Microplastics in Human Blood: Exclusive Interview with Dr. Vethaak

Dr. Vethaak photo courtesy of The Plastic Soup Foundation

It’s official: microplastics are found in human blood!

There is scientific evidence that both microplastics and nanoplastics (difference in size) are respirated or ingested. And they don’t just pass through our bloodstreams, they have been shown to stay there for a period of time. It will likely influence our health in one way or another, as plastic particles are nonbiodegradable, and petrol-based material absorbed in our internal organs.

This article is the first in a series of Palanan interviewing specialists from different fields. Our goal is to gain more in-depth insights about plastic, sustainability, human health, and environmental impact - straight from the experts. With new findings being discovered, this interview series aims to differentiate facts from disinformation.

Microplastics in Human Blood: Our Interview with Dr. Vethaak

The ground-breaking discovery is led by Vrije Universiteit Amsterdam, funded by ZonMW Dutch Health Organization. Dr. Dick Vethaak is the lead researcher of the team, and he graciously spent time answering our questions here at Palanan exclusively. Here is the entire interview:

Dr. Vethaak, thank you for your work on discovering microplastics in blood for the first time. It's an achievement. How did you get interested in this field?

>> I am a biologist and toxicologist by training, and I have worked since 1983 on water quality and ecotoxicological issues, such as diseases and cancer in fish in relation to marine pollution, effects of endocrine disruption chemicals on marine snails and fish, effects of oil pollution in the marine environments, etc.

My interest shifted towards the veterinary and biomedical science field.  In 2009, I became a professor of ecotoxicology / water quality and health at VU University Amsterdam and particularly focused on the link between the ecosystem and human health.  Since May 2020, I am partly retired, so my current official title is “professor emeritus”.

I started to investigate the (micro) plastic pollution issues in 2009, by looking in the marine environment, but later also focusing on the rivers. At that time, I became involved in and initiated various national and EU-funded projects on marine and riverine litter and microplastics. I became more aware of potential human health risks of microplastics. In 2016 we published a perspective article in a top journal entitled “Plastic is a human health issue”.

In 2018, I became advisor and figurehead of the Dutch Health Organization ZonMw which started its Microplastics and Human Health research program. The Netherlands is a front runner in this field. In 2018-19 ZonMw started with 15 1-year pioneering/breakthrough projects with showed disturbing results. 

In fact, our plastic particles in blood research and the resulting paper were one of the ZonMw breakthrough projects, and the work was done at our lab at VU University Amsterdam by an interdisciplinary team of scientists, including environmental toxicologists, analytical chemists, and a medical immunologist of VU University Medical Centre. On basis of the results of the 15 breakthrough projects, we build the Dutch MOMENTUM consortium on Microplastics and Human Health (I am one of the co-coordinators) with about 6 million euros and 27 partners, including the American and European chemical industries. In 2021 we published an article in Science on the issue.

Dr. Vethaak photo courtesy of The Plastic Soup Foundation

Although partially retired, I am co-supervising a handful of Ph.D. students on plastic pollution, and I work on various projects on [the] health effects of nano/microplastics, including a project on the detection of plastic particles in human matrices and several projects funded by the Dutch health organization and several projects on plastic litter and pathogens in Indonesia and Spain. I brief/advise the Dutch government, Dutch Health Council, World Health Council, European Commission, chemical industry, and NGOs on monitoring guidelines and risks of plastic litter, nano-, and microplastics.

What is going on in the Netherlands that makes it seem to be a global leader in the research of plastic, and businesses centered around removing it from the environment?

>> ZonMw was in 2018 the first organization that started to investigate this. Later other countries followed.

When did you become suspicious that it would be found in blood?

>> Plastic particles can be absorbed by test animals when exposed to plastic powder and we also find plastic particles in the bodies of many animals such as marine animals. Since 2014, it became clear that microplastics were found in various marine food items and also drinking water. In the past few years microplastic were found almost everywhere in the global biosphere. So logically that you want to know: What about me? What about humans? In 2016, there were the first reports of microplastics in the air and the possibility that plastic particles are a component of fine dust air pollution.

We don't know how microplastics have effects on our health, but what are the current hypotheses on where they could be causing harm?

>> Microplastics can enter the human body through ingestion and inhalation where they may be taken up in various organs and might affect health, However, our understanding of the health effects of plastic particles is still very limited.

Potential health impacts on humans include a whole range of health effects, mainly based on results of occupational exposure studies, animal experiments and recent work done with human cell models (outside the body). Experimental studies with aquatic animals and rodents indicating translocation of small plastic particles from the lungs and gut cavity to the circulatory systems, causing systemic exposure and accumulation in several tissues.

These studies further indicate that MPs can cause inflammatory and immune reactions, DNA damage, as well as neurotoxic, developmental, and metabolic effects. Effects on the kidney and carcinogenic effects in both lungs and gastrointestinal tract could also occur. Further, the potential impact of microplastics on the intestinal microbiota has been suggested.  So there is a wide range of potential hypothesis that can investigated.

In general, there are many uncertainties and knowledge gaps. Major knowledge gaps we have to fill are. First, we need to know much plastic is in our body and where does it go? Are the plastic particle doses in our blood and tissues sufficiently high to trigger or mediate responses leading to disease. 

The main concern is with particle toxicity and how the immune system is coping with them and how they can interfere with immune homeostasis.  The hypothesis is that plastic particles have a negative impact on the maintenance of immune homeostasis. Of course, amongst others, this largely depends on the plastic particle burdens in our body, and we do not have this knowledge yet.  

We know that particulate air pollution/fine dust causes premature death due to respiratory and cardiovascular diseases including lung cancer…we need to determine the plastic particle fraction of fine and ultrafine dust and we need to understand how plastic particles differ from other non-plastic ambient particles. Do they have a unique toxicological profile?  Most current projects are trying to resolve these questions.

Another hypothesis is that plastics and microplastics in the environment act as distinct reservoirs for human pathogens and antimicrobial resistance, contributing to the spread and outbreak of infectious diseases in susceptible communities. This may be especially in highly polluted areas in events of natural disasters and occurring epidemics. Currently we are investigating this hypothesis in Indonesia and Spain in our projects by the knowledge institute Deltares, commissioned by the NGOs CommonSeas (UK) and Minderoo Foundation (Australia).

There is early research findings that polystyrene microplastics are causing health issues with mice. Is similar research starting with humans? 

>> Clearly, there are ethical concerns in the conduct of biomedical research involving the participation of human beings (human experimentation). So, it is virtually impossible to conduct such experiments, but mice are the most commonly used animal model for studying human disease. They are biologically very similar to humans and get many of the same diseases, and they can be genetically manipulated to mimic virtually any human disease or condition.

How do microplastics behave in the bloodstream? Are they like hormones, or really just foreign material in the blood?

>> Plastic particles do not belong in the environment, let alone in our bloodstream, and are foreign materials. It is not clear how they are present in the whole blood. They could be in free suspension in the plasma or incorporated into lipid particles, or they may be captured into the pores and channels of platelets. This requires further study.

If microplastics are already in the air/water, can we even get rid of them in our environment? 

>> Unfortunately, not really, only to a very limited degree, for example by using indoor air filters or filtering washing machine water before it goes to the sewage.

Have your colleagues or yourself potential technologies that would allow them to be removed from our bodies, and specifically blood? Should we expect to have kidney cleaning in the future?

>> No, there is no such technology and this may not be feasible or very helpful anyhow, given the trace levels in the blood. The point is that blood can carry these particles to the rest of the body with the possibility that they might accumulate in certain organs. Unresolved questions are: where does the plastic go, what fraction is excreted via the bile or urine, and what fraction is retained in the body? What are the target organs for accumulation?

You say that it will that it will take 5 - 10 years to know the health effects of microplastics, but meanwhile many people want to avoid microplastics where they can. What are the top 3 things people can do to avoid them?

>> We urgently need a system change (which will not happen overnight). We need to identify, stop and replace ugly and bad plastics for alternative materials. The way forward is to reduce the amount of plastic in the system and design circular safe plastics or alternative materials.

What we can do ourselves?

1. Reduce the amount of plastics in your house and office. Avoid problematic or unnecessary plastic items, in particularly ban single-used plastics from your daily life .

2. Avoid the use of cosmetics or products that contain MNP beats. In other words: Do not buy any personal care products that contain microbeads or nanoplastics. The PSF has an app, so as a consumer you can screen the products and make your own choice. 

3. Work on awareness and behavioral changes. Do not litter (I life in Spain and there is still a lot of littering along the beaches, roads and in fields. Promote plastic recycling in your community. 

Tell everybody who likes to hear about the plastic crisis, and how we can all have our small share in contributing to reducing the problem. Most importantly, we have to educate and engage our children. I believe that this is essential in helping to save this planet, to save our health and the health of future generations.

Are there any other habits we can take up? What else should people consider while we wait for science to catch up to the issue?

I can think of many more things one can do on a personal level. Some examples:

Ventilate your house or office regularly (plastic particles tend to accumulate in house dust);

Buy durable non-synthetic clothes (that do not release synthetic fibers during usage or washing);

Do not heat food or drinks in plastic containers or bottles (this results in direct ingestion of vast numbers of plastic particles); 

Do not re-use medical face masks ((this results in direct inhalation of vast numbers of plastic particles);

Pregnant women should avoid eating canned food (the inside contains a layer of plastic that may release hazardous chemicals and plastic particles)

Microplastics in Human Blood: The Takeaway

We would like to thank Dr. Vethaak for sharing his insights and the upcoming studies furthering what we know about microplastics’ health effects. 

We’ve learned firsthand from an expert what the possible implications are of microplastics being present in our bloodstreams. The situation is dire, as the more plastic is around, the higher degree of exposure for us humans and animals.

While there is still a lot of research underway to concretely tie plastics with certain health issues, Dr. Vethaak emphasizes that plastic is foreign material that stays in the bloodstream. Plastics aren’t supposed to be there, and yet they are. And it’s only logical to think that they would interact with our blood circulation, hormones, and organ functions.

And even though we’re just peeling away the pages on this finding, Dr. Vethaak has several concrete steps to lessen the microplastics that we ingest or respirate. Those are our first steps to using the knowledge we have and putting into action a plastic-free lifestyle.