Microplastics

Science updates

Three recent studies that affect how this site explains measurement and exposure. Each entry separates the observation from the inference.

Diagram of a nanoplastics method: filtering bottled water onto a membrane, imaging it on a stimulated Raman microscope, then spectral identification and particle statistics
A published measurement, end to end: water is filtered onto a membrane (A–C), the membrane is imaged on a stimulated Raman scattering microscope (D), and every detected particle is matched against polymer standards before it is counted and sized (E). A reported number is the output of all of these choices. Qian et al., PNAS (2024), Rapid single-particle chemical imaging of nanoplastics · CC BY 4.0

2026 · Smaller-particle drinking-water measurements

Emerging
Seven microscope images of individual sub-micrometre particles, each paired with a spectrum matching a plastic standard
How a speck becomes a named polymer. Each panel is one particle imaged in bottled water, and each graph compares its measured spectrum (blue) with a reference standard (orange) for polyamide, polypropylene, polyethylene, PMMA, PVC, polystyrene, and PET. Most of these particles are under a micrometre—far below what visual counting can reach. Qian et al., PNAS (2024), Rapid single-particle chemical imaging of nanoplastics · CC BY 4.0
What was studied
Jamison Hart & Lenhart measured treated and bottled drinking water in the United States across a micro- and nano-range.
What was found
The study reported 1.6–2.6 million particles/L in treated water and 2.6–11.5 million particles/L in bottled water.
What it cannot show
Those counts cannot be added to or ranked against conventional studies with much larger detection thresholds, and they do not establish health effects.
What changes here
The calculator keeps these coefficients in a separate nano-inclusive track instead of using them in the headline conventional-microplastic estimate.

2025 · Microplastics across drinking-water treatment

Emerging
What was studied
Balkenbusch et al. sampled source and finished water across ten U.S. drinking-water treatment facilities, targeting particles above 2 µm.
What was found
The study adds multi-facility evidence about where particles are retained or remain through treatment.
What it cannot show
Ten facilities are not a national concentration estimate, and treatment performance does not imply a personal dose or health outcome.
What changes here
It informs the explanation of treatment and geographic coverage; it is not reduced to one intake coefficient in the calculator.

2024 · Nanoplastics in bottled water

Emerging
What was studied
Qian et al. used stimulated Raman scattering microscopy on bottled water, targeting particles approximately 0.1–5 µm.
What was found
The study reported a mean of about 240,000 particles/L, with 110,000–400,000 particles/L across samples.
What it cannot show
The small product sample does not represent every brand or country, and particle presence alone does not establish harm.
What changes here
The coefficient is modeled as a triangular 110,000 / 240,000 / 400,000 distribution and shown only in the nano-inclusive result.
Qian et al., Proceedings of the National Academy of Sciences