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Calculator Methodology

Current version: v2.3

1. Overview

The Winnow Microplastic Exposure Calculator estimates personal microplastic exposure based on 34 questions across seven categories. The calculator can be taken by adults for themselves or by parents/caregivers on behalf of a child or infant. Demographics are collected first (Step 1) so that irrelevant questions can be hidden for younger age groups.

Step order:

  1. About You (demographics & biology)
  2. Where You Live (environment)
  3. What You Drink (water & beverages)
  4. What You Eat (diet & food)
  5. Your Home (indoor environment)
  6. Daily Habits (lifestyle & occupation)
  7. Health & Recovery

Each step 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 = 35 (baseline) + sum of matched factor weights, clamped to 1–100

The baseline of 35 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
1–30 Low Below-average exposure; protective factors outweigh risk
31–55 Moderate Typical modern exposure; some room for improvement
56–75 Elevated Above-average exposure; several significant sources identified
76–100 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. Factor Weights

All answer options with a non-zero weight are listed below, grouped by category. Answers not shown carry a weight of 0 (no effect on your score).

About You

Who is this assessment for?

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).
61_plus +4.0 moderate both — Older adults have longer cumulative MP exposure and may have reduced clearance, with studies finding higher tissue concentrations in older age groups.
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.

What is your biological sex?

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.

What is your approximate body weight?

Answer Weight Evidence Pathway Particles/day Basis
under_50kg +4.0 strong both — Lower body weight means higher effective dose per kg for the same particle intake. A 40kg person has ~1.75x the dose/kg of a 70kg person.
50_70kg +2.0 strong both — Near-reference body weight. Slightly higher dose/kg than the 70kg reference adult used in most exposure studies.
over_90kg -2.0 strong both — Higher body weight means lower effective dose per kg for the same particle intake. A 100kg person has ~0.7x the dose/kg of a 70kg person.

Where You Live

Which country do you live in?

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.
HN +6.0 modeled both — Estimated from national indicators.
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.
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).

How would you describe your setting?

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 close do you live to a plastic, chemical, or recycling facility?

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 close do you live to a major highway or busy road?

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

What is your primary drinking water source?

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 you drink from plastic bottles (water, sports drinks, juice)?

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 do you drink hot beverages from disposable paper/plastic cups?

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).

What You Eat

How often do you eat seafood, and what type?

Answer Weight Evidence Pathway Particles/day Basis
mixed_frequent +12.0 strong ingestion ~300 Frequent mixed seafood consumption is a leading dietary MP source. Filter-feeding shellfish contain 0.1-10 particles/gram (10-100x finfish); finfish accumulate through food chain. Combined frequent intake: ~300 particles/day estimated (Van Cauwenberghe & Janssen 2014; Rochman et al. 2015).
shellfish +11.0 strong ingestion ~250 Regular shellfish consumption (mussels, oysters, shrimp): 0.1-10 particles/gram, ~100-1,000 particles per serving. A typical serving of mussels = 90 particles (Van Cauwenberghe & Janssen 2014).
regular_finfish +5.0 strong ingestion ~50 Regular finfish consumption contributes MP through bioaccumulation, primarily in GI tract (removed before eating) but also in muscle tissue. ~50 particles/day estimated (Rochman et al. 2015).
occasional_finfish +2.0 moderate ingestion ~15 Occasional finfish intake contributes modest MP via bioaccumulation. Lower than shellfish; GI tract removal reduces exposure.

How much dairy do you consume daily?

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.

What type of salt do you primarily use?

Answer Weight Evidence Pathway Particles/day Basis
sea_salt +2.0 moderate ingestion ~3 Sea salt contains 50-800 particles/kg vs rock salt 10-300/kg. At ~5g/day intake, sea salt contributes ~0.25-4 particles/day.

How often do you eat canned food?

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 do you eat from takeaway plastic containers?

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 does your child use single-use plastic items (pouches, sippy cups, plastic wrap)?

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.

Is the infant fed formula prepared in plastic bottles?

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.

Your Home

How do you use plastic with food at home?

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).

Do you use plastic cutting boards regularly?

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.

What is the condition of your nonstick (Teflon) cookware?

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 is the predominant flooring in your home?

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.

How would you describe your bedding, curtains, and upholstery?

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).

Do you use an air purifier at home?

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 you clean your floors?

Answer Weight Evidence Pathway Particles/day Basis
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.

Daily Habits

How do you handle laundry of synthetic garments (polyester, nylon, fleece)?

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).

How would you describe your clothing wardrobe composition?

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.

What best describes your occupation?

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 do you primarily commute?

Answer Weight Evidence Pathway Particles/day Basis
car_highway +4.0 moderate inhalation ~40 In-car cabin air contains 10-40 MP/m3 from both external tire wear ingress and cabin material shedding. Highway driving = ~40 extra particles/day (Kole et al. 2017).
cycling_roadside +4.0 moderate inhalation ~45 Roadside cycling combines elevated ambient MP (5-15/m3) with 2-3x higher breathing rate. ~45 extra particles inhaled per commute (Amato-Lourenco et al. 2020).
car_city +3.0 moderate inhalation ~25 City driving exposes to 5-25 MP/m3 in cabin. Lower than highway but significant (Kole et al. 2017).
public_transit +1.0 emerging inhalation ~10 Public transit exposes to 3-10 MP/m3. Lower exposure than driving due to lower cabin material shedding.

Do you use personal care products with microbeads or glitter?

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

How would you describe your physical activity and where you exercise?

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.
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 do you use a sauna?

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.

Do you eat a high-fiber diet?

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).

Do you regularly consume probiotics or fermented foods?

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, commute, 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
Commute mode Age group != under 2 Infants don't commute 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

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
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 +29.0 ~240

Score: 35 + 29 = 64 / 100 — Elevated

Estimated daily particles: ~240

Top factors:

  1. Canned food daily (+7.0, ingestion) — his canned sparkling water habit is the biggest single contributor
  2. Plastic cutting board (+5.0, ingestion, ~100 p/day) — vegetarians chop a lot of produce; switching to wood or bamboo would eliminate this
  3. Plastic food storage (+5.0, ingestion, ~50 p/day) — storing leftovers in plastic allows MP migration, especially when reheating
  4. Vigorous activity (+4.0, inhalation) — higher breathing rate means more airborne particles inhaled, but exercising at home limits this
  5. 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 54 (Moderate).

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 50 kg +4.0 —
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
Commute Car in city +3.0 ~25
Total weights +58.0 ~985

Score: 35 + 58 = 93 / 100 — High

Estimated daily particles: ~985

Top factors:

  1. Daily plastic water bottle (+18.0, ingestion, ~700 p/day) — by far the largest single contributor
  2. Plastic cutting board (+5.0, ingestion, ~100 p/day)
  3. Plastic food storage (+5.0, ingestion, ~50 p/day)
  4. Body weight under 50 kg (+4.0) — at 25 kg, ~2.8x the dose per kilogram vs a 70 kg adult
  5. 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 93 to 75 and reduce her particle intake from ~985 to ~285 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 50 kg +4.0 —
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 +60.0 ~1,920

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

Score: 35 + 60 = 95 / 100 — High

Estimated daily particles: ~1,920

Top factors:

  1. Infant formula in plastic bottles (+10.0, ingestion, ~1,600 p/day) — PP baby bottles release 16.2M particles/L at formula prep temperature
  2. Synthetic carpet (+8.0, both, ~50 p/day) — infants crawl on floors with high hand-to-mouth transfer
  3. Synthetic crib textiles (+6.0, inhalation, ~30 p/day) — polyester crib sheets shed microfibres into air breathed 12-16 hours/day
  4. Age under 2 (+6.0) — higher dose/kg, hand-to-mouth behavior, floor-level dust exposure
  5. 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 95 to 85 and reduce particle intake from ~1,920 to ~320 per day.

10. Revision History

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

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  • Ragusa, A. et al. (2021). Plasticenta: First evidence of microplastics in human placenta. Environ Int, 146, 106274.
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  • Sommer, F. et al. (2018). Tire abrasion as a major source of microplastics in the environment. Aerosol Air Qual Res, 18, 2014-2028.
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  • 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.