Kim believes that robotics can provide a future platform or bridge between medical personnel and remote patients with “the potential to play an essential role in the new era of remote healthcare.”
The research is partially supported by a Discovery and Accelerator Supplement Grant, funded by the Natural Sciences and Research Council of Canada (NSERC).
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How are the different shapes of our organs and tissues generated? To answer this question, a team from the University of Geneva (UNIGE), Switzerland, forced muscle cells to spontaneously reproduce simple shapes in vitro. By confining them on adhesion discs, the biochemists and physicists observed that the cells rapidly self-organise by aligning themselves in the same direction. A circular motion is created around a vortex — called a topological defect — which, by orienting the cells, allows them to join forces, deforming the cell monolayer into a protrusion, a structure commonly observed in embryo development. This cylindrical protrusion is maintained by the collective rotational forces of the cells, creating a tornado-like effect. The formation of these cellular tornadoes would therefore constitute a simple mechanism of spontaneous morphogenesis, dictated by the unique properties of multicellular assemblies. These results can be read in the journal Nature Materials.
Our bodies are made up of organs and tissues, each with its peculiar shape. But how do cells manage to form the folds of the intestine or the alveoli of the lungs? Is it possible to reconstitute these shapes in vitro? To answer these questions, biochemists have joined forces with theoretical physicists to test the ability of cellular tissues to spontaneously self-model.
“In theoretical physics, we know that if there are active constraints between cells, then they will order themselves and spontaneously adopt collective behaviours known as ’emergent’, because they do not exist at the scale of a single cell,” explains Karsten Kruse, professor in the departments of biochemistry and theoretical physics at the UNIGE Faculty of Science. The theory predicts that one of these emerging behaviours is the adoption of particular shapes by a multicellular tissue. It is this hypothesis that we wanted to test in vitro.
To do this, the Geneva team selected human muscle cells that are capable of contracting and whose rod shape allows them to align themselves: “When the cells are placed on a flat surface, they align themselves and form structures similar to a field of wheat where the wind has passed through: there is an overall order with sudden changes in direction at punctual places,” says Aurélien Roux, a professor in the Department of Biochemistry at the UNIGE Faculty of Science. These changes in direction are called ‘topological defects’: they represent the places where the physical forces exerted on the cells are either very weak or, on the contrary, immense.
Topological defects create cellular tornadoes
So what impact do these topological defects have on the shape of the tissue? To understand their role, the interdisciplinary team grew cells on adhesion discs. “This involves confining our muscle cells to a surface surrounded by repulsive molecules that force them to form a circle,” explains Aurélien Roux. The cells quickly start to rotate together to form an ordered spiral. “We can see a spontaneous movement of the cells, like when a crowd is forced to walk around a room and ends up going in the same direction for ease,” he continues.
Thus ordered, only one topological defect remains at the centre of the circle. “We see that the spiral, which concentrates the cellular forces in its centre, accumulates the newly formed cells there by cell division. Thus, the spiral will gradually become a vortex, creating a protrusion in the middle of the disc,” explains Karsten Kruse. And this protrusion can reach up to half a millimetre, which is enormous for a base that is not a hundredth of a millimetre in size. The Geneva team is therefore observing a real little 3D cellular tornado that is spinning around.
Spontaneous cell morphogenesis subject to the laws of physics
The researchers found that the muscle cells spontaneously formed tornado-like structures, which resemble the structures observed in the development of the embryo, such as the fingers or the folds of the intestinal layer. “This spontaneous self-organisation without biochemical regulation could be the initial stage in the formation of protrusions in the embryo,” says Aurélien Roux. The scientists also highlighted that it is indeed the topological defects that control the organisation of cells and determine the shape they will adopt. “Finally, our study shows that cells do not escape the laws of physics but, subjected to the same constraints as all materials, they exploit them to concentrate their forces and create shapes only seen in living organisms,” adds Karsten Kruse.
The researchers will now study simple examples of embryos in order to compare them with theoretical models and in vitro experiments and understand the different possible mechanisms regulating the forces in the embryo.
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A new machine learning process designed to identify and classify hip fractures has been shown to outperform human clinicians.
Two convolutional neural networks (CNNs) developed at the University of Bath were able to identify and classify hip fractures from X-rays with a 19% greater degree of accuracy and confidence than hospital-based clinicians, in results published this week in Nature Scientific Reports.
The research team, from Bath’s Centre for Therapeutic Innovation and Institute for Mathematical Innovation, as well as colleagues from the Royal United Hospitals Trust Bath, North Bristol NHS Trust, and Bristol Medical School, set about creating the new process to help clinicians make hip fracture care more efficient and to support better patient outcomes.
They used a total of 3,659 hip X-rays, classified by at least two experts, to train and test the neural networks, which achieved an overall accuracy of 92%, and 19% greater accuracy than hospital-based clinicians.
Effective treatment is crucial in managing high costs
Hip fractures are a major cause of morbidity and mortality in the elderly, incurring high costs to health and social care. Classifying a fracture prior to surgery is crucial to help surgeons select the right interventions to treat the fracture and restore mobility and improve patient outcomes.

Using a technique called spatial transcriptomics, researchers at Karolinska Institutet in Sweden have analysed the gene expression in the mouse colon and created a map showing where in the tissue individual genes are expressed. When they superimposed previously known human transcription data onto the map, the researchers gained new insights into inflammatory bowel disease (IBD). The study is published in the journal Nature Communications.
The group used a technique known as spatial transcriptomics (ST) to map the gene activity of individual cells in the murine colon. According to the researchers, this is the first time anyone has been able to visualise the gene expression landscape of the entire intestine, in health and recovery after injury.
“Our spatial transcriptomics-driven visualisation enabled us to discover several previously unknown aspects, such as that the colon is divided into more segments than once thought,” says the study’s corresponding author Eduardo J. Villablanca, docent at the Department of Medicine, Solna at Karolinska Institutet.
When the results were combined with known transcription data from human tissue, the scientists noticed that the location of certain intestinal cells was the same in both mice and humans, which makes the model a tool for understanding how different diseases, such as IBD, affect the colon.
In an earlier study, Eduardo J. Villablanca’s research group showed that ulcerative colitis can be divided into two subgroups with different gene expressions. With reference to the new map, they were able to show that the genes for the more difficult to treat forms of the disease were found in tissue that was also more damaged.
“Similarly, the gene map can be used to see where in the colon human cells are active, which can make a significant contribution to the development of new treatments and drugs,” Villablanca says.
Spatial transcriptomics was developed at SciLifeLab by scientists from KTH Royal Institute of Technology and Karolinska Institutet. It allows the visualization of gene expression in the tissue. However, to visualize a long tubular organ like the colon, the researchers behind this study applied the technique in a novel way. By rolling up the colon like a Swiss roll, they managed to fit and map the entire gene expression landscape of a long organ.
“We now want to use the same method to create a similar atlas for all digestive organs, from the mouth to the rectum,” Villablanca explains. “Our aim is to create a reference map for the gene expression of all these tissues.”
A gene atlas of the entire digestive organ will be useful in many ways, such as for exploring the link between gut bacteria and cellular gene expression, and for gaining a better understanding of how different diets affect its various functions.
The study was conducted at Karolinska Institutet with financial support from, among others, the Swedish Research Council, the Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (Formas), the Swedish Cancer Society and the Knut and Alice Wallenberg Foundation.
Some of the authors have reported declarations of interest: Eduardo J. Villablanca has received research funding from the pharmaceutical company F. Hoffmann-La Roche; and Camilla Engblom, Ludvig Larsson and Joakim Lundeberg are scientific advisors to 10X Genomics, which acquired the company Spatial Transcriptomics in 2018.
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Every year, roughly 550 women develop ovarian cancer in Finland. Ovarian cancer is difficult to treat and it is commonly fatal, with 320 women dying of ovarian cancer annually in Finland.
Cancer can only develop and progress when the tumour cells are able to hide from the body’s immune system. Cancer immunotherapies, which boost the body’s immune defence against cancer, have emerged as promising therapies in multiple tumor types. However, the effectiveness of immunotherapies against ovarian cancer has remained modest. This is mainly since the mechanisms how ovarian cancer cells hide from the immune system have been unknown.
Now, researchers at the University of Helsinki have uncovered how tumour cells interact with the immune system in ovarian cancer. Utilising a novel imaging technology, the researchers characterized more than 110,000 individual cells from clinical ovarian cancer samples. The researchers investigated how the genetic characteristics of ovarian cancer the shape human immune system, and how tumour and immune cells communicate with each other.
“With the help of this revolutionary imaging technology and advanced data analysis, we were able to study individual tumour cells, their functional properties and interactions with unprecedented precision,” says Associate professor Anniina Färkkilä, the corresponding author of the study.
Tumour genes trick the immune system
“By studying individual cells directly in the tissue, we demonstrated how cancer cells hide in different ways, depending on the specific gene mutation. We found that the body’s immune system is more effective against tumors with a mutation in BRCA1/2 genes. By contrast, tumours without such mutations have a connective tissue barrier prohibiting the interaction between the cancer and immune cells,” says doctoral researcher Inga-Maria Launonen, BM.
BRCA1/2 mutations occur in approximately 20% of poorly differentiated serous carcinomas, the most common form of ovarian cancer. The killer T-cells closely guarded the aggressive tumour cells particularly in tumours with BRCA1/2 mutations, which is why these patients had a markedly better prognosis.
“By increasing our understanding of how tumour genes trick the immune system, we will be able to develop more effective ways to activate the body’s own immune defences to kill the cancer cells,” Inga-Maria says.
Results will promote the tailoring of precision therapies
The results of the study confirm the significance of the interaction between tumour and immune cells in identifying new and more effective therapies as well as in choosing the right therapy for each patient.
“Our findings will enable us to tailor precision immuno- and combination therapies that have the potential to even cure ovarian cancer in the future,” Färkkilä says.
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Professor Josef Käs from Leipzig University led these investigations in collaboration with the head of the Institute of Pathology Hamburg-West, Professor Axel Niendorf, and the independent statistical consultant Bernhard Ulm. They have just published their findings in PLOS ONE, a multidisciplinary journal that pays particular attention to whether experiments and data analyses have been conducted rigorously.
Gene expression tests examine how active certain genes are in tumour cells. Often, these genes are related to characteristic features of cancer, such as tumour growth or invasion of surrounding tissue by tumour cells. A gene expression test therefore represents a method of quantifying the activities of several genes, i.e. a gene list, and thus calculating the probability of whether and when the patient will develop metastases.
The results of these studies show, on the one hand, the limits of the certainty of the predictions achieved with such gene lists and further indicate that the examination of different combinations of gene lists does not differ significantly in terms of outcome. Interestingly, the researchers have shown that even random genes can be prognostic: that means even those genes that seem unrelated to the characteristic features of cancer.
Here, using a classical statistical analysis and a new approach in machine learning, the physicists showed that such gene lists are in fact prognostic in a sufficiently large collective and show high correspondences between prognosis and the actual course of the disease.
Contrary to the common recommendation in clinical practice to perform only one test, these gene lists showed that the certainty regarding a chemotherapy recommendation is much higher if more than one test is performed.
“The fact that the tests are very successful in a collective and tend to be less successful on the individual patient seems at first to be a contradiction,” said Professor Käs, “but these tests are based on gene lists and make mistakes at different points, so to speak. This could be exploited by combining several tests and thus increasing the probability of finding the patients who definitely will not benefit from chemotherapy.”
With ongoing debates about whether gene expression tests are useful, this is an important contribution to the decision-making process and will have great impact in terms of how clinicians use such tools. For individual patients in particular, these results imply that circumspection is required in the use of gene expression tests.
A limitation from a methodological point of view is that the researchers did not perform commercially available tests; the analyses are based on gene expression values recorded in public breast cancer databases.
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Materials provided by Universität Leipzig. Original written by Susann Huster. Note: Content may be edited for style and length.

Researchers at the University of Copenhagen have found several hundred different chemical substances in tap water stored in reusable plastic bottles. Several of these substances are potentially harmful to human health. There is a need for better regulation and manufacturing standards for manufacturers, according to the chemists behind the study.
Have you ever experienced the strange taste of water after it has been in a reusable plastic bottle for a while? It appears that there is a solid, yet worrying reason for this.
Two chemists from the University of Copenhagen have studied which chemical substances are released into liquids by popular types of soft plastic reusable bottles. The results were quite a surprise.
“We were taken aback by the large amount of chemical substances we found in water after 24 hours in the bottles. There were hundreds of substances in the water — including substances never before found in plastic, as well as substances that are potentially harmful to health. After a dishwasher cycle, there were several thousand,” says Jan H. Christensen, Professor of Environmental Analytical Chemistry at the University of Copenhagen’s Department of Plant and Environmental Sciences.
Endocrine disruptors and insecticide
Professor Christensen and fellow researcher Selina Tisler detected more than 400 different substances from the bottle plastic and over 3,500 substances derived from dishwasher soap. A large portion of these are unknown substances that the researchers have yet to identify. But even of the identified chemicals, the toxicity of at least 70 % remains unknown.