AIR QUALITY STANDARDS

STANDARDS FOR AMBIENT AIR QUALITY IN VICTORIA

Ambient air quality is measured and regulated in Victoria against a set of standards found in the State Environment Protection Policy (Ambient Air Quality) (State Ambient Air Quality standard). Victoria has adopted the air quality requirements of the National Environment Protection Council (Ambient Air Quality) Measure (National Ambient Air Quality standard), which sets national standards for the  monitoring and reporting of the following six common pollutants (also known as criteria pollutants):

  • carbon monoxide
  • nitrogen dioxide
  • photochemical oxidants – ozone
  • sulphur dioxide
  • lead
  • particles as PM10.

The State Ambient Air Quality standard also includes a separate objective for visibility reducing particles, which is not included in the national standard.

Standards for air quality are based on rigorous science, an understanding of the state of the environment, and current and future environmental risks. The Environmental Quality Objectives found within the State Ambient Air Quality standard is designed to protect against long-term chronic exposure across populations (see Figure 4.4). They are not designed for acute or emergency scenarios.45 Standards in Victoria, Australia and internationally have evolved over time in response to changing environmental conditions, national and international standards, evidence-based research and community expectations.46

Figure 4.4 State Environment Protection Policy (Ambient Air Quality) standard47

Environmental Indicator
(Pollutant)

Averaging Period

Environmental Quality Objectives

Maximum allowable exceedences within a period of 10 years

Carbon monoxide (CO) (maximum concentration) 8 hours 9.0 ppm 1 day a year
Nitrogen dioxide (NO2) (maximum concentration) 1 hour
1 year
0.12 ppm
0.03 ppm
1 day a year
none
Photochemical oxidants Ozone (O3) (maximum concentration) 1 hour
4 hours
8 hours
8 hours
0.10 ppm
0.08 ppm
0.05 ppm
0.08 ppm
1 day a year
1 day a year
3 days a year
none
Sulphur dioxide (SO2) (maximum concentration) 1 hour
1 day
1 year
0.20 ppm
0.08 ppm
0.02 ppm
1 day a year
1 day a year
none
Lead
(maximum concentration)
1 year 0.50 μg/m3 none
Particles as PM10
(maximum concentration)
1 day 50 μg/m3 5 days a year
Visibility reducing particles (minimum visual distance) 1 hour 20 km 3 days a year
Note the last category titled ‘Visibility reducing particles’ is particular to Victoria. The units of measurement for the standards listed above are parts per million (ppm) by volume and micrograms per cubic metre of air (µg/m3).

 

ADVISORY STANDARD FOR PM2.5

At the time of writing this report, standards for PM2.5 were advisory at both state and national levels (see Figure 4.5).

Figure 4.5 State and National Ambient Air Quality PM2.5 Advisory Reporting Standard48

Pollutant

Averaging Period

Advisory Reporting Standard

Goal

PM2.5 1 day
1 year
25 μg/m3
8 μg/m3
Goal is to gather sufficient data nationally to facilitate a review of the Advisory Reporting Standards as part of the review of this Measure to commence in 2005

On 13 May 2014, the National Environment Protection Council (NEPC) published a notice in the Victorian Gazette titled ‘Notice of intention to vary the National Environment Protection (Ambient Air Quality) Measure’. The notice reads:

The National Environment Protection Council (NEPC) is a national council of Commonwealth, State and Territory Ministers. The NEPC’s role is to make National Environment Protection Measures (NEPMs). NEPMs are designed to improve national consistency in environment protection outcomes.

The NEPC gives notice that it intends to make a variation to the Ambient Air Quality NEPM in relation to the standards for particles. This variation will reflect latest scientific understanding and will allow for an adequate level of health protection against the impacts of particle air pollution for the Australian community.49

INTERNATIONAL AIR QUALITY STANDARDS FOR PM2.5

The United States Environmental Protection Agency (US EPA) has National Ambient Air Quality Standards (NAAQS) for pollutants considered harmful to public health and the environment. Two types of national ambient air quality standards are produced–primary and secondary standards. Primary standards provide public health protection, including protecting the health of sensitive or vulnerable populations such as asthmatics, children, and the elderly. Secondary standards provide public welfare protection, including protection against decreased visibility and damage to animals, crops, vegetation, and buildings.50

The US EPA has set NAAQS for six principal pollutants that cover the same criteria pollutants included in the national and state standards. It is important to note that although the same criteria pollutants are included, the levels at which they are measured are different in some cases, as set out in Figure 4.6. Importantly, PM2.5 is addressed under a compliance standard rather than an advisory standard. Although the current thresholds under NAAQS are not as strict as the current advisory standard set at state and national levels in Australia, they have been in force since 1997 and are continually upgraded, most recently in 2012 (see Figure 4.6).51

Figure 4.6 US National Ambient Air Quality Standards52

Pollutant

Primary / Secondary

Averaging Time

Level

Form

Carbon monoxide (CO) Primary 8 hour 9 ppm Not to be exceeded more than once
per year
1 hour 35 ppm
Lead Primary and secondary Rolling 3 month average 0.15 μg/m3 Not to be exceeded
Nitrogen dioxide (NO2) Primary 1 hour 100 ppb 98th percentile, averaged over 3 years
Primary and secondary Annual 53 ppb Annual Mean
Ozone (O3) Primary and secondary 8 hour 0.075 ppm Annual fourth-highest daily maximum 8 hour concentration, averaged over 3 years
Particle pollution PM2.5 Primary Annual 12 μg/m3 Annual mean, averaged over 3 years
Secondary Annual 15 μg/m3 Annual mean, averaged over 3 years
Primary and secondary 24 hour 35 μg/m3 98th percentile, averaged over 3 years
PM10 Primary and secondary 24 hour 150 μg/m3 Not to be exceeded more than once per year on average over 3 years
Sulphur dioxide (SO2) Primary 1 hour 75 ppb 99th percentile of 1 hour daily maximum concentrations, averaged over 3 years
Secondary 3 hour 0.5 ppm Not to be exceeded more than once per year
Units of measurement for the standards are parts per million (ppm) by volume, parts per billion (ppb) by volume, and micrograms per cubic metre of air (µg/m3).

The World Health Organisation (WHO) recognises that particulate matter, specifically PM2.5 and PM10,  poses a serious risk to human health and currently has the following guidelines for particulate matter:

  • PM2.5: 10 μg/m3 annual mean; 25 μg/m3 24-hour mean
  • PM10: 20 μg/m3 annual mean; 50 μg/m3 24-hour mean.53