What we know about the health effects of microplastics

We live in a world where microplastics are everywhere. This is no exaggeration. From rainwater to the bottom of the Mariana Trench, to our bodies and even the air we breathe, researchers have been amazed to find microplastics almost everywhere they look. Microplastics are tiny pieces of plastic less than 5 millimeters long that come from a variety of sources, including the breakdown of plastic products, cosmetics and industrial processes.

Plastic particles can take hundreds, or even thousands, of years to decompose, contributing to the massive amounts of environmental pollution we see. found Microplastics were also found in the men's testicles, not just in a few samples but in all of the participants tested.

GBH Taking everything into consideration Host Arun Rath spoke with Dr. Phil Landrigan, pediatrician, epidemiologist, and director of the Global Public Health and Public Interest Program at Boston University, about the potential health impacts of these microplastics. Below is a lightly edited transcript.

Arun Rath: So firstly, what do we currently know about how microplastics get into the human body, and is there any way to avoid it?

Phil Landrigan: Microplastics enter the body in two main ways. The first is through ingestion, when we eat foods contaminated with microplastics (such as seafood or meat). The second is through inhalation, as a certain amount of microplastics is present in the atmosphere – in the air we breathe. Microplastics are invisible and can be absorbed into the body through the lungs.

Once microplastic particles enter the body through the digestive tract or lungs, especially the smallest ones, they can enter the bloodstream. The smaller the particle, the easier it is to enter the bloodstream. From there, they can reach all the organs in the body.

Russ: What do we know so far about the health effects of microplastics?

Landrigan: Well, to answer that question, let's take a moment to talk about what's in microplastics. Essentially, microplastics, like plastic itself, are made up of two main components. First, there's the polymer – the structure that holds the plastic together. This can be polyvinyl chloride, polystyrene, or polyurethane. Second, there are thousands of chemicals (an estimated 16,000 different chemicals) embedded in the polymer that give the plastic certain properties like color, flexibility, fire resistance, etc.

Many of the 16,000 chemicals are highly toxic. They include chemicals that can cause cancer (carcinogens), neurotoxins, and endocrine disruptors that interfere with the functioning of the endocrine system.

Once plastic enters the human body, it can harm our health in two ways: first, it can act as a Trojan horse, releasing toxic chemicals into the bloodstream, and second, the particles themselves can find their way into cells and clog them.

We know quite a bit about the toxicity of the major chemicals, but at this stage we know very little about what damage the particles themselves might cause.

Russ: I think a lot of people have the perception that what we're talking about is a relatively new substance, but this goes back to man-made fibers and all kinds of modern products, right?

Landrigan: Yes. Plastic production started in the 1950s, after World War II. But it's really exploded in the last 20 years. Half of all the plastic ever made has been made since 2000, and production is accelerating. It's exponentially increasing as we speak. And as plastic is made, used, and thrown away, it starts to break down. The result is microplastics.

Russ: People and the environment at large have been exposed to microplastics for a long time now, and especially increasing over the past two decades, but is there awareness of the long-term effects?

Landrigan: No, it's still early days, but there was a very worrying article published March The New England Journal of Medicine has published a paper on the effects of microplastic particles on the cardiovascular system. Italian researchers found that about 60% of 300 people tested had microplastics in their hearts and large blood vessels. They also found that people with microplastics in their bodies were four times more likely to suffer a heart attack or stroke, or die within the next three years, or 400% more likely, than people without microplastics in their bodies.

This is just one study, and it doesn't prove causation, but it's a strong indication, and as I said, very worrying.

Russ: Where should we focus our research to understand how these microplastics are affecting us?

Landrigan: I think we need two things: We absolutely need studies that look at the effects of microplastics not only on the heart but also on the brain, kidneys, immune system and other tissues in the human body. But at the same time, while we wait for that research to be completed (which could take years in some cases), we need to act now based on what we already know about plastics.

We know that plastics already pose a risk to human health at every stage of their production, use and disposal. We can't just sit back and wait for all the research details to be completed. We need to act on what we know, or things will get even worse.

Fortunately, the United Nations understands this well. in progress We should draft a global plastics treaty like the Paris Climate Agreement. If this treaty is as strong as we would like it to be, its central focus would be a global cap on plastic production, limiting the amount of plastic each country can produce. That way countries can continue to produce the plastics we really need for medicine, engineering, aerospace, for example, but we can reduce the production of pointless, unnecessary single-use plastics that we simply use, peel off the packaging and throw away. It is these single-use plastics that are actually causing the plastic waste problem.

Russ: I know that doesn't necessarily mean anything, but is there a consensus that we need to move towards structuring the way we handle plastics in that way?

Landrigan: Well, UN negotiations are moving forward and many countries around the world have formed what’s called the “High Ambition Coalition” with the aim of pushing for a strong treaty. The problem is, there’s very serious resistance from the fossil fuel industry.

The fossil fuel industry is the major producer of plastics – 99% of it comes from coal, oil and gas – and the last thing the industry wants is for any limits to be placed on global production.