A new study has found a possible link between a specific type of air pollution and premature babies.
The world-first study of 1.3 million pregnancies in China has found the risk of a pre-term birth increases by nine per cent if PM-1 pollutant levels rise by 10 micrograms over the pregnancy.
This specific type of pollutants is generally caused by burning coal and vehicle emissions, which means Australians could also be at risk.
The study's Australian-based author, Dr Yuming Guo, from Monash University, said in areas of high pollution – over 52 micrograms, the risk increases by 36 per cent.
"As of at this moment, no country has developed a standard for PM-1," he told SBS News.
“PM-1 is much smaller than PM-2.5. It might be a health risk for Australian people."
While Australia is seen to have relatively good air quality, generally only larger levels of pollution are looked at.
But Bronya Lipski, from Environmental Justice Australia, is concerned these smaller pollutants are being overlooked.
“Because it is so small, it can get into the body in ways that larger particles can't necessarily get into the body,” she said.
“So, if you've got like a little bit of pollution that's ... like a PM-1 pollution, it gets into the bloodstream.”
The study's authors are now urgently calling for a global review of air-pollution standards.
Got a story tip? Send it to firstname.lastname@example.org