In a small European study, people who’d suffered a serious heart attack were more likely to have micro- and nanoplastics in their blood.
Looking at about 60 people, scientists found the tiny plastics in the blood of 30% of healthy participants, and 40% of heart disease patients who hadn’t had a heart attack.
However, over 80% of heart attack patients had micro- and nanoplastics in their blood.
People who smoked or experienced worse air pollution also had more tiny plastics, suggesting these make it easier for plastics to get into the bloodstream via the lungs.
The SMC asked NZ experts to comment.
Ian Shaw, Emeritus Professor of Toxicology, University of Canterbury, comments:
“Interest in the impact of microplastics on health is growing exponentially because our exposure via food, drinking water and air is increasing.
“This is an excellent, well thought out and conducted study. The number of patients in the study is small – I would regard it as a pilot study.
“Not only myocardial infarction (heart attack) patients showed microplastics in their coronary circulation. Control and other heart disease patients also showed microplastics, this indicates widespread exposure.
“Heart attack patients had significantly higher levels of microplastics than controls or other coronary disease patients. The fact that microplastics are present at higher levels in heart attack patients does not prove that they are the root cause of the disease. It might be that exposure to something else is associated with microplastics, but the ‘something else’ has not been measured in the study.
“Microplastics are likely to initiate an inflammatory response, as evidenced by raised biochemical inflammation markers in the study. This presents a credible mechanism for a link between microplastics and heart disease.”
Conflict of interest statement: “I have no conflict of interest relating to the authors of the paper, the journal in which it is published or the study per se.”
Dr Julia Shanks, Senior Research Fellow in Physiology, University of Auckland, comments:
“The compounding effect of total environmental exposures across the life span is a well-known risk factor for developing cardiovascular disease (or heart disease). These compounding risks are also known to lead to the development of cardiovascular disease at a younger age, contributing to increased heart disease-related deaths and reduced quality of life.
“We know that environmental exposures rarely occur in isolation. This study highlights the presence of micro- and nanoplastics in the blood that supplies the heart muscle itself, in individuals experiencing a heart attack. While it is noted that this study cannot definitively say that the micro-and nano-plastics were the cause of the heart attack, it is noteworthy that, in the modern world, we are increasingly finding micro- and nanoplastics in unexpected places.
“Studies of micro- and nanoplastics at the cellular and molecular levels have shown that they can disrupt normal cellular processes and affect blood vessel function. This study provides clinical evidence for the presence of micro-and nano-plastics at the exact site of cardiac dysfunction in individuals having a heart attack.”
Conflict of interest statement: “No conflict of interest to declare.”
Jeroen Douwes, Professor of Public Health, Massey University, comments:
“This is an interesting, albeit small, study suggesting a role for micro and nano plastics (MNPs) in ischaemic heart disease. Despite the large increases in MNP exposure observed since it was first reported 20 years ago, few health studies have been conducted. However, evidence from in vitro and animal models show: inflammatory and other immune responses; oxidative stress; endocrine disruption; cyto-, geno-, and neuro-toxicity; metabolic effects; and gut-microbiota disruption. Emerging clinical studies show associations with cardiovascular disease, stroke, neurodegeneration, neurological symptoms, anxiety and depression. This suggests that MNPs may be a significant and emerging health risk, but research on MNPs and health is still in its infancy and more well-designed and larger studies in human populations are urgently needed.
“This study adds to the emerging evidence that MNP exposure may increase the risk of cardiovascular disease. Previous studies have been criticised for using methods that were not specifically designed to eliminate plastic contamination from sample collection and processing, which the current study addressed, adding to the importance of the study.
“The paper focuses on airborne MNP exposure, and only in passing refers to MNP exposure through diet, which is another significant exposure route that may be at least as important for cardiovascular risk.
“MNPs originate from items (packaging, car tyres, clothing, toys, household products, etc), or are manufactured for use as additives, e.g., to fertilisers, cleaning agents, and personal-care products, and have become ubiquitous in the environment. As a result, they can be detected in food, drinking water, and air, with exposure occurring through ingestion (e.g., via consumption of highly processed foods, reheated foods in plastic containers, bottled drinks, and teabags), inhalation (associated with synthetic clothing, floor coverings, car-tyre wear, and indoor dust), or skin absorption (via personal-care products and synthetic-fibre clothing). So, other exposure routes may be equally or likely more important.
“Due to their small size, MNPs have the potential to migrate through the body, including, as shown in recent studies, the gut, blood, airways, liver, kidney, cerebrospinal fluid, brain, placenta, breast milk, testicles, etc., so health effects will likely not be limited to the cardiovascular system.
“Of interest, in addition to synthetic, mostly oil-derived, polymers, MNPs may contain >16,000 chemical additives, including plasticisers, flame retardants, UV stabilisers, colourants, manganese, other heavy metals, etc, which can leach into surrounding tissue, thus further contributing to health risks, highlighting the need to study the potential health effects that may arise from this new environmental pollutant. This is urgently needed as MNP pollution is rapidly increasing, and currently estimated at 10-40 million tonnes per annum, with an expected doubling of emissions by 2040. If these exposures are, as emerging evidence suggests, causally associated with ill health then we need to start looking at safer options not involving plastics.”
Conflict of interest statement: “No COIs”.
Our colleagues at the UK SMC have also gathered comments. A selection follows.
Dr Ria Devereux, Environmental Research Fellow, University of East London (UEL), comments:
“Previous studies have shown that micro and nano plastics are present in the human body including blood samples. This study expands on existing studies by looking at coronary blood and looking at these samples and chronic coronary disease and acute myocardial infarction.
“The study does not show that micro and nanoplastics cause heart attacks. Instead, this study strengthens the theory or hypothesis that micro and nanoplastics may be harmful to our health but it does not change our current understanding or provide definitive causality.
“There are multiple limitations within this study, including a small sample size (61 people), observational cross-sectional design, excluding a lot of potential micro and nanoplastics routes i.e diet, occupational exposure to name a few. Due to the study’s design being cross sectional, it looks at exposure and disease at the same time and as a result it cannot say whether micro and nanoplastics caused the disease, increased due to the disease or are just in the blood due to environmental exposure. Another issue is that samples were taken during or after an event so it’s not clear if the presence of microplastic was high before the event.
“The high percentage of smokers within the STEMI and CCS both over 70% also raises questions especially as the packs per year is higher in the STEMI group. This confirms what we already know about heart attacks being linked to smoking, but it makes it harder to work out if there is a link between microplastics and heart attacks, microplastics and smoking or if microplastic exposure is from something else.
“The study is interesting and whilst it does not prove that micro-nano plastics cause heart attacks it does show the difficulties of moving microplastic studies that investigate impact on the human body from an extremely highly controlled laboratory study to real world human populations where studies become complicated by multiple factors like genetics, lifestyle, exposure and other factors influence disease risk.”
Conflict of interest statement: “Nothing to declare.”
Prof Alun Hughes, Professor of Cardiovascular Physiology and Pharmacology, UCL Institute of Cardiovascular Science, University College London (UCL), comments:
“The health implications of micro- and nano-plastics is highly topical and potentially important given the ubiquity of these particles.
“This is a small observational study that reports that people with a form of heart attack (ST elevation myocardial infarction (STEMI)) undergoing coronary angiography and percutaneous coronary intervention had higher levels of microplastics in their blood compared with people undergoing coronary angiography with confirmed chronic coronary artery disease or people with no evidence of coronary artery disease.
“The authors clearly state that ‘these findings should be interpreted as exploratory and hypothesis-generating rather than as definitive or confirmatory risk estimate’. Readers should bear this caution in mind and not jump to assuming a cause-effect relationship.
“The study has several limitations, some of which the authors acknowledge. It is small and we are given very little information about how participants were selected. The authors also do not state whether analysis was performed blinded to clinical status. The issues of patient selection and blinding raise concerns over the potential for bias.
“The authors have not adequately dealt with confounding or reverse causation as explanations of the association.
“Regarding confounding, the high levels of microplastics in people with heart attacks could be due to some factor that causes elevated microplastics and heart attacks – an example might be social disadvantage which could lead to increased exposure to microplastics and increased risk of heart attack. Surprisingly social deprivation is not measured or considered in the article. Unmeasured factors such as food or drink intakes are other potential confounders.
“Regarding reverse causation, this is where the heart attack results in elevated microplastics. This isn’t implausible; people who present to hospital with a suspected heart attack typically receive intravenous infusions as part of their management. It is known that intravenous infusions shed microplastics into the blood. Given that microplastics do not usually remain in the blood stream for long, this seems a credible mechanism and is not discussed by the authors.
“None of these criticisms should be read as indicating that microplastics are benign. However, given my concerns about potential bias, confounding and reverse causation, I don’t think the article provides convincing evidence for their potential harms.“
Conflict of interest statement: “I receive grant funding for my research from the British Heart Foundation, Horizon Europe Programmes of the European Union through Innovate UK, the Karlsson-Jativa Foundation, the Wellcome Trust and the National Institute for Health Research University College London Hospitals Biomedical Research Centre.”
Our colleagues at the AusSMC have also gathered comments. A selection follows.
Dr Paul Harvey, independent environmental scientist (pollution specialist), science communicator and the owner of Environmental Science Solutions, comments:
“This study adds to an alarming body of evidence connecting micro- and nano-plastic exposure to adverse human health outcomes.
“This is in contradiction to the current regulatory posture in Australia. As recently as April of 2026, the Australian Centre for Disease Control has actively discredited compelling evidence that points to adverse human health outcomes arising from exposure to microplastics.
“Although this new research by Paolisso et al. is constrained by its study population size, it puts forward damning evidence linking plastic exposure to one of Australia’s leading causes of death – coronary artery disease (CAD).
“More work certainly needs to be done to better understand the drivers behind CAD, but in light of this new evidence the question must be asked: what precautionary steps is the government, through its various regulatory arms, taking to mitigate risks to human health, wildlife and the environment, that arise from plastic exposure?”
Professor Thava Palanisami, Team Leader of the Australian Plastics Research and Innovation Laboratory at the University of Newcastle, comments:
“This study provides important new evidence that micro- and nanoplastics can be detected in the coronary circulation of patients experiencing heart attacks and are associated with higher levels of inflammation and environmental exposures such as air pollution and smoking. While the findings do not prove that plastics directly cause heart attacks, they strengthen the growing scientific evidence that plastic pollution is an emerging public health issue deserving serious attention.
“Although the authors implemented rigorous contamination controls, measuring micro- and nanoplastics in blood remains technically challenging. There is still no internationally standardised method for sampling, extraction, identification and quantification, making comparisons between studies difficult. In addition, current analytical methods cannot fully characterise the smallest nanoplastics (<1 µm), which may have different biological behaviour. Another limitation is that the study measured the presence of plastic polymers but did not distinguish whether the observed biological effects were caused by the particles themselves, the chemicals they carry, or co-exposure to other environmental pollutants such as air pollution and tobacco smoke. The finding that smoking was the only independent predictor of microplastic detection in multivariable analysis highlights the complexity of separating these environmental exposures.
“The study highlights the need for larger, long-term human studies to determine whether reducing exposure to micro- and nanoplastics can lower the risk of cardiovascular disease. Given the widespread presence of plastics in our food, water and air, we need coordinated action to reduce unnecessary plastic pollution, improve human exposure monitoring, and accelerate research into the health impacts of plastics. Protecting people from plastic pollution should become a key component of future environmental and public health policy.
“Overall, this study is an important step forward, but much larger prospective studies with harmonised analytical methods and detailed exposure assessment are needed before firm conclusions can be drawn about the causal role of micro- and nanoplastics in cardiovascular disease.”
Conflict of interest statement: Thava has not declared any conflicts of interest.