Calculator Methodology

Current version: v3.3

1. Overview

The Winnow Microplastic Exposure Calculator estimates personal microplastic exposure based on 40 questions, presented as six scenes. Every question is answered with a single tap: ranges (age, body weight, distances) are offered as the same bands the scoring model uses, food frequencies share one monthly count table, and country stays a searchable select given the length of the list. Each question carries a tap-to-open explainer that links to its own section of this page. The calculator can be taken by adults for themselves or by parents/caregivers on behalf of a child or infant; question wording is perspective-neutral so it works the same either way. Demographics are collected first (Scene 1) so that irrelevant questions can be hidden for younger age groups.

Scene order:

The Basics (demographics & biology)
The Neighborhood (environment)
Food & Water (diet & hydration)
Around the House (indoor environment)
Daily Life (lifestyle, occupation & exercise)
What May Help (protective habits)

Each scene contains questions about habits, environment, and lifestyle. Your answers are matched to factor weights derived from published microplastic research. The result is a score from 1 to 100 representing your relative exposure, along with a particle-per-day estimate and your top influencing factors.

2. Scoring Model

Your exposure score is calculated using a weighted sum model:

score = 32.5 (baseline) + sum of matched factor weights, clamped to 1–100

The baseline of 32.5 represents a mid-to-low estimated exposure for a person with no particularly high-risk habits in the modern world — reflecting the fact that microplastics are now broadly present in food, water, and air globally.

Each question maps your answer to a weight — a positive value increases your score (higher exposure) and a negative value decreases it (protective factor). Weights are additive: your final score is the sum of all matched weights plus the baseline, clamped to 1–100.

Score bands:

Score	Band	Interpretation
1–24	Low	Below-average exposure; protective factors outweigh risk
25–49	Moderate	Typical modern exposure; some room for improvement
50–74	Elevated	Above-average exposure; several significant sources identified
75–100	High	Well above average; multiple high-exposure pathways active

Note: factor weights are derived from published microplastic research literature and are intended as relative estimates, not precise measurements. This calculator produces an indicative exposure profile, not a medical or clinical assessment.

3. Particle Estimate

In addition to the score, the calculator estimates your daily particle intake based on quantified factors from the published literature. Each factor with a known particles-per-day value contributes to the total when your answer matches. This estimate is reported in particles/day and provides a more concrete, physical interpretation of your exposure profile.

The particle estimate is a rough order-of-magnitude figure, not a precise measurement. It reflects geometric means from published detection studies and is intended to make the score more tangible, not to replace controlled exposure assessment.

How it is computed: for each of your answers that matches a factor with a non-null particles_per_day value, that value is summed. The total is displayed alongside your score on the results page.

4. Evidence Levels

Each factor is classified by evidence strength:

Strong

Multiple published studies consistently identify this factor as a significant exposure route. Effect direction and relative magnitude are well-established.

Moderate

Supported by published research but evidence is less consistent or based on fewer studies. Direction of effect is likely correct; magnitude is less certain.

Emerging

Early-stage or limited research suggests this relationship exists. Weight is a cautious estimate and may be updated as evidence accumulates.

Modeled

Weight is estimated from national-level indicators (waste mismanagement rates, water treatment coverage) using a covariate model rather than direct environmental sampling. Used for country-level data.

5. Pathway Tagging

Every factor is tagged with an exposure pathway: ingestion, inhalation, or both. This tagging identifies how you are exposed, not just how much.

Ingestion

Exposure through eating or drinking — contaminated food, water, beverages, or contact with food-preparation surfaces.

Inhalation

Exposure through breathing — airborne microfibres from textiles, tire wear particles, indoor dust, and industrial emissions.

Both

Factor contributes to exposure through both ingestion and inhalation pathways.

Pathway tags are displayed alongside your top influencing factors so you can see whether your exposure is driven primarily by what you eat and drink, what you breathe, or both.

6. The Questions & Factor Weights

Every question the calculator asks is listed below, grouped by category: what it measures, the research it rests on, and every answer option that carries a non-zero weight. Answers not shown carry a weight of 0 (no effect on your score). The ⓘ explainer beside each question in the calculator links directly to that question's entry here.

About You

Age

Infants and children take in more particles per kilogram of body weight, and cumulative exposure keeps climbing with age, so each range carries its own weight in the model.

Sources: Dris 2017

Answer	Weight	Evidence	Pathway	Particles/day	Basis
under_2	+6.0	moderate	both	—	Infants have higher dose/kg body weight, more hand-to-mouth behavior, and crawl on floors with high dust MP levels (3,100-22,000 synthetic fibers/day from dust ingestion, Dris et al. 2017).
2_17	+4.0	moderate	both	—	Children have higher dose/kg body weight and more floor contact than adults. Higher dust ingestion rates increase MP exposure.
76_plus	+3.5	moderate	both	—	Cumulative exposure is highest at the oldest ages studied, and some studies report reduced clearance follows the same pattern, so 76 and older carries the highest weight on this slope.
61_75	+2.0	moderate	both	—	Older adults show longer cumulative MP exposure and, in some studies, reduced clearance, with higher tissue concentrations reported in older age groups; 61 to 75 is graded below the oldest band rather than treated identically to it.
46_60	+1.0	moderate	both	—	Cumulative exposure tends to keep climbing with age; 46 to 60 sits further along the same slope, still short of the ages where some studies report reduced clearance.
31_45	+0.5	moderate	both	—	Cumulative microplastic exposure tends to climb gradually with age; 31 to 45 is one step above the 18-30 reference band on that slope.

Biological sex

Some studies report different microplastic concentrations in male and female tissue samples, though evidence for different intake is limited. The model applies a small weight graded as emerging evidence.

Sources: Ragusa 2021

Answer	Weight	Evidence	Pathway	Particles/day	Basis
female	+1.0	emerging	both	—	Some studies find higher MP concentrations in female reproductive tissues, but evidence for differential intake is limited. Most findings reflect tissue distribution rather than exposure level.

Body weight

The same daily particle intake lands harder on a smaller body, so the model scales exposure by weight. A range is enough; precision beyond the band does not change the score.

Answer	Weight	Evidence	Pathway	Particles/day	Basis
under_40kg	+4.5	strong	both	—	Lower body weight means higher effective dose per kg for the same particle intake. A person in this band has roughly 3x the dose/kg of the 70-80kg reference band.
40_50kg	+3.5	strong	both	—	A person in this band has roughly 1.7x the dose/kg of the 70-80kg reference band, one step down the ramp from the under-40kg band.
over_120kg	-2.5	strong	both	—	Higher body weight means lower effective dose per kg for the same particle intake. A person in this band has roughly 0.55x the dose/kg of the 70-80kg reference band, the far end of the ramp.
50_60kg	+2.5	strong	both	—	A person in this band has roughly 1.35x the dose/kg of the 70-80kg reference band.
105_120kg	-2.0	strong	both	—	A person in this band has roughly 0.65x the dose/kg of the 70-80kg reference band.
60_70kg	+1.5	strong	both	—	A person in this band has roughly 1.15x the dose/kg of the 70-80kg reference band, a modest correction just below reference.
90_105kg	-1.5	strong	both	—	A person in this band has roughly 0.8x the dose/kg of the 70-80kg reference band.
80_90kg	-0.5	strong	both	—	A person in this band has roughly 0.9x the dose/kg of the 70-80kg reference band, a small correction just above reference.

A note on pregnancy and breastfeeding

Earlier versions asked about pregnancy and breastfeeding. The question was retired in v3.3 and previously stored answers were deleted; it never changed any score. The research it pointed to still matters: microplastics have been detected in placental tissue and in breast milk, so reducing intake during pregnancy and lactation remains sensible even though it does not change measured exposure. Sources: Ragusa 2021 Ragusa 2022

Where You Live

Country of residence

Countries differ in how much plastic waste is mismanaged and how well drinking water is treated. The model folds both into a per-country contamination index calibrated against environmental sampling.

Sources: Jambeck 2015

Answer	Weight	Evidence	Pathway	Particles/day	Basis
CD	+10.5	modeled	both	—	Estimated from national indicators: mismanaged waste: 77% (Jambeck et al. 2015); safely managed water: 11.6% (WHO/UNICEF JMP 2022). Calibrated against 3 environmental media. ICRP 66 lung deposition + GI bioavailability.
LK	+10.5	emerging	both	—	Based on 7 measurements (air: 7), supplemented by covariate model (mismanaged waste: 82%; safely managed water: 47.1%). ICRP 66 lung deposition + GI bioavailability.
SN	+10.0	modeled	both	—	Estimated from national indicators: mismanaged waste: 82%; safely managed water: 26.6%; waste collection: 21%. ICRP 66 lung deposition + GI bioavailability.
ID	+9.5	moderate	both	—	Based on 15 measurements (freshwater: 1, ocean: 14), blended with national indicators (mismanaged waste: 81%; safely managed water: 30.3%). ICRP 66 + GI bioavailability.
PH	+9.0	moderate	both	—	Based on 22 measurements (air: 17, freshwater: 1, ocean: 4), blended with national indicators (mismanaged waste: 81%; safely managed water: 48.0%). ICRP 66 + GI bioavailability.
VN	+8.5	modeled	both	—	Estimated from national indicators: mismanaged waste: 86%; safely managed water: 57.6%. ICRP 66 lung deposition + GI bioavailability.
NG	+8.0	modeled	both	—	Estimated from national indicators: mismanaged waste: 81%; safely managed water: 28.9%. ICRP 66 lung deposition + GI bioavailability.
MM	+7.5	modeled	both	—	Estimated from national indicators: mismanaged waste: 87%; safely managed water: 59.6%. ICRP 66 lung deposition + GI bioavailability.
TN	+7.5	moderate	both	—	Based on 11 measurements (ocean: 11), blended with national indicators (mismanaged waste: 60%; safely managed water: 67.8%). ICRP 66 + GI bioavailability.
GH	+7.0	emerging	both	—	Based on 1 measurement (ocean: 1), supplemented by covariate model (mismanaged waste: 81%; safely managed water: 40.2%). ICRP 66 + GI bioavailability.
TH	+7.0	modeled	both	—	Estimated from national indicators: mismanaged waste: 73%. ICRP 66 lung deposition + GI bioavailability.
DZ	+6.5	moderate	both	—	Based on 10 measurements (air: 1, ocean: 9).
AF	+6.5	modeled	both	—	Estimated from national indicators: safely managed water: 29.2%.
BD	+6.5	moderate	both	—	Based on 18 measurements (ocean: 18), blended with national indicators (mismanaged waste: 87%; safely managed water: 59.2%).
DO	+6.5	emerging	both	—	Based on 2 measurements (ocean: 2), supplemented by covariate model.
KH	+6.5	emerging	both	—	Based on 1 measurement (freshwater: 1), supplemented by covariate model.
MZ	+6.5	modeled	both	—	Estimated from national indicators: mismanaged waste: 84%; safely managed water: 25.4%.
NP	+6.5	modeled	both	—	Estimated from national indicators: safely managed water: 16.2%.
PK	+6.5	emerging	both	—	Based on 7 measurements (air: 7), supplemented by covariate model.
ZA	+6.5	emerging	both	—	Based on 3 measurements (ocean: 3), supplemented by covariate model.
CN	+6.0	moderate	both	—	Based on 130 measurements (air: 95, freshwater: 3, ocean: 32).
EG	+6.0	emerging	both	—	Based on 2 measurements (freshwater: 2), supplemented by covariate model.
GT	+6.0	modeled	both	—	Estimated from national indicators.
HN	+6.0	modeled	both	—	Estimated from national indicators.
PE	+6.0	modeled	both	—	Estimated from national indicators.
TZ	+6.0	emerging	both	—	Based on 3 measurements (freshwater: 1, ocean: 2).
MA	+5.5	modeled	both	—	Estimated from national indicators.
other	+5.5	modeled	both	—	Global median estimate based on covariate model.
PA	+5.0	emerging	both	—	Based on 2 measurements (ocean: 2).
EC	+5.0	modeled	both	—	Estimated from national indicators.
TR	+5.0	moderate	both	—	Based on 10 measurements (ocean: 10).
CM	+4.5	modeled	both	—	Estimated from national indicators.
CR	+4.5	emerging	both	—	Based on 5 measurements (ocean: 5).
ET	+4.5	modeled	both	—	Estimated from national indicators.
JM	+4.5	moderate	both	—	Based on 27 measurements (ocean: 27).
AR	+4.0	emerging	both	—	Based on 5 measurements (air: 1, ocean: 4).
CO	+4.0	modeled	both	—	Estimated from national indicators.
IN	+4.0	moderate	both	—	Based on 39 measurements (freshwater: 2, ocean: 37).
IQ	+4.0	modeled	both	—	Estimated from national indicators.
KE	+4.0	modeled	both	—	Estimated from national indicators.
KZ	+4.0	modeled	both	—	Estimated from national indicators.
MX	+4.0	moderate	both	—	Based on 22 measurements (air: 4, ocean: 18).
MY	+4.0	emerging	both	—	Based on 1 measurement (air: 1).
UY	+4.0	modeled	both	—	Estimated from national indicators.
UA	+3.5	modeled	both	—	Estimated from national indicators.
VE	+3.5	emerging	both	—	Based on 2 measurements (ocean: 2).
BR	+3.0	moderate	both	—	Based on 11 measurements (air: 1, freshwater: 2, ocean: 8).
IR	+3.0	moderate	both	—	Based on 20 measurements (air: 20).
RU	+3.0	moderate	both	—	Based on 14 measurements (air: 1, ocean: 13).
SA	+3.0	emerging	both	—	Based on 4 measurements (air: 4).
BG	+2.5	modeled	both	—	Estimated from national indicators.
JO	+2.5	modeled	both	—	Estimated from national indicators.
RO	+2.5	modeled	both	—	Estimated from national indicators.
AT	+2.5	emerging	both	—	Based on 1 measurement (freshwater: 1).
CZ	+2.0	modeled	both	—	Estimated from national indicators.
PL	+2.0	modeled	both	—	Estimated from national indicators.
HU	+1.5	modeled	both	—	Estimated from national indicators.
CH	+1.5	modeled	both	—	Estimated from national indicators.
CL	+1.5	moderate	both	—	Based on 23 measurements (ocean: 23).
EE	+1.5	modeled	both	—	Estimated from national indicators.
DK	+1.0	modeled	both	—	Estimated from national indicators.
ES	+1.0	moderate	both	—	Based on 92 measurements (ocean: 92).
FI	+1.0	emerging	both	—	Based on 1 measurement (air: 1).
FR	+1.0	moderate	both	—	Based on 138 measurements (air: 26, freshwater: 2, ocean: 110).
IT	+1.0	moderate	both	—	Based on 59 measurements (ocean: 59).
NZ	+1.0	emerging	both	—	Based on 4 measurements (ocean: 4).
PT	+1.0	moderate	both	—	Based on 45 measurements (ocean: 45).
QA	+1.0	modeled	both	—	Estimated from national indicators.
SE	+1.0	moderate	both	—	Based on 14 measurements (air: 2, ocean: 12).
GB	+1.0	moderate	both	—	Based on 114 measurements (air: 24, freshwater: 1, ocean: 89).
SG	+1.0	modeled	both	—	Estimated from national indicators.
GR	+1.0	moderate	both	—	Based on 18 measurements (ocean: 18).
US	+1.0	moderate	both	—	Based on 963 measurements (air: 25, freshwater: 667, ocean: 271).
IE	+1.0	moderate	both	—	Based on 20 measurements (ocean: 20).
IL	+1.0	moderate	both	—	Based on 81 measurements (air: 1, ocean: 80).
IS	+1.0	emerging	both	—	Based on 6 measurements (air: 1, ocean: 5).
AE	+1.0	modeled	both	—	Estimated from national indicators: 0% mismanaged waste.
JP	+1.0	moderate	both	—	Based on 19 measurements (freshwater: 1, ocean: 18).
AU	+1.0	moderate	both	—	Based on 14 measurements (freshwater: 1, ocean: 13).
KR	+1.0	emerging	both	—	Based on 1 measurement (freshwater: 1).
BE	+1.0	modeled	both	—	Estimated from national indicators.
CA	+1.0	moderate	both	—	Based on 46 measurements (freshwater: 2, ocean: 44).
DE	+1.0	emerging	both	—	Based on 3 measurements (freshwater: 2, ocean: 1).
KW	+1.0	modeled	both	—	Estimated from national indicators.
NL	+1.0	emerging	both	—	Based on 2 measurements (ocean: 2).
NO	+1.0	moderate	both	—	Based on 16 measurements (air: 1, ocean: 15).

Where is home?

City air carries more microplastic from traffic and textiles than rural air. This answer sets the ambient baseline the rest of the answers build on.

Sources: Dris 2017 Sommer 2018

Answer	Weight	Evidence	Pathway	Particles/day	Basis
urban	+4.0	moderate	inhalation	—	Urban environments have higher airborne MP from traffic tire wear, road dust, and industrial sources (Dris et al. 2017).
suburban	+2.0	moderate	inhalation	—	Suburban areas show intermediate MP levels between urban and rural settings.

How far to the nearest plastics, chemical, or recycling facility?

Plastics, chemical, and recycling facilities shed particles into surrounding air, and concentrations fall with distance. A map search for 'recycling center' or 'plastics' near the address settles this quickly.

Sources: Sheridan 2023

Answer	Weight	Evidence	Pathway	Particles/day	Basis
under_1km	+5.0	moderate	inhalation	~120	Airborne MP concentrations near plastic/recycling facilities are ~5x background (Sheridan et al. 2023: 3-40 particles/m3 downwind vs ~1 upwind). At 16 m3/day breathing rate, ~120 extra particles/day.
1_5km	+3.0	moderate	inhalation	~60	Elevated airborne MP within 5 km of facilities, ~2.5x background. Distance-decay follows PM2.5 patterns (Sheridan et al. 2023).
5_20km	+1.0	emerging	inhalation	~12	Slightly elevated MP at 5-20 km, approaching background. PM2.5 half-distance is ~16 km from source.

How far to the nearest highway or busy road?

Tire wear is one of the largest microplastic sources, so distance from heavy traffic changes airborne exposure. The ranges step down from beside the road to beyond its reach.

Sources: Kole 2017 Sommer 2018

Answer	Weight	Evidence	Pathway	Particles/day	Basis
under_100m	+5.0	moderate	inhalation	~80	Tire wear particles are the #1 MP source by mass (Kole et al. 2017). Roadside airborne MP 5-15 particles/m3 vs 0.3-1.5 background (Dris et al. 2017). Living <100m from highway = 24h elevated exposure.
100m_1km	+2.0	moderate	inhalation	~24	TWP concentrations drop ~90% by 100m from road edge (Sommer et al. 2018). Airborne levels at 100m-1km are ~2x background.

What You Drink

Where does drinking water come from?

Water source is one of the largest single factors in the model: unfiltered tap and plastic-bottled water carry the most particles, while reverse osmosis and groundwater carry close to none.

Sources: Mason 2018 Mintenig 2019 WHO 2019

Answer	Weight	Evidence	Pathway	Particles/day	Basis
ro_filtered	-5.0	strong	ingestion	~5	Reverse osmosis removes ~99% of MP from drinking water (membrane filtration, Mintenig et al. 2019, WHO 2019). The most effective home treatment. ~5 particles/day estimated.
filtered_tap_carbon	-3.0	moderate	ingestion	~150	Activated carbon filters remove 70-80% of MP from drinking water, effective for particles >1 um (WHO 2019). ~150 particles/day estimated.
bottled_plastic	+2.0	strong	ingestion	~634	Bottled water in PET plastic contains ~317 MPs/L from bottling process. At 2L/day: ~634 particles/day, comparable to or higher than treated tap water (Schymanski et al. 2018).
well_spring	-2.0	strong	ingestion	~0	Groundwater contains <0.007 MPs/L (Mintenig et al. 2019). Negligible contribution to MP intake vs surface or municipal water sources.
filtered_tap_pitcher	-1.0	emerging	ingestion	~400	Pitcher filters (e.g. Brita) provide limited MP removal (~10-30%), primarily capturing larger particles. ~400 particles/day estimated (Mintenig et al. 2019).
bottled_glass	-1.0	moderate	ingestion	~50	Glass-bottled water contains 1,000-10,000 particles/bottle vs PET 300-250,000/L. ~10-100x lower contamination than PET single-use (~50 particles/day estimated).

How often do drinks come in plastic bottles?

Drinks pick up particles from the bottle itself, most of all single-use bottles that have been warm or reused. Frequency matters more than brand.

Sources: Mason 2018

Answer	Weight	Evidence	Pathway	Particles/day	Basis
daily_single_use	+18.0	strong	ingestion	~700	Daily PET single-use bottled water: 300-250,000 particles/L. Geometric mean ~350/L; at 2L/day = ~700 particles/day from bottle shedding alone (Schymanski et al. 2018). PET particles confirmed in blood and tissues.
regularly_reusable	+8.0	moderate	ingestion	~80	Reusable plastic bottles shed MP through scratching, UV degradation, and dishwasher use. Estimated ~40-120 particles/day depending on bottle age and condition.
occasionally	+4.0	strong	ingestion	~25	Occasional plastic bottle use (few times per month) contributes measurable PET microplastic ingestion, estimated ~25 particles/day averaged across the month.

How often does a hot drink come in a disposable cup?

Disposable cups are lined with polyethylene, which releases particles into a hot drink. The count is per month, averaged over a normal routine.

Sources: Busse 2023

Answer	Weight	Evidence	Pathway	Particles/day	Basis
daily	+6.0	strong	ingestion	~50	PE-lined disposable cups release ~25,000 MP per cup at hot beverage temperature (Busse et al. 2023). 2 cups/day = ~50,000 particles, though most are nano-sized.
weekly	+3.0	strong	ingestion	~7	Regular use of disposable hot cups contributes measurable PE microplastic ingestion (Busse et al. 2023).

How is water heated for hot drinks?

Lab work from 2025 found polypropylene kettles shed nanoplastics into water at a boil. Metal kettles and stovetop heating avoid that release point.

Answer	Weight	Evidence	Pathway	Particles/day	Basis
plastic_electric	+2.0	emerging	ingestion	—	Polypropylene kettles were shown to release nanoplastics into water at a boil (2025), with release levels influenced by water chemistry (2021).

What You Eat

How much dairy in a typical day?

Published sampling has found microplastics in milk and cheese at modest levels. Daily servings set the weight; occasional dairy barely moves the score.

Sources: Kutralam-Muniasamy 2020

Answer	Weight	Evidence	Pathway	Particles/day	Basis
heavy	+4.0	moderate	ingestion	~80	Milk contains 2,000-10,000 particles/L; cheese ~1,857/kg. Heavy daily consumption (3+ servings) contributes ~80 particles/day.
moderate	+2.0	moderate	ingestion	~30	Moderate dairy consumption (1-2 servings) contributes ~30 particles/day from milk and cheese contamination.

How often does a meal include finfish like salmon, tuna, or cod?

Finfish accumulate microplastics through the food chain, though gutting removes most of the load before a fillet reaches the plate. Count meals in a typical month.

Sources: Rochman 2015

Answer	Weight	Evidence	Pathway	Particles/day	Basis
daily	+5.0	strong	ingestion	~50	Near-daily finfish consumption contributes ~50 particles/day through bioaccumulation in muscle tissue (Rochman et al. 2015).
weekly	+3.0	strong	ingestion	~25	Weekly finfish meals accumulate MP through bioaccumulation, primarily in the GI tract (removed before eating) but also in muscle tissue (Rochman et al. 2015).
monthly	+1.0	moderate	ingestion	~5	Occasional finfish intake contributes modest MP via bioaccumulation through the food chain; gutting removes most GI-tract particles, and muscle tissue carries the remainder (Rochman et al. 2015).

How often does a meal include shellfish like mussels, shrimp, or oysters?

Mussels, oysters, and shrimp are eaten whole, digestive tract included, so shellfish carry 10 to 100 times the particle concentration of finfish. Count meals in a typical month.

Sources: Van Cauwenberghe & Janssen 2014 Rochman 2015

Answer	Weight	Evidence	Pathway	Particles/day	Basis
daily	+11.0	strong	ingestion	~250	Filter-feeding shellfish concentrate MP from seawater; near-daily consumption at ~100-1,000 particles per serving makes this the heaviest single dietary factor in the model (Van Cauwenberghe & Janssen 2014).
weekly	+7.0	strong	ingestion	~120	Weekly shellfish meals (mussels, oysters, shrimp) are a leading dietary MP source at 0.1-10 particles/gram, 10-100x finfish concentrations (Van Cauwenberghe & Janssen 2014; Rochman et al. 2015).
monthly	+3.0	strong	ingestion	~30	Shellfish are eaten whole, digestive tract included, so even occasional servings carry the full particle load: 0.1-10 particles/gram, ~100-1,000 particles per serving (Van Cauwenberghe & Janssen 2014).

How often does a meal come out of a can?

Can linings are epoxy resins that can shed particles into food, most of all acidic or oily contents.

Sources: Karami 2018

Answer	Weight	Evidence	Pathway	Particles/day	Basis
daily	+7.0	moderate	ingestion	~25	Canned food linings (epoxy resins) are a source of MP and BPA exposure. Canned fish: 5-25 particles/tin.

How often does dinner arrive in a plastic takeaway container?

Hot food picks up particles from single-use plastic containers, and the release climbs with temperature.

Sources: Hussain 2023

Answer	Weight	Evidence	Pathway	Particles/day	Basis
daily	+8.0	moderate	ingestion	~100	Single-use takeaway containers contribute MP through direct contact, particularly when food is hot or acidic.

How often are pouches, sippy cups, or plastic wrap used?

Pouches, sippy cups, and plastic wrap put plastic in direct contact with what children eat and drink. Frequency of use is what the model scores.

Sources: Hussain 2023

Answer	Weight	Evidence	Pathway	Particles/day	Basis
always	+5.0	moderate	ingestion	~60	Frequent single-use plastic use (pouches, sippy cups, plastic wrap) in children increases direct contact between plastic and food/beverages.
often	+3.0	moderate	ingestion	~30	Regular single-use plastic in children's eating and drinking routines contributes to dietary MP exposure through food contact.

What are formula bottles made of?

A Nature Food study measured polypropylene bottles releasing millions of particles per liter at formula-preparation temperature. Glass and stainless bottles avoid that pathway.

Sources: Li 2020

Answer	Weight	Evidence	Pathway	Particles/day	Basis
yes	+10.0	strong	ingestion	~1600	PP baby bottles release 16.2 million MP/L at formula preparation temperature (Li et al. 2020, Nature Food). Infants fed formula from plastic bottles ingest millions of MP daily.

How often does tea brew from a mesh or pyramid bag?

Mesh and pyramid bags are plastic, and they release micro- and nanoplastics directly into the cup at brewing temperature. Paper bags and loose leaf avoid this pathway.

Sources: Hernandez 2019

Answer	Weight	Evidence	Pathway	Particles/day	Basis
daily	+5.0	strong	ingestion	~150	Daily brewing with plastic mesh bags releases particles directly into the cup at high temperature (Hernandez et al. 2019). Estimate is conservative and counts micro-sized particles only.
weekly	+2.5	strong	ingestion	~50	Regular brewing with plastic mesh bags is a recurring ingestion source. Paper bags and loose leaf avoid this pathway.
monthly	+1.0	strong	ingestion	~10	Plastic mesh tea bags release micro- and nanoplastics at brewing temperature (Hernandez et al. 2019; 2026 systematic reviews). Occasional use contributes a small averaged daily dose.

How often does gum get chewed?

Gum base is a synthetic polymer. A 2025 study measured roughly 100 particles released per gram of gum during chewing.

Answer	Weight	Evidence	Pathway	Particles/day	Basis
daily	+2.0	emerging	ingestion	~200	Daily gum chewing at roughly 100 particles per gram of gum base adds a measurable direct ingestion source (2025 study).
weekly	+1.0	emerging	ingestion	~50	Regular gum chewing releases polymer particles from the gum base into saliva (2025 mastication study).
monthly	+0.5	emerging	ingestion	~10	Gum base is a synthetic polymer. A 2025 study measured roughly 100 microplastic particles released per gram during chewing.

How often are meals seasoned with sea or rock salt?

Sea salt ranges from 0 to 1,674 microplastic particles per kilogram depending on origin, and rock or Himalayan salt carries a smaller load. Iodized table salt is the low-particle reference, so a kitchen using only it can answer never.

Sources: Kim 2018 Karami 2017

Answer	Weight	Evidence	Pathway	Particles/day	Basis
daily	+2.0	moderate	ingestion	~3	Sea salt spans 0-1,674 particles/kg depending on origin, rock salt 0-148/kg (Kim et al. 2018). At ~5g/day intake, daily use contributes up to ~8 particles/day.
weekly	+1.0	moderate	ingestion	~1	Global sampling found 0-1,674 particles/kg in sea salt and 0-148/kg in rock salt (Kim et al. 2018); an earlier 17-brand survey found lower counts (Karami et al. 2017). Seasoning some meals with either adds a small averaged daily dose.

Your Home

How does food come into contact with plastic?

Microwaving in plastic releases far more particles than cold storage, so the answers keep the two apart. Glass, steel, and silicone avoid the pathway entirely.

Sources: Hussain 2023

Answer	Weight	Evidence	Pathway	Particles/day	Basis
both_regular	+14.0	strong	ingestion	~200	Microwaving polypropylene releases billions of nano/microplastic particles per use (Hussain et al. 2023); storing fatty/acidic food in plastic adds migration over time. Combined regular use: ~200 particles/day estimated.
microwave_occasional	+9.0	strong	ingestion	~150	Occasional microwaving in plastic: PP containers release ~4.22 million MP per use at 100°C (Hussain et al. 2023). Even infrequent use contributes significant particle release.
store_only	+5.0	moderate	ingestion	~50	Storing food in plastic containers allows MP migration over time, particularly with fatty/acidic foods and temperature cycling (~50 particles/day estimated).

What kind of cutting board?

Chopping on plastic boards releases millions of particles a year from knife scarring. Wood, bamboo, and glass boards do not shed polymer.

Sources: Habib 2022

Answer	Weight	Evidence	Pathway	Particles/day	Basis
yes	+5.0	strong	ingestion	~100	Plastic cutting boards release 14-71 million MP/year from chopping (Habib et al. 2022). That's ~38,000-195,000/day, primarily from knife scarring.

Any nonstick cookware?

Intact nonstick coatings shed little, but scratched and flaking PTFE releases particles into food during cooking. Condition is what the model scores, not ownership.

Sources: Luo 2022

Answer	Weight	Evidence	Pathway	Particles/day	Basis
heavily_damaged	+5.0	strong	ingestion	~80	Heavily damaged Teflon releases thousands of PTFE MP per cooking event (Luo et al. 2022). Flaking coatings directly contaminate food.
scratched	+3.0	moderate	ingestion	~30	Scratched nonstick surfaces release PTFE particles during cooking, especially with metal utensils (Luo et al. 2022).

What are the floors?

Synthetic carpet sheds fibres into house dust, while hard flooring accumulates less. Indoor dust is a significant route, for small children especially.

Sources: Dris 2017

Answer	Weight	Evidence	Pathway	Particles/day	Basis
synthetic_carpet	+8.0	moderate	both	~50	Synthetic carpets shed microfibres into indoor dust. Indoor dust contains 190-670 fibers/mg (Dris et al. 2017). Inhalation and incidental ingestion are both significant.
hardwood_tile	-3.0	moderate	both	—	Hard flooring reduces synthetic fibre accumulation in indoor dust vs carpeted homes.

What are bedding, curtains, and upholstery made of?

Bedding, curtains, and upholstery shed fibres continuously into indoor air. Cotton, linen, and wool shed cellulose and protein instead of plastic.

Sources: Dris 2017

Answer	Weight	Evidence	Pathway	Particles/day	Basis
mostly_synthetic	+6.0	moderate	inhalation	~30	Synthetic bedding and upholstery shed microfibres into indoor air. Indoor fibre concentrations 1-60 fibres/m3, ~33% synthetic (Dris et al. 2017).

Is there an air purifier at home?

HEPA filtration measurably cuts airborne fibre counts indoors; basic purifiers and ionizers help less. This is one of the few answers that subtracts from the score.

Sources: Dris 2017

Answer	Weight	Evidence	Pathway	Particles/day	Basis
yes	-6.0	moderate	ingestion	—	HEPA-type air purifiers are designed to capture fine airborne particles including microplastic fibres. Research suggests air filtration can meaningfully reduce indoor airborne particle concentrations. [1] [2] [3] [4] [5]
hepa	-6.0	moderate	inhalation	—	HEPA air purifiers achieve 40-57% reduction in airborne particulates including MP fibres (Dris et al. 2017). Reduces indoor/outdoor PM ratio from 76% to 39%.
basic	-2.0	emerging	inhalation	—	Basic/ionizer air purifiers provide some particulate reduction but are significantly less effective than HEPA for MP-sized particles.

How do the floors get cleaned?

Removing settled dust removes the particles that would otherwise be stirred back into the air. Vacuuming plus wet mopping clears the most; infrequent cleaning lets dust accumulate.

Sources: Dris 2017

Answer	Weight	Evidence	Pathway	Particles/day	Basis
vacuum_and_mop	-2.0	moderate	inhalation	—	Combining vacuuming with wet mopping is the most effective approach for removing settled microplastic dust from floors. Vacuuming captures particles while wet mopping picks up remaining fine dust that dry sweeping would miss.
rarely	+2.0	emerging	inhalation	—	Infrequent floor cleaning allows dust MP accumulation, increasing chronic low-level exposure via inhalation and incidental ingestion.
vacuum_regularly	+1.0	moderate	inhalation	—	Standard vacuums increase airborne MP 4-61x during use via exhaust (Dris et al. 2017). Net effect is slight increase in airborne exposure, though floor MP load is reduced over time.
sweep_mop	+0.5	emerging	inhalation	—	Sweeping and mopping removes settled dust from floors but can re-suspend fine particles into the air. Less effective than vacuuming for capturing microplastic fibres, but wet mopping mitigates re-suspension.

Daily Habits

How do synthetic clothes get washed and dried?

Washing synthetics releases microfibres, and tumble drying vents millions more per cycle. Line drying skips the dryer stage entirely.

Sources: De Falco 2019 O'Brien 2020

Answer	Weight	Evidence	Pathway	Particles/day	Basis
wash_frequent_tumble	+7.0	strong	inhalation	~55	Frequent synthetic washing (700k-6M microfibres/wash, De Falco et al. 2019) combined with tumble drying (millions vented per cycle, O'Brien et al. 2020) creates the highest indoor microfibre load. ~55 particles/day estimated.
wash_tumble_occasional	+3.0	moderate	inhalation	~15	Regular synthetic washing with occasional tumble drying contributes meaningful microfibre exposure. Occasional dryer use reduces venting versus regular tumble drying (De Falco et al. 2019; O'Brien et al. 2020).
wash_line_dry	+1.0	strong	inhalation	~5	Washing synthetics without tumble drying eliminates dryer venting of microfibres. Line/rack drying contributes modest indoor microfibre load via fibres attached to garments (De Falco et al. 2019).

What are most clothes made of?

Polyester, nylon, and fleece shed fibres during wear; a mostly-natural wardrobe sheds fewer. The answer describes the wardrobe as a whole, not any single garment.

Sources: De Falco 2019

Answer	Weight	Evidence	Pathway	Particles/day	Basis
mostly_synthetic	+7.0	moderate	inhalation	~30	Wearing predominantly synthetic clothing results in continuous microfibre shedding and inhalation, particularly during movement. Synthetic garments shed 100-9,000 fibres/hour during wear.
mixed	+4.0	moderate	inhalation	~15	A mixed wardrobe of natural and synthetic fabrics contributes intermediate microfibre exposure through inhalation during wear and laundering.

Where do workdays happen?

A few settings carry documented occupational exposure well above ambient: plastics manufacturing, textile work, and waste sorting are the highest measured. Most desk and outdoor jobs sit near baseline.

Sources: Sheridan 2023 Wright & Kelly 2017

Answer	Weight	Evidence	Pathway	Particles/day	Basis
industrial	+12.0	strong	inhalation	~500	Industrial/manufacturing workers face the highest occupational MP exposure: 32-49 particles/m3 in plastic manufacturing (Sheridan et al. 2023, Nagpur 2026).
waste_recycling	+11.0	strong	inhalation	~450	Waste/recycling workers are exposed to 3,474-3,964 MP/m3 in sorting facilities (Thailand study, PMC 2023). Among the highest documented occupational exposures.
textile_worker	+10.0	strong	inhalation	~400	Textile workers are exposed to very high airborne synthetic fibre concentrations. Flock workers show elevated respiratory disease (Wright & Kelly 2017).
outdoor	+5.0	moderate	inhalation	~100	Outdoor workers in urban environments face elevated airborne MP from traffic tire wear and atmospheric deposition.
food_service	+4.0	emerging	both	~80	Food service workers handle plastic packaging, disposable containers, and heated plastics frequently, increasing both ingestion and inhalation exposure.
beauty_salon	+3.0	emerging	inhalation	~60	Nail salons and beauty services involve frequent contact with acrylic/synthetic particles and chemical solvents that may contain or release MP.

How many hours a week are spent on highways or freeways?

Cabin air on highways carries tire-wear particles at measurable concentrations. Hours per week are what the model scores, whoever is driving.

Sources: Kole 2017 Amato-Lourenco 2020

Answer	Weight	Evidence	Pathway	Particles/day	Basis
over_10	+4.0	moderate	inhalation	~65	10 or more weekly hours on highways is the top of this scale; sustained near-daily highway driving carries the highest cabin-air tire-wear MP exposure of any road-hours band (Kole et al. 2017).
5_10	+2.5	moderate	inhalation	~40	5 to 10 weekly hours on highways is a heavy commuter's range; sustained highway driving carries elevated tire-wear MP in cabin air (Kole et al. 2017).
2_5	+1.5	moderate	inhalation	~20	A few weekly hours on highways compounds tire-wear and cabin-shedding inhalation measurably above the lightest band (Kole et al. 2017).
under_2	+0.5	moderate	inhalation	~8	In-car cabin air contains 10-40 MP/m3 from both external tire wear ingress and cabin material shedding (Kole et al. 2017). Under 2 weekly hours is the lightest measurable step on the highway-hours scale.

How many hours a week are spent on city or town streets?

Stop-and-go traffic adds brake and tire dust to cabin air, at somewhat lower concentrations than highway driving.

Sources: Kole 2017 Amato-Lourenco 2020

Answer	Weight	Evidence	Pathway	Particles/day	Basis
over_10	+3.0	moderate	inhalation	~40	10 or more weekly hours in city traffic is the top of this scale; heavy stop-and-go exposure compounds brake and tire particle inhalation.
5_10	+2.0	moderate	inhalation	~25	5 to 10 weekly hours in city traffic is a heavy commuter's range for surface streets, with sustained exposure to brake and tire dust.
2_5	+1.0	moderate	inhalation	~15	A few weekly hours in city traffic compounds tire-wear and road-dust inhalation above the lightest band (Kole et al. 2017).
under_2	+0.5	moderate	inhalation	~6	City driving exposes to 5-25 MP/m3 in cabin air (Kole et al. 2017). Under 2 weekly hours is the lightest measurable step on the city-hours scale.

How many hours a week are spent on rural or country roads?

Rural roads carry the lightest traffic-related particle load, so these hours weigh less than highway or city time.

Sources: Kole 2017 Amato-Lourenco 2020

Answer	Weight	Evidence	Pathway	Particles/day	Basis
over_10	+1.5	emerging	inhalation	~18	10 or more weekly hours on rural roads is the top of this scale, capped lower than highway or city because rural traffic density is lower.
5_10	+1.0	emerging	inhalation	~12	5 to 10 weekly hours on rural roads is a heavier rural commute, still well below highway or city exposure at the same weekly hours.
2_5	+0.5	emerging	inhalation	~6	Rural and country roads carry lower traffic density than highway or city driving, so the lightest measurable step is smaller; the under-2 step is the zero-weight reference for this row.

How many hours a week are spent on public transit?

Buses and trains expose riders to less vehicle-cabin shedding than cars. The hours still count, at the lowest weight of the four road types.

Sources: Kole 2017 Amato-Lourenco 2020

Answer	Weight	Evidence	Pathway	Particles/day	Basis
over_10	+1.5	emerging	inhalation	~15	10 or more weekly hours on public transit is the top of this scale, capped lower than driving because cabin material shedding is lower.
5_10	+1.0	emerging	inhalation	~10	5 to 10 weekly hours on public transit is a heavier commute pattern, still below the equivalent highway or city driving exposure at the same hours.
2_5	+0.5	emerging	inhalation	~5	Public transit exposes to 3-10 MP/m3, lower than driving due to lower cabin material shedding (Kole et al. 2017); the under-2 step is the zero-weight reference for this row.

Any exfoliating scrubs or glitter cosmetics?

Exfoliating scrubs and glitter cosmetics can contain polyethylene microbeads. Polyethylene in an ingredient list is the giveaway.

Sources: Napper 2015

Answer	Weight	Evidence	Pathway	Particles/day	Basis
yes	+2.0	moderate	ingestion	~10	Microbead-containing products (exfoliants, toothpaste, glitter cosmetics) release polyethylene particles. Oral products contribute to direct ingestion (Napper et al. 2015).

Health & Recovery

Where does exercise happen?

Exercise multiplies breathing rate, so the setting matters: roadside training draws in traffic particles, parks sit near background, and artificial turf adds tire-derived rubber.

Sources: Amato-Lourenco 2020 Dris 2017

Answer	Weight	Evidence	Pathway	Particles/day	Basis
active_outdoors_roads	+7.0	moderate	inhalation	~45	Outdoor roadside activity combines elevated ambient MP (8-15 particles/m3) with 2-3.5x higher breathing rate during exercise. ~20-53 extra particles per session (Amato-Lourenco et al. 2020). Regular outdoor road exercise compounds this significantly.
artificial_turf	+4.0	emerging	both	—	Artificial turf infill is crumb rubber, a tire-derived microplastic. Play sessions raise inhalation and incidental ingestion of rubber particles.
active_indoors	+3.0	moderate	inhalation	~20	Indoor gyms and studios have 3-10 MP/m3 from synthetic mats, flooring, and clothing. Higher breathing rate during activity = 6-30 extra particles per session (Dris et al. 2017).

How often is there a sauna session?

Sweating is being studied as an elimination pathway for some contaminants, so regular sauna time subtracts a small amount. The evidence is graded as emerging.

Answer	Weight	Evidence	Pathway	Particles/day	Basis
daily	-4.0	emerging	both	—	Regular sauna use promotes contaminant elimination via sweat. Emerging evidence suggests sweating may support clearance of MP-associated chemicals. Recalibrated from prior estimate.
weekly	-3.0	emerging	both	—	Weekly sauna associated with moderate contaminant elimination enhancement via sweating.

How much fiber from whole grains, legumes, and vegetables?

A 2022 study found dietary fiber increases fecal excretion of microplastics. Reliable daily fiber earns the full subtraction.

Sources: Zhang 2022

Answer	Weight	Evidence	Pathway	Particles/day	Basis
yes	-3.0	emerging	ingestion	—	Dietary fiber increases fecal MP excretion through particle binding and reduced gut transit time (Zhang et al. 2022). A high-fiber diet may reduce net MP absorption.
somewhat	-1.0	emerging	ingestion	—	A mixed diet with some fiber provides partial benefit for MP excretion vs a low-fiber diet, through modest particle binding and gut transit support (Zhang et al. 2022).

How often are yogurt, kefir, kimchi, or probiotic supplements eaten?

Emerging research links the gut microbiome to how ingested particles interact with the gut lining, so daily fermented foods or probiotics subtract a small amount.

Answer	Weight	Evidence	Pathway	Particles/day	Basis
daily	-1.0	emerging	ingestion	—	Emerging evidence suggests gut microbiome composition affects MP interaction and clearance. Probiotic supplementation may support gut barrier function against particle translocation.

7. Country Contamination Index

Country weights are derived from a per-capita contamination index (CI):

CI = sqrt(mismanagement_pct × per_capita_intensity) × water_gap

Where:

mismanagement_pct is the fraction of plastic waste that is mismanaged (Jambeck et al. 2015, updated with World Bank 2022 data)
per_capita_intensity is a normalized metric combining plastic waste generation, population density, and environmental monitoring data
water_gap = 1 + (1 − safely_managed_water_fraction), reflecting that poor water treatment increases ingestion exposure (WHO/UNICEF JMP 2022)

The raw CI is calibrated against environmental sampling data (air, freshwater, ocean) from 963+ measurement points across 40+ countries and converted to a 1.0–10.5 weight scale.

For countries with sufficient monitoring data (>10 measurement points), the weight blends the modeled CI with observed concentrations. For countries with sparse or no data, the weight relies on the covariate model alone and is tagged as “modeled” evidence strength.

Inhalation exposure is modeled using the ICRP 66 human respiratory tract deposition model. Ingestion exposure uses GI bioavailability estimates from the literature.

8. Conditional Questions

Questions are shown or hidden based on prior answers to keep the questionnaire relevant. This is especially important for children and infants, where certain questions (occupation, road hours, personal care) do not apply.

Question	Condition	Rationale
Pregnancy / breastfeeding	Biological sex = female	Only applicable to females
Infant formula in plastic	Age group = under 2	Directly relevant to infant exposure
Occupation	Age group != under 2	Infants don't have occupations
Road hours (highway, city, rural, transit)	Age group != under 2	Infants aren't on the road independently
Personal care microbeads	Age group != under 2	Infants don't use personal care products
Sauna frequency	Age group != under 2	Sauna is not appropriate for infants

The four road-hours questions (Highway hours, City street hours, Rural road hours, Public transit hours) share one weekly prompt: “In a typical week, hours spent on the road”. Each is answered none, under 2, 2 to 5, 5 to 10, or 10+ hours. They are not exclusive: a respondent who drives both highways and city streets answers both, and both weights sum into the score.

9. Worked Examples

These three examples walk through realistic profiles to show how the score is computed and what drives it. For each, we list the answers with non-zero weights, the total score, particle estimate, and the top influencing factors.

Example 1: Mark — middle-aged vegetarian, works from home in Colorado

38-year-old male, 75 kg, vegetarian. Works from home in suburban Colorado. Drinks a lot of canned sparkling water but avoids plastic water bottles. Exercises vigorously at home. House has mixed flooring, some synthetic clothes and linens. Uses a plastic cutting board and stores leftovers in plastic containers. No water filter. Standard vacuum and tumble dryer.

Question	Answer	Weight	Particles/day
Age group	31-45	+0.5	—
Country	US	+1.0	—
Setting	Suburban	+2.0	—
Dairy consumption	Moderate	+2.0	~30
Cooking oil	Moderate	+1.0	~15
Canned food	Daily	+7.0	~25
Plastic cutting board	Yes	+5.0	~100
Plastic food storage	Yes	+5.0	~50
Laundry synthetics	Weekly	+1.0	~5
Dryer use	Tumble dryer	+3.0	~15
Vacuum type	Standard	+1.0	—
Activity level	Vigorous	+4.0	—
High-fiber diet	Yes	-3.0	—
Total weights		+29.5	~240

Score: 32.5 + 29.5 = 62 / 100 — Elevated

Estimated daily particles: ~240

Top factors:

Canned food daily (+7.0, ingestion) — his canned sparkling water habit is the biggest single contributor
Plastic cutting board (+5.0, ingestion, ~100 p/day) — vegetarians chop a lot of produce; switching to wood or bamboo would eliminate this
Plastic food storage (+5.0, ingestion, ~50 p/day) — storing leftovers in plastic allows MP migration, especially when reheating
Vigorous activity (+4.0, inhalation) — higher breathing rate means more airborne particles inhaled, but exercising at home limits this
Tumble dryer (+3.0, inhalation, ~15 p/day) — venting synthetic microfibres indoors

Takeaway: Mark's score is "Elevated" despite a health-conscious lifestyle because common kitchen habits (plastic cutting board, plastic food storage, canned food) add up quietly. Switching to a wooden cutting board and glass food storage would drop his score by 10 points to 52 (Elevated).

Example 2: Emma — 8-year-old in Connecticut

8-year-old girl, 25 kg. Typical American diet — school lunch, mac and cheese, chicken nuggets. Drinks from a single-use plastic water bottle at school most days. Family uses plastic cutting boards and stores food in plastic containers. Gets driven to school in city traffic. Plays at the neighborhood playground. Wears a lot of synthetic athletic wear. Standard vacuum, tumble dryer, no air purifier or water filter.

Question	Answer	Weight	Particles/day
Age group	2-17	+4.0	—
Biological sex	Female	+1.0	—
Body weight	Under 40 kg	+4.5	—
Country	US	+1.0	—
Setting	Suburban	+2.0	—
Bottled water frequency	Daily	+18.0	~700
Dairy consumption	Moderate	+2.0	~30
Cooking oil	Moderate	+1.0	~15
Plastic cutting board	Yes	+5.0	~100
Plastic food storage	Yes	+5.0	~50
Laundry synthetics	Weekly	+1.0	~5
Dryer use	Tumble dryer	+3.0	~15
Vacuum type	Standard	+1.0	—
Synthetic clothing	Often	+4.0	~15
Single-use plastic	Often	+3.0	~30
City street hours	2 to 5	+1.0	~15
Total weights		+56.5	~975

Score: 32.5 + 56.5 = 89 / 100 — High

Estimated daily particles: ~975

Top factors:

Daily plastic water bottle (+18.0, ingestion, ~700 p/day) — by far the largest single contributor
Plastic cutting board (+5.0, ingestion, ~100 p/day)
Plastic food storage (+5.0, ingestion, ~50 p/day)
Body weight under 40 kg (+4.5) — at 25 kg, roughly 3x the dose per kilogram for the same particle intake vs a 75 kg adult
Age 2-17 (+4.0) — children have higher dose/kg and more incidental dust ingestion

Takeaway: Emma's score is "High" primarily because of one habit: drinking from a single-use PET water bottle every day at school (+18). Switching to a stainless steel water bottle would drop her score from 89 to 71 and reduce her particle intake from ~975 to ~275 per day.

Example 3: Lily — 6-month-old infant in Arizona

6-month-old girl, 7 kg. Fed formula prepared in polypropylene plastic bottles. Home has synthetic carpet, crib bedding is mostly synthetic. Arizona home uses filtered HVAC year-round. Multiple loads of baby laundry per week in the tumble dryer. Baby wears mostly synthetic onesies. Lots of single-use plastic (diapers, wipes, toys). Standard vacuum. Baby food stored in plastic containers.

Question	Answer	Weight	Particles/day
Age group	Under 2	+6.0	—
Biological sex	Female	+1.0	—
Body weight	Under 40 kg	+4.5	—
Country	US	+1.0	—
Setting	Suburban	+2.0	—
Dairy consumption	Heavy	+4.0	~80
Plastic food storage	Yes	+5.0	~50
Infant formula in plastic	Yes	+10.0	~1,600
Flooring	Synthetic carpet	+8.0	~50
Synthetic textiles	Mostly synthetic	+6.0	~30
Laundry synthetics	Multiple/week	+3.0	~20
Dryer use	Tumble dryer	+3.0	~15
Vacuum type	Standard	+1.0	—
Home ventilation	Filtered HVAC	-3.0	—
Synthetic clothing	Often	+4.0	~15
Single-use plastic	Always	+5.0	~60
Total weights		+60.5	~1,920

Note: Occupation, road hours, personal care, and sauna questions are hidden for infants.

Score: 32.5 + 60.5 = 93 / 100 — High

Estimated daily particles: ~1,920

Top factors:

Infant formula in plastic bottles (+10.0, ingestion, ~1,600 p/day) — PP baby bottles release 16.2M particles/L at formula prep temperature
Synthetic carpet (+8.0, both, ~50 p/day) — infants crawl on floors with high hand-to-mouth transfer
Synthetic crib textiles (+6.0, inhalation, ~30 p/day) — polyester crib sheets shed microfibres into air breathed 12-16 hours/day
Age under 2 (+6.0) — higher dose/kg, hand-to-mouth behavior, floor-level dust exposure
Single-use plastic always (+5.0, ingestion, ~60 p/day) — diapers, wipes, plastic toys, and food pouches

Takeaway: Lily's daily particle estimate (~1,920) is 8x Mark's and 2x Emma's. The dominant factor is formula in plastic bottles, contributing 83% of total intake. Switching to glass or stainless steel baby bottles would drop her score from 93 to 83 and reduce particle intake from ~1,920 to ~320 per day.

10. Revision History

v3.3 Aug 14, 2026 Privacy: 40 questions (was 41). The pregnancy/breastfeeding question was removed and previously stored answers to it were deleted, from both saved answer sets and the top-factor snapshots on past results. It carried a scoring weight of exactly 0.0 in every version that asked it, so no score changes and no recalibration: the baseline stays 32.5. The research it pointed to, microplastics detected in placental tissue (Ragusa 2021) and in breast milk (Ragusa 2022), now lives as a note in the About You section of this page instead of a personalized results card.

v3.2 Aug 14, 2026 Refinement: 41 questions (was 40). The v3.1 sliders are gone: age, body weight, and the two distance questions are answered as tappable ranges again, because the scoring model only ever used the bands and a drag control implied precision the model does not have. The single seafood question split into independent finfish and shellfish frequency rows inside the monthly food table, so type and frequency are recorded separately, and 'what kind of salt' became 'how often are meals seasoned with sea or rock salt', which a kitchen using more than one salt can actually answer. The food table now shows the count in every cell rather than a dot under a header row. Every question gained a tap-to-open explainer that links to its section of this page, and each section cites the research behind the question. Unanswered-question highlighting was rebuilt to change only color, never layout. Scoring baseline unchanged at 32.5: every new seafood and salt weight is pinned to a retired option's calibration anchor, so the v3.1 calibration carries over.

v3.1 Aug 13, 2026 Refinement: 40 questions (was 37). Age and body weight are now set directly with a slider rather than picked from a bracket, which let the body-weight scale grow from four bands to nine and the age scale from six to seven for finer per-kilogram and per-decade resolution. A single commute-choice question was retired in favor of four independent road-hours questions (highway, city, rural, transit), each answered in hours per week, so someone who works from home but drives on weekends is no longer forced into one commute category. Question wording rewritten in plainer, single-idea phrasing throughout. Scoring baseline recalibrated again, up slightly from v3.0's 32 to 32.5, re-derived the same way against a larger cohort of real v2.3 production assessments.

v3.0 Aug 10, 2026 Major restructure: 37 questions (was 34) presented as six tap-based scenes instead of seven category steps of dropdowns (country remains a searchable select), with perspective-neutral wording so the same questions work whether the respondent is answering for themselves or for a child or infant. Frequency questions for canned food, plastic takeaway containers, disposable hot-drink cups, plastic mesh tea bags, and chewing gum now share one monthly count scale ('0', '1 to 3', '4 to 15', '16+') mapped onto the existing never/monthly/weekly/daily scoring buckets. Added four new research-backed scoring factors: plastic mesh tea bags, chewing gum, plastic electric kettles, and artificial turf as an exercise setting. Scoring baseline recalibrated from 35 to 32, re-derived by replaying previously completed assessments through the new model so the overall distribution of scores stays comparable to the previous version, since the new factors only ever add exposure and the baseline had to come down to compensate; the calibration found a range of near-equivalent values and 32 sits inside it.

v2.3 Apr 08, 2026 UX fixes: perspective-aware voice for child/infant assessments (14 questions adapted), scroll-to-top on step transitions, tap-friendly tooltips, infant question filtering (hot beverages hidden for under-2, sauna hidden for children), added 'Vacuum and mop/sweep' combined option.

v2.2 Apr 08, 2026 Polish: 34 questions across 7 categories (was 35/6). Merged overlapping questions (water source + filtering, seafood frequency + type, etc.), added 'What You Drink' and 'Health & Recovery' steps, localized distance units for US users, step and question tooltips, kids-only single-use plastic question.

v2.0 Apr 08, 2026 Major restructure: 35 questions across 6 categories (was 19/5). Demographics moved to Step 1 for child/infant conditional logic. Added pathway tagging, daily particle estimates, literature-calibrated country index, conditional questions, expanded occupations. 130+ factors.

v1.0 Mar 20, 2026 Initial release. 19 questions, 29 factors across five categories.

11. References

Each entry is link-addressable; the per-question Sources lines in section 6 point here.

Amato-Lourenco, L.F. et al. (2020). Presence of airborne microplastics in human lung tissue. J Hazard Mater, 416, 126124.
Busse, K. et al. (2023). Release of microplastics from takeaway drink cups. J Hazard Mater, 441, 129982.
De Falco, F. et al. (2019). The contribution of washing processes of synthetic clothes to microplastic pollution. Sci Rep, 9, 6633.
Dris, R. et al. (2017). A first overview of textile fibers, including microplastics, in indoor and outdoor environments. Environ Pollut, 221, 453-458.
Habib, R.Z. et al. (2022). Microplastic contamination of chicken meat and fish through plastic cutting boards. Int J Environ Res Public Health, 19(20), 13442.
Hernandez, L.M. et al. (2019). Plastic teabags release billions of microparticles and nanoparticles into tea. Environ Sci Technol, 53(21), 12300-12310.
Hussain, K.A. et al. (2023). Assessing the release of microplastics and nanoplastics from plastic containers and reusable food pouches: Implications for human health. Environ Sci Technol, 57(26), 9782-9792.
Jambeck, J.R. et al. (2015). Plastic waste inputs from land into the ocean. Science, 347(6223), 768-771.
Karami, A. et al. (2017). The presence of microplastics in commercial salts from different countries. Sci Rep, 7, 46173.
Karami, A. et al. (2018). Microplastic and mesoplastic contamination in canned sardines and sprats. Sci Total Environ, 612, 1380-1386.
Kim, J.S. et al. (2018). Global pattern of microplastics (MPs) in commercial food-grade salts: sea salt as an indicator of seawater MP pollution. Environ Sci Technol, 52(21), 12819-12828.
Kole, P.J. et al. (2017). Wear and tear of tyres: A stealthy source of microplastics in the environment. Int J Environ Res Public Health, 14(10), 1265.
Kutralam-Muniasamy, G. et al. (2020). Branded milks – Are they immune from microplastics contamination? Sci Total Environ, 714, 136823.
Li, D. et al. (2020). Microplastic release from the degradation of polypropylene feeding bottles during infant formula preparation. Nat Food, 1, 746-754.
Luo, Y. et al. (2022). Raman imaging for the identification of Teflon microplastics and nanoplastics released from non-stick cookware. Sci Total Environ, 851, 158293.
Mason, S.A. et al. (2018). Synthetic polymer contamination in bottled water. Front Chem, 6, 407.
Mintenig, S.M. et al. (2019). Low numbers of microplastics detected in drinking water from ground water sources. Sci Total Environ, 648, 631-635.
Napper, I.E. et al. (2015). Characterisation, quantity and sorptive properties of microplastics extracted from cosmetics. Mar Pollut Bull, 99(1-2), 178-185.
O'Brien, S. et al. (2020). Airborne emissions of microplastic fibres from domestic laundry dryers. Sci Total Environ, 747, 141175.
Ragusa, A. et al. (2021). Plasticenta: First evidence of microplastics in human placenta. Environ Int, 146, 106274.
Ragusa, A. et al. (2022). Raman microspectroscopy detection and characterisation of microplastics in human breastmilk. Polymers, 14(13), 2700.
Rochman, C.M. et al. (2015). Anthropogenic debris in seafood: Plastic debris and fibers from textiles in fish and bivalves sold for human consumption. Sci Rep, 5, 14340.
Sheridan, E. et al. (2023). Investigating airborne microplastics and their potential sources. Environ Sci Technol, 57(47), 18913-18922.
Sommer, F. et al. (2018). Tire abrasion as a major source of microplastics in the environment. Aerosol Air Qual Res, 18, 2014-2028.
Van Cauwenberghe, L. & Janssen, C.R. (2014). Microplastics in bivalves cultured for human consumption. Environ Pollut, 193, 65-70.
WHO (2019). Microplastics in drinking-water. World Health Organization.
Wright, S.L. & Kelly, F.J. (2017). Plastic and human health: A micro issue? Environ Sci Technol, 51(12), 6634-6647.
Zhang, J. et al. (2022). Dietary fiber enhances the excretion of microplastics in human feces. Environ Pollut, 312, 120071.

This calculator is for informational purposes only and does not constitute medical advice. Weights reflect published research as of the version date and will be updated as the literature evolves. Questions? support@winnowlabs.com

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.