Bushfire smoke effects on air quality monitored by the Blue Mountains and Lithgow Air Watch Project
PM2.5 particle monitoring results showed:
- Between 30 October and 31 December, Katoomba recorded 29 days over the PM2.5 benchmark, with the highest daily average of 436 µg/m3 on 26 December being the second highest daily reading in the year.
- However, monitoring data were not available for 27 to 30 December, due to high levels of particles overloading the instruments. The daily average on the 27 December of the nephelometer visibility measurements, was 33% higher than 26 December. As there is a high correlation between visibility and PM2.5 measurements when the particle source is mostly comprised of smoke, it could be expected that this day might have recorded a PM2.5 daily average above 436 µg/m3.
PM10 particle monitoring has shown:
- Between 30 October and 31 December, Katoomba recorded 23 days over the PM10 benchmark, with 22 of these days also recording PM2.5 exceedances due to bushfire smoke and an additional 1 day related to a dust storm on 26 October.
Ozone monitoring has shown:
- National ozone standards were exceeded on 10 days in Katoomba between 21 November and 31 December.
- On 4 of these days there were no ozone exceedances observed in Sydney. These days were typical of prevailing winds directing smoke from the Blue Mountains fires towards western Blue Mountains and inland areas in the Central Tablelands and Central-west regions of NSW.
Bushfire emergency air quality monitoring
An extensive bushfire near Port Macquarie spread from a peat fire in a dry wetland, following a lightning strike in June 2019. In late July, an air quality monitoring station was established, monitoring PM10 and PM2.5 particles, visibility, and the gases ozone, nitrogen dioxide, sulfur dioxide and carbon monoxide. Monitoring results are summarised below.
PM2.5 particle monitoring:
- From 29 July to 31 December, the 25 µg/m3 benchmark was exceeded on 56 days (41%) of 136 days where daily PM2.5 averages were available,
- Between 29 July and 16 September, the PM2.5 daily average was greater than the 25 µg/m3 benchmark on 23 days out of 43 days with data available, due to combination of peat fire, local bushfires and smoke transport from northern NSW fires in September.
- Between 7 November and 12 December, the daily PM2.5 levels were above the benchmark on 26 out of 34 days with data available (high particle loads impacted the instrument, reducing data availability on 2 additional days).
- The highest PM2.5 daily average of 443 µg/m3 was recorded on 15 November, setting the highest on record in NSW since 1994 for the PM2.5 daily average at any monitoring station to the end of 2019.
PM10 particle monitoring:
- From 29 July to 31 December, PM10 daily averages were above the benchmark on 45 days (33% of the time), with 41 of these days coinciding with PM2.5 exceedance days due to bushfire smoke.
- 4 days with PM10 averages above the benchmark were due to dust storms affecting northern NSW on 22 August, 27-28 November and 2 December.
Gaseous air pollutant monitoring:
- Carbon monoxide levels were above the 8-hour average benchmark of 9 ppm on 11 November (9.3 ppm) and 15 November (9.6 ppm). Only 1 other CO exceedance has been observed at the non-roadside monitoring stations in NSW since 1994, which was at Campbelltown West during the 2013 Blue Mountains bushfires.
- Ozone levels were also recorded above the 4-hour benchmark of 8 parts per hundred million (pphm) on 19 November (8.2 pphm) and 5 December (9.0 pphm).
Coffs Harbour and Lismore
In mid-November, due to the poor air quality observed in Port Macquarie and the extent of the northern NSW fires, emergency air quality monitoring stations were established at Coffs Harbour and Lismore. Monitoring results are summarised below.
PM2.5 particle monitoring:
- PM2.5 monitoring began at Coffs Harbour on 22 November, with 14 days recorded over the benchmark by 31 December. Between 23 November and 11 December, 12 of the 19 days were over the benchmark. The highest daily PM2.5 level recorded was 114 µg/m3 on 23 November.
- PM2.5 monitoring began at Lismore on 24 November, with 9 days recorded over the benchmark by 31 December, occurring during a 10-day period from 3 to 12 December. The highest daily PM2.5 level recorded was 43.7 µg/m3 on 9 December.
- Ozone levels were above the national benchmarks at Coffs Harbour on 5 December, recording a 1-hour ozone level of 10.2 pphm and 4-hour ozone level of 9.8 pphm. This event coincided with one of the ozone events at Port Macquarie.
Grafton, Coffs Harbour, Taree, Ulladulla and Batemans Bay
Additional indicative monitoring was established on the NSW north coast at Grafton, Coffs Harbour and Taree in November and on the south coast at Ulladulla and Batemans Bay in December. Indicative monitors were installed to measure only hourly particle pollution levels. Data from these monitors have a lower level of accuracy compared to certified instrumentation. The hourly levels recorded by indicative monitors are not intended to be compared with the daily PM2.5 or PM10 benchmarks. Monitoring results are summarised below.
- NSW north coast:
- From 21 November to 31 December, indicative monitors recorded their maximum hourly PM2.5 levels on 23 November 2019, with 689 µg/m3 at Grafton, 610 µg/m3 at Taree, and 461 µg/m3 at Coffs Harbour.
- NSW south coast:
- From 7 to 31 December (25 days), indicative monitors recorded maximum hourly PM2.5 levels of 2500 µg/m3 at Batemans Bay (31 December) and 1675 µg/m3 at Ulladulla (23 December 2019).