Plastic Consumption: A Lethal Dietary Mystery

It's been over 20 years since a necropsy found plastic in the stomach of a fulmar seabird in Scotland. Since then, microplastics have been found in the most remote places on Earth, from the poles to Mount Everest, and in the deepest depths of the ocean. They've also been found in human placentas, blood and organs, and are thought to harm unborn babies. But how much plastic would it take to kill a human?

Microplastics are found in human blood and organs

It is not known how much plastic a person would have to eat to die, but microplastics have been found in human blood and organs. A 2017 study from King's College London hypothesised that the cumulative effect of ingesting plastic could be toxic, but the amount of plastic a body can tolerate is not yet known.

Microplastics are tiny particles of plastic, between 0.001 and 5 millimetres in size, which are found in the natural environment. They can enter the human body through the consumption of seafood, fruit and vegetables, and drinking water from plastic bottles. A study from the Medical University of Vienna found that people consume an average of five grams of microplastics per week, which is the equivalent of a credit card.

Microplastics have been found in the human gastrointestinal tract, and a 2019 joint study by Dalberg and the University of Newcastle in Australia found that people eat an average of one Lego brick's worth of plastic per week, a dinner plate's worth per year, and a lifebuoy's worth per decade.

The presence of microplastics in the human body is a serious concern, as they have been found to harm unborn babies. With more than 8.3 billion tonnes of plastic produced since the 1950s, the majority of which has ended up in landfill and the natural environment, it is clear that action is needed to reduce the amount of plastic entering our bodies.

Microplastics can harm unborn babies

It is not known how much plastic a person would have to eat to die, but it is known that microplastics are everywhere, including in our bodies. On average, five grams of plastic particles enter the human gastrointestinal tract per person, per week. This is roughly equivalent to the weight of a credit card.

Microplastics have been found to harm unborn babies. In 2020, microplastics were found in the placentas of unborn babies for the first time. The particles were small enough to be carried in the bloodstream and may have entered the babies' bodies. The health impact of microplastics in the body is as yet unknown, but scientists have said they could carry chemicals that could cause long-term damage or upset the foetus's developing immune system. The particles are likely to have been consumed or breathed in by the mothers.

In 2019, researchers reported the discovery of air pollution particles on the foetal side of placentas, indicating that unborn babies are also exposed to the dirty air produced by motor traffic and fossil fuel burning.

One study found that people who drink 1.5 to 2 litres of water a day from plastic bottles take in 90,000 plastic particles per year. Another study, from King's College London, hypothesised that the cumulative effect of ingesting plastic could be toxic.

Microplastics are found in the human gastrointestinal tract

Microplastics are between 0.001 and 5 millimetres in size, and nanoplastics are less than 0.001 millimetres. They enter our food chain via seafood, fruit and vegetables, and drinking water. They can also enter the body when we drink from plastic bottles, with people who drink 1.5 to 2 litres of water a day from these bottles taking in 90,000 plastic particles per year.

Previous studies have found particles in human blood and organs, and microplastics have also been found to harm unborn babies. In 2017, a study out of King's College London hypothesised that, over time, the cumulative effect of ingesting plastic could be toxic. Different types of plastic have varying toxic properties.

A 2019 joint study by Dalberg and the University of Newcastle in Australia found that, on average, people eat one Lego brick's worth of plastic per week, a dinner plate's worth per year (100,000 tiny pieces of plastic), and a lifebuoy's worth per decade.

Microplastics are found in the deepest section of the lung

It is not possible to say how much plastic a person would have to eat to die. However, microplastics are found in the deepest section of the lung, as well as in the human gastrointestinal tract, blood and organs. A recent study found that people eat five grams of micro and nanoplastics every week, which is roughly equivalent to the weight of a credit card. A 2017 study from King's College London hypothesised that the cumulative effect of ingesting plastic could be toxic, but scientists are still unsure about the amount of microplastics a body can tolerate or how much damage they do.

Microplastics are found in the human placenta

It is not known how much plastic a person would have to eat to die, but it is estimated that humans consume around 40 pounds of plastic in their lifetime. On average, five grams of plastic particles enter the human gastrointestinal tract per person per week, which is roughly equivalent to the weight of a credit card.

Microplastics have been found in the human placenta. A study published in Toxicological Sciences used new tools to detect microplastics in human placentas, and found microplastics in all 62 of the placentas sampled. The study, led by Matthew Campen, PhD, Regents’ Professor in the UNM Department of Pharmaceutical Sciences, reported finding microplastics in all 62 of the placenta samples tested, with concentrations ranging from 6.5 to 790 micrograms per gram of tissue. Polyethylene, which is used to make plastic bags and bottles, accounted for 54% of the microplastics found. Polyvinyl chloride (PVC) – which contains the toxic chemical vinyl chloride, a known carcinogen – accounted for another 10% of the microplastics detected.

Microplastics were first detected in placentas in 2020, in samples from four healthy women who had normal pregnancies and births in Italy. The scientists said: "Microplastics carry with them substances which, acting as endocrine disruptors, could cause long-term effects on human health." The concentration of microplastics in placentas was especially troubling, Campen said. The tissue grows for only eight months, as it starts to form about a month into pregnancy. "If we're seeing effects on placentas, then all mammalian life on this planet could be impacted," Campen said. "That's not good."

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