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Air quality measurements in the Netherlands 2025

RIVM Annual report (provisional)

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Authors
Affiliation

Pleuni Bongers

National Institute for Public Health and the Environment (RIVM)

Dennis Mooibroek

Published

March 10, 2026

Note

Please note that this is not the final report for 2025 as not all air quality measurement results for 2025 are available yet. The key statistics for lead, arsenic, cadmium, nickel, and benzo(a)pyrene and the winter means for sulphur dioxide will be added in a later version.

1 Air quality monitoring network in the Netherlands

Air quality in the Netherlands is monitored by the National Air Quality Monitoring Network (LML), which is administered by the National Institute for Public Health and the Environment (RIVM) in collaboration with its regional partners. The resulting data provide a detailed picture of air quality and the concentrations of the various pollutants at the monitoring stations.

This annual report gives an overview of the key measurement values for specific pollutants in 2025 from measurements by RIVM and two of its regional partners DCMR Environmental Protection Agency (DCMR) and The Public Health Service of Amsterdam (GGD Amsterdam). Measurements are carried out under EN ISO/IEC 17025:2017 accreditation by RIVM under L224 in collaboration with its regional partners DCMR (L520) and GGD Amsterdam (L426) who are accredited according to the same ISO standard. Analysis of heavy metals is outsourced to an external analytical laboratory that is accredited according to EN ISO/IEC 17025:2017 under L086. See Appendix A for an overview of all the accreditation certificate numbers for the measurements in this report. Appendix A also includes an overview of ambient air quality limit values. Besides the current limit values from the 2008/50/EC and 2004/107/EC directives, this report will take into account the revised EU directive (2024/2881) on ambient air quality and cleaner air for Europe and, in some occasions, the Air Quality Guideline (AQG) levels from the World Health Organisation (WHO) reported in 2021.

The air quality monitoring sites have specific encoding for EU reporting, where all sites in the Netherlands start with NL, followed by 10 for RIVM sites (L224), 01 for DCMR measurement sites (L520) and 49 for sites from GGD Amsterdam (L426). The remaining 3 numbers denote the unique monitoring site. For some sites starting with 49, measurements are carried out by GGD Amsterdam on behalf of Provincie Noord-Holland (PNH). Those sites have PNH listed as the responsible network. When hovering over the site codes in this report’s tables, the Dutch site name and location along with the responsible monitoring network will show up. The map below provides an overview of all stations for which key statistics are shown in this report, split up per pollutant group. Every dot represents an individual station and clicking on it will bring up a pop-up with the station name and code, the responsible network, area type, and station type. For more information on the monitoring sites, monitoring instruments, and sampling practices, please consult the metadata on the LML data catalog on the public RIVM website. For additional information including measurement uncertainties, see the accompanying README.

2 Key concentration values per component

The upcoming tables contain the key statistics per component for 2025, where mean is the yearly averaged concentration - based on either hourly or daily (24-h) values, P50 and P98 denote the 50th and 98th percentile, max is the maximum measured concentration value, n is the number of valid data points in hours or days, % is the percentage of valid data, max.roll.24 denotes the maximum value of the rolling 24-h mean and max.roll.8 of the 8-h mean. All of these values are in µg/m³ unless otherwise specified and with the exception of values for lead, arsenic, cadmium, nickel and benzo(a)pyrene, which are in ng/m3. Columns that are colored in red indicate an exceedance of the EU limit values from 2008/50/EC or 2004/107/EC, orange represents an exceedance of the revised EU limit values from EU Directive 2024/2881. For several pollutants, additional columns have been added relating to component-specific target values. The summary tables where the annual means have been grouped by site type, only contain yearly averages where data capture meets EU requirements.

Most numbers in this report have been rounded to one decimal place and where deemed logical, to 0 or 2 decimal places. However, for testing against the limit values, the rounding practices of the limit values in the relevant EU Directives have been taken into account, of which most are a whole number. Key statistics rounded to more decimal places than in this report are available on the RIVM public data catalog for air quality measurements, as well as the underlying hourly and daily data.

For some pollutants, relevant statistics are also plotted on an interactive map to provide a quick overview of the concentration distribution throughout the Netherlands and compliance with limit values, and to view specific stations more easily. Upon clicking on a colored dot representing a station, a pop-up with the site name and code, the responsible network, the site type, the component, and the relevant value for that component is displayed. Please note that the colors do not necessarily match the colors in the tables of the key statistics. Instead, where possible, the same color categories have been used as the European Environment Agency (EEA) applies in their maps for easier comparison with European data. Only stations with at least 85% of valid data have been included in the maps.

2.1 Nitrogen dioxide

Key statistics for NO2 in 2025
mean1 P50 P98 max median n % exc_2002 max.roll.24 max.roll.8
Rural Background

NL01497

 17.0 11.0 72.2 138.7 11.0 8749 99.9 0 77.3 103.1

NL10107

 10.6 8.2 31.3 62.0 8.2 8712 99.5 0 34.7 37.4

NL10131

 11.2 8.6 36.2 91.8 8.6 8734 99.7 0 40.4 56.0

NL10133

 7.9 6.4 25.2 43.0 6.4 8616 98.4 0 32.2 36.1

NL10230

 13.2 9.9 42.2 230.3 9.9 8735 99.7 3 62.0 144.6

NL10235

 12.5 10.3 38.1 88.8 10.3 8719 99.5 0 43.9 62.0

NL10246

 14.3 11.1 45.0 73.4 11.1 8724 99.6 0 45.9 62.3

NL10248

 11.9 8.7 43.0 144.6 8.7 8657 98.8 0 48.2 87.9

NL10301

 11.3 8.3 40.3 93.2 8.3 8684 99.1 0 43.3 73.1

NL10318

 11.8 8.5 40.4 85.9 8.5 8726 99.6 0 48.6 67.9

NL10437

 13.6 10.2 44.9 85.9 10.2 8656 98.8 0 46.8 64.5

NL10444

 10.8 8.0 40.1 65.3 8.0 8734 99.7 0 43.3 51.7

NL10538

 9.7 5.8 42.8 103.5 5.8 8632 98.5 0 48.9 60.6

NL10617

 7.7 5.8 28.7 51.4 5.8 8630 98.5 0 36.2 40.3

NL10633

 10.1 7.6 35.3 72.2 7.6 8467 96.7 0 42.4 56.9

NL10644

 11.4 8.8 36.0 66.1 8.8 8691 99.2 0 40.2 49.7

NL10722

 9.2 7.1 31.6 58.6 7.1 8658 98.8 0 37.3 43.9

NL10738

 9.4 7.4 30.5 87.2 7.4 8688 99.2 0 39.2 48.7

NL10807

 7.3 5.7 26.6 43.6 5.7 8633 98.6 0 36.9 41.1

NL10818

 7.7 5.7 28.7 47.5 5.7 8349 95.3 0 37.1 41.2

NL10918

 6.2 4.5 25.9 52.6 4.5 8656 98.8 0 35.1 43.7

NL10929

 6.7 5.1 23.6 41.0 5.1 8650 98.7 0 28.7 34.7

NL10934

 6.1 4.6 22.5 94.2 4.6 8613 98.3 0 33.8 40.0

NL49564

 16.9 13.0 55.3 105.8 13.0 8567 97.8 0 55.7 78.1

NL49565

 17.4 12.9 59.2 108.8 12.9 8663 98.9 0 58.4 78.4

NL49680

 10.6 7.6 41.2 67.9 7.6 8657 98.8 0 49.2 56.7

NL49703

 14.3 10.5 48.3 91.2 10.5 8661 98.9 0 53.8 70.8
Urban Background

NL01485

 19.0 14.5 61.8 106.1 14.5 8722 99.6 0 60.8 85.0

NL01488

 18.2 13.6 60.2 108.0 13.6 8746 99.8 0 68.7 91.7

NL01494

 21.9 17.4 65.3 132.7 17.4 8743 99.8 0 72.1 105.3

NL01495

 22.3 18.2 70.2 132.7 18.2 8731 99.7 0 71.1 99.5

NL01912

 18.6 14.6 55.1 95.4 14.6 8650 98.7 0 59.6 72.0

NL10138

 10.8 8.0 37.1 62.7 8.0 8721 99.6 0 39.1 50.7

NL10241

 13.4 10.3 44.1 81.9 10.3 8712 99.5 0 47.1 63.9

NL10247

 12.6 9.8 39.0 66.0 9.8 8680 99.1 0 40.3 47.8

NL10404

 18.0 12.5 66.3 131.2 12.5 8683 99.1 0 74.3 96.4

NL10418

 20.2 16.2 59.8 100.8 16.2 8711 99.4 0 66.9 88.9

NL10442

 14.2 11.0 44.5 81.2 11.0 8712 99.5 0 45.8 56.1

NL10446

 17.5 12.7 57.1 99.7 12.7 8730 99.7 0 60.0 82.7

NL10643

 13.4 10.3 43.8 78.3 10.3 8595 98.1 0 55.9 64.2

NL10742

 14.9 11.4 46.6 78.6 11.4 8646 98.7 0 51.7 64.7

NL10821

 13.3 11.2 34.6 44.5 11.2 649 7.4 0 35.1 42.7

NL10938

 6.9 5.2 25.5 50.5 5.2 8450 96.5 0 32.3 38.4

NL49003

 14.2 10.6 49.1 125.1 10.6 8342 95.2 0 54.3 68.0

NL49014

 15.3 11.7 49.1 85.5 11.7 8737 99.7 0 50.6 66.0

NL49019

 17.6 13.6 56.8 87.6 13.6 8746 99.8 0 57.1 71.0

NL49021

 13.1 9.8 44.5 76.8 9.8 8238 94.0 0 49.3 60.9

NL49022

 14.7 10.7 51.8 85.7 10.7 8739 99.8 0 58.8 69.5

NL49561

 19.3 14.5 60.3 106.4 14.5 8718 99.5 0 67.5 84.4

NL49701

 15.6 10.7 55.1 99.2 10.7 8737 99.7 0 66.3 85.3
Roadside

NL01487

 24.4 20.4 67.1 103.9 20.4 8737 99.7 0 70.9 91.4

NL01489

 20.9 17.2 58.5 93.4 17.2 8286 94.6 0 68.8 82.9

NL01491

 22.3 18.0 64.2 124.4 18.0 8733 99.7 0 71.8 99.2

NL01493

 24.7 20.4 66.6 102.8 20.4 8747 99.9 0 74.5 89.5

NL10136

 16.7 13.4 50.5 127.1 13.4 8679 99.1 0 47.5 60.5

NL10236

 15.0 11.9 43.9 79.5 11.9 8613 98.3 0 43.7 57.3

NL10237

 16.6 13.9 44.6 89.3 13.9 8651 98.8 0 44.1 64.8

NL10240

 19.8 17.1 52.3 88.6 17.1 8585 98.0 0 53.4 66.5

NL10445

 21.0 16.2 64.6 140.6 16.2 8696 99.3 0 91.6 113.0

NL10449

 24.9 20.2 68.7 98.9 20.2 8668 99.0 0 91.3 89.1

NL10450

 24.9 20.9 71.4 127.5 20.9 8655 98.8 0 81.8 97.2

NL10550

 15.8 12.3 49.4 84.8 12.3 8670 99.0 0 51.8 69.6

NL10636

 15.3 12.2 47.8 86.4 12.2 8634 98.6 0 56.5 68.7

NL10639

 16.8 13.3 50.8 88.8 13.3 8599 98.2 0 56.1 74.0

NL10641

 17.9 15.2 48.1 121.3 15.2 8623 98.4 0 60.8 91.7

NL10741

 20.9 17.8 56.0 171.2 17.8 8732 99.7 0 58.0 81.0

NL10937

 15.1 12.8 39.9 93.8 12.8 8668 99.0 0 45.3 75.8

NL49002

 22.7 19.1 64.0 109.1 19.1 8748 99.9 0 65.6 89.2

NL49007

 28.4 24.8 72.3 245.3 24.8 8654 98.8 1 79.8 111.1

NL49012

 22.1 18.1 62.8 138.0 18.1 8561 97.7 0 68.0 97.3

NL49017

 20.0 16.4 57.6 97.4 16.4 8720 99.5 0 61.1 79.8

NL49020

 22.7 18.6 64.5 116.4 18.6 8657 98.8 0 68.2 96.6
Industrial

NL01496

 22.9 18.4 79.7 185.7 18.4 8724 99.6 0 84.2 141.4

NL01913

 16.1 12.8 53.4 120.4 12.8 8694 99.2 0 56.5 75.6

NL49546

 21.8 17.4 67.6 156.3 17.4 8663 98.9 0 74.4 133.2

NL49551

 19.9 16.1 56.3 134.0 16.1 8686 99.2 0 65.6 93.2

NL49553

 15.6 9.9 56.9 102.1 9.9 8635 98.6 0 57.1 78.0

NL49704

 21.0 16.4 63.0 184.7 16.4 8671 99.0 0 73.3 116.3
Rows where the text is greyed out indicates a data capture < 85%
1 Orange color indicates exceedance of the future EU limit value from 01-01-2030 (2024/2881/EC)
and red of the current EU limit value (2008/50/EC)
2 Number of hours where concentrations exceed 200 µg/m³
- Color indicates exceedance of > 3 times (orange) or > 18 times (red) per calendar year
* Hovering over the station code will show the site name, location and responsible monitoring network
Table 1: Key concentration values for nitrogen dioxide in 2025 (in μg/m3)
Annual NO2 means per station type in 2025
type mean n
Rural Background 11.0 27
Urban Background 16.0 22
Roadside 20.4 22
Industrial 19.5 6
Table 2: Summary table for nitrogen dioxide in 2025 (in μg/m3)

2.2 Particulate matter

Key statistics for PM10 in 2025
mean1 P50 P98 max median n % exc_50_d2
Rural Background

NL01497

 16.1 13.3 43.6 61.5 13.3 365 100.0 5

NL10131

 17.3 14.9 46.9 64.3 15.0 360 98.6 4

NL10133

 15.1 13.7 33.8 51.9 13.7 344 94.2 1

NL10230

 17.3 15.2 45.3 52.8 15.2 364 99.7 2

NL10235

 15.8 13.7 40.1 53.9 13.7 363 99.5 3

NL10246

 16.0 13.8 46.0 54.2 13.8 363 99.5 4

NL10248

 15.8 12.7 42.5 52.2 12.7 355 97.3 1

NL10318

 17.6 14.8 46.7 74.1 14.8 358 98.1 3

NL10437

 15.5 13.4 42.5 52.6 13.5 352 96.4 1

NL10444

 14.3 12.8 33.9 55.4 12.8 359 98.4 1

NL10538

 14.3 12.5 36.8 52.9 12.5 353 96.7 2

NL10617

 14.1 11.7 40.4 54.2 11.7 344 94.2 2

NL10633

 14.6 12.6 38.9 55.1 12.6 345 94.5 2

NL10644

 14.4 11.5 43.5 53.5 11.5 354 97.0 3

NL10722

 15.2 13.3 38.7 61.5 13.3 363 99.5 2

NL10738

 16.6 14.5 39.8 58.6 14.5 360 98.6 4

NL10807

 14.3 12.1 47.0 61.5 12.1 353 96.7 4

NL10818

 13.9 11.5 41.4 53.0 11.5 352 96.4 3

NL10918

 12.7 10.6 37.3 54.0 10.6 355 97.3 1

NL10929

 13.3 10.7 38.9 49.3 10.7 358 98.1 0

NL10934

 14.0 11.7 43.1 51.1 11.7 349 95.6 1

NL49556

 12.5 10.6 38.6 51.4 10.6 349 95.6 1

NL49564

 16.0 14.0 42.9 56.6 14.0 353 96.7 3

NL49565

 14.8 12.7 42.7 55.8 12.7 362 99.2 2

NL49680

 14.7 12.8 37.1 52.7 12.8 363 99.5 2

NL49703

 17.3 15.0 46.6 56.0 15.0 348 95.3 3

NL49980

 11.5 10.4 21.3 24.9 10.4 181 49.6 0
Urban Background

NL01485

 16.9 14.5 44.9 58.3 14.5 365 100.0 5

NL01488

 17.6 15.3 46.9 64.1 15.3 365 100.0 4

NL01494

 18.6 16.3 47.6 62.9 16.3 365 100.0 6

NL01495

 16.2 13.6 42.9 54.8 13.6 364 99.7 3

NL01912

 16.5 14.0 44.7 63.3 14.0 363 99.5 3

NL10138

 14.1 12.6 32.7 50.1 12.7 362 99.2 0

NL10241

 18.8 16.3 47.4 56.5 16.3 342 93.7 5

NL10247

 17.2 15.4 41.2 59.6 15.4 357 97.8 3

NL10404

 19.0 16.8 46.8 61.2 16.8 359 98.4 6

NL10418

 19.9 17.6 49.4 61.6 17.6 365 100.0 7

NL10442

 16.7 14.6 43.8 56.8 14.6 362 99.2 3

NL10446

 16.4 14.5 39.8 54.1 14.6 364 99.7 3

NL49014

 17.7 15.4 44.7 57.9 15.4 359 98.4 4

NL49016

 16.3 13.9 44.7 55.7 14.0 336 92.1 3

NL49561

 16.9 14.8 43.6 111.3 14.9 362 99.2 4

NL49570

 18.3 16.5 45.9 64.2 16.5 346 94.8 4

NL49701

 15.4 13.3 39.1 53.6 13.3 364 99.7 2
Roadside

NL01487

 18.8 16.3 48.9 65.0 16.3 365 100.0 4

NL01489

 18.5 15.6 47.4 61.9 15.6 358 98.1 4

NL01491

 18.8 16.2 49.6 60.7 16.2 365 100.0 6

NL01493

 18.3 15.8 46.2 65.3 15.8 365 100.0 5

NL10136

 15.5 14.0 38.0 56.9 14.0 357 97.8 3

NL10236

 16.5 14.7 39.9 50.3 14.7 361 98.9 0

NL10237

 18.9 17.4 43.8 61.4 17.4 362 99.2 6

NL10240

 18.9 16.8 43.1 52.2 16.8 360 98.6 2

NL10445

 19.3 17.4 44.9 59.7 17.4 363 99.5 4

NL10449

 19.9 17.6 47.4 63.3 17.6 356 97.5 6

NL10450

 21.0 18.6 51.3 64.5 18.7 364 99.7 8

NL10550

 18.6 16.5 43.8 63.5 16.5 365 100.0 4

NL10636

 16.0 14.1 40.6 52.6 14.1 359 98.4 1

NL10639

 17.2 14.9 41.3 56.1 14.9 363 99.5 4

NL10641

 15.7 13.3 42.5 58.2 13.3 360 98.6 4

NL10741

 18.6 16.3 45.2 65.4 16.3 361 98.9 5

NL10937

 17.5 14.9 46.2 59.0 15.0 362 99.2 3

NL49007

 20.3 18.4 46.9 62.5 18.4 355 97.3 5

NL49012

 16.8 14.7 42.6 55.2 14.7 365 100.0 2

NL49017

 15.8 13.8 40.2 56.6 13.8 361 98.9 2

NL49020

 17.8 15.3 44.6 56.9 15.3 365 100.0 2
Industrial

NL01496

 18.0 15.2 44.9 60.5 15.2 364 99.7 5

NL01913

 20.3 17.8 52.3 71.6 17.8 359 98.4 8

NL49546

 20.0 14.6 54.9 391.0 14.7 360 98.6 9

NL49551

 18.4 16.1 44.9 60.6 16.1 362 99.2 5

NL49553

 21.0 19.6 45.7 66.5 19.6 359 98.4 5

NL49557

 20.1 18.2 48.4 68.7 18.2 359 98.4 6

NL49572

 16.3 15.2 37.4 57.6 15.3 340 93.2 2

NL49573

 24.0 20.0 63.6 95.2 20.0 362 99.2 26

NL49704

 14.5 12.1 39.8 54.6 12.1 363 99.5 2
Rows where the text is greyed out indicates a data capture < 85%
1 Orange color indicates exceedance of the future EU limit value from 01-01-2030 (2024/2881/EC)
and red of the current EU limit value (2008/50/EC)
2 Number of days where concentrations exceed 50 µg/m³
- Red color indicates exceedance of > 35 times per calendar year
Table 3: Key concentration values for PM10 in 2025 (in μg/m3)
Annual PM10 means per station type in 2025
type mean n
Rural Background 15.1 26
Urban Background 17.2 17
Roadside 18.0 21
Industrial 19.2 9
Table 4: Summary table for PM10 in 2025 (in μg/m3)
Key statistics for PM2.5 in 2025
mean1 P50 P98 max median n %
Rural Background

NL01497

 8.9 6.1 34.0 49.2 6.1 365 100.0

NL10131

 9.4 7.2 31.0 45.5 7.2 357 97.8

NL10230

 9.7 7.5 33.1 46.6 7.5 359 98.4

NL10248

 10.4 8.0 30.1 46.3 8.1 346 94.8

NL10444

 8.5 6.5 29.5 46.4 6.5 361 98.9

NL10538

 9.2 6.9 35.1 46.9 6.9 357 97.8

NL10644

 8.3 5.6 31.1 44.4 5.6 358 98.1

NL10738

 8.7 6.2 29.7 47.6 6.2 361 98.9

NL10934

 7.2 5.0 32.9 41.2 5.0 357 97.8

NL49556

 7.2 4.5 36.1 50.3 4.5 362 99.2

NL49680

 8.9 6.3 34.8 47.1 6.3 363 99.5

NL49703

 10.2 7.2 36.4 50.8 7.2 348 95.3

NL49980

 8.6 7.8 17.0 20.1 7.8 181 49.6
Urban Background

NL01485

 9.5 6.5 36.7 47.2 6.5 365 100.0

NL01488

 9.5 6.7 35.4 45.4 6.7 365 100.0

NL01494

 10.2 6.9 39.7 50.3 6.9 365 100.0

NL01495

 8.9 6.1 32.8 45.6 6.1 364 99.7

NL01912

 8.7 6.1 34.3 44.0 6.1 363 99.5

NL10138

 6.7 4.6 24.2 40.8 4.7 334 91.5

NL10241

 9.2 6.6 34.1 44.3 6.6 356 97.5

NL10247

 9.3 7.1 32.5 44.6 7.1 355 97.3

NL10404

 10.1 7.5 35.8 47.3 7.5 354 97.0

NL10418

 10.2 7.6 34.2 44.3 7.6 357 97.8

NL10643

 8.2 5.6 32.9 42.3 5.6 333 91.2

NL10742

 7.8 5.6 26.8 45.6 5.6 331 90.7

NL10821

 8.3 6.2 31.9 46.8 6.2 360 98.6

NL10938

 7.4 5.2 30.9 37.4 5.2 357 97.8

NL49014

 9.6 7.4 31.8 43.6 7.4 361 98.9

NL49016

 9.8 6.8 36.4 50.9 6.8 336 92.1

NL49561

 10.6 8.0 34.7 45.6 8.1 362 99.2

NL49570

 10.8 8.3 35.8 50.3 8.3 360 98.6

NL49701

 9.0 6.3 31.7 47.0 6.4 364 99.7
Roadside

NL01487

 10.4 7.4 38.3 49.8 7.4 365 100.0

NL01489

 9.9 6.9 36.4 48.2 7.0 358 98.1

NL01491

 10.0 7.0 35.7 48.9 7.0 365 100.0

NL01493

 9.4 6.6 35.0 49.1 6.6 365 100.0

NL10136

 7.2 5.5 23.7 41.6 5.5 351 96.2

NL10240

 9.8 7.4 35.2 43.3 7.4 350 95.9

NL10449

 12.3 9.5 40.2 108.4 9.5 360 98.6

NL10450

 10.5 8.1 37.6 47.6 8.1 358 98.1

NL10636

 9.1 6.6 34.1 42.5 6.6 360 98.6

NL10641

 8.7 5.9 34.5 47.0 6.0 346 94.8

NL10741

 8.7 6.5 29.9 49.4 6.5 360 98.6

NL10937

 6.7 4.4 30.3 40.1 4.4 350 95.9

NL49007

 11.0 8.7 32.2 44.1 8.7 345 94.5

NL49012

 9.6 6.8 33.4 47.8 6.8 365 100.0

NL49017

 9.1 6.9 32.0 45.4 6.9 356 97.5
Industrial

NL01496

 10.1 6.9 35.7 51.2 6.9 364 99.7

NL01913

 11.2 8.5 36.2 50.1 8.5 359 98.4

NL49551

 7.9 5.5 31.9 47.4 5.5 352 96.4

NL49553

 9.8 7.4 34.8 51.5 7.4 362 99.2

NL49557

 9.6 6.7 33.6 51.1 6.7 362 99.2

NL49572

 11.5 9.2 35.4 48.9 9.2 358 98.1

NL49573

 12.6 9.9 38.3 48.7 9.9 357 97.8

NL49704

 8.4 5.8 30.2 44.7 5.8 363 99.5
Rows where the text is greyed out indicates a data capture < 85%
1 Orange color indicates exceedance of the future EU limit value from 01-01-2030 (2024/2881/EC)
and red of the current EU limit value (2008/50/EC)
Table 5: Key concentration values for PM2.5 in 2025 (in μg/m3)
Annual PM2.5 means per station type in 2025
type mean n
Rural Background 8.9 12
Urban Background 9.1 19
Roadside 9.5 15
Industrial 10.1 8
Table 6: Summary table for PM2.5 in 2025 (in μg/m3)
Statistics to determine the AEI for PM2.5
2023 2024 2025 average_3y
Urban Background

NL01494

 8.7 8.8 10.2 9.2

NL10138

 6.5 7.4 6.7 6.9

NL10241

 7.7 9.8 9.2 8.9

NL10247

 10.2 - 9.3 9.8

NL10404

 6.9 7.4 10.1 8.1

NL10418

 7.8 7.8 10.2 8.6

NL10643

 7.5 9.3 8.2 8.3

NL10742

 8.4 8.2 7.8 8.1

NL10821

 7.2 6.1 8.3 7.2

NL10938

 6.0 6.3 7.4 6.5

NL49014

 7.8 8.6 9.6 8.7

NL49701

 8.8 8.2 9.0 8.7
* A hyphen is used in case of insufficient valid data to provide an annual mean
Table 7: Annual means for PM2.5 (in μg/m3) on selected urban background sites and the 3-year average to determine the Average Exposure Indicator (AEI)

The Average Exposure Indicator (AEI) for PM2.5 assesses the general population’s long-term exposure to fine particles in urban areas and is based on a 3-year average measured at urban background stations. The AEI in year 2025 is 8.2 µg/m³.

Key statistics for UFP in 2025
mean P50 P98 max median n % max.roll.24 max.roll.8
Rural Background

NL49680

 5186 4790 12750 31390 4790 8418 96.1 15570 18051
Urban Background

NL01494

 13406 11823 33746 118215 11823 8533 97.4 66914 49966

NL49022

 12590 9710 43660 85420 9710 8064 92.1 36050 54621
Industrial

NL01913

 10285 8513 32264 109548 8513 7415 84.6 33771 43540
Rows where the text is greyed out indicates a data capture < 85%
Table 8: Key concentration values for ultrafine particles (UFP) in 2025 (in number of particles/cm3)

2.3 Sulphur dioxide

Key statistics for SO2 in 2025
mean1 P50 P98 max median n % exc_350_h2 max.roll.24 max.roll.8 exc_125_d3
Rural Background

NL10133

 0.4 0.3 2.3 15.8 0.3 8595 98.1 0 3.2 6.6 0

NL10318

 0.8 0.4 4.4 32.0 0.4 8651 98.8 0 6.6 10.8 0

NL10444

 0.6 0.4 3.1 11.2 0.4 8668 99.0 0 5.4 6.9 0

NL10644

 0.5 0.3 2.6 7.9 0.3 8615 98.3 0 3.9 5.4 0

NL10722

 0.5 0.2 4.2 20.0 0.2 8624 98.4 0 5.4 9.3 0

NL10934

 0.3 0.2 1.5 5.1 0.2 8567 97.8 0 2.1 2.6 0
Urban Background

NL01485

 1.3 0.6 7.1 79.3 0.6 8714 99.5 0 27.8 46.8 0

NL49016

 0.6 0.4 2.4 12.5 0.4 8108 92.6 0 5.0 5.4 0
Industrial

NL01484

 2.3 1.3 14.4 359.1 1.3 8637 98.6 1 32.8 58.9 0

NL01496

 1.7 1.1 8.5 33.0 1.1 8583 98.0 0 11.4 14.4 0

NL49551

 4.2 1.5 33.9 116.9 1.5 8520 97.3 0 47.2 94.2 0

NL49553

 4.4 1.0 33.5 87.6 1.0 8606 98.2 0 44.9 70.8 0

NL49704

 1.1 0.9 4.2 24.5 0.9 8738 99.7 0 4.9 10.7 0
Rows where the text is greyed out indicates a data capture < 85%
1 Orange color indicates exceedance of the yearly limit value of 20 µg/m³ (2024/2881/EC)
2 Number of hours where concentrations exceed 350 µg/m³
- Color indicates exceedance of > 3 times (orange) or > 24 times (red) per calendar year
3 Number of days where concentrations exceed 125 µg/m³
- Red color indicates exceedance of > 3 times per calendar year
Table 9: Key concentration values for sulphur dioxide in 2025 (in μg/m3)
Annual SO2 means per station type in 2025
type mean n
Rural Background 0.5 6
Urban Background 0.9 2
Industrial 2.7 5
Table 10: Summary table for sulphur dioxide in 2025 (in μg/m3)

2.4 Ozone

For ozone, there is no limit value based on the annual mean, instead the number of days where the maximum daily rolling 8-h mean of ozone concentrations exceed 120 µg/m³ is assessed. For the long-term objective, this may not be exceeded on any day. The target value for the protection of human health takes into account data that is averaged over three years. Until 1 January 2030, 120 µg/m³ may not be exceeded on more than 25 days per calendar year averaged over three years and thereafter, it’s set to a maximum of 18 days. See Table 13 for the number of exceedance days in 2023, 2024 and 2025 and their 3-year averages.

In addition, the number of days on which at least one exceedance of the information or alert threshold value is observed, is shown in the columns exc_info and exc_alert in the table below. The information threshold for ozone is 180 µg/m³ for one-hour ozone concentrations and the alert threshold for ozone is 240 µg/m³ for one-hour ozone concentrations.

The ‘Accumulated Ozone exposure over a Threshold of 40 parts per billion’ (AOT40), expressed in (µg/m³) × hours, means the sum of the difference between hourly concentrations greater than 80 µg/m³ (= 40 parts per billion) and 80 µg/m³ over a given period using only the 1-hour values measured between 8:00 and 20:00 Central European Time (CET) each day (EU Directive 2024/2881). The target value for AOT40 is 18000 µg/m³ x h averaged over 5 years. Note that the aot40 values in the table are only for the year 2025 and based on measurements from May up to and including July.

Another widely used ozone indicator for health impact assessment recommended by WHO called somo35 is given in the table. This represents the sum of all daily maximum 8 hour moving averages over 35 ppb - equivalent to 70 µg/m³.

Key statistics for O3 in 2025
mean P50 P98 max median n % max.roll.24 max.roll.8 exc_1201 exc_info2 exc_alert3 aot404 somo355
Rural Background

NL10107

 48.2 46.7 118.7 175.8 46.7 8634 98.6 119.2 162.3 20 0 0 13210.9 3846.2

NL10131

 47.8 46.0 115.2 198.3 46.0 8644 98.7 116.4 167.6 17 2 0 11967.0 3584.3

NL10230

 50.4 48.6 116.6 173.5 48.6 8565 97.8 126.9 162.6 16 0 0 12445.3 3846.7

NL10235

 48.5 47.5 113.1 206.6 47.5 8639 98.6 117.2 162.6 13 1 0 10955.6 3464.6

NL10301

 57.2 58.2 113.6 210.8 58.2 8505 97.1 142.4 176.7 17 4 0 12229.2 3907.6

NL10318

 52.2 51.5 109.2 178.4 51.5 8629 98.5 110.2 163.3 11 0 0 9293.3 3220.9

NL10437

 48.3 48.4 102.4 205.9 48.4 8577 97.9 125.4 162.7 8 3 0 7286.9 2491.8

NL10444

 55.5 58.0 108.2 191.2 58.0 8642 98.7 127.9 178.1 12 1 0 10808.6 3685.5

NL10538

 58.6 60.3 106.1 160.7 60.3 8540 97.5 133.3 154.8 7 0 0 9109.4 3415.3

NL10617

 50.8 50.7 101.4 194.1 50.7 8508 97.1 108.9 161.6 7 1 0 6767.4 2386.7

NL10633

 49.8 49.5 104.9 177.4 49.5 8488 96.9 123.5 156.7 11 0 0 8072.8 2810.5

NL10644

 49.1 48.2 107.7 191.1 48.2 8629 98.5 130.2 165.8 13 2 0 9069.1 3008.4

NL10722

 46.9 44.1 112.0 186.7 44.1 8625 98.5 119.7 176.3 12 1 0 9584.5 3048.4

NL10738

 48.8 47.8 108.7 210.0 47.8 8574 97.9 122.7 187.1 15 1 0 9648.2 3155.1

NL10807

 50.2 49.4 110.8 171.5 49.4 8521 97.3 125.5 157.8 12 0 0 9155.6 3009.5

NL10818

 52.0 52.3 102.2 181.3 52.3 8625 98.5 121.1 166.1 7 1 0 7800.6 2618.8

NL10918

 56.0 56.5 101.3 172.8 56.5 8617 98.4 117.0 151.5 6 0 0 6997.0 2740.6

NL10929

 51.7 50.8 104.7 174.2 50.8 8590 98.1 108.9 156.1 10 0 0 7212.1 2916.6

NL10934

 55.3 56.3 98.9 164.6 56.3 8479 96.8 97.7 136.5 4 0 0 5805.1 2685.7
Suburban Background

NL10133

 49.9 50.1 118.7 173.5 50.1 8606 98.2 121.7 155.5 19 0 0 13272.2 3888.0

NL10247

 51.0 49.5 119.8 182.6 49.5 8600 98.2 131.1 165.4 20 1 0 13116.7 4021.1

NL10938

 53.1 53.6 102.3 164.5 53.6 8654 98.8 108.5 141.3 7 0 0 6460.9 2585.9
Urban Background

NL01485

 49.3 49.9 106.9 191.7 49.9 8702 99.3 136.0 180.0 10 2 0 8833.2 2978.4

NL01494

 45.7 46.2 100.5 189.3 46.2 8653 98.8 127.2 168.4 9 2 0 7110.5 2425.9

NL01495

 45.6 45.6 101.6 181.4 45.6 8582 98.0 119.7 155.3 9 1 0 6382.4 2303.5

NL10138

 50.6 50.5 120.9 163.7 50.5 8639 98.6 125.5 155.9 22 0 0 14053.1 3913.0

NL10241

 51.0 50.2 114.8 192.6 50.2 8632 98.5 131.4 162.1 15 2 0 10913.5 3661.1

NL10404

 53.1 56.0 105.4 193.3 56.0 8619 98.4 122.4 161.4 10 1 0 8636.8 3056.0

NL10418

 48.2 48.2 105.0 198.2 48.2 8578 97.9 130.8 162.6 12 2 0 9625.8 2931.1

NL10442

 47.9 47.9 105.3 180.8 47.9 8577 97.9 126.2 161.5 12 1 0 7789.0 2770.3

NL10446

 49.8 51.9 107.9 191.7 51.9 8644 98.7 128.2 159.8 13 1 0 8876.0 3017.7

NL10643

 50.0 50.1 108.6 196.3 50.1 8642 98.7 125.6 163.8 12 1 0 8601.1 3045.4

NL10742

 50.3 49.2 113.3 207.7 49.2 8564 97.8 126.2 183.6 14 3 0 10867.4 3339.8

NL49003

 50.9 53.1 96.8 163.1 53.1 8398 95.9 103.7 133.5 2 0 0 4860.5 2113.5

NL49014

 53.1 54.7 107.4 167.5 54.7 8689 99.2 124.1 159.3 12 0 0 8247.3 3180.9
Roadside

NL01493

 43.1 43.5 99.6 179.4 43.5 8659 98.8 120.9 158.9 8 0 0 5510.8 2023.7

NL10236

 50.3 49.2 114.2 170.0 49.2 8522 97.3 126.3 160.2 15 0 0 10969.2 3436.6

NL10449

 44.1 44.8 102.1 180.9 44.8 8612 98.3 130.4 172.7 8 1 0 6739.3 2192.2

NL10450

 44.8 46.2 90.3 162.2 46.2 8635 98.6 105.6 144.9 3 0 0 3084.0 1362.5

NL10550

 51.4 53.9 102.8 174.3 53.9 8577 97.9 123.6 157.5 8 0 0 7280.3 2653.5

NL10639

 45.1 45.0 96.7 160.4 45.0 8468 96.7 112.5 134.8 6 0 0 4819.2 1795.7

NL10641

 46.0 45.5 101.2 168.3 45.5 8579 97.9 117.3 141.1 10 0 0 7070.9 2129.0

NL49012

 50.8 52.0 100.2 159.5 52.0 8213 93.8 119.7 149.0 4 0 0 6127.6 2210.8
Industrial

NL01496

 49.8 51.0 103.6 184.3 51.0 8519 97.2 116.6 152.6 10 2 0 8396.2 3118.5
Rows where the text is greyed out indicates a data capture < 85%
1 Number of days where the maximum daily rolling 8-h mean of ozone concentrations exceed 120 µg/m³
- Orange color indicates exceedance of > 18 times per calendar year
2 Number of days on which at least one exceedance of the threshold value for information of the public is observed
(one-hour ozone concentration > 180 µg/m³ (information threshold))
3 Number of days on which at least one exceedance of the threshold value for alerting the public is observed
(one-hour ozone concentration > 240 µg/m³ (alert threshold))
4 Accumulated amount of Ozone over the Threshold value of 40 ppb (May - July), related to vegetation [µg/m³ h]
- Blue color indicates exceedance of 18000 [µg/m³ h]
5 Sum of max. 8 hour moving averages > 35 ppb or 70 [µg/m³ d] (WHO)
Table 11: Key concentration values for ozone in 2025 (in μg/m3)
Annual O3 means per station type in 2025
type mean n
Rural Background 51.4 19
Suburban Background 51.3 3
Urban Background 49.7 13
Roadside 47.0 8
Industrial 49.8 1
Table 12: Summary table for ozone in 2025 (in μg/m3)
Number of exceedance days for O3
2023 2024 2025 average_3y1
Rural Background

NL10107

 15 10 20 15

NL10131

 17 10 17 15

NL10230

 18 9 16 14

NL10235

 15 6 13 11

NL10301

 16 10 17 14

NL10318

 16 10 11 12

NL10437

 14 5 8 9

NL10444

 18 10 12 13

NL10538

 11 3 7 7

NL10617

 15 6 7 9

NL10633

 12 5 11 9

NL10644

 16 5 13 11

NL10722

 17 9 12 13

NL10738

 19 16 15 17

NL10807

 16 8 12 12

NL10818

 13 8 7 9

NL10918

 10 2 6 6

NL10929

 11 4 10 8

NL10934

 10 2 4 5
Suburban Background

NL10133

 15 10 19 15

NL10247

 21 16 20 19

NL10938

 11 5 7 8
Urban Background

NL01485

 13 1 10 8

NL01494

 13 6 9 9

NL01495

 10 2 9 7

NL10138

 21 8 22 17

NL10241

 18 14 15 16

NL10404

 16 8 10 11

NL10418

 15 6 12 11

NL10442

 16 12 12 13

NL10446

 18 11 13 14

NL10643

 17 10 12 13

NL10742

 22 8 14 15

NL49003

 16 0 2 6

NL49014

 19 9 12 13
Roadside

NL01493

 4 1 8 4

NL10236

 13 12 15 13

NL10449

 15 8 8 10

NL10450

 4 4 3 4

NL10550

 9 3 8 7

NL10636

 14 - - 14

NL10639

 16 4 6 9

NL10641

 12 5 10 9

NL49012

 10 3 4 6
Industrial

NL01496

 3 2 10 5
1 Number of days averaged over 3 years where the maximum daily rolling 8-h mean of ozone concentrations exceed 120 µg/m³
- Orange color indicates exceedance of > 18 times per calendar year and red of > 25 times per calendar year
* A hyphen is used in case of insufficient valid data to provide an annual mean
Table 13: Number of days where the maximum daily rolling 8-h mean of ozone concentrations exceed 120 µg/m³ in 2023, 2024 and 2025

2.5 Carbon monoxide

Key statistics for CO in 2025
mean1 P50 P98 max median n % max.roll.24 max.roll.8 exc_100002
Urban Background

NL49014

 271.7 252.8 513.1 1018.5 252.8 8616 98.4 556.7 841.1 0

NL49561

 317.9 285.6 688.4 1699.5 285.6 8493 97.0 811.2 1190.3 0
Roadside

NL49007

 384.5 352.8 759.0 3695.1 352.9 8622 98.4 978.8 1167.1 0

NL49012

 412.2 393.1 705.9 1193.7 393.1 8580 97.9 729.1 968.9 0
Industrial

NL49551

 290.6 246.8 749.9 3061.9 246.8 8704 99.4 929.3 1349.9 0

NL49553

 267.5 197.7 1044.6 3839.0 197.7 8623 98.4 1036.2 1428.4 0
Rows where the text is greyed out indicates a data capture < 85%
1 Orange color indicates exceedance of the future EU limit value from 01-01-2030 (2024/2881/EC)
and red of the current EU limit value (2008/50/EC)
2 Number of days where the maximum daily 8 hour mean concentrations exceed 10000 µg/m³
- Red color indicates an exceedance of at least 1 time per calendar year
Table 14: Key concentration values for carbon monoxide in 2025 (in μg/m3)
Annual CO means per station type in 2025
type mean n
Urban Background 294.8 2
Roadside 398.4 2
Industrial 279.1 2
Table 15: Summary table for carbon monoxide in 2025 (in μg/m3)

2.6 Black carbon

There currently is no limit value for black carbon as the evidence base is not yet sufficient enough to provide a basis for legally binding limit values (WHO, 2021).

Key statistics for BC in 2025
mean P50 P98 max median n % max.roll.24 max.roll.8
Rural Background

NL01437

 0.6 0.4 2.1 5.0 0.4 8576 97.9 3.2 3.2

NL10131

 0.6 0.4 2.4 7.9 0.4 8691 99.2 2.8 3.6

NL10444

 0.5 0.3 2.2 3.6 0.3 8668 99.0 2.7 3.2

NL10633

 0.5 0.3 2.2 6.7 0.3 8540 97.5 2.7 3.3

NL10644

 0.6 0.4 2.5 11.1 0.4 8730 99.7 3.8 5.4

NL10807

 0.5 0.3 2.0 14.3 0.3 8062 92.0 3.3 4.0

NL10929

 0.5 0.3 2.2 16.9 0.3 8705 99.4 6.9 13.9
Urban Background

NL01488

 0.7 0.5 2.6 14.8 0.5 8729 99.6 3.8 4.2

NL01494

 0.8 0.5 3.2 10.2 0.5 8746 99.8 3.8 6.0

NL10138

 0.6 0.4 3.1 7.0 0.4 8742 99.8 3.4 4.7

NL10247

 0.7 0.4 3.1 11.2 0.4 8640 98.6 3.9 5.6

NL10742

 0.6 0.4 2.5 7.5 0.4 8661 98.9 3.0 3.9

NL10821

 0.6 0.3 2.8 7.3 0.3 8472 96.7 5.8 4.4

NL10938

 0.4 0.2 1.8 8.7 0.2 8698 99.3 3.2 5.3

NL49003

 0.6 0.4 2.5 8.6 0.4 8457 96.5 2.8 4.1

NL49014

 0.6 0.4 2.1 10.3 0.4 8559 97.7 2.7 4.5

NL49701

 0.6 0.4 2.8 9.9 0.4 8726 99.6 3.3 4.2
Roadside

NL01487

 0.9 0.7 3.0 12.3 0.7 8096 92.4 3.7 6.5

NL01491

 0.8 0.6 3.1 8.4 0.6 8736 99.7 3.9 4.9

NL01493

 1.0 0.8 3.4 7.7 0.8 8719 99.5 4.3 4.9

NL10237

 0.9 0.7 3.2 9.1 0.7 8745 99.8 3.9 5.2

NL10641

 0.7 0.5 2.3 7.6 0.5 8634 98.6 2.7 3.1

NL10741

 0.9 0.7 3.0 7.1 0.7 8721 99.6 3.4 4.5

NL49007

 0.8 0.6 2.8 9.1 0.6 8623 98.4 3.4 4.0

NL49012

 0.7 0.5 2.5 10.4 0.5 8539 97.5 2.8 4.2

NL49017

 0.7 0.6 2.4 5.9 0.6 8654 98.8 5.2 3.4

NL49020

 0.8 0.6 2.7 13.2 0.6 8708 99.4 3.3 4.9
Industrial

NL01496

 0.7 0.5 2.7 19.2 0.5 8602 98.2 3.5 5.6

NL01913

 0.8 0.6 3.4 12.8 0.6 8672 99.0 6.6 10.2

NL49551

 0.7 0.6 2.8 8.4 0.6 8746 99.8 3.1 4.2

NL49553

 0.6 0.3 2.4 4.5 0.3 8680 99.1 2.8 3.4
Rows where the text is greyed out indicates a data capture < 85%
Table 16: Key concentration values for black carbon in 2025 (in μg/m3)
Annual BC means per station type in 2025
type mean n
Rural Background 0.5 7
Urban Background 0.6 10
Roadside 0.8 10
Industrial 0.7 4
Table 17: Summary table for black carbon in 2025 (in μg/m3)

2.7 Volatile organic compounds

For toluene there is no legally binding limit value. Other non-methane volatile organic compounds (NMVOC), such as the ones listed in Annex X of 2008/50/EC (ozone precursor substances), are also measured by the LML, but are excluded from this report.

Key statistics for benzene in 2025
mean1 P50 P98 max median n %
Rural Background

NL49703

 0.3 0.2 0.9 1.8 0.2 339 92.9
Urban Background

NL01485

 0.4 0.3 1.1 1.7 0.3 268 73.4

NL01494

 0.8 0.7 1.7 2.8 0.7 338 92.6

NL01495

 0.4 0.2 1.5 3.2 0.2 128 35.1

NL10643 *

 0.3 0.2 1.0 1.2 0.2 344 94.2
Roadside

NL49017

 0.4 0.3 0.9 1.2 0.3 316 86.6
Industrial

NL01484

 0.5 0.3 1.9 2.7 0.3 330 90.4

NL01496

 0.4 0.3 1.4 2.0 0.3 348 95.3

NL49546

 0.3 0.2 1.1 1.6 0.2 333 91.2

NL49557

 0.3 0.2 1.2 2.0 0.2 340 93.2

NL49704

 0.5 0.3 1.6 8.3 0.3 339 92.9
Rows where the text is greyed out indicates a data capture < 85%
1 Orange color indicates exceedance of the future EU limit value from 01-01-2030 (2024/2881/EC)
and red of the current EU limit value (2008/50/EC)
* The measurement of benzene at NL10643 is part of the measurement of ozone precursor VOC (NMVOC),
as laid out in Annex X of 2008/50/EC and Annex VII of EU Directive 2024/2881
Table 18: Key concentration values for benzene in 2025 (in μg/m3)
Annual benzene means per station type in 2025
type mean n
Rural Background 0.3 1
Urban Background 0.8 1
Industrial 0.4 5
Table 19: Summary table for benzene in 2025 (in μg/m3)
Key statistics for toluene in 2025
mean P50 P98 max median n %
Rural Background

NL49703

 0.7 0.5 2.6 4.5 0.5 339 92.9
Urban Background

NL01485

 0.9 0.7 3.2 11.0 0.7 270 74.0

NL01494

 2.4 2.0 6.5 10.2 2.1 338 92.6

NL01495

 0.9 0.6 3.1 4.5 0.6 129 35.3

NL10643 *

 0.6 0.4 2.1 3.2 0.4 344 94.2
Roadside

NL49017

 1.0 0.9 2.7 3.6 0.9 316 86.6
Industrial

NL01484

 0.7 0.6 2.0 3.0 0.6 330 90.4

NL01496

 0.6 0.4 2.0 2.9 0.4 348 95.3

NL49546

 0.9 0.6 3.6 5.8 0.6 333 91.2

NL49557

 0.4 0.2 1.4 2.6 0.2 340 93.2

NL49704

 1.3 0.7 5.9 11.7 0.7 339 92.9
Rows where the text is greyed out indicates a data capture < 85%
* The measurement of toluene at NL10643 is part of the measurement of ozone precursor VOC (NMVOC),
as laid out in Annex X of 2008/50/EC and Annex VII of EU Directive 2024/2881
Table 20: Key concentration values for toluene in 2025 (in μg/m3)
Annual toluene means per station type in 2025
type mean n
Rural Background 0.7 1
Urban Background 2.4 1
Industrial 0.8 5
Table 21: Summary table for toluene in 2025 (in μg/m3)

3 Discussion

For all annual LML data from 1976 up to the present year, please consult the RIVM Data catalog. The monitoring data over several years including long-term trend charts can be assessed in the section on air quality on the Environmental Data Compendium website (Compendium voor de Leefomgeving). This website also provides information about the health impact of certain pollutants. The burden of disease due to air pollution can be significant, even if concentrations comply with the European limit values. Substantial improvements in public health can be achieved with further reduction of concentrations below the limit values.

4 References

Appendix A - Overview of accreditation information and limit values

The following table lists the accreditation certificate numbers for the LML for the measurements reported here and the limit values in µg/m³ for each pollutant from the three relevant guidelines. Measurements are carried out under EN ISO/IEC 17025:2017 accreditation by RIVM (L224) in collaboration with its regional partners DCMR (L520) and GGD Amsterdam (L426) who are accredited according to the same ISO standard. Analysis of heavy metals is outsourced to an external analytical laboratory that is accredited according to EN ISO/IEC 17025:2017 under L086.

component accreditation_numbera averaging_period EU_limit_value EU_limit_value_revised WHO_AQG
NO2 L520, L224, L426 year 40 20 10
PM10 L520, L224, L426 year 40 20 15
PM10 L520, L224, L426 day 50 max 35×b 45 max 18×b 45 max 3-4×b
PM2.5 L520, L224, L426 year 25 10 5
PM2.5 L520, L224, L426 day
25 max 18×b
O3 L520, L224, L426 max_8_h 120 max 25×b 120 max 18×b,c 100 max 3-4×b
O3 L520, L224, L426 peak_season

60
SO2 L520, L224, L426 day 125 max 3× 50 max 18× 40
SO2 L520, L224, L426 year
20b
CO L426 max_8_h 10000 10000 10000
CO L426 day
4000 max 18×b 4000 max 3-4×b
benzene L520, L426 year 5 3.4 1.7
Pb
year 0.5 0.5 0.5
As
year 0.006 0.006 0.066
Cd
year 0.005 0.005 0.005
Ni
year 0.02 0.02 0.025
benzo(a)pyrene
year 0.001 0.001 0.12
a L224 is RIVM, L520 is DCMR, L426 is GGD Amsterdam, L086 is Eurofins Omegan B.V. analytical laboratory
b max n× means a maximum number of n exceedance days per calendar year
- For WHO this is also denoted as the 99th percentile, which is equivalent to 3-4 exceedance days per year
c Averaged over 3 years
Table 22: Accreditation information and limit values in μg/m3 from EU Directives 2008/50/EC and 2004/107/EC (EU_limit_value),
EU Directive 2024/2881 (EU_limit_value_revised), and WHO global air quality guidelines from 2021 (WHO_AQG)