Qualité de l’air à Hobart

How bad is Hobart’s air quality?

As the capital city of Tasmania, the Australian island state situated approximately 240 kilometers south of Victoria, Hobart has relatively healthy air quality compared to the rest of the world. However, like the rest of Australia’s air quality, Tasmania can be prone to short-term extreme air pollution events, most often in the form of dust storms and wildfires. Nevertheless, Tasmania has garnered a reputation as having some of the world’s cleanest air quality, and Hobart, home to 40% of the state’s population, does not contradict this with its recorded levels of air pollution. In IQAir’s 2019 World Air Quality Report, Hobart emerged as Australia’s 12th cleanest location for PM2.5 pollution out of 95 measured cities, with an annual average PM2.5 concentration of 4.4 μg/m³.¹ This achieves Australia’s National Environment Protection (Ambient Air Quality) Measure (Air NEPM) standard for annual PM2.5 (less than 8 μg/m³), as well as the World Health Organisation (WHO)’s annual PM2.5 guideline of 10 μg/m³, by some way. It also ranked Hobart as the 121st cleanest city in the world for PM2.5 during 2019 out of over 4,600 cities included in the ranking.

The main pollutants of concern in Hobart, Tasmania are particulate matter (PM), as these function as the main indicator of urban air pollution within the state.² PM describes microscopic airborne particles that are smaller than 2.5 or 10 micrometers in diameter, abbreviated as PM2.5 and PM10 respectively. These particles can have a range of chemical makeups, and can be emitted from a range of natural and human-influenced sources, such as fuel combustion in vehicles, heating and industry, as well as sea salt and airborne dust.

Real-time air quality conditions, including levels of particulate matter, are displayed in the Hobart air quality map at the top of this page, along with wildfire information. These can be followed on-the-go, together with a 7-day Hobart air quality forecast, using the IQAir AirVisual air pollution app.

Does Tasmania have the cleanest air?

Tasmania’s reputation for having some of the world’s cleanest air has developed partly thanks to continuously low recorded air pollution levels across the state depicting a relatively clean environment, and also partly thanks to the Cape Grim Baseline Air Pollution Station, installed on the north-western tip of Tasmania on its Cape Grim Peninsula. The Cape Grim station has been established in this particular spot since 1976 by Australia’s Bureau of Meteorology, to measure air quality levels to provide a representative “baseline” for the Earth’s ambient air pollution, without interference from human-influenced pollution. This location was chosen as an appropriate spot to capture such a pristine baseline, due to its remote location: both distant from human activity on Tasmania, and on the peninsula, the nearest land mass from the west is Argentina, and to the south, Antarctica.³

Within IQAir’s 2019 World Air Quality Report, Tasmania’s air quality consistently ranked among the cleanest within Australia, with 23 out of the 24 cleanest locations for PM2.5 pollution in Australia located in Tasmania. The one exception was Moranbah’s air quality located in Queensland (4.1 μg/m³) which ranked as Australia’s 9th cleanest city, with a slightly lower concentration than Hobart.

What are the main sources of Hobart air pollution?

Tasmania experiences seasonal variations in its levels of particulate matter pollution, including Hobart. The main contributors towards particulate pollution in Tasmania and Hobart are smoke from wood heaters in homes, particularly during winter, while summer months usually experience lower levels of PM2.5, except for when forest fires take place during the hotter and drier conditions.⁴ In addition to these seasonal variations, autumn and springtime are most likely to experience PM2.5 elevations due to forest fires arising from planned burning.⁵

What are the health effects of Hobart air pollution?

Exposure to air pollution can result in a range of short- and long-term health effects. Even despite Hobart’s relatively low level of air pollution, the World Health Organisation emphasises that there is no known “safe” limit of air pollution below which no health effects can be observed. Accordingly, it is in the interest of Tasmanians to minimise exposure to air pollution whenever possible, particularly when air pollution levels may become elevated, as a result of heightened wood burning (for example during winter) or during forest fires.

A study published by researchers from a range of Australian institutions found that Tasmania smoke coming from biomass burning activities such as wood heaters and landscape fire smoke between 2010 to 2019, can be associated with notable health impacts, even within the relatively clean Tasmania. The study estimated that exposure to PM2.5 from these sources results in 69 excess deaths, 86 additional hospital admissions, and 15 emergency department admissions related to asthma each year, with over 74% of these impacts attributable to wood heater smoke.⁵ Furthermore, the economic impacts associated with these health damages are estimated to cost approximately $293 million AUD (~$221 million USD) for wood heater smoke, and $16 million AUD (~$12 million USD) for landscape fire smoke, with this figure increasing to $34 million AUD (~$ 26 million USD) during bushfire seasons in Tasmania.⁵ These figures indicate the significant health and economic impacts that can arise as a consequence of even relatively low air pollution levels by global standards.

What is Hobart doing about its air pollution?

The Tasmania Environment Protection Authority (EPA) runs a statewide network of air quality monitors, to track air quality levels around the state and try to ensure they meet the national Air NEPM standards. Tasmania’s monitoring network, known as the Base Line Air Network of EPA Tasmania (BLANkET), has several stations at 35 locations (as of December 2020), measures PM2.5 and PM10 concentrations.⁶ Hobart has a government monitoring station located in New Town, approximately 3.5km north-east of Hobart’s Central Business District (CBD).

Tasmania’s EPA then reports the air quality readings from the BLANkET network to the public, using a system of ‘air quality categories’. Instead of adopting a Hobart Air Quality Index, or Hobart AQI to convey pollution levels, following Australia’s broader system of using an air quality index; the Tasmania EPA expresses Hobart’s air quality through categories which are designed to quickly convey the level of health hazard posed by current conditions. Tasmania’s air quality categories represent air quality based on an average PM2.5 concentration, of “Good” (0-10 μg/m³), “Fair” (10-25 μg/m³), “Poor” (25-100 μg/m³), and “Very Poor” (100+ μg/m³).⁶ In this way, the Tasmania EPA strives to quickly communicate air quality to empower Tasmanians, including those in Hobart, to respond to air pollution when necessary.

+ Article resources

[1] IQAir. “2019 World Air Quality Report”. IQAir website, March 18, 2020.
[2] Tasmania EPA. “National Environment Protection Measure (Ambient Air) Monitoring”. Tasmania EPA website, n.d.
[3] Alexander Liddington-Cox. “Tasmania has some of the cleanest air in the world – but it’s not as clean as it used to be”. Business Insider Australia, March 20, 2019.
[4] Tasmania EPA. “Particle Matter”. Tasmania EPA website, n.d.
[5] Nicolas Borchers-Arriagada et al. “Health Impacts of Ambient Biomass Smoke in Tasmania, Australia”. International Journal of Environmental Research and Public Health 17(9): 3264, May 7, 2020. DOI: 10.3390/ijerph17093264
[6] Tasmania EPA. “Real-time Air Quality Data for Tasmania”. Tasmania EPA website, 2013.