Previous: Should Hank and I ... box each other??
Next: On Disease



View count:232,760
Last sync:2022-11-30 18:30
No. But how we ended up here is very weird and I really wanted to talk about it. Here are the things that had to go wrong for this headline to spread across the internet:

1. An organization funded science because they wanted a talking point.
2. The organization amplified a misleading version of what the study found.
3. The authors of another paper were mislead, though it would have been easy not to be mislead because they're scientists.
4. Peer review did not catch the stat because it was a background stat, not part of the papers methods or results which peer review doesn't spend much (if any) time on.
5. News outlets did not investigate the source of the background stat and published it as if it were fact.
6. Humans with varying levels of reach and power online took mainstream headlines at face value and did not check before sharing.

Subscribe to our newsletter!
And join the community at
Help transcribe videos -
Learn more about our project to help Partners in Health radically reduce maternal mortality in Sierra Leone:
If you're able to donate $2,000 or more to this effort, please join our matching fund:
John's twitter -
Hank's twitter -
Hank's tumblr -
Good morning, John!

You are not eating a credit card's worth of microplastics a

Now you might not have been worried about that but a lot of people are. And that makes sense because a lot of very credible news organizations have run stories saying that you are eating a
credit card's worth of microplastics every week.

The fact that this definitely untrue statement was spread in so many legitimate news organizations has been quite annoying to me but it's also been something of a curiosity to me.

Like these places do fact check. They don't just publish whatever comes across their desk itself, knowing that it is almost always better to lean into curiosity than frustration.

I did that and what I found is remarkable. This was an 11-step process.

Step one- the World Wildlife Fund is worried about plastics, and they should be there are too many, way too many single-use plastics and we need to stop this.

So step two- the WWF commissioned a study from the University
of Newcastle to do a literature review. Basically, look at a bunch of different studies that measured how plastics might enter people and then add all of those sources up.

Every study that they reviewed had a different range. They added all those ranges up and they came to their own range of 0.1 grams to 5 grams of plastic ingested every week.

And this isn't useful data to the average person, it's just too imprecise. It's like saying that the average person eats between one pound and 50 pounds of food per day.

The WWF then did a normal thing. They used the study they commissioned to create a talking point: people could be consuming five grams of microplastics per week.

This is not a lie, but it's kind of a misrepresentation, It's kind of
misleading. All this happened in 2019, and none of it reached very far because headlines that said you could be eating a credit card of plastic per week is like well, I could be eating a thousand spiders per night. Tell me when you're sure!

No one wrote that people definitely were eating a credit card's worth of plastic per week until 2022. Why?

Step number four- scientists at the Medical University of Vienna were among those who were misled. They took the upper
bound of the estimate, the five grams, and used it as just a background stat in the introduction to their paper.

When they did that they removed the context of the lower bound.  They didn't say 0.1 grams to 5 grams. They just said 5 grams.

It didn't have anything to do with their methodology or what they were studying, it was just a background stat. And that's not really what people paid the most attention to when they're doing peer

So step six- peer review didn't catch it.

Step number seven- that publication then got run through the university PR team, which is tasked with presenting research in ways that might be interesting to the average person and
to the press.

And unsurprisingly the very first sentence in that press release was "Five grams of plastic particles on average entered the human gastrointestinal tract per person per week."

Because indeed if that were true it would be a very interesting statistic. So you're going to put it at the beginning of your press release.

So now we have a press release of a peer-reviewed paper that says that people on average eat a credit card's worth of plastic every

Step number eight- less than a week later had found that press release and published a headline containing the claim.

Step number nine- that article spread fast enough that the very next day the New York Post published an article with the claim in the headlines.

Step number 10- legitimate news outlets saw the New York Post article and they were like "Well we can't just publish that because the New York Post lies for a living, but we will do a fact check."

And they did and they found a peer-reviewed paper that contained the claim. Peer-reviewed article plus a really great headline that's going to be good enough for them.

Step number 11- it was a really good headline so lots of people clicked on it and lots of people shared it.

Meaning it wasn't just published, it spread.

When I first saw this headline I was super lucky because
it was in the New York Post. And I know to be skeptical of the New York Post.

But if you saw it first at USA Today or ABC News or Nautilus, all totally legitimate news organizations, and if you're like primed by this world to believe that everything is as bad as could possibly
be, I totally understand not being skeptical of that headline.

It is kind of wild to me how many steps and how many mistakes were made along the way in order for this false fact to get published in mainstream news outlets.

Every person in their own way is trying to make sense of the world and we would like the sense that we make of the world to be based on reality.

But even though we've built up many systems for doing that as individuals and as a society, our own very normal biases and the realities of what it takes to capture people's attention these days makes sense-making a monster of a challenge.

John, I'll see you on Tuesday