Air quality measurements in the Netherlands 2020

RIVM Annual report
Version 1

Rva logo

Authors

Affiliation

Pleuni Bongers

National Institute for Public Health and the Environment (RIVM)

Dennis Mooibroek

Published

July 28, 2025

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 2020 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 L026. 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 information on the used monitoring instruments and sampling practices, see the metadata on the LML data catalog on the public RIVM website. For additional information including measurement uncertainties, please consult the accompanying README.

2 Key concentration values per component

The upcoming tables contain the key statistics per component for 2020, 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.

2.1 Nitrogen dioxide

	mean¹	P50	P98	max	median	n	%	exc_200²	max.roll.24	max.roll.8
Key statistics for NO₂ in 2020
Rural Background
NL10107	13.2	10.6	37.1	74.6	10.6	8735	99.4	0	47.9	58.7
NL10131	13.2	10.1	40.5	73.0	10.1	8742	99.5	0	39.0	60.4
NL10133	9.5	7.8	29.8	57.2	7.8	8733	99.4	0	43.9	48.2
NL10230	16.9	12.3	58.1	315.0	12.3	8693	99.0	13	73.0	167.4
NL10235	13.8	11.6	37.6	82.0	11.6	8659	98.6	0	49.4	57.5
NL10246	14.0	11.2	42.9	81.6	11.2	8741	99.5	0	48.1	63.4
NL10301	11.7	8.8	40.6	131.1	8.8	8655	98.5	0	49.9	59.9
NL10318	12.4	8.6	43.8	118.7	8.6	8687	98.9	0	48.2	83.6
NL10437	16.1	13.2	45.6	110.5	13.2	8690	98.9	0	49.6	66.7
NL10444	12.0	8.9	41.5	73.4	8.9	8515	96.9	0	50.8	54.2
NL10538	13.0	8.6	49.0	140.3	8.6	8683	98.8	0	57.0	88.6
NL10617	10.0	7.7	34.7	55.4	7.7	8707	99.1	0	44.9	50.8
NL10633	11.4	8.9	37.3	64.0	8.9	8662	98.6	0	45.7	48.7
NL10644	13.2	10.7	39.0	62.4	10.7	8378	95.4	0	44.4	49.6
NL10722	11.6	9.4	32.6	46.2	9.4	8754	99.7	0	38.7	43.2
NL10738	12.1	9.8	36.0	78.2	9.8	8546	97.3	0	55.1	54.5
NL10807	9.2	7.2	30.0	48.9	7.2	8694	99.0	0	40.0	43.8
NL10818	8.9	7.0	29.2	65.7	7.0	8721	99.3	0	43.7	49.2
NL10918	8.2	6.1	29.6	58.0	6.1	8690	98.9	0	51.0	55.2
NL10929	8.6	6.6	27.7	89.8	6.6	8620	98.1	0	35.6	47.1
NL10934	7.3	5.6	24.4	53.0	5.6	8618	98.1	0	36.9	50.9
NL49703	15.2	11.7	48.0	100.3	11.7	8654	98.5	0	54.7	57.9
Urban Background
NL01485	20.8	16.6	62.1	177.6	16.6	8649	98.5	0	80.0	135.8
NL01488	20.5	16.4	59.2	158.5	16.4	8752	99.6	0	73.6	114.0
NL01494	25.6	21.8	66.1	156.4	21.8	8716	99.2	0	87.9	103.0
NL01495	24.6	21.4	63.2	176.9	21.4	8763	99.8	0	95.0	134.9
NL01912	20.5	17.0	56.4	120.9	17.0	8761	99.7	0	66.6	97.3
NL10138	12.1	9.2	38.8	69.8	9.2	8627	98.2	0	49.0	50.4
NL10241	17.1	13.9	50.2	121.2	13.9	8687	98.9	0	58.0	71.0
NL10247	13.3	10.6	38.9	66.4	10.6	8754	99.7	0	45.0	54.9
NL10404	18.8	14.2	59.4	130.7	14.2	8700	99.0	0	69.5	85.2
NL10418	23.7	20.0	61.7	144.9	20.0	8651	98.5	0	72.4	90.5
NL10442	16.5	13.5	48.2	142.2	13.5	8752	99.6	0	55.1	81.6
NL10446	20.0	15.9	59.4	120.1	15.9	8549	97.3	0	65.9	84.9
NL10643	15.5	12.4	46.3	83.5	12.4	8764	99.8	0	54.9	62.3
NL10742	16.1	13.3	45.3	115.0	13.3	8726	99.3	0	48.3	76.8
NL10938	8.8	6.8	28.1	65.7	6.8	8645	98.4	0	45.7	52.0
NL49003	16.7	13.6	50.7	93.4	13.6	8712	99.2	0	59.0	61.9
NL49014	17.1	13.9	50.2	80.7	13.9	8694	99.0	0	61.3	66.4
NL49019	19.9	16.2	58.4	122.7	16.2	8655	98.5	0	64.4	90.0
NL49021	15.1	12.2	46.3	77.9	12.2	8755	99.7	0	55.5	60.6
NL49022	15.3	11.5	49.7	78.6	11.5	8669	98.7	0	66.4	66.2
NL49701	18.2	13.3	56.6	102.4	13.3	8727	99.4	0	63.8	67.3
Roadside
NL01487	32.5	29.8	76.4	157.6	29.8	8754	99.7	0	114.2	137.5
NL01489	26.7	23.9	67.2	131.2	23.9	8755	99.7	0	73.1	112.3
NL01491	26.1	22.9	66.3	147.6	22.9	8656	98.5	0	69.3	99.4
NL01493	30.6	27.3	75.1	191.2	27.3	8750	99.6	0	101.9	123.3
NL01908	26.3	23.3	65.7	129.9	23.3	8228	93.7	0	86.8	98.8
NL10136	18.4	15.3	54.2	117.2	15.3	8715	99.2	0	57.4	75.5
NL10236	17.4	14.9	46.8	88.1	14.9	8764	99.8	0	50.0	71.8
NL10237	21.1	18.3	54.6	112.3	18.3	8758	99.7	0	58.4	86.9
NL10240	23.4	20.4	62.1	143.4	20.4	8607	98.0	0	72.1	98.4
NL10445	23.6	20.2	62.5	114.9	20.2	8600	97.9	0	67.0	83.1
NL10449	27.2	23.6	68.5	139.6	23.6	8645	98.4	0	87.7	113.2
NL10550	19.5	16.2	53.6	116.9	16.2	8752	99.6	0	60.9	73.6
NL10636	19.6	16.7	53.6	94.1	16.7	8581	97.7	0	61.0	73.8
NL10639	21.8	18.3	57.3	114.5	18.3	8710	99.2	0	63.3	89.4
NL10641	20.4	17.9	54.4	92.4	17.9	8726	99.3	0	61.0	73.0
NL10741	24.1	21.5	58.0	171.7	21.5	8761	99.7	0	80.0	109.1
NL10937	19.1	16.9	48.3	100.7	16.9	8745	99.6	0	53.5	68.2
NL49002	30.9	27.7	76.3	169.3	27.7	8658	98.6	0	96.1	124.1
NL49007	33.8	30.6	81.3	119.7	30.6	8594	97.8	0	90.8	111.3
NL49012	26.9	22.7	72.1	143.4	22.7	8747	99.6	0	87.6	107.2
NL49017	24.5	21.3	62.7	125.7	21.3	8464	96.4	0	82.8	102.2
NL49020	28.1	24.3	74.4	136.8	24.3	7994	91.0	0	88.3	105.6
Industrial
NL01496	24.4	21.0	71.1	192.3	21.0	8685	98.9	0	110.6	135.1
NL01913	16.7	15.3	39.8	51.5	15.3	518	5.9	0	30.5	36.1
NL49704	21.4	16.8	62.8	126.0	16.8	8713	99.2	0	67.5	94.4
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

Table 1: Key concentration values for nitrogen dioxide in 2020 (in μg/m³)

type	mean	n
Annual NO₂ means per station type in 2020
Rural Background	11.88	22
Urban Background	17.91	21
Roadside	24.65	22
Industrial	22.92	2

Table 2: Summary table for nitrogen dioxide in 2020 (in μg/m³)

2.2 Particulate matter

	mean¹	P50	P98	max	median	n	%	max.roll.24	max.roll.8	exc_50_d²
Key statistics for PM₁₀ in 2020
Rural Background
NL10131	18.2	14.7	62.0	380.8	14.7	8687	98.9	199.4	153.6	11
NL10133	14.3	12.1	41.5	743.0	12.1	8732	99.4	446.5	300.8	1
NL10230	18.1	14.7	62.0	329.6	14.7	8741	99.5	79.2	107.5	6
NL10235	15.9	14.7	45.4	127.3	14.7	8706	99.1	127.3	80.0	0
NL10246	14.6	13.4	44.1	218.2	13.4	8607	98.0	95.3	88.0	0
NL10318	15.4	13.4	48.0	132.4	13.4	8701	99.1	67.2	84.9	0
NL10437	15.3	13.4	48.0	142.7	13.4	8677	98.8	108.5	93.4	1
NL10444	15.9	14.7	42.8	336.0	14.7	8694	99.0	177.2	155.0	1
NL10538	14.9	13.4	44.1	163.2	13.4	8693	99.0	103.0	68.6	1
NL10617	14.4	13.4	45.4	184.9	13.4	8647	98.4	102.7	94.8	1
NL10633	13.7	12.1	42.8	444.8	12.1	8588	97.8	240.8	189.6	1
NL10644	14.4	12.1	46.7	323.1	12.1	8706	99.1	323.1	158.5	1
NL10722	14.9	13.4	44.1	177.2	13.4	8767	99.8	53.4	65.6	0
NL10738	16.5	14.7	49.2	575.3	14.7	8709	99.1	575.3	207.5	1
NL10807	14.6	13.4	42.8	229.7	13.4	8612	98.0	72.8	93.0	1
NL10818	13.4	12.1	42.8	170.8	12.1	8621	98.1	67.9	72.3	1
NL10918	12.7	10.8	40.3	103.0	10.8	8589	97.8	103.0	69.2	1
NL10929	13.3	10.8	41.5	406.4	10.8	8537	97.2	169.6	197.4	2
NL10934	14.4	13.4	45.4	197.7	13.4	8481	96.6	145.2	106.6	1
NL49703	14.6	12.2	40.6	285.5	12.2	8702	99.1	285.5	176.2	1
Urban Background
NL01485	16.5	14.0	44.3	828.3	14.0	8607	98.0	828.3	212.6	1
NL01488	17.6	15.5	45.0	994.9	15.5	8451	96.2	994.9	315.6	1
NL01494	19.2	17.1	46.3	591.6	17.1	8568	97.5	591.6	218.1	1
NL01495	16.1	13.7	42.6	645.5	13.7	8194	93.3	645.5	199.9	1
NL01912	19.0	16.8	47.1	405.3	16.8	8689	98.9	405.3	164.8	3
NL10138	14.6	13.4	40.3	691.8	13.4	8576	97.6	691.8	195.6	1
NL10241	17.6	15.9	50.5	353.9	15.9	8628	98.2	353.9	120.7	1
NL10247	15.9	14.7	46.7	352.6	14.7	8743	99.5	352.6	110.9	1
NL10404	18.9	15.9	50.5	904.3	15.9	8377	95.4	904.3	358.8	3
NL10418	18.3	15.9	50.5	963.1	15.9	8659	98.6	963.1	318.9	1
NL10442	16.1	14.7	42.8	598.4	14.7	8726	99.3	598.4	204.3	2
NL10446	16.2	14.7	45.4	548.4	14.7	8706	99.1	548.4	197.9	2
NL49014	15.7	13.3	40.6	258.5	13.3	8648	98.5	258.5	146.1	1
NL49016	16.9	15.2	43.3	476.1	15.2	8345	95.0	476.1	217.6	1
NL49701	16.3	14.0	41.0	128.8	14.0	8713	99.2	128.8	85.2	1
Roadside
NL01487	21.7	19.0	55.9	560.0	19.0	8316	94.7	560.0	239.0	6
NL01489	20.6	18.6	48.6	607.1	18.6	8632	98.3	607.1	200.9	2
NL01491	17.2	15.2	42.2	587.0	15.2	8490	96.7	587.0	248.0	1
NL01493	20.3	18.0	48.7	382.2	18.0	8622	98.2	312.4	185.7	2
NL01908	20.2	18.1	49.4	161.0	18.1	8503	96.8	127.0	102.0	3
NL10136	16.9	14.7	48.0	1234.5	14.7	8727	99.4	1234.5	349.0	3
NL10236	16.5	14.7	48.0	599.6	14.7	8722	99.3	599.6	236.3	1
NL10237	18.9	17.2	51.8	854.4	17.2	8731	99.4	854.4	212.2	1
NL10240	17.8	15.9	54.4	274.5	15.9	8722	99.3	64.6	95.3	1
NL10445	19.5	17.2	49.2	841.5	17.2	8666	98.7	832.6	480.4	3
NL10449	19.2	17.2	50.5	622.7	17.2	8733	99.4	622.7	175.9	2
NL10550	17.5	15.9	48.0	594.5	15.9	8724	99.3	594.5	267.9	1
NL10636	16.1	14.7	42.8	996.4	14.7	8663	98.6	996.4	368.4	1
NL10639	16.8	15.9	49.2	323.1	15.9	8639	98.3	323.1	175.9	1
NL10641	15.0	13.4	45.4	379.5	13.4	8728	99.4	173.8	150.6	1
NL10741	21.0	19.8	58.2	1110.3	19.8	8712	99.2	1110.3	242.9	5
NL10937	19.1	17.2	50.5	882.5	17.2	8716	99.2	882.5	271.7	2
NL49007	17.2	15.3	45.0	513.9	15.3	8640	98.4	513.9	204.2	1
NL49012	18.7	16.7	45.9	336.6	16.7	8598	97.9	336.6	194.2	1
NL49017	17.2	15.6	41.6	451.1	15.6	8684	98.9	451.1	190.8	1
NL49020	17.9	16.0	43.9	257.4	16.0	8650	98.5	237.5	135.4	1
Industrial
NL01496	18.5	16.4	47.8	224.7	16.4	8499	96.8	164.9	114.3	3
NL01913	15.0	14.2	29.0	64.9	14.2	506	5.8	39.0	29.7	0
NL49704	16.4	13.2	44.9	241.8	13.2	8709	99.1	166.1	143.0	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 2020 (in μg/m³)

type	mean	n
Annual PM₁₀ means per station type in 2020
Rural Background	14.97	20
Urban Background	16.99	15
Roadside	18.35	21
Industrial	17.44	2

Table 4: Summary table for PM₁₀ in 2020 (in μg/m³)

	mean¹	P50	P98	max	median	n	%	max.roll.24	max.roll.8
Key statistics for PM_2.5 in 2020
Rural Background
NL10131	10.4	8.2	32.2	198.8	8.2	8622	98.2	118.1	100.5
NL10230	9.8	7.5	34.5	117.8	7.5	8642	98.4	56.2	54.0
NL10444	8.2	6.7	27.8	129.3	6.7	8585	97.7	129.3	101.7
NL10538	7.3	5.5	27.9	98.2	5.5	7937	90.4	71.1	48.8
NL10644	7.9	6.0	30.2	196.7	6.0	8448	96.2	196.7	108.7
NL10738	9.2	7.0	30.7	421.0	7.0	8560	97.4	421.0	140.8
NL10934	6.5	4.7	25.3	141.2	4.7	8696	99.0	105.1	79.3
NL49703	9.2	7.4	31.3	282.8	7.4	8527	97.1	282.8	157.1
Urban Background
NL01488	10.1	7.9	35.5	934.6	7.9	8496	96.7	934.6	297.9
NL01494	9.7	7.4	33.1	584.6	7.4	8596	97.9	584.6	212.1
NL01495	10.0	8.0	33.8	654.4	8.0	8088	92.1	654.4	195.5
NL10138	7.2	5.5	27.0	424.7	5.5	8599	97.9	424.7	128.0
NL10241	7.6	5.2	31.9	235.9	5.2	8326	94.8	235.9	81.5
NL10247	9.9	7.9	32.7	231.8	7.9	8685	98.9	231.8	79.7
NL10404	7.1	4.7	29.8	605.7	4.7	8554	97.4	605.7	297.3
NL10418	8.4	6.0	31.1	651.4	6.0	8672	98.7	651.4	225.6
NL10643	9.0	6.9	31.0	1146.5	6.9	8662	98.6	1146.5	318.2
NL10742	9.8	7.7	32.0	1558.1	7.7	8628	98.2	1558.1	317.5
NL10821	7.6	5.5	28.2	1095.5	5.5	8444	96.1	1095.5	329.5
NL10938	7.0	5.2	27.3	371.3	5.2	7976	90.8	371.3	156.2
NL49014	9.6	7.5	32.3	237.2	7.5	8596	97.9	237.2	131.5
NL49016	9.7	7.6	32.0	457.9	7.6	8530	97.1	457.9	195.7
NL49701	9.9	7.9	32.3	399.6	7.9	8677	98.8	399.6	164.6
Roadside
NL01487	13.3	10.8	39.0	572.0	10.8	8376	95.4	572.0	231.3
NL01489	9.2	7.0	32.1	599.0	7.0	8562	97.5	599.0	188.2
NL01491	9.8	7.8	32.8	556.4	7.8	8383	95.4	556.4	236.1
NL10136	8.2	6.3	28.1	790.6	6.3	8603	97.9	790.6	230.6
NL10240	9.4	7.1	33.7	94.8	7.1	8695	99.0	52.1	56.6
NL10448	9.8	7.7	32.5	331.0	7.7	8706	99.1	274.9	161.8
NL10449	10.1	7.7	34.2	797.8	7.7	8571	97.6	797.8	248.1
NL10636	10.4	8.2	32.0	666.0	8.2	8631	98.3	666.0	245.5
NL10641	8.5	6.5	30.4	158.3	6.5	8617	98.1	108.8	96.3
NL10741	9.8	7.7	32.1	720.1	7.7	8631	98.3	720.1	164.3
NL10937	7.3	5.3	26.8	691.9	5.3	8641	98.4	691.9	192.4
NL49007	8.7	6.7	30.3	479.1	6.7	8577	97.6	479.1	178.7
NL49012	10.5	8.3	33.7	308.1	8.3	8604	98.0	308.1	175.9
NL49017	9.4	7.5	31.3	438.8	7.5	8683	98.8	438.8	173.9
Industrial
NL01496	8.9	6.9	33.1	215.5	6.9	8421	95.9	157.3	103.0
NL01913	9.2	8.2	22.0	30.6	8.2	506	5.8	18.5	21.9
NL49704	10.5	8.3	33.5	205.8	8.3	8506	96.8	140.3	121.1
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 PM_2.5 in 2020 (in μg/m³)

type	mean	n
Annual PM_2.5 means per station type in 2020
Rural Background	8.55	8
Urban Background	8.84	15
Roadside	9.59	14
Industrial	9.70	2

Table 6: Summary table for PM_2.5 in 2020 (in μg/m³)

	2018	2019	2020	average_3y
Statistics to determine the AEI for PM_2.5
Urban Background
NL01494	13.7	12.8	9.7	12.1
NL10138	10.0	8.5	7.2	8.6
NL10241	12.7	9.1	7.6	9.8
NL10247	12.9	11.9	9.9	11.5
NL10404	10.2	8.6	7.1	8.6
NL10418	11.0	9.5	8.4	9.6
NL10643	11.5	10.5	9.0	10.3
NL10742	12.0	10.6	9.8	10.8
NL10821	10.3	8.9	7.6	8.9
NL10938	10.7	8.5	6.9	8.7
NL49014	10.8	10.4	9.6	10.3
NL49701	12.8	11.2	9.9	11.3
* A hyphen is used in case of insufficient valid data to provide an annual mean

Table 7: Annual means for PM_2.5 (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 PM_2.5 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 2020 is 10 µg/m³.

2.3 Sulphur dioxide

	mean¹	P50	P98	max	median	n	%	exc_350_h²	max.roll.24	max.roll.8	exc_125_d³	mean_winter⁴
Key statistics for SO₂ in 2020
Rural Background
NL10133	0.5	0.3	3.2	13.6	0.3	8580	97.7	0	5.3	10.5	NA	0.4
NL10318	0.8	0.3	4.8	43.5	0.3	8653	98.5	0	5.4	12.9	NA	0.6
NL10444	0.6	0.4	3.1	31.6	0.4	8622	98.2	0	3.1	7.4	NA	0.6
NL10644	0.5	0.3	2.7	11.6	0.3	8701	99.1	0	4.1	6.9	NA	0.4
NL10722	0.5	0.2	3.0	15.2	0.2	8417	95.8	0	3.5	8.6	NA	0.4
NL10934	0.3	0.2	1.6	7.8	0.2	8655	98.5	0	1.9	3.3	NA	0.2
Urban Background
NL01485	1.8	1.0	11.8	53.0	1.0	8565	97.5	0	30.4	33.9	0	1.4
NL01495	0.9	0.5	6.2	84.1	0.5	8775	99.9	0	11.3	28.9	0	1.1
NL49016	0.3	0.1	2.4	15.6	0.1	8661	98.6	0	3.2	8.3	0	0.5
Industrial
NL01484	3.9	2.2	22.3	94.7	2.2	8762	99.8	0	27.1	43.0	0	5.3
NL01496	1.4	0.9	7.6	128.6	0.9	8621	98.1	0	11.3	30.5	0	1.3
NL49704	0.5	0.3	3.1	19.7	0.3	8718	99.2	0	4.7	9.9	0	0.6
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
⁴ Mean concentrations in winter (1 October 2020 to 31 March 2021) for assessing the critical level for the protection of vegetation and natural ecosystems - Red color indicates exceedance of 20 µg/m³

Table 8: Key concentration values for sulphur dioxide in 2020 (in μg/m³)

type	mean	n
Annual SO₂ means per station type in 2020
Rural Background	0.53	6
Urban Background	1.01	3
Industrial	1.92	3

Table 9: Summary table for sulphur dioxide in 2020 (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 12 for the number of exceedance days in 2018, 2019 and 2020 and their 3-year averages.

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 2020 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.

	mean	P50	P98	max	median	n	%	max.roll.24	max.roll.8	exc_120¹	aot40²	somo35³
Key statistics for O₃ in 2020
Rural Background
NL10107	50.1	50.0	122.0	215.6	50.0	8670	98.7	120.4	179.2	22	10508.4	4092.0
NL10131	48.9	48.3	122.7	208.0	48.3	8660	98.6	114.6	178.9	20	10334.0	4062.0
NL10230	48.9	48.6	122.6	206.0	48.6	8587	97.8	128.6	179.8	22	8932.5	3767.9
NL10235	47.9	46.7	121.9	221.6	46.7	8624	98.2	129.7	196.1	21	9120.1	3899.2
NL10301	55.9	56.5	115.1	223.7	56.5	8591	97.8	135.0	187.9	18	7905.3	3748.2
NL10318	52.3	51.7	118.0	246.2	51.7	8526	97.1	137.2	193.8	15	8723.1	3703.2
NL10437	49.2	49.3	114.2	197.4	49.3	8653	98.5	121.6	173.1	15	7159.6	3163.1
NL10444	55.9	59.3	120.5	222.7	59.3	8610	98.0	128.1	192.0	19	8392.2	4115.6
NL10538	55.3	57.2	108.6	168.9	57.2	8661	98.6	116.5	147.9	11	5978.4	3099.1
NL10617	50.1	50.5	109.2	171.7	50.5	8647	98.4	108.9	156.6	11	6282.1	3050.1
NL10633	49.9	50.0	114.8	184.5	50.0	8561	97.5	119.3	165.8	13	7115.6	3270.6
NL10644	48.9	48.3	118.6	201.8	48.3	8664	98.6	123.1	169.2	16	8192.7	3587.4
NL10722	46.1	43.9	116.4	166.4	43.9	8673	98.7	112.1	157.5	17	7589.1	3325.6
NL10738	47.1	47.5	113.8	191.2	47.5	8455	96.3	117.8	164.3	12	5821.3	3061.0
NL10807	49.9	49.8	114.2	188.5	49.8	8497	96.7	119.1	177.2	12	6442.5	3357.5
NL10818	52.5	53.0	113.5	180.2	53.0	8575	97.6	119.8	168.4	13	6851.2	3402.7
NL10918	54.7	55.3	109.2	172.4	55.3	8624	98.2	112.5	153.4	10	5798.4	3108.2
NL10929	50.8	50.8	112.7	184.9	50.8	8526	97.1	110.9	167.2	11	5826.1	3282.6
NL10934	52.5	53.4	100.7	147.2	53.4	8650	98.5	99.8	141.9	7	3632.3	2585.7
Urban Background
NL01485	46.7	47.2	108.2	205.0	47.2	8725	99.3	121.8	171.3	14	5275.2	2658.8
NL01494	42.4	42.5	101.7	181.8	42.5	8769	99.8	117.9	169.0	10	3996.4	2197.2
NL01495	46.0	45.8	106.4	221.7	45.8	8769	99.8	129.7	188.4	12	5171.2	2743.2
NL10133⁴	48.6	49.2	117.5	177.5	49.2	8652	98.5	116.8	162.2	15	8785.4	3478.8
NL10138	54.6	54.7	124.9	215.8	54.7	8668	98.7	124.9	184.8	26	12521.9	4727.5
NL10241	48.9	48.2	124.1	208.8	48.3	8644	98.4	138.0	187.6	20	8575.6	3717.0
NL10247⁴	52.0	51.4	129.8	208.2	51.4	8667	98.7	140.3	189.0	26	11341.9	4668.8
NL10404	49.9	51.9	113.3	204.8	51.9	8656	98.5	139.2	180.4	14	5854.1	2713.4
NL10418	47.2	47.3	115.1	207.1	47.3	8640	98.4	137.3	182.5	16	7302.8	3276.6
NL10442	51.5	51.4	125.2	207.1	51.4	8646	98.4	129.1	180.1	21	9964.0	4109.8
NL10446	49.7	51.7	112.3	207.4	51.7	8582	97.7	179.4	184.5	15	7386.0	3219.9
NL10643	47.8	47.6	114.6	176.0	47.6	8669	98.7	123.2	165.5	13	5873.7	3047.0
NL10742	50.2	48.9	119.9	186.1	48.9	8583	97.7	124.2	170.3	16	8443.9	3748.0
NL10938⁴	53.0	53.9	105.9	159.9	53.9	8614	98.1	101.7	146.8	9	5497.8	3082.6
NL49003	48.1	49.9	101.0	157.4	49.9	8647	98.4	103.2	147.5	7	3300.6	2161.6
NL49014	49.9	51.1	112.7	187.1	51.1	8720	99.3	125.8	178.2	13	5227.0	3034.2
Roadside
NL01489	40.1	38.3	109.2	212.2	38.3	8768	99.8	128.7	176.6	13	4697.4	2601.0
NL01493	40.0	40.5	95.0	178.8	40.5	8758	99.7	115.5	154.5	8	2499.9	1649.3
NL10236	49.1	48.1	119.0	191.6	48.1	8598	97.9	140.3	172.4	17	8058.7	3487.1
NL10449	42.7	42.3	105.8	190.8	42.3	8671	98.7	115.6	166.8	12	5218.0	2475.5
NL10550	50.1	52.6	108.2	193.0	52.6	8631	98.3	114.5	171.5	11	4905.5	2808.8
NL10636	46.2	45.5	114.7	180.5	45.5	8558	97.4	128.5	170.8	13	5892.1	3131.0
NL10639	46.2	46.0	111.7	179.8	46.0	8599	97.9	128.4	166.7	12	5429.0	2879.8
NL10641	43.3	42.9	105.1	169.8	42.9	8642	98.4	106.6	153.5	8	4052.2	2183.7
NL49012	45.3	47.0	97.0	158.0	47.0	8660	98.6	100.0	145.8	6	1967.0	1700.6
Industrial
NL01496	51.2	51.4	114.0	273.9	51.4	8706	99.1	152.5	226.0	15	6637.1	3540.2
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 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]
³ Sum of max. 8 hour moving averages > 35 ppb or 70 [µg/m³ d] (WHO)
⁴ These sites are considered suburban background sites under the ozone directive

Table 10: Key concentration values for ozone in 2020 (in μg/m³)

type	mean	n
Annual O₃ means per station type in 2020
Rural Background	50.88	19
Urban Background	49.15	16
Roadside	44.76	9
Industrial	51.24	1

Table 11: Summary table for ozone in 2020 (in μg/m³)

	2018	2019	2020	average_3y¹
Number of exceedance days for O₃
Rural Background
NL10107	27	18	22	22
NL10131	33	16	20	23
NL10230	13	20	22	18
NL10235	20	18	21	20
NL10301	11	17	18	15
NL10318	10	-	15	12
NL10437	13	13	15	14
NL10444	16	19	19	18
NL10538	12	17	11	13
NL10617	16	15	11	14
NL10644	12	17	16	15
NL10722	22	23	17	21
NL10738	9	19	12	13
NL10807	22	20	12	18
NL10818	30	-	13	22
NL10918	13	15	10	13
NL10929	27	17	11	18
NL10934	6	-	7	6
NL10633	-	16	13	14
Urban Background
NL01485	6	16	14	12
NL01494	6	16	10	11
NL01495	13	16	12	14
NL10138	40	22	26	29
NL10241	37	12	20	23
NL10247	43	14	26	28
NL10404	7	13	14	11
NL10418	15	17	16	16
NL10442	18	16	21	18
NL10446	16	17	15	16
NL10643	17	17	13	16
NL10742	23	19	16	19
NL10938	14	16	9	13
NL49003	15	16	7	13
NL49014	21	17	13	17
NL10133	-	19	15	17
Roadside
NL01489	6	13	13	11
NL01493	6	12	8	9
NL10236	12	19	17	16
NL10550	7	15	11	11
NL10636	4	-	13	8
NL10639	17	15	12	15
NL10641	4	16	8	9
NL49012	10	-	6	8
NL10449	-	-	12	12
Industrial
NL01496	6	16	15	12
* A hyphen is used in case of insufficient valid data to provide an annual mean
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

Table 12: Number of days where the maximum daily rolling 8-h mean of ozone concentrations exceed 120 µg/m³ in 2018, 2019 and 2020

2.5 Carbon monoxide

	mean¹	P50	P98	max	median	n	%	max.roll.24	max.roll.8	exc_10000²
Key statistics for CO in 2020
Rural Background
NL10644	236.0	199.6	832.0	1548.4	199.6	1112	12.7	986.7	1115.3	0
Urban Background
NL49014	296.1	274.9	560.9	3697.8	274.9	8601	97.9	640.3	847.4	0
Roadside
NL10741	309.4	276.1	705.5	1347.9	276.3	1192	13.6	728.9	774.3	0
NL49007	412.3	384.7	770.7	1395.4	384.7	8734	99.4	881.9	1054.4	0
NL49012	342.7	312.7	695.9	1099.4	312.7	8665	98.6	812.5	912.2	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 13: Key concentration values for carbon monoxide in 2020 (in μg/m³)

type	mean	n
Annual CO means per station type in 2020
Urban Background	296.08	1
Roadside	377.51	2

Table 14: Summary table for carbon monoxide in 2020 (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).

	mean	P50	P98	max	median	n	%	max.roll.24	max.roll.8
Key statistics for BC in 2020
Rural Background
NL01437	0.6	0.4	2.3	5.0	0.4	8760	99.7	3.6	4.6
NL10131	0.7	0.5	2.5	7.3	0.5	8758	99.7	3.3	4.3
NL10444	0.5	0.3	2.1	5.2	0.3	8710	99.2	3.9	3.9
NL10633	0.5	0.4	2.2	8.4	0.4	8390	95.5	4.0	3.8
NL10644	0.6	0.4	2.5	9.3	0.4	8695	99.0	5.2	4.4
NL10807	0.5	0.3	1.9	8.2	0.3	8648	98.5	5.7	3.0
NL10929	0.5	0.3	1.9	27.1	0.3	8576	97.6	10.0	19.1
Urban Background
NL01488	0.7	0.5	2.8	9.1	0.5	8515	96.9	7.2	4.6
NL01494	0.8	0.6	3.3	10.8	0.6	8673	98.7	6.2	6.7
NL10138	0.6	0.4	3.0	6.9	0.4	8732	99.4	4.7	5.4
NL10247	0.7	0.5	3.0	7.9	0.5	8737	99.5	3.6	5.6
NL10742	0.7	0.5	2.5	12.3	0.5	8719	99.3	7.8	4.9
NL10821	0.6	0.4	2.3	13.9	0.4	8733	99.4	13.9	6.8
NL10938	0.4	0.3	1.7	18.4	0.3	8736	99.5	18.4	11.7
NL49003	0.6	0.4	2.4	8.1	0.4	8768	99.8	3.4	5.0
NL49014	0.6	0.4	2.2	5.2	0.4	8744	99.5	3.6	3.6
NL49701	0.7	0.4	2.8	34.5	0.4	8750	99.6	21.6	15.0
Roadside
NL01487	1.4	1.2	4.4	9.7	1.2	8750	99.6	5.7	6.5
NL01491	0.9	0.7	3.3	11.1	0.7	8757	99.7	4.8	5.6
NL01492	1.0	0.8	3.3	13.7	0.8	8650	98.5	5.1	6.6
NL01493	1.4	1.1	4.9	12.3	1.1	8773	99.9	5.9	8.1
NL10237	1.0	0.8	3.6	14.8	0.8	8767	99.8	6.3	8.8
NL10641	0.8	0.7	2.5	8.4	0.7	8751	99.6	3.4	4.4
NL10741	1.1	0.9	3.5	12.8	0.9	8695	99.0	5.2	5.8
NL49007	1.0	0.8	3.1	12.0	0.8	8644	98.4	12.0	6.5
NL49012	0.8	0.7	2.9	6.2	0.7	8653	98.5	4.2	5.0
NL49017	0.9	0.7	2.7	6.5	0.7	8773	99.9	6.0	4.6
NL49020	1.1	0.8	3.4	9.1	0.8	8760	99.7	5.8	6.0
Industrial
NL01496	0.7	0.5	3.1	9.5	0.5	8580	97.7	4.5	6.7
Rows where the text is greyed out indicates a data capture < 85%

Table 15: Key concentration values for black carbon in 2020 (in μg/m³)

type	mean	n
Annual BC means per station type in 2020
Rural Background	0.54	7
Urban Background	0.65	10
Roadside	1.04	11
Industrial	0.75	1

Table 16: Summary table for black carbon in 2020 (in μg/m³)

2.7 Volatile organic compounds

	mean¹	P50	P98	max	median	n	%
Key statistics for benzene in 2020
Rural Background
NL49703	0.44	0.33	1.75	2.46	0.33	355	97.00
Urban Background
NL01485	0.57	0.51	1.34	1.72	0.51	341	93.17
NL01494	0.53	0.50	1.59	2.05	0.50	363	99.18
NL01495	1.11	0.76	5.08	10.96	0.76	354	96.72
NL10643	0.27	0.21	0.87	2.20	0.21	366	100.00
Roadside
NL49017	0.69	0.59	1.78	3.36	0.59	340	92.90
Industrial
NL01484	0.71	0.51	2.69	4.57	0.51	365	99.73
NL01496	0.42	0.32	1.56	2.38	0.32	356	97.27
NL49704	0.46	0.34	1.59	2.03	0.34	301	82.24
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 17: Key concentration values for benzene in 2020 (in μg/m³)

type	mean	n
Annual benzene means per station type in 2020
Rural Background	0.44	1
Urban Background	0.62	4
Roadside	0.69	1
Industrial	0.57	2

Table 18: Summary table for benzene in 2020 (in μg/m³)

For toluene there is no legally binding limit value. Other VOCs are also measured by the LML, but are excluded from this report.

	mean	P50	P98	max	median	n	%
Key statistics for toluene in 2020
Rural Background
NL49703	1.00	0.57	4.76	9.96	0.57	355	97.00
Urban Background
NL01485	1.80	1.52	4.68	6.70	1.52	341	93.17
NL01494	2.14	1.76	6.24	10.03	1.76	363	99.18
NL01495	2.10	1.64	6.90	11.86	1.65	354	96.72
NL10643	0.58	0.41	2.19	4.37	0.41	366	100.00
Roadside
NL49017	1.83	1.63	4.49	8.40	1.63	329	89.89
Industrial
NL01484	1.73	1.20	5.08	61.35	1.20	365	99.73
NL01496	0.73	0.49	3.54	4.82	0.49	356	97.27
NL49704	1.47	0.93	5.34	7.32	0.93	301	82.24
Rows where the text is greyed out indicates a data capture < 85%

Table 19: Key concentration values for toluene in 2020 (in μg/m³)

type	mean	n
Annual toluene means per station type in 2020
Rural Background	1.00	1
Urban Background	1.65	4
Industrial	1.23	2

Table 20: Summary table for toluene in 2020 (in μg/m³)

2.8 Heavy metals

The measurements of lead, arsenic, cadmium and nickel as shown in the tables below are based on PM_2.5 and PM₁₀ filter sampling.

	mean¹	P50	P98	max	median	n	%	filter_type
Key statistics for Pb in 2020
Rural Background
NL10627	3.7	2.7	13.8	26.0	2.7	180	49.2	PM₁₀
NL10644	3.7	2.7	15.0	18.7	2.7	87	23.8	PM_2.5
Rows where the text is greyed out indicates a data capture < 45%
¹ Orange color indicates exceedance of the annual EU limit value

Table 21: Key concentration values for lead in 2020 (in ng/m³)

	mean¹	P50	P98	max	median	n	%	filter_type
Key statistics for As in 2020
Rural Background
NL10627	0.5	0.4	1.8	3.8	0.4	180	49.2	PM₁₀
NL10644	0.4	0.3	1.1	1.8	0.3	82	22.4	PM_2.5
Rows where the text is greyed out indicates a data capture < 45%
¹ Orange color indicates exceedance of the annual EU limit value

Table 22: Key concentration values for arsenic in 2020 (in ng/m³)

	mean¹	P50	P98	max	median	n	%	filter_type
Key statistics for Cd in 2020
Rural Background
NL10627	0.1	0.1	0.3	0.5	0.1	180	49.2	PM₁₀
NL10644	0.1	0.1	0.3	0.5	0.1	87	23.8	PM_2.5
Rows where the text is greyed out indicates a data capture < 45%
¹ Orange color indicates exceedance of the annual EU limit value

Table 23: Key concentration values for cadmium in 2020 (in ng/m³)

	mean¹	P50	P98	max	median	n	%	filter_type
Key statistics for Ni in 2020
Rural Background
NL10627	0.6	0.5	1.6	3.5	0.5	177	48.4	PM₁₀
NL10644	0.5	0.4	1.1	1.7	0.4	86	23.5	PM_2.5
Rows where the text is greyed out indicates a data capture < 45%
¹ Orange color indicates exceedance of the annual EU limit value

Table 24: Key concentration values for nickel in 2020 (in ng/m³)

component	mean	n
Annual heavy metals means per station type in 2020
As	0.45	2
Cd	0.08	2
Ni	0.54	2
Pb	3.72	2

Table 25: Summary table for lead, arsenic, cadmium and nickel in 2020 (in ng/m³)

2.9 Benzo(a)pyrene

Benzo(a)pyrene concentrations based on PM₁₀ filter sampling for 2020 are given in the following table.

	mean¹	P50	P98	max	median	n	%
Key statistics for benzo(a)pyrene in 2020
Rural Background
NL10444	0.03	0.01	0.13	0.13	0.01	177	48.4
Urban Background
NL10418	0.04	0.02	0.17	0.18	0.02	180	49.2
Rows where the text is greyed out indicates a data capture < 30%
¹ Orange color indicates exceedance of the annual EU limit value

Table 26: Key concentration values for benzo(a)pyrene in 2020 (in ng/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

RIVM public data catalog for air quality measurements. Accessed via: https://data.rivm.nl/data/luchtmeetnet/. Export id of file used in this report for 2020: EXP-2025-002 (2025-05-19T15:35:06+01:00)
Directive 2008/50/EC of the European Parliament and of the Council of 21 May 2008 on ambient air quality and cleaner air for Europe. Official Journal of the European Union. Accessed via: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32008L0050
Directive 2004/107/EC of the European Parliament and of the Council of 15 December 2004 relating to arsenic, cadmium, mercury, nickel and polycyclic aromatic hydrocarbons in ambient air. Official Journal of the European Union. Accessed via: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32004L0107
Directive (EU) 2024/2881 of the European Parliament and of the Council of 23 October 2024 on ambient air quality and cleaner air for Europe (recast). Official Journal of the European Union. Accessed via: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=OJ:L_202402881
World Health Organization (2021) WHO global air quality guidelines. Particulate matter (PM2.5 and PM10), ozone, nitrogen dioxide, sulfur dioxide and carbon monoxide. Geneva. Licence: CC BY-NC-SA 3.0 IGO. Accessed via: https://iris.who.int/bitstream/handle/10665/345329/9789240034228-eng.pdf
Environmental Data Compendium (CLO) website. Accessed via: https://www.clo.nl/onderwerpen/luchtkwaliteit

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 L026.

component	accreditation_number^a	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
PM_2.5	L520, L224, L426	year	25	10	5
PM_2.5	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		20^b
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	sampling L224/analysis L026	year	0.5	0.5	0.5
As	sampling L224/analysis L026	year	0.006	0.006	0.066
Cd	sampling L224/analysis L026	year	0.005	0.005	0.005
Ni	sampling L224/analysis L026	year	0.02	0.02	0.025
benzo(a)pyrene	L224	year	0.001	0.001	0.12
^a L224 is RIVM, L520 is DCMR, L426 is GGD Amsterdam, L026 is the analytical laboratory of TNO
^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 27: 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)