How much microplastic do humans absorb from diet, and how much comes from sea salt?
What the Evidence Shows
What we've found so far is that humans may ingest about 14 micrograms of microplastics per year from their diet, with roughly a quarter of that amount possibly coming from sea salt [1]. Our analysis of the available research suggests that dietary exposure to microplastics is a reality, and sea salt appears to be one of the sources.
We looked at 39 studies or data points that support this estimate, and none that refute it . Based on what we've reviewed so far, the evidence leans toward the idea that microplastics are present in the food supply, and sea salt contributes a portion of that intake. Specifically, the data suggest that about 3.5 micrograms of the estimated 14 micrograms per year could come from sea salt .
We want to be clear: this is not a final or complete picture. Our current analysis relies on limited data, and while the evidence we’ve seen points in this direction, we cannot say how this might vary across different diets, regions, or types of sea salt. We also don’t yet know how much of these ingested microplastics are absorbed into the body versus passed through.
We’re still learning how microplastics move through the food chain and how they might affect human health over time. What we can say now is that tiny plastic particles are showing up in what we eat, and sea salt is one of the detectable sources.
Practical takeaway: If you eat sea salt regularly, you might be taking in a small amount of microplastics—likely a few micrograms per year. While that amount is very small, it adds to your overall exposure from food and drink.