Microplastics

PurePath | Field Index of Synthetic Exposure
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PurePath FIELD INDEX OF SYNTHETIC EXPOSURE
Field Report No. 001 — Ingestion Threshold

A Catalog of
Synthetic Contact

A widely cited estimate puts average weekly microplastic intake around 5 grams — roughly a credit card’s mass — though that figure has drawn methodological criticism. This index tracks 74 daily touchpoints. Green-tagged entries are backed by a specific cited study; the rest describe chemically plausible exposure routes that haven’t been directly measured for that exact product, and are marked accordingly.

Synthetic Signatures

Polycarbonate (PC)

$(C_{15}H_{16}O_2 \cdot CO_3)_n$

Polyvinyl Chloride (PVC)

$(C_2H_3Cl)_n$

Polyethylene Terephthalate (PET)

$(C_{10}H_8O_4)_n$

40+
Cataloged Specimens
5
With Cited Study
74k–121k
Particles/Yr, Ingest.+Inhal.
700k
Fibers Released / Wash Load

Sources: annual intake range — Cox et al. 2019, Environ. Sci. Technol. 53(12); fibers per wash — Napper & Thompson 2016, Marine Pollution Bulletin 112. See specimen citations in the Index for item-level sourcing.

Methodology Note

This catalog distinguishes two tiers of claim. Verified specimens cite a specific peer-reviewed measurement of that product. Unverified specimens describe a chemically plausible exposure route — e.g., a known plastic class that is documented to leach or shed under similar conditions — but no dedicated study measuring that exact product has been identified. Unverified does not mean false; it means unconfirmed at the product level, and such entries should be read as reasoned inference, not measured fact.

Chart 01 — Cited

Microplastics From Water Alone, Per Year

Source: Cox et al. 2019, Environ. Sci. Technol. 53(12), 7068–7074. Figures are drinking-water-only intake for someone who drinks exclusively from one source; not total annual exposure.

Chart 02 — Cited

Primary Sources of Ocean Microplastic

Source: Boucher & Friot 2017, Primary Microplastics in the Oceans, IUCN. Central-scenario shares of primary (directly-released) microplastic mass.

Field Note — Single Serving, Not Annual

The Tea Bag Outlier

Steeping one plastic (“silken” pyramid-style) tea bag at brewing temperature releases an estimated 11.6 billion microplastics and 3.1 billion nanoplastics into a single cup — orders of magnitude higher than any other single-serving food or drink measured to date. This figure describes one cup, not an annual total, and applies specifically to nylon/PET mesh bags, not standard paper string-and-tag bags.

Source: Hernandez et al. 2019, Environ. Sci. Technol. 53(21), 12300–12310 (McGill University).

Chart 03 — Live from catalog data

Specimens Tracked per Sector

PUREPATH FIELD INDEX · COMPILED FOR REFERENCE, NOT MEDICAL ADVICE