Air pollution in New South Wales is estimated to cause 603 premature deaths and increase health costs by $4.8bn each year, according to a long-term government study.
Published online the day before the Perrottet government went into caretaker mode ahead of this month’s state election, the Sydney air quality study suggests most people in the city’s greater metropolitan region are exposed to air pollution at levels considered unsafe by the World Health Organization.
The largest source of air pollution was found to be wood heaters, which are used in about 10% of homes across the region. The study found they were likely to contribute to 269 premature deaths annually. Users of wood heaters were estimated to have lost 3,279 years of life between them– an average of about 12 years a person.
The increase in state health costs due to wood heater pollution was calculated to be more than $2bn.
Other major causes of air pollution affecting health were industrial sites including mines (133 deaths and $1bn in health costs), cars and trucks (110 deaths and $832m) and coal power stations (46 deaths and $346m).
Brad Smith, policy director with the Nature Conservation Council, said the results showed air pollution was a “silent epidemic”. He said it underlined the need for governments to “leave coal, gas and oil in the ground and wood in forests”.
“It’s clear that burning wood, petrol and coal is killing us, and imposing a huge health cost on Sydneysiders,” he said.
The study examined the concentration of PM2.5 – particulate matter 2.5 micrometers or smaller. These invisible fine particles can be inhaled and enter the bloodstream. They cause heart and lung disease. The aged, children and people with previous heart and lung problems are considered most at risk.
WHO guidelines, updated in 2021, recommend exposure to average PM2.5 levels of less than 5 micrograms a cubic metre over a year. The study estimated the average for Sydney was 6.43. They reached 12 in parts of the Upper Hunter.
Across the region, about half (48%) the modelled air pollution was from human-made sources and half (52%) natural sources.
While wood heaters and road vehicles were the biggest sources of air pollution in Sydney itself, pollution in the Hunter was largely caused by coalmines, coal power generation and diesel vehicles used at mines.
Coal mining was found to be responsible for about 50% of industrial emissions across the region, though this may be a slightly outdated figure. The study used 2013 data and coal power generation has declined by nearly 20% in the decade since.
The Department of Planning and Environment said NSW enjoyed its best air quality last year since the monitoring network began nearly three decades ago, but international health studies had shown that long-term exposure to air pollution could “shorten lives and hasten the burden of disease”.
A department spokesperson stressed the number of premature deaths attributable to poor air quality was an estimate, based on the methods used in global studies. They said the state was taking steps to reduce the adverse effects of air pollution as set out in the state’s clean air strategy.
“The [study] provides valuable information to government, business and communities on air quality and its impacts on public health and the environment,” the spokesperson said.
Donna Green, an environmental scientist at the University of New South Wales, has previously told Guardian Australia that high levels of PM2.5 could “affect every system in your body, which means you’re not only talking about respiratory-related and heart-related problems, people are linking it to diabetes [and] dementia”. She said rising temperatures due to greenhouse gas emissions could increase the levels of some air pollutants.
Smith said the reliance on wood heaters could be solved by banning their sale and offering incentives for households to switch to reverse-cycle electric heaters. By 2030, every bus and garbage truck in the state should be electric and coal power should be replaced by renewable energy and storage, he said.
“These astronomical health costs really put radical policy solutions on the table,” he said.
“For example, the cost of reducing all public transport fares to $1 is estimated at $750m. That’s less than the annual health cost caused by petrol and diesel vehicles of $900m.”
