The Department of Water and Environmental Regulation’s (DWER) air monitoring team recently analysed data showing plots of carbon monoxide (CO) and oxides of nitrogen (NOx) at South Lake, Duncraig and Caversham from March to July over the period 2015 to 2020.
One notable aspect the team identified is a reduction in concentration of CO and NOx during the months March to July of 2020, which coincide with the reduction in all forms of travel due to the COVID-19 pandemic.
Arthur Grieco, Manager of Air Quality (Technical Services) for DWER, said this reduction was more marked at South Lake than at Duncraig, where the mean CO concentrations in the morning and evenings for the months March to July 2020 are similar to the mean mid-day concentrations in the five year period 2015 to 2019. Normally, CO concentrations are higher during the morning and evening periods, which reflect peak traffic times.
“The profile shows that the reduced concentrations this year were possibly caused by a reduction in motor vehicle usage” Mr Grieco said.
While the figures are preliminary, Mr Grieco said the findings are interesting and something the department will continue to track in the coming months.
“The reduction is interesting, but regardless Perth has very good air quality and did so prior to COVID-19,” Mr Grieco said.
The findings coincide with the installation of two new air monitoring stations in Armadale and Mandurah, which will further enhance the department’s ability to collect air quality data.
The Mandurah monitoring station measures CO, nitrogen dioxide, ozone and particles, while particles are measured at Armadale. Several meteorological parameters such as wind, speed and direction are also measured at the stations.
The World Health Organisation estimates that worldwide about 3 million people die each year from ailments caused by air pollution, and that more than 80 per cent of people living in urban areas around the world are exposed to air quality levels that exceed safe limits.
CO and NOx in urban areas are mainly due to combustion from motor vehicles, wood heaters and vegetation fires.
Access to air quality information for the Armadale and Mandurah sites, along with DWER’s other monitoring stations, is available from https://www.der.wa.gov.au/your-environment/air/203-air-quality-publications.
