Reuters reports that recent record-breaking temperatures and wildfires ravaging the UK, France, and southern Europe have also worsened air pollution. While heatwaves interact with greenhouse gases to increase ozone pollution, wildfires are also contributing to rising concentrations of fine particulate matter (PM2.5). New research shows that the combination of extreme heat and extreme PM2.5 levels can be even more harmful to humans.
Heatwave accelerates ozone production; atmospheric monitoring warns: Southern European air pollution is spreading northward
Scientists from the European Union's Copernicus Atmosphere Monitoring Service (CAMS) warned on the 19th that rising ozone pollution in southern and western Europe may soon affect northwestern regions.
The World Health Organization (WHO) standard for ozone is an eight-hour average of less than 100 micrograms per cubic meter. However, daily concentrations in southeast England, northern France and the Benelux region are currently exceeding 120 micrograms.
Ozone pollution is produced when heat and sunlight interact with greenhouse gases such as nitrous oxide, carbon monoxide, and volatile organic compounds released by fossil fuel combustion. "The air quality issues associated with this heat wave cannot be ignored," said Mark Parrington, a senior scientist at CAMS. Ozone production is accelerated during heat waves because these chemical reactions occur more quickly.
Scientists say ozone pollution will increase under climate change, and not only are global temperatures about 1.2°C higher than pre-industrial levels, but heat waves are also more frequent and severe.
Ozone is known to worsen respiratory and cardiovascular diseases and is associated with increased mortality. According to a 2019 study in the journal Environmental Research Letters, long-term exposure to ozone pollution is linked to 55,000 premature deaths in Europe each year.
The study found that under climate change, ozone-related death rates in some central and southern European countries could be 11% higher by 2050. However, if greenhouse gas emissions were reduced, ozone-related deaths would also decline.
Air pollution and high temperatures pose dual extremes: Scholars urge comprehensive considerations before issuing alerts
Ozone pollution isn't the only air quality concern. In recent days, wildfires raging in Portugal, Spain, and France have released choking plumes of smoke containing fine particulate matter called PM2.5.
Athanasios Nenes, an atmospheric chemist at the Swiss Federal Institute of Technology Lausanne, said the particles in smoke are among the most toxic and inhaling them can increase the risk of cancer.
Patients with cardiovascular or respiratory diseases also face a greater risk of acute attacks. In a June 2022 study by the University of Southern California, researchers found that on days with extreme heat or severe PM2.5, the risk of death was 5% to 6% higher than on normal days; however, if extreme heat and extreme PM2.5 occurred simultaneously, the risk of death increased by 21% compared to a normal day.
"We should consider integrating public health alerts into assessing both air pollution and heat," said Erika Garcia, a public health scientist at the University of Southern California and co-author of the study. "Exposure to two extreme weather phenomena in a single day is much more dangerous than just one."
Source: Environmental Information Center (https://e-info.org.tw/node/234637)
