With each new study about air pollution, the situation is exposed as worse than we believed.
The number of health problems linked to air pollution could be far higher than previously thought, according to research suggesting hospital admissions for conditions ranging from heart failure to urinary tract infections increase as air becomes dirtier.
Air pollution has already been associated with a number of conditions, from strokes to brain cancer, miscarriage and mental health problems.
However, the research suggests the impact could be far wider, despite looking at only one component of air pollution, chiming with a global review published earlier this year that indicated almost every cell in the body may be affected by dirty air.
Writing in the BMJ, Dominici and colleagues report how they analysed more than 95m insurance claims made between 2000 and 2012 by hospital inpatients in the US aged 65 or older enrolled in the Medicare programme.
They then looked at air pollution, focusing on levels of a type of fine particulate matter, known as PM2.5, which is produced by sources including vehicles and power stations. By harnessing air quality data from a range of sources, they were able to estimate PM2.5 levels for each patient based on their home zip code
The team then compared air pollution levels for each patient during the two days around their hospital visit with levels from other points in time.
The analysis suggests even a small average rise in PM2.5 of 1 micrograms per cubic metre over a two-day period is linked to an increase of 68 older people per billion being taken to hospital with heart failure the next day.
The team’s analysis further reveals air pollution is linked to more than just hospital visits: the data shows short-term increases in PM2.5 were linked to an average annual increase of 634 deaths, and about $100m in costs for inpatients and post-acute care.
Dr Ioannis Bakolis, of King’s College London, who was not involved in the study, agreed. He said: “These guidelines needs to be revised, as even the 9% of the population that lives within the WHO limits may be substantially by affected by air pollution concentrations and its associated costs, according to the findings of the study.”
Writing in an accompanying editorial, a team of experts from the University of Southampton say the study suggests figures for the number of early deaths down to air pollution – put at 800,000 a year in Europe – are likely to be considerable underestimates, and stressed action is needed.
“Clearly, there is much still to learn, but we should not mistake knowledge gaps for paucity of evidence,” they write. “The sooner we act, the sooner the world’s population will reap the benefits.”