Scientists suspect that the plastics can be linked to a host of medical conditions, but clear evidence is elusive without appropriate biomarkers for clinical laboratory testing
Recent research indicates that microplastics and nanoplastics (MNPs) are accumulating in human organs at an increasing rate. The health impact is not entirely clear, but the research suggests that clinical laboratories could someday find themselves testing for levels of MNPs in patients.
In one study, scientists at the University of New Mexico and Oklahoma State University analyzed autopsy samples of liver, kidney, and frontal cortex brain tissue collected in 2016 and 2024. “Brains exhibited higher concentrations of MNPs than liver or kidney samples,” they wrote. However, “all organs exhibited significant increases from 2016 to 2024.”
“The concentrations we saw in the brain tissue of normal individuals, who had an average age of around 45 or 50 years old, were 4,800 micrograms per gram, or 0.5% by weight,” lead author Matthew Campen, PhD, Regents’ Professor, Pharmaceutical Sciences, University of New Mexico, and Director of the New Mexico Center for Metals in Biology and Medicine (CMBM), told CNN. “Compared to autopsy brain samples from 2016, that’s about 50% higher.”
Researchers have not yet uncovered clear evidence of specific health risks, but “what scientists worry about is several trends in disease prevalence that have been unexplained—Alzheimer’s disease and dementia, colorectal cancer in people under 50, inflammatory bowel disease, and global reductions in sperm count,” Campen told Everyday Health.
In another recent study, a different team of researchers at the University of New Mexico found high levels of microplastics in human and canine testicular tissue.
“At the beginning, I doubted whether microplastics could penetrate the reproductive system,” said lead author Xiaozhong Yu, MD, PhD, Professor, University of New Mexico College of Nursing in a university news story. “When I first received the results for dogs I was surprised. I was even more surprised when I received the results for humans.”
“The rate of increase in microplastics in the environment is exponential and we have every reason to believe that the concentrations in our bodies will continue to increase in the coming years and decades,” Matthew Campen, PhD (above), of the University of New Mexico told Everyday Health. As studies continue to produce evidence that nanoplastics affect human health, testing companies may develop biomarkers for clinical laboratory tests that measure the amount of microplastics in different organ locations. (Photo copyright: University of New Mexico.)
Landrigan told CNN that most people are exposed to MNPs through their diet, “but inhalation is also an important route.”
However, he added, “it’s important not to scare the hell out of people, because the science in this space is still evolving, and nobody in the year 2024 is going to live without plastic.”
CNN noted that experts consider nanoplastics to be the biggest concern [as opposed to microplastics] because they can infiltrate human cells.
“Somehow these nanoplastics hijack their way through the body and get to the brain, crossing the blood-brain barrier,” Campen told CNN. “Plastics love fats, or lipids, so one theory is that plastics are hijacking their way with the fats we eat which are then delivered to the organs that really like lipids—the brain is top among those.”
The US Food and Drug Administration (FDA) states that microplastics typically measure less than 5mm, whereas nanoplastics are less than a micron (micrometer). However, the agency notes that “there are currently no standard definitions for the size of microplastics or nanoplastics.”
What Are the Health Risks?
Scientists suspect that MNPs could be associated with cancer, cardiovascular disease, kidney disease, Alzheimer’s disease, and infertility, The Washington Post reported, but that they “still don’t have a clear sense of what these materials are doing to the human body.”
“In a 2021 study, researchers in Switzerland identified more than 10,000 chemicals used in the manufacture of plastic—of which over 2,400 were potentially ‘of concern’ for human health,” The Post noted.
“To be able to say we have a health impact, we need to have a direct correlation between a product and a health outcome,” Phoebe Stapleton, PhD, Associate Professor at the Rutgers University Ernest Mario School of Pharmacy (EMSOP), told The Post. “It’s very narrow, that straight line. And there’s so many different health outcomes there could be, and we’re finding these particles in so many different tissues.”
One study published in the New England Journal of Medicine (NEJM) suggested that MNPs in arteries could be risk factors for heart attacks or strokes. But even here, the authors wrote, “direct evidence that this risk extends to humans is lacking.”
Yu suspects that MNPs could be a factor in a global decline in sperm count, along with other environmental contaminants such as heavy metals and pesticides. His study found that polyethylene was the most prevalent plastic in dogs, followed by polyvinyl chloride (PVC). Higher levels of PVC correlated with lower sperm count, but there was no correlation with polyethylene.
“PVC can release a lot of chemicals that interfere with spermatogenesis, and it contains chemicals that cause endocrine disruption,” he said in the UNM news story.
Clinical laboratory managers should recognize that interest in identifying micro- and nanoplastics in every organ of the human body will increase. At some point, physicians may want labs to test their patients for microplastic levels in certain organ sites. This will likely be when enough published studies show a correlation between high levels of microplastics in certain locations of the body and specific disease states.
Results of an earlier study in which locks of Beethoven’s hair underwent genetic analysis showed the composer ‘had a predisposition for liver disease and became infected with hepatitis B’
Here is an example of modern technologies being used with “historical biospecimens” to solve long-standing mysteries or questions about the illnesses of famous historical figures. Clinical laboratory scientists at the Mayo Clinic have used modern-day chemical analysis techniques to answer a 200-year-old question: What caused Ludwig van Beethoven’s deafness and other health problems?
“Such lead levels are commonly associated with gastrointestinal and renal ailments and decreased hearing but are not considered high enough to be the sole cause of death,” the authors wrote.
Beethoven’s death at age 56 has been attributed to kidney and liver disease, CNN reported. Even if the lead concentrations were not the sole cause, they would nevertheless be regarded as lead poisoning, lead study author Nader Rifai, PhD, told CNN.
“If you walk into any emergency room in the United States with these levels, you will be admitted immediately and you will undergo chelation therapy,” he said.
“It is believed that Beethoven died from liver and kidney disease at age 56. But the process of understanding what caused his many health problems has been a much more complicated puzzle, one that even Beethoven himself hoped doctors could eventually solve,” CNN reported, adding, “The composer expressed his wish that his ailments be studied and shared so ‘as far as possible at least the world will be reconciled to me after my death.’” Mayo clinical laboratory scientists are using chemical analysis on authenticated locks of Beethoven’s hair to do just that. (Photo copyright: Joseph Karl Stieler/Public Domain.)
Mass Spectrometry Analysis
Mayo Clinic’s metals laboratory, led by chemist Paul Jannetto, PhD, an associate professor in the Department of Laboratory Medicine and Pathology and Laboratory Director at the Mayo Clinic, performed the analysis on two authenticated locks of Beethoven’s hair, using inductively coupled plasma mass spectrometers.
The researchers found that one lock had 258 micrograms of lead/gram and the other had 380 micrograms. Normally they would expect to find less than four micrograms.
“These are the highest values in hair I’ve ever seen,” Jannetto told The New York Times. “We get samples from around the world and these values are an order of magnitude higher.”
The researchers also found that the composer’s hair had four times the normal level of mercury and 13 times the normal amount of arsenic.
Rifai and other researchers noted that Beethoven drank large amounts of plumbed wine, and at the time it was common to sweeten wine with lead acetate, CNN reported.
The composer also could have been exposed to lead in glassware. He likely absorbed high levels of arsenic and mercury by eating fish caught from the Danube River in Vienna.
David Eaton, PhD, a toxicologist, pharmacologist, and Professor Emeritus, Department of Environmental and Occupational Health Sciences at the University of Washington, told The New York Times that high levels of lead could have impaired Beethoven’s hearing through their effect on the nervous system. Additionally, he said the composer’s gastrointestinal ailments “are completely consistent with lead poisoning.”
Rifai told CNN that he’d like to study locks of hair from other 19th century Vienna residents to see how their lead levels compared with Beethoven’s.
Beethoven’s Genome and Genetic Predisposition for Liver Disease
Additional research published in May built on an earlier genomic analysis of Beethoven’s hair, which appeared in March 2023 in the journal Current Biology.
The international team included geneticists, archeologists, and immunologists who analyzed eight locks of hair attributed to the composer. They determined that five were authentic. One, known as the Stumpff Lock, appeared to be the best preserved. They used this lock to sequence Beethoven’s DNA.
“Although we could not identify a genetic explanation for Beethoven’s hearing disorder or gastrointestinal problems, we found that Beethoven had a genetic predisposition for liver disease,” the authors wrote. “Metagenomic analyses revealed furthermore that Beethoven had a hepatitis B infection during at least the months prior to his death. Together with the genetic predisposition and his broadly accepted alcohol consumption, these present plausible explanations for Beethoven’s severe liver disease, which culminated in his death.”
One surprising discovery was the likelihood of an extramarital affair on the composer’s father’s side, CNN reported. The researchers learned this in part by comparing his genetic profile with those of living relatives.
“Through the combination of DNA data and archival documents, we were able to observe a discrepancy between Ludwig van Beethoven’s legal and biological genealogy,” study coauthor Maarten Larmuseau, PhD, told CNN. Larmuseau is assistant professor, Faculty of Medicine, and head of the Laboratory of Human Genetic Genealogy at KU Leuven in Belgium.
The Mayo Clinic team used two locks authenticated in the 2023 study—the Bermann Lock and Halm-Thayer Lock—to perform their chemical analysis, CNN reported.
Beethoven’s Wishes
The earlier study noted that Beethoven wanted his health problems to be made public. In 1802, he wrote a document known as the Heiligenstadt Testament in which he asked that his physician, surgeon/ophthalmologist Johann Adam Schmidt, MD, discuss his disease after he died.
“For almost two years I have ceased to attend any social functions, just because I find it impossible to say to people: I am deaf,” Beethoven wrote at age 30, The New York Times reported. “If I had any other profession, I might be able to cope with my infirmity, but in my profession, it is a terrible handicap. And if my enemies, of whom I have a fair number, were to hear about it, what would they say?”
The authors of the Current Biology paper wrote, “Genomic sequence data from authenticated locks of Beethoven’s hair provide Beethoven studies with a novel primary source, already revealing several significant findings relating to Beethoven’s health and genealogy, including substantial heritable risk for liver disease, infection with HBV [Hepatitis B], and EPP [extra pair paternity]. This dataset additionally permits numerous future lines of scientific inquiry.
“The further development of bioinformatics methods for risk stratification and continued progress in medical genetic research will allow more precise assessments both for Beethoven’s disease risk and for the genetic inference of additional phenotypes of interest.
“This study illustrates the contribution and further potential of genomic data as a novel primary source in historical biography,” the scientists concluded.
The work of the clinical laboratory professionals at Mayo Clinic also demonstrates how advances in various diagnostic technologies can enable pathologists and lab scientists to participate in solving long-standing health questions about historical figures, especially if their hair or other types of specimens survived and can be used in the analysis.
Good behavior in federal prison by the disgraced founder of the now-defunct clinical laboratory company earned her the reduction in her original sentence of 11 years
Elizabeth Holmes, founder of failed clinical laboratory blood analysis company Theranos, continues to serve a lengthy term in prison after being convicted of multiple counts of fraud in 2022. However, now comes news that good behavior at her federal prison has shortened her sentence by nearly two years, according to NBC News.
The latest reduction took Holmes’ release from December 2032 to August 2032 in her “11-plus-year (135 month) prison sentence for wire fraud and conspiracy,” NBC reported, adding that Holmes, though Theranos, “defrauded investors out of hundreds of millions of dollars.”
Holmes entered FPC Bryan, a federal prison camp in Bryan, Texas, to begin serving her term in May 2023.
“Holmes had her sentence computation done within the first 30 days of arriving at Bryan,” Forbes reported. Given Good Conduct Time (GCT), Holmes was given 608 days off calculated from the start of her sentence. “If she were to incur a disciplinary infraction, some of those days can be taken away. Most all prisoners receive 54 days per year of GCT based on the sentence imposed,” Forbes added.
The Federal Bureau of Prisons (BOP) can additionally shave off up to a year through its Residential Drug Abuse Program (RDAP). “To qualify, the prisoner must not have a disqualifying offense, such as terrorism or gun charge, and voluntarily provided information that they had a drug or alcohol problem prior to their arrest. This disclosure has to be done prior to sentencing during the pre-sentence interview and must be also documented in the Presentence Report, a detailed report used by the BOP to determine things like classification and programming for the prisoner,” Forbes noted.
Additionally, the federal First Step Act, which President Trump signed into law in 2018, enables Holmes to “earn up to 365 days off any imposed sentence by participating in prison programming such as a self-improvement classes, a job, or religious activities,” Forbes reported.
Given the opportunities to shave time off her sentence, Holmes may ultimately serve just 66 months of her original 135 month sentence in federal prison.
Elizabeth Holmes (above) taken backstage at TechCrunch Disrupt San Francisco 2014 when Holmes was at the height of her fame and popularity. At this point, Theranos’ Edison blood testing device had not yet been shown to be a fake. But evidence was mounting as clinical laboratory scientists and anatomic pathologists became aware of the technology’s shortcomings. (Photo copyright: Max Morse/Wikimedia Commons.)
Fall of a Silicon Valley Darling
Theranos boasted breakthrough technology and became an almost overnight sensation in Silicon Valley when it burst onto the scene in 2003. Holmes, a then 19-year-old Stanford University dropout, claimed Theranos would “revolutionize the world of blood testing by reducing sample sizes to a single pin prick,” Quartz reported.
The height of the company saw Theranos valued at $9 billion, which came crashing down when the Wall Street Journal reported in 2015 that questionable accuracy and procedures were being followed by the company, CNN reported.
“From the moment Holmes concluded her presentation and stepped off the podium on Monday afternoon, she, her company, and her comments became the number one subject discussed by attendees in the halls between sessions and in the AACC exhibit hall,” Michel wrote, adding, “The executive team and the investors at Theranos have burned through their credibility with the media, the medical laboratory profession, and the public. In the future, the company’s claims will only be accepted if presented with scientific data developed according to accepted standards and reviewed by credible third parties. Much of this data also needs to be published in peer-reviewed medical journals held in highest esteem.”
Ultimately, investors who had jumped in early with financial support for Theranos were defrauded of hundreds of millions of dollars and Holmes was sentenced to 11 years/three months behind bars.
“Theranos had only ever performed roughly a dozen of the hundreds of tests it offered using its proprietary technology, and with questionable accuracy. It also came to light that Theranos was relying on third-party manufactured devices from traditional blood testing companies rather than its own technology,” CNN added.
The company shut down in 2018.
And so, the Elizabeth Holmes saga continues with reductions in her prison sentence for “good behavior.” The irony will likely not be lost on the anatomic pathologists, clinical laboratory scientists, and lab managers who followed the federal trials.
Phages are miniscule, tripod-looking viruses that are genetically programmed to locate, attack, and eradicate a specific kind of pathogen. These microscopic creatures have saved lives and are being touted as a potential solution to superbugs, which are strains of bacteria, viruses, parasites, and fungi that are resistant to most antibiotics and other treatments utilized to counteract infections.
“These multi-drug-resistant superbugs can cause chronic infections in individuals for months to years to sometimes decades,” Dwayne Roach, PhD, Assistant Professor of Bacteriophages, Infectious Disease, and Immunology at SDSU told CNN. “It’s ridiculous just how virulent some of these bacteria get over time.”
Labs across the country are conducting research on phages in eradicating superbugs. Roach’s lab is currently probing the body’s immune response to phages and developing purification techniques to prepare phage samples for intravenous use in patients.
“There are a lot of approaches right now that are happening in parallel,” said Dwayne Roach, PhD (above), Assistant Professor of Bacteriophages, Infectious Disease, and Immunology at San Diego State University (SDSU), in a CNN interview. “Do we engineer phages? Do we make a phage cocktail, and then how big is the cocktail? Is it two phages or 12 phages? Should phages be inhaled, applied topically, or injected intravenously? There’s a lot of work underway on exactly how to best do this.” Clinical laboratories that test for bacterial infections may play a key role in diagnosis and treatment involving bacteriophages. (Photo copyright: San Diego State University.)
Building Libraries of Phages
When certain a bacterial species or its genotypes needs to be annihilated, a collection of phages can be created to attack it via methods that enter and weaken the bacterial cell. The bacteria will attempt to counter the intrusion by employing evasive actions, such as shedding outer skins to eliminate the docking ports utilized by the phages. These maneuvers can cause the bacteria to lose their antibiotic resistance, making them vulnerable to destruction.
Some research labs are developing libraries of phages, accumulating strains found in nature in prime breeding grounds for bacteria to locate the correct phage for a particular infection. Other labs, however, are speeding up the process by producing phages in the lab.
“Rather than just sourcing new phages from the environment, we have a bioreactor that in real time creates billions upon billions of phages,” Anthony Maresso, PhD, Associate Professor at Baylor College of Medicine in Houston told CNN. “Most of those phages won’t be active against the drug-resistant bacteria, but at some point, there will be a rare variant that has been trained, so to speak, to attack the resistant bacteria, and we’ll add that to our arsenal. It’s a next-generation approach on phage libraries.”
For the Baylor study, 12 patients were treated with phages customized to each individual’s unique bacterial profile. The antibiotic-resistant bacteria were exterminated in five of the patients, while several others showed improvement.
Clinical trials are currently being executed to test the effectiveness of phages against a variety of chronic health conditions, including:
Using a phage cocktail could be used to treat a superbug outbreak in real time, while preventing a patient from a future infection of the same superbug.
“The issue is that when patients have infections with these drug-resistant bacteria, they can still carry that organism in or on their bodies even after treatment,” Maroya Walters, PhD, epidemiologist at the federal Centers for Disease Control and Prevention (CDC) told CNN.
“They don’t show any signs or symptoms of illness, but they can get infections again, and they can also transmit the bacteria to other people,” she added.
The colorized transmission electron micrograph above shows numerous phages attached to a bacterial cell wall. Phages are known for their unique structures, which resemble a cross between NASA’s Apollo lunar lander and an arthropod. (Caption and photo copyright: Berkeley Lab.)
More Studies are Needed
According to CDC data, more than 2.8 million antimicrobial-resistant (AMR) infections occur annually in the United States. More than 35,000 people in the country will die as a result of these infections.
In addition, AMR infections are a huge global threat, associated with nearly five million deaths worldwide in 2019. Resistant infections can be extremely difficult and sometimes impossible to treat.
More research is needed before phages can be used clinically to treat superbugs. But if phages prove to be useful in fighting antibiotic-resistant bacteria, microbiologists and their clinical laboratories may soon have new tools to help protect patients from these deadly pathogens.
New artificial intelligence model agrees with interpretations of human medical technologists and microbiologists with extraordinary accuracy
Microbiology laboratories will be interested in news from Brescia University in Italy, where researchers reportedly have developed a deep learning model that can visually identify and analyze bacterial species in culture plates with a high level of agreement with interpretations made by medical technologists.
They initially trained and tested the system to digitally identify pathogens associated with urinary tract infections (UTIs). UTIs are the source for a large volume of clinical laboratory microbiological testing.
The system, known as DeepColony, uses hierarchical artificial intelligence technology. The researchers say hierarchical AI is better suited to complex decision-making than other approaches, such as generative AI.
In their Nature paper, the researchers explained that microbiologists use conventional methods to visually examine culture plates that contain bacterial colonies. The scientists hypothesize which species of bacteria are present, after which they test their hypothesis “by regrowing samples from each colony separately and then employing mass spectroscopy techniques,” to confirm their hypotheses.
However, DeepColony—which was designed for use with clinical laboratory automation systems—looks at high-resolution digital scans of cultured plates and attempts to identify the bacterial strains and analyze them in much the same way a microbiologist would. For example, it can identify species based on their appearance and determine which colonies are suitable for analysis, the researchers explained.
“Working on a large stream of clinical data, and a complete set of 32 pathogens, the proposed system is capable of effectively assisting plate interpretation with a surprising degree of accuracy in the widespread and demanding framework of urinary tract infections,” the study authors wrote. “Moreover, thanks to the rich species-related generated information, DeepColony can be used for developing trustworthy clinical decision support services in laboratory automation ecosystems from local to global scale.”
“Compared to the most common solutions based on single convolutional neural networks (CNN), multi-network architectures are attractive in our case because of their ability to fit into contexts where decision-making processes are stratified into a complex structure,” wrote the study’s lead author Alberto Signoroni, PhD (above), Associate Professor of Computer Science, University of Brescia, and his researcher team in their Nature paper. “The system must be designed to generate useful and easily interpretable information and to support expert decisions according to safety-by-design and human-in-the-loop policies, aiming at achieving cost-effectiveness and skill-empowerment respectively.” Microbiologists and clinical laboratory managers will want to follow the further development of this technology. (Photo copyright: University of Brescia.)
How Hierarchical AI Works
Writing in LinkedIn, patent attorney and self-described technology expert David Cain, JD, of Hauptman Ham, LLP, explained that hierarchical AI systems “are structured in layers, each with its own distinct role yet interconnected in a way that forms a cohesive whole. These systems are significant because they mirror the complexity of human decision-making processes, incorporating multiple levels of analysis and action. This multi-tiered approach allows for nuanced problem-solving and decision-making, akin to a seasoned explorer deftly navigating through a multifaceted terrain.”
DeepColony, the researchers wrote, consists of multiple convolutional neural networks (CNNs) that exchange information and cooperate with one another. The system is structured into five levels—labeled 0 through 4—each handling a different part of the analysis:
At level 0, the system determines the number of bacterial colonies and their locations on the plate.
At level 1, the system identifies “good colonies,” meaning those suitable for further identification and analysis.
At level 2, the system assigns each good colony to a bacterial species “based on visual appearance and growth characteristics,” the researchers wrote, referring to the determination as being “pathogen aware, similarity agnostic.”
The CNN used at this stage was trained by using images of 26,213 isolated colonies comprising 32 bacterial species, the researchers wrote in their paper. Most came from clinical laboratories, but some were obtained from the American Type Culture Collection (ATCC), a repository of biological materials and information resources available to researchers.
At level 3, the system attempts to improve accuracy by looking at the larger context of the plate. The goal here is to “determine if observed colonies are similar (pure culture) or different (mixed cultures),” the researchers wrote, describing this step as “similarity aware, pathogen agnostic.” This enables the system to recognize variants of the same strain, the researchers noted, and has the effect of reducing the number of strains identified by the system.
At this level, the system uses two “Siamese CNNs,” which were trained with a dataset of 200,000 image pairs.
Then, at level 4, the system “assesses the clinical significance of the entire plate,” the researchers added. Each plate is labeled as:
“Positive” (significant bacterial growth),
“No significant growth” (negative), or
“Contaminated,” meaning it has three or more “different colony morphologies without a particular pathogen that is prevalent over the others,” the researchers wrote.
If a plate is labeled as “positive,” it can be “further evaluated for possible downstream steps,” using MALDI-TOF mass spectrometry or tests to determine susceptibility to antimicrobial measures, the researchers stated.
“This decision-making process takes into account not only the identification results but also adheres to the specific laboratory guidelines to ensure a proper supportive interpretation in the context of use,” the researchers wrote.
Nearly 100% Agreement with Medical Technologists
To gauge DeepColony’s accuracy, the researchers tested it on a dataset of more than 5,000 urine cultures from a US laboratory. They then compared its analyses with those of human medical technologists who had analyzed the same samples.
Agreement was 99.2% for no-growth cultures, 95.6% for positive cultures, and 77.1% for contaminated or mixed growth cultures, the researchers wrote.
The lower agreement for contaminated cultures was due to “a deliberately precautionary behavior, which is related to ‘safety by design’ criteria,” the researchers noted.
Lead study author Alberto Signoroni, PhD, Associate Professor of Computer Science, University of Brescia, wrote in Nature that many of the plates identified by medical technologists as “contaminated” were labeled as “positive” by DeepColony. “We maximized true negatives while allowing for some false positives, so that DeepColony [can] focus on the most relevant or critical cases,” he said.
Will DeepColony replace medical technologists in clinical laboratories any time soon? Not likely. But the Brescia University study indicates the direction AI in healthcare is headed, with high accuracy and increasing speed. The day may not be far off when pathologists and microbiologists regularly employ AI algorithms to diagnose disease.
