Air quality special statement spring–summer 2019–20: PM10 particles

Note: PM10 refers to airborne particles less than 10 micrometres in diameter.

Key points

The record for the highest daily PM10 concentration since 2009 was set 4 times between 15 November 2019 and 11 January 2020:

• Daily PM10 levels were above the benchmark on 140 days (or 79% of days) due to dust and bushfire smoke in spring-summer 2019-20, compared with 78 days (or 43%) in spring–summer 2018–19. Bushfire emergency monitoring stations recorded 43 days above the benchmark, including four days not recorded by the standard monitoring network.
• The highest daily PM10 concentration reached 621 µg/m3, 12 times the benchmark, recorded at Merriwa in the Upper Hunter on 11 January 2020 during a dust storm impacting most of inland eastern Australia. This daily PM10 concentration ranked the fourth highest since 1994 and the highest since 2009.

More detail

Maximum daily and hourly PM10 concentrations recorded across the regions of the NSW Air Quality Monitoring Network are summarised below:

• Maximum daily PM10 levels ranged from 128 µg/m³ (3 times the benchmark) on the Central Coast to 621 µg/m³ (12 times the benchmark) in the Upper Hunter. In comparison, the highest daily PM10 level since 1994 was recorded on 23 September 2009, with 2427 µg/m³ (50 times the benchmark) during the Red Dawn dust storm.
• Maximum daily PM10 levels at bushfire air quality monitoring stations ranged from 134 µg/m³ (almost 3 times the benchmark) at Coffs Harbour to 480 µg/m³ (almost 10 times the benchmark) at Port Macquarie on the Mid-North Coast. Lismore in the Northern Rivers recorded 157 µg/m³ (3 times the benchmark).
• Maximum hourly PM10 levels at standard monitoring stations ranged from 613 µg/m³ in the Illawarra to 5575 µg/m³ in the Upper Hunter (at Merriwa).
• Maximum hourly PM10 levels at bushfire air quality monitoring stations ranged from 348 µg/m³ at Coffs Harbour to 1319 µg/m³ at Port Macquarie.
• Maximum hourly PM10 levels at bushfire emergency indicative monitoring stations ranged from 523 µg/m³ at Coffs Harbour on the Mid-North Coast to 2863 µg/m³ at Batemans Bay on the South Coast.

Daily average PM10 levels in spring-summer 2019–20

Days above the PM10 benchmark, across the standard network by region

The standard monitoring network recorded a total of 140 days above the benchmark, due to bushfire smoke and windblown dust.

• Ranging from 23 to 96 days at stations on the Central Coast, Newcastle local region and the Lower and Upper Hunter
• 40 to 62 days across the Northern Tablelands and North-west Slopes
• 42 to 58 days across the Southern and Central Tablelands and the South-west Slopes
• 31 to 49 days across the Illawarra and Sydney regions (Sydney East, Sydney North-west and Sydney South-west)
• 32 days in the Blue Mountains (measured at Katoomba)

Note: The Southern Tablelands most likely experienced PM10 levels above the benchmark before monitoring began (at Goulburn) on 6 November 2019.

Days above the PM10 benchmark, at bushfire air quality monitoring stations

Bushfire emergency monitoring stations recorded 43 days above the benchmark, including 4 days not recorded by the standard monitoring network:

• 42 days at Port Macquarie on the Mid-North Coast
• 12 days at Coffs Harbour on the Mid-North Coast
• 9 days at Lismore in the Northern Rivers.

Note: The Northern Rivers and Mid-North Coast most likely experienced PM10 levels above the benchmark before monitoring began (at Lismore and Coffs Harbour) on 22 November 2019.

Maximum daily PM10 levels, across the standard network by region

• Ranging from 128 to 621 µg/m³, approximately 3 to 12 times the benchmark, across stations in the Central Coast, Newcastle local region and the Lower Hunter and Upper Hunter. PM10 levels were elevated by dust activity and bushfire smoke, as well as some contribution form mining activity in the Upper Hunter and sea salt at Stockton in the Lower Hunter.
• 298 to 557 µg/m³, approximately 6 to 11 times the benchmark, across the South-west Slopes and Central and Southern Tablelands
• 447 µg/m³, almost 9 times the benchmark, in the Blue Mountains (at Katoomba)
• 240 to 310 µg/m³, approximately 5 to 6 times the benchmark, across the North-west Slopes and the Northern Tablelands
• 187 to 269 µg/m³, approximately 3 to 5 times the benchmark, across the Illawarra and Sydney regions

Maximum daily PM10 levels, at bushfire air quality monitoring stations

• 480 µg/m³, almost 10 times the benchmark, at Port Macquarie on the Mid-North Coast on 15 November 2019. At the time of the event, this was the highest daily PM10 level recorded in the State since 2009 and the fourth highest since 1994.
• 157 µg/m³, 3 times the benchmark, at Lismore in the Northern Rivers
• 134 µg/m³, almost 3 times the benchmark, at Coffs Harbour on the Mid-North Coast

NSW records for the highest daily PM10 levels, 1994 to February 2020

Hourly average PM10 levels in spring-summer 2019–20

The NSW Government began reporting hourly average PM10 levels in February 2020 in response to public needs.

Maximum hourly PM10 levels, across the standard monitoring network by region

• Ranging from 667 to 5575 µg/m³ across stations in the Central Coast, Newcastle local region, Upper Hunter and Lower Hunter. Merriwa in the Upper Hunter recorded a hourly maximum level of 5575 µg/m³ at 3am on 11 January 2020, during a widespread dust storm, as noted above.
• 1782 to 2743 µg/m³ across stations in the South-west Slopes and the Southern and Central Tablelands
• 1416 µg/m³ in the Blue Mountains (at Katoomba)
• 954 to 1843 µg/m³ across the Northern Tablelands and North-west Slopes
• 613 to 1199 µg/m³ across the Illawarra and Sydney regions

Maximum hourly PM10 levels, at bushfire air quality monitoring stations

• 1319 µg/m³ at Port Macquarie on the Mid-North Coast, at 11am on 5 November 2019
• 368 µg/m³ at Lismore in the Northern Rivers at 11pm, 2 December 2019
• 348 µg/m³ at Coffs Harbour on the Mid-North Coast, at 9am on 23 November 2019

Maximum hourly PM10levels, at bushfire indicative air quality monitoring stations

• 2863 µg/m³, at Batemans Bay in the South Coast at mid-day, 31 December 2019
• 1775 µg/m³, at Ulladulla in the South Coast at 5am, 23 December 2019
• 883 µg/m³, at Taree in the Mid-North Coast at mid-night, 27 November 2019
• 831 µg/m³, at Grafton in the Northern Rivers at 11am, 23 November 2019
• 673 µg/m³, at Cooma in the Snowy Mountains at 7am, 31 January 2020.
• 557 µg/m³, at Merimbula in the South Coast at 10am, 16 January 2020
• 523 µg/m³, at Coffs Harbour in the Mid-North Coast at 8am, 23 November 2019

Maximum hourly PM10 levels, at indicative monitoring stations in the Rural Air Quality Monitoring Network

• Ranging from 1955 to 14,365 µg/m³ across 2 stations in the Victorian Mallee Catchment Management Authority region, due to dust
• 2454 to 11,418 µg/m³ across 11 stations in the Western region, mainly due to dust
• 2395 to 5095 µg/m³ across 2 stations in the North West region, due to dust
• 3527 µg/m³ in the Murray region (measured at Kyalite), due to dust
• 3020 µg/m³ in the Central West region (measured at Dubbo), due to dust
• 2418 to 2955 µg/m³ across 2 stations in the Riverina region, due to dust and bushfire smoke

Note: Region refers to NSW Local Land Services region.