The Average Human Swallows 2,000 Microplastics a Week, Study Finds

Remember the urban legend that the average human swallows eight spiders while asleep every year? Well, that may not be true, but apparently, humans are accidentally swallowing something that might be even worse: plastic. According to a new analysis commissioned by the World Wildlife Fund (WWF) and conducted at the University of Newcastle, the average human potentially ingests about 2,000 microplastics every week. Eek.

As explained in a press release on the University of Newcastle's website, the study, which is titled No Plastic in Nature: Assessing Plastic Ingestion from Nature to People, compiled data from more than 50 studies regarding human microplastic ingestion. The analysis defines microplastics as plastic particles no larger than 5 millimeters. 5,000 microplastics comes out to about 5 grams per week, which is about the weight of a credit card. To make that statistic ever scarier, that comes out to about 21 grams of plastic swallowed per month, or more than 250 grams per year. 

So, how is so much plastic allegedly entering our bodies? According to the University of Newcastle, the greatest source of plastic ingestion is through drinking water (both bottled water and tap water), followed by shellfish, beer, salt, fish, honey, and sugar. It's no surprise that water and shellfish are on the list, considering how much plastic is in the oceans. 8 million metric tons of plastics enter oceans every year, with an estimated total of 150 million metric tons currently in the oceans, according to Ocean Conservancy. 

Plus, a study published in February by the Royal Society Open Science found microplastics in the bodies of more than 72 percent of marine animals who live in the ocean's deepest depths. So when humans eat fish or other sea animals (especially shellfish, because "shellfish are eaten whole, including their digestive system, after a life in plastic polluted seas," the study explains, as per CNN), they are also eating what is in those animals' bodies. 

While the results of this study may seem pretty alarming, the researchers stress that they did not intend for it to be. "The conservative approach was adopted to minimize the risk of over-predicting and from alarming the public, or risking incredulity from decision-makers and other stakeholders," reads a statement on the University of Newcastle's website. Additionally, the actual amount of microplastics that each person may ingest depends on a variety of factors, including where they live, and the foods they're eating.

“While the awareness of microplastics and their impact on the environment is increasing, this study has helped to provide an accurate calculation of ingestion rates for the first time," co-lead researcher Dr. Thava Palanisami said in a statement. "Developing a method for transforming counts of microplastic particles into masses will help determine the potential toxicological risks for humans moving forward."

All that being said, the University of Newcastle notes that the full study has not yet been officially published, as it is still being reviewed. However, the findings align with a peer-reviewed study published last week in the journal Environmental Science and Technology, which found that humans can consume up to 74,000 microplastic particles per year, according to National Geographic.

So, what can we do about this? As the WWF explains, the study proves that plastic pollution is a global issue, impacting every creature on Earth — and the most effective way to attack a global issue is by getting lawmakers involved. The WWF recommends starting by signing the WWF's worldwide petition, which already has more than 694,000 signatures as of Wednesday, June 12. You can also contact your elected officials and ask them to pass legislation restricting single-use plastic.