Understanding air quality data

The Department of Planning, Industry and Environment and NSW Health have created air quality categories to guide you on what activities you can do, based on what the air quality is like in your area.

Air pollution has a significant impact on human health and the economy. Air quality in New South Wales is usually very good by international standards, however it is important to protect your health when air quality is poor by modifying your activities.

Air quality measurements from your local monitoring station is summarised using 5 air quality categories (AQC), rating air quality as 'Good', 'Fair', 'Poor', 'Very Poor' or 'Extremely Poor'.  For example, if your local air quality category is ‘Very Poor’ (red), you can look at the health advice in the activity guide to understand how this might affect your health and recommended actions to take. The activity guide is included in an accordion on this page and also on the EES website.

To understand how the activity guide relates to measured concentrations of air pollutants, the table below includes information on threshold concentrations used for categorising air quality into the 5 air quality categories. Note that air quality categorisation is no longer defined from Air Quality Index (AQI) values.

 

Air quality categories (AQC)

Air pollutant

Averaging period

Units

GOOD  

FAIR  

POOR  

VERY POOR

EXTREMELY POOR

Ozone
O3

1-hour

pphm

<6.7

6.7–10.0

10.0–15.0

15.0–20.0

20.0 and above

4-hour rolling

pphm

<5.4

5.4–8.0

8.0–12.0

12.0–16.0

16.0 and above

Nitrogen dioxide
NO2

1-hour

pphm

<8

8–12

12–18

18–24

24 and above

Visibility
Neph

1-hour

bsp

<1.5

1.5–3.0

3.0–6.0

6.0–18.0

18.0 and above

Carbon monoxide CO

8-hour rolling

ppm

<6.0

6.0–9.0

9.0–13.5

13.5–18.0

18.0 and above

Sulfur dioxide
SO2

1-hour

pphm

<13.3

13.3–20.0

20.0–30.0

30.0–40.0

40.0 and above

Particulate matter
< 10 µm PM10

1-hour

µg/m3

<50

50–100

100–200

200–600

600 and above

Particulate matter
< 2.5 µm PM2.5

1-hour

µg/m3

<25

25–50

50–100

100–300

300 and above

For a broader picture of air quality in New South Wales, you can view the latest NSW Annual Air Quality Statement 2019 or download past NSW Annual Air Quality Statements and NSW Annual NEPM Compliance Reports.

The 5 air quality categories, represented by the 5 colours, scale air pollution concentration data in a way that helps us understand how clean or polluted the air is. By following the colours as described in the activity guide (below), you will be able to understand how current air quality might affect your health.

The air quality categories are updated hourly, based on air pollutant measurements of:

  • ozone
  • carbon monoxide
  • sulfur dioxide
  • nitrogen dioxide
  • airborne particles (such as PM10, PM2.5)
  • visibility.

Visibility is a good indicator for smoke. While visibility is affected by dust, the instrument (a nephelometer or neph) is more sensitive to smoke.

The activity guide below has been derived by categorising air quality into colour indicators, based on threshold values for air pollutants’ concentrations and visibility data. Go with the colours and follow the recommended actions to protect your health.

Air quality category

General health advice and recommended actions

Sensitive groups including:

  • people with a heart or lung condition, including asthma
  • people over the age of 65
  • infants and children
  • pregnant women

Everyone else

Good

  • NO CHANGE needed to your normal outdoor activities.
  • NO CHANGE needed to your normal outdoor activities.

Fair

  • REDUCE outdoor physical activity if you develop symptoms such as cough or shortness of breath.
  • Consider closing windows and doors until outdoor air quality is better.
  • Follow the treatment plan recommended by your doctor.
  • If you are concerned about symptoms call the 24-hour HealthDirect helpline on 1800 022 222 or see your doctor.
  • In a health emergency, call triple zero (000) for an ambulance.
  • NO CHANGE needed to your normal outdoor activities.

Poor

  • AVOID outdoor physical activity if you develop symptoms such as cough or shortness of breath.
  • When indoors, close windows and doors until outdoor air quality is better.
  • Follow the treatment plan recommended by your doctor.
  • If you are concerned about symptoms call the 24-hour HealthDirect helpline on 1800 022 222 or see your doctor.
  • In a health emergency, call triple zero (000) for an ambulance.
  • REDUCE outdoor physical activity if you develop symptoms such as cough or shortness of breath.

Very poor

  • STAY INDOORS as much as possible with windows and doors closed until outdoor air quality is better.
  • If you feel that the air in your home is uncomfortable, consider going to a place with cleaner air (such as an air-conditioned building like a library or shopping centre) if it is safe to do so.
  • Actively monitor symptoms and follow the treatment plan recommended by your doctor.
  • If you are concerned about symptoms call the 24-hour HealthDirect helpline on 1800 022 222 or see your doctor.
  • In a health emergency, call triple zero (000) for an ambulance.
  • AVOID outdoor physical activity if you develop symptoms such as cough or shortness of breath.
  • When indoors, close windows and doors until outdoor air quality is better.
  • If you are concerned about symptoms call the 24-hour HealthDirect helpline on 1800 022 222 or see your doctor.
  • In a health emergency, call triple zero (000) for an ambulance.

Extremely poor

  • STAY INDOORS with windows and doors closed until outdoor air quality is better and reduce indoor activity.
  • If you feel that the air in your home is uncomfortable, consider going to a place with cleaner air (such as an air-conditioned building like a library or shopping centre) if it is safe to do so.
  • Actively monitor symptoms and follow the treatment plan recommended by   your doctor.
  • If you are concerned about symptoms call the 24-hour HealthDirect helpline on 1800 022 222 or see your doctor.
  • In a health emergency, call triple zero (000) for an ambulance.
  • STAY INDOORS as much as possible with windows and doors closed until   outdoor air quality is better.
  • If you feel that the air in your home is uncomfortable, consider going to a place with cleaner air (such as an air-conditioned building like a library or shopping centre) if it is safe to do so.
  • If you are concerned about symptoms call the 24-hour HealthDirect helpline on 1800 022 222 or see your doctor.
  • In a health emergency, call triple zero (000) for an ambulance.

When it’s smoky, everyone should:

  • Follow your doctor’s advice about medicines and your asthma management plan if you have one. Keep your medication close at hand. Consult your doctor if symptoms worsen.
  • Reduce or avoid vigorous outdoor activity see activity guide below.
  • Spend more time indoors. Keep doors and windows shut to keep the smoke out. Open windows and doors whenever the smoke clears.
  • Spend time in air conditioned venues like cinemas, libraries and shopping centres.
  • Avoid indoor sources of air pollution like cigarettes, candles and incense sticks.​​​​​

If your child has diagnosed asthma:

  • Have an up to date Asthma Action Plan​. Seek review with your child’s GP to assess their current asthma management.
  • Check your child’s reliever medication and spacer is up-to-date and accessible by a responsible adult.
  • Provide written asthma first aid instructions, completed by your child’s GP, to their preschool, childcare centre or school.
  • Visit the Sydney Children’s Hospital Network’s Aiming for Asthma Improvement in Children​ website which includes a Good asthma control checklist​.
  • Free asthma helpline: If you need information specific to people with asthma, visit the Asthma Australia website to access their free helpline.

Information for sensitive groups

Some people may be more sensitive to air pollution. Sensitive groups include people with lung disease or heart disease, children, older adults, pregnant women.

If you need information specific to people with asthma, visit the Asthma Australia website to access their free helpline.

Anyone with persistent symptoms should seek medical advice or call Health Direct Australia on 1800 022 222.

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