PlasticProtocols

The science

The science, honestly

What we actually know about microplastics, the strong parts, the uncertain parts, and the headlines that went too far.

The starting point

Tiny plastics are everywhere, including in us

Micro- and nanoplastics have been found in human blood, lungs, placenta and even brain tissue. That detection is real and reproducible. But detection is not the same as harm, the measurements carry huge uncertainty, and the World Health Organization concluded the available evidence does not yet demonstrate a health risk at current exposure levels, while flagging major data gaps.

Exposure

How much do we really take in?

The honest answer is: nobody knows precisely, and the range is enormous. The most-cited estimate is roughly 74,000–121,000 particles a year, but a review of 76 studies found daily estimates spanning six orders of magnitude. Counting methods aren't standardized, so treat every specific number as an order-of-magnitude indication, not a fact.

Plastic particles from water, per year

particles / year

Sources

Where your exposure comes from

Not all sources are equal. Ranked by how confidently they're linked to human exposure, a handful of everyday habits dominate, and most are cheap to change.

Daily-life sources, ranked by exposure contribution

The crucial distinction

Particles vs. chemicals

This is the single most important idea on the site. The harm from plastics is far better-evidenced for the chemicals associated with plastic (BPA, phthalates, PFAS) than for the plastic particles themselves. Regulators have acted on the chemicals: the EU banned BPA in food-contact materials in 2025, and PFOA is now classified as carcinogenic to humans. The particles remain a plausible but largely unproven risk.

Particles

Exposure proven; harm in humans largely unproven. The strongest signal is a 2024 study linking particles in artery plaque to higher cardiovascular risk, striking, but observational and unreplicated.

Chemicals

Better-evidenced toxicology and real regulatory action. Reducing these, via fresh food, fewer fragranced products, no PFAS packaging, is where the science is firmest.

Evidence map

How strong is the evidence, really?

Across the claims we reviewed, most sit in 'emerging' or 'strong', but several popular ideas land in 'weak', 'unproven' or outright 'debunked'.

The bottom line

Precaution without panic

You don't need to fear every water bottle. But because exposure is real, rising, and cheap to reduce, sensible swaps are worth making, especially the ones that also cut chemical exposure. That's exactly what the protocols are for.

See the protocols