Very fine particles of air pollution caused by burning coal or vehicle exhausts are linked to an increased risk of premature births, scientists have warned.
A recent study, which examined more than 1 million births across China, was the first to consider the impact of the smallest pollution particles, or PM1, on pre-terms births.
Premature births can increase the long-term risk of many types of health problems including diabetes, cardiovascular disease and asthma.
Study author Yuming Guo from Monash University said while we already know much about the polluting effects of larger particles, his research focused on those smaller than 1 micron in diameter.
“Our study is the first to look at PM1, which is much smaller than PM 2.5 and PM 10, and we got results. We saw increased risk of premature birth,” Dr Guo said.
“Currently in other countries, there is no standard for PM1. They only have standards for PM 2.5 and PM 10 at this moment.”
Dr Guo said he hopes the research may pave the way for better monitoring of pollution levels around the world.
“Our study is giving some clue to develop a standard for PM1. It should be good evidence for the WHO, for the national EPA to develop their PM1 standard in the future,” he said.
“There is no safe level of air pollution. Even a very low level PM has a severe risk for health, so that means this study is also useful for the Australian Government.”
Air pollution has become a public health crisis in major industrial economies like India, where New Delhi schools were temporarily closed last year due to levels of smog.
The Chinese Premier, Li Keqiang, at last year’s National People’s Congress pledged to tackle his country’s problem with air pollution caused by burning coal.
‘We can’t be complacent in Australia’
Dr Guo’s study found that an increase of just 10 micrograms of PM1 particles was associated with a 9 per cent increase in pre-term births.
And when the concentrations were increased to over 50 micrograms, the chance of a premature birth rose by more than a third.
Professor Peter Sly from the University of Queensland said while that may seem small, the impacts of pollution on pre-term births could be significant.
“If you have an increase of 9 to 10 per cent across an entire population, that translates into a lot of premature births,” Professor Sly said.
“The risk is much higher for those who were born more prematurely, and it gets up to almost 30 per cent.”
Although the study’s data was collected in China, Professor Sly said its findings are still very relevant in Australia where PM1 particles are not currently monitored.
“We do know that the levels of air pollution we have in Australia do affect foetal growth. There was a study published from Brisbane some years back showing that,” he said.
“I think what the message that’s coming out from these recent reports on the health effects of pollution is that we can’t be complacent in Australia.”
The study has been published in the American Medical Association’s Journal of Paediatrics.