By Imogen Howse via SWNS
Europe’s air quality has shown significant improvements over the last two decades, a new study has revealed.
But high levels of nitrogen dioxide, a byproduct of car pollution, were still found in the south of the Britain.
However, despite the improvements, the majority of people still live in areas that exceed the World Health Organization’s (WHO) recommended levels of pollutants and harmful particle matter.
Researchers from the Barcelona Institute for Global Health in Spain estimated the daily air concentrations of nitrogen dioxide (NO2), ozone (O3), and small particulate matter across more than 1,400 regions in 35 European countries between 2003 and 2019, representing 543 million people.
NO2 and O3 are gases that primarily come from the combustion of fossil fuels, especially those used in cars.
In high levels, these pollutants can cause damage to the human respiratory tract, increase a person’s vulnerability to, and the severity of, conditions such as asthma, and even lead to chronic lung disease.
O3 can also harm agricultural crops and ecosystems, including forests.
They also tracked particulate matter of 10 micrometers (PM10) and 2.5 micrometers (PM2.5)or less in diameter.
Examples of PM10 include dust from construction sites and landfills or smoke from factories, while PM2.5 can be emissions from the combustion of oil, petrol, diesel, or wood.
Pollution from fine particles is a concern when air pollutant levels are unhealthy – and can increase the risk of problems like heart disease, lung disease, and asthma.
Results of the team’s study, published in the journal Nature Communications, revealed that levels of PM10, PM2.5, and NO2 had decreased in most parts of Europe.
PM10 levels had reduced the most, followed by NO2 and PM2.5, with annual decreases of 2.72 percent, 2.45 percent, and 1.72 percent respectively.
But despite air quality improvements, 98.10 percent, 80.15 percent, and 86.34 percent of the European population continue to live in areas that exceed the WHO-advised levels for PM2.5, PM10, and NO2.
PM2.5 levels were highest in eastern Europe, particularly in Poland, while PM10 levels were highest in southern Europe.
High NO2 levels were observed in northern Italy and in the south of the United Kingdom, Belgium, and the Netherlands.
Meanwhile, levels of O3 increased annually by 0.58 percent in southern Europe, which led to nearly four times as many ‘unclean air days’ across the continent.
In fact, no country met the O3 annual standard during the peak season from 2003 to 2019.
“The results of our study highlight the significant improvements in air quality in Europe influenced by the decline of NO2, PM10, and PM2.5,” said lead author and researcher Zhao-Yue Cuen.
“But PM2.5 and O3 levels continue to exceed WHO guidelines in many regions, resulting in a higher number of people exposed to unclean air levels.”
Senior author Professor Joan Ballester Claramunt added: “The average exposure time to unclean air concentrations of O3 and PM2.5 is much higher than for the other two pollutants, highlighting the urgency of greater control for these pollutants.”
Ballester Claramunt explained that the management of O3 in particular presents ‘a complex challenge’ – due to the way in which it is formed.
“This means that conventional air pollution control strategies, which focus on reducing primary pollutant emissions, may not be sufficient to effectively mitigate O3 exceedances and associated compound unclean days,” he said.
The study also examined the number of days on which the limits for two or more pollutants were exceeded simultaneously, known as a ‘compound unclean air day’.
Findings showed that 86.3 percent of the European population still experienced at least one compound unclean day per year, with PM2.5-NO2 and PM2.5-O3 emerging as the most common compound combinations.
These were most common in southern Europe during the summers, which Ballester Claramunt said was linked to the impacts of climate change.
“Warmer temperatures and stronger sunlight boost O3 formation through chemical reactions,” he explained.
“This accelerates the oxidation of compounds in the air, which can lead to the condensation of certain oxidized compounds, forming new PM2.5 particles.
“Climate changes also increase the likelihood of wildfire, which further elevate both O3 and PM2.5 levels.”
Chen argued that this creates a harmful interplay – which highlights the need to address climate change and air pollution simultaneously.
“We need targeted efforts to address PM2.5 and O3 levels and associated compound unclean days, especially in the context of rapidly increasing threats from climate change in Europe,” he said.
“This will be crucial for the protection of public health.”
