Individuals who are regularly exposed to ozone pollution are more likely to be hospitalised with a cardiovascular complication compared to those with limited exposure, new research reveals.
A study conducted by the European Society of Cardiology has found an association between high levels of ozone pollution and a higher risk of heart failure, heart attack and a stroke.
First author Professor Shaowei Wu said: “During this three-year study, ozone was responsible for an increasing proportion of admission for cardiovascular disease as time progressed.
“It is believed that climate change, by creating atmospheric conditions favouring ozone formation, will continue to raise concentrations in many parts of the world.”
Professor Wu added: “Our results indicate that older people are particularly vulnerable to the adverse cardiovascular effects of ozone, meaning that worsening ozone pollution with climate change and the rapid ageing of the global population may produce even greater risks of cardiovascular disease in the future.”
Ozone is a reactive gas comprised of three oxygen atoms. It is found naturally in the earth’s stratosphere, where it absorbs the ultraviolet component of incoming solar radiation that could be harmful to life on earth.
Ozone pollution is formed in the atmosphere through chemical reactions between pollutants emitted from vehicles, factories, other industrial sources, fossil fuels, combustion, consumer products, evaporation of paints and many other sources.
Prior research has found that ozone pollution can damage an individual’s heart and blood vessels.
During the study, the team of academics examined the health data of 258 million people living in China to assess whether ozone pollution triggered the development of cardiovascular complications.
The researchers found that the average daily eight-hour maximum ozone concentration was 79.2 μg/m3.
Throughout the experiment, more than six million of the participants were admitted to hospital with heart disease.
According to the findings, most of the participants admitted to hospital with a cardiovascular complication were regularly exposed to ambient ozone.
For each 10 μg/m3 rise in the two-day average eight-hour maximum ozone concentration was linked to a 0.40% increase in hospital admissions for stroke and 0.75% for acute myocardial infarction.
“Although these increments look modest, it should be noted that ozone levels may surge to higher than 200 μg/m3 in summer, and these increases in hospitalisations would be amplified by more than 20 times to over 8% for stroke and 15% for acute myocardial infarction,” said Professor Wu.
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Between 2015 and 2017, ozone triggered the development of 109,400 hospital admissions for coronary heart disease.
Professor Wu added: “This suggests that 109,400 coronary heart disease admissions could have been avoided if ozone concentrations were 0 µg/m3.
“This may be impossible to achieve given the presence of ozone from natural sources. However, we can conclude that considerable numbers of hospital admission for cardiovascular disease could be avoided if levels were below 100 μg/m3, with further reductions at lower concentrations.”
Fellow researcher Professor Thomas Münzel and the other authors noted: “Projections for Europe suggest that ozone will play a more dominant role as a health risk factor in the future due to climate change with rising temperature and, accordingly, increasing photochemical formation of ozone.
“The strong link between climate change and air quality means that reducing emissions in the long term to tackle global warming will play a key role in alleviating ozone pollution and improving the air that we breathe.”
The study has been published in the European Heart Journal.