You look at yourself in the mirror first thing in the morning and last thing in the evening.

About 1 billion plastic toothbrushes are thrown away in the US every year. None of them are recyclable. Here's exactly where they go and how long they stay there.

Research shows plastic toothbrush bristles shed millions of microplastic particles per year directly into your mouth. Here's what the studies found and what you can do about it.

Bamboo has tensile strength comparable to steel, grows three feet a day, and has been solving human problems for 5,000 years. So why did we spend 80 years replacing it with plastic?

The nylon toothbrush was invented in 1938. Almost nothing about it has changed since. Here's why, who benefits from the status quo, and what a better design actually looks like.

In March 2022, a team of researchers at Vrije Universiteit Amsterdam published a paper that received a few days of news coverage and then largely disappeared. The finding was this: for the first time in recorded science, microplastics were detected in human blood. Not in fish. Not in soil samples. In 17 of the 22 adult volunteers tested, researchers found particles of plastic smaller than five millimeters circulating in their bloodstream. PET - the same material used in water bottles. Polystyrene. Polyethylene. The stuff of modern packaging, now confirmed to be inside the people who use it. The paper didn't claim to know what this meant for long-term health. That's not how science works. What it did was establish, definitively, that the blood-brain barrier is not impermeable to plastic particles, that we are ingesting and inhaling microplastics faster than our bodies are clearing them, and that the question is no longer whether we're absorbing plastic - it's how much, from where, and at what cost. The exposure routes nobody talks about Most microplastics conversation focuses on water. Bottled water contains an estimated 240 plastic particles per liter on average. Tap water is better but not clean. The ocean contamination angle gets regular coverage, particularly anything involving sea salt or fish consumption. What gets far less attention is oral exposure - meaning what enters your body through your mouth during daily routines that aren't eating or drinking. A conventional plastic toothbrush is made from polypropylene - the handle - and nylon bristles. Over the course of use, bristles break down microscopically. Filaments fray. You are, in the most literal sense, brushing nylon particles against your gum tissue twice a day, for two minutes at a time, three-quarters of a billion times across an average lifetime of toothbrush use. Researchers at the University of Exeter identified toothbrush bristles as a direct microplastic exposure source in 2021, ahead of the blood study by a year. This doesn't make plastic toothbrushes uniquely catastrophic compared to other sources. But it does make them something specific: a voluntary, daily, intimate exposure that takes place inside your mouth, a site of high mucosal absorption, in close proximity to your throat and digestive system - and one that is almost trivially easy to change. What the science actually says we should do The honest answer is that the science on microplastics and human health is still early. We know they're present in blood, lungs, liver, and placental tissue. We know that at high concentrations they cause inflammation in cell cultures. We don't yet have longitudinal human data on disease outcomes - that research is underway but takes time by definition. What that means practically is this: the precautionary argument is strong even without a definitive harm threshold. You're already reducing exposure in other areas - maybe you don't microwave in plastic containers, maybe you use a filter for your water. The question is just whether you've thought about what you put in your mouth before breakfast. Bamboo toothbrushes with plant-based bristles exist. They work the same way. They're not significantly more expensive over a year of use, especially on subscription. The bamboo handle biodegrades in months rather than centuries. The plant-based bristles - typically derived from castor oil - don't shed nylon particles. That's it. That's the whole intervention. Not a diet overhaul. Not a supplement stack. Just a different object that does the same job, without adding to what that 2022 blood study found. A note on what we don't know Good science writing requires saying this clearly: we don't know the threshold at which circulating microplastics cause measurable harm in humans. Some researchers believe the quantities currently found in blood are below any meaningful biological effect. Others argue that accumulation over decades is the variable we're not yet measuring properly. What we do know is that microplastic concentrations in human tissue are rising in parallel with global plastic production, which has increased by a factor of 200 since 1950. The direction of the trend is not ambiguous, even if the destination is still being mapped. The 2022 Amsterdam study was not a verdict. It was a finding. The verdict is still being written. In the meantime, two minutes. Twice a day. It's worth thinking about what's in your hand. Toothily brushes are made from Moso bamboo with soft bristles - a bamboo handle instead of a plastic one, and a message you will actually read.