54 Microplastic Statistics

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These microplastic figures cover the measurement periods and populations identified in the available source material. Estimates, surveys and forecasts retain their reported scope.

Key Microplastic Statistics

The main findings are:

  • Only 9 studies were identified that measured microplastics in drinking-water (2019 review; drinking-water studies).
  • The systematic review analyzed 73 primary studies published since 2010 (2010–2023 literature; five oceans).
  • A global 0–5 metre marine-surface dataset estimated 3.29 × 10^14 microplastic items, primarily 0.33–5 millimetres in size (1998–2023 observations; global marine surface).
  • The modeled 2020 stock of initially buoyant marine plastics was 3,200 kilotonnes, with a 95% confidence interval of 3,000–3,400 kilotonnes (global 3D ocean).
  • The model estimated total marine plastic input at 500 kilotonnes per year, with a 95% confidence interval of 470–540 kilotonnes per year (2020 reference year; global marine environment).
  • Individual drinking-water samples reported 0 to 10,000 microplastic particles per litre (studies available through 2019; drinking water).
  • Across the five oceans, the review reported a concentration range of 0.002 to 22 items per cubic metre (2010–2023 studies; ocean surface waters).
  • Microplastic concentrations increased in 72.59% of global marine areas in the compiled dataset (1998–2023; global marine surface).
  • Particles larger than 25 millimetres contributed more than 95% of initially buoyant marine plastic mass: 3,100 of 3,200 kilotonnes (2020; global 3D ocean).
  • The estimated share of marine input from coastlines was 39% to 42% (2020 reference year; global marine environment).
  • Mean drinking-water concentrations ranged from 0.001 to 1,000 particles per litre (studies available through 2019; drinking water).
  • The same review reported a mean abundance of 1.21 items per cubic metre (2010–2023 studies; five-ocean surface waters).
  • The estimated annual growth rate of marine-surface microplastic concentration was 4.53% (1998–2023; global marine surface).
  • The model placed 59% to 62% of initially buoyant plastic mass at the ocean surface (2020; global 3D ocean).
  • The estimated share of marine input from fishing activity was 45% to 48% (2020 reference year; global marine environment).

Contents

Microplastic statistics in drinking water and water-supply systems

  • Only 9 studies were identified that measured microplastics in drinking-water (2019 review; drinking-water studies). (Microplastics in drinking-water: WHO news…)
  • Individual drinking-water samples reported 0 to 10,000 microplastic particles per litre (studies available through 2019; drinking water). (Microplastics in drinking-water: WHO news…)
  • Mean drinking-water concentrations ranged from 0.001 to 1,000 particles per litre (studies available through 2019; drinking water). (Microplastics in drinking-water: WHO news…)
  • Freshwater studies reported approximately 0 to 1,000 particles per litre (studies available through 2019). (Microplastics in drinking-water: WHO news…)
  • WHO used 10.4 particles per litre as a high average estimate for spectroscopically confirmed particles larger than 100 micrometres (2019 risk assessment; drinking water exposure assessment). (Microplastics in drinking-water)
  • WHO’s conservative exposure scenario used a particle diameter of 150 micrometres (2019 risk assessment; drinking water exposure assessment). (Microplastics in drinking-water)
  • The 150-micrometre sphere assumption has about 60 times the volume of a 150-micrometre-long, 10-micrometre-diameter fibre (2019 risk assessment; exposure-model particle shapes). (Microplastics in drinking-water)
  • A 150-micrometre sphere has three times the volume of a 100-micrometre sphere (2019 risk assessment; exposure-model particle sizes). (Microplastics in drinking-water)
  • WHO’s density assumption was 2.3 grams per cubic centimetre, compared with a reported polymer range of 0.9 to 2.3 grams per cubic centimetre (2019 risk assessment; drinking-water exposure assessment). (Microplastics in drinking-water)
  • The studied water-supply system had 13.23 to 134.79 particles per litre in water samples (2021 sampling reported in 2022 paper; one drinking-water treatment and distribution system). (Occurrence and distribution of microplastics…)
  • The same water-supply study found 569.99 to 751.73 particles per kilogram in pipe-scale samples (2021 sampling reported in 2022 paper; pipe scales in one water-supply system). (Occurrence and distribution of microplastics…)
  • Predominant pipe-scale particles were 50 to 100 micrometres, while water-sample particles were larger than 200 micrometres (2021 sampling reported in 2022 paper; one water-supply system). (Occurrence and distribution of microplastics…)

Evidence base was limited and methods differed.

Range spans individual samples using non-uniform methods.

Means came from different studies and size cutoffs.

Freshwater and drinking-water figures are not directly comparable because filter sizes differed.

High estimate based on available evidence, not a global monitoring average.

Scenario assumption for risk assessment.

Geometric comparison under the report’s idealized shapes.

Geometric comparison, not an observed particle distribution.

Uses a high density to make a conservative exposure estimate.

Single system study; results are not a national estimate.

Pipe-scale concentration is not tap-water concentration.

Size categories describe this study’s samples.

Microplastic statistics across oceans and surface waters

Review inclusion and measurement harmonization affect the pooled evidence.

Values combine heterogeneous sampling and identification methods.

Pooled mean is sensitive to skew and study methods.

Median reflects included studies, not uniform global sampling.

Quartile summarizes heterogeneous study results.

Ocean means depend on study coverage and methods.

Lowest pooled mean does not mean absence and may reflect sparse coverage.

Recalculated values depend on corrections for methodological inaccuracies.

Reported as (1.5 ± 36.2) × 10^5; very high variability and model correction are material.

Reported as (2.7 ± 117.9) × 10^5; very high variability and correction assumptions apply.

  • A global 0–5 metre marine-surface dataset estimated 3.29 × 10^14 microplastic items, primarily 0.33–5 millimetres in size (1998–2023 observations; global marine surface). (The Abundance of Microplastics in…)
  • Microplastic concentrations increased in 72.59% of global marine areas in the compiled dataset (1998–2023; global marine surface). (The Abundance of Microplastics in…)
  • The estimated annual growth rate of marine-surface microplastic concentration was 4.53% (1998–2023; global marine surface). (The Abundance of Microplastics in…)
  • Northern Hemisphere marine-surface microplastic loads were estimated to be 18.31% higher in summer than winter (1998–2023 seasonal comparison; Northern Hemisphere marine surface). (The Abundance of Microplastics in…)
  • The NOAA database contained about 14,000 microplastic records as of June 2023 (marine microplastic observations). (The NOAA NCEI marine microplastics…)
  • The NOAA database had 33 datasets from 23 unique lead authors (June 2023; marine microplastic observations). (The NOAA NCEI marine microplastics…)
  • Thirty of the NOAA database’s 33 datasets were obtained by email solicitation and 3 were self-reported (database compilation through June 2023; NOAA NCEI marine microplastic database). (The NOAA NCEI marine microplastics…)
  • Four of the 33 NOAA datasets came from citizen-science initiatives (database compilation through June 2023; NOAA NCEI marine microplastic database). (The NOAA NCEI marine microplastics…)
  • The Nature model estimated marine plastic input rising about 4% per year (model calibrated to recent decades; global marine environment). (Global mass of buoyant marine…)

Model/data compilation covers primarily the stated size range.

Trend is model-derived from compiled observations.

Growth rate is model-based and depends on data coverage.

Estimate includes a 95% confidence interval of 13.75% to 27.57%.

Database records are observations, not a globally representative sample.

Dataset count is not the same as site or sample count.

Provenance describes the database assembly, not environmental prevalence.

Citizen-science datasets may use different sampling designs.

This is a modeled all-plastic input trend, not a direct microplastic-only time series.

Microplastic mass, size classes and marine reservoirs

  • The modeled 2020 stock of initially buoyant marine plastics was 3,200 kilotonnes, with a 95% confidence interval of 3,000–3,400 kilotonnes (global 3D ocean). (Global mass of buoyant marine…)
  • Particles larger than 25 millimetres contributed more than 95% of initially buoyant marine plastic mass: 3,100 of 3,200 kilotonnes (2020; global 3D ocean). (Global mass of buoyant marine…)
  • The model placed 59% to 62% of initially buoyant plastic mass at the ocean surface (2020; global 3D ocean). (Global mass of buoyant marine…)
  • The model placed 36% to 39% of initially buoyant plastic mass deeper in the ocean (2020; global 3D ocean). (Global mass of buoyant marine…)
  • The model placed 1.5% to 1.9% of initially buoyant plastic mass on beaches (2020; global beaches). (Global mass of buoyant marine…)
  • The model estimated 49 to 53 kilotonnes of microplastics smaller than 5 millimetres in the modeled buoyant marine stock (2020; global marine environment). (Global mass of buoyant marine…)
  • Plastic between 5 and 25 millimetres accounted for 150 to 170 kilotonnes in the modeled stock (2020; global marine environment). (Global mass of buoyant marine…)
  • Large plastic items above 25 millimetres accounted for 90% to 98% of modeled plastic mass, or 2,800 to 3,300 kilotonnes (2020; global marine environment). (Global mass of buoyant marine…)
  • Microplastics smaller than 5 millimetres made up 8% of total plastic mass at the ocean surface in the cited Great Pacific Garbage Patch analysis (cited analysis; publication context 2023; Great Pacific Garbage Patch surface). (Global mass of buoyant marine…)

Model covers initially buoyant plastics across 0.1–1,600 mm.

Mass dominance differs from particle-number dominance.

Reservoir shares are model outputs.

Size class is model-defined and refers to initially buoyant plastics.

Size class is model-defined.

Range reflects model uncertainty and size-spectrum treatment.

This is a site-specific cited analysis, not a global ocean share.

Microplastic inputs, fragmentation and sediment export statistics

  • The model estimated total marine plastic input at 500 kilotonnes per year, with a 95% confidence interval of 470–540 kilotonnes per year (2020 reference year; global marine environment). (Global mass of buoyant marine…)
  • The estimated share of marine input from coastlines was 39% to 42% (2020 reference year; global marine environment). (Global mass of buoyant marine…)
  • The estimated share of marine input from fishing activity was 45% to 48% (2020 reference year; global marine environment). (Global mass of buoyant marine…)
  • The estimated share of marine input from rivers was 12% to 13% (2020 reference year; global marine environment). (Global mass of buoyant marine…)
  • Global riverine plastic input was estimated at 57 to 69 kilotonnes per year in the Nature model (2020 reference year; global rivers to ocean). (Global mass of buoyant marine…)
  • Coastline input was estimated at 190 to 220 kilotonnes per year (2020 reference year; global coastlines to ocean). (Global mass of buoyant marine…)
  • Fishing-related input was estimated at 220 to 260 kilotonnes per year (2020 reference year; global marine environment). (Global mass of buoyant marine…)
  • The model estimated 220 kilotonnes of plastics exported to marine sediments per year, including 6 kilotonnes of microplastics smaller than 5 millimetres (global marine sediments). (Global mass of buoyant marine…)
  • The model estimated 6,200 kilotonnes of initially buoyant plastics had reached marine sediments since 1950 (1950–2020 model period; global marine sediments). (Global mass of buoyant marine…)
  • About 73 kilotonnes per year were estimated to fragment into particles smaller than 0.1 millimetres (model estimate; global marine environment). (Global mass of buoyant marine…)
  • An estimated 2.2% of plastics larger than 5 millimetres fragmented into particles smaller than 5 millimetres each year (model estimate; global marine environment). (Global mass of buoyant marine…)
  • The model estimated that a sudden stop in new plastic input would remove only 10% of marine plastic mass within two years (counterfactual scenario beginning 2025; global marine environment). (Global mass of buoyant marine…)
  • At a continued 4% annual input-growth rate, the model projected marine plastic standing stock could double within two decades (scenario projection; global marine environment). (Global mass of buoyant marine…)

All initially buoyant marine plastics, not microplastics alone.

Model allocation of all-plastic input.

All-plastic riverine input; lower than earlier estimates cited by the authors.

All-plastic modeled input.

All-plastic modeled input, not microplastic-only.

Sediment export is modeled and the microplastic subset is size-defined.

Excludes plastics denser than seawater and may underestimate near-source sedimentation.

Fragmentation flux is model-derived and below the stated size threshold.

Model rate, not a direct global observation.

Scenario projection, not an observed intervention outcome.

Conditional projection assuming no effective additional mitigation or cleanup.

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