Australian study casts doubt on WHO safe standards of air pollution, showing low levels of pollution are deadly.
A landmark study of more than 240,000 deaths in Queensland over a 15-year period to 2013 has found even low levels of PM2.5, fine particulate matter found in air pollution, results in an increased risk of death from diseases such as cardiovascular and respiratory disease.
Importantly, the study showed that for every 1 ug/m3 increase in PM 2.5 there is a 2 percent increased risk of early death – and that these pollutants can kill even when they are at less than the current World Health Organization (WHO) annual standards.
While overall concentrations of PM2.5 were low in Queensland during the study - between 1 and 9 ug/m3 (highest in Brisbane) - it still impacted death rates. The WHO annual standard for safety is 10 mg/m3.
Air pollution containing PM2.5 was identified in 2015 as the fifth leading cause of mortality but this study is the first to link very low levels to increased mortality and to show that – as the particulate matter increases – so does the risk of disease and death.
The study, published in PLOS Medicine, looked at 242,320 deaths in 7 categories: mental and behavioural disorders, and diseases of the nervous system, circulatory system, respiratory system, digestive system and genito-urinary system, with an emphasis on respiratory and cardiovascular conditions, according to Professor Guo.
“What we found is that even very low levels of air pollution can have a serious effect on health and hasten death, and there is a potential threshold around 4.5 ug/m3 above which there is increased risk of death. When renewing the air quality standard, this threshold should be considered” he said.
Previous Animal studies have found PM2.5 can go from the lungs into the bloodstream and into specific organs, leading to oxidative stress, inflammation and plaque instability, potentially causing stroke or heart disease.