Currently, the limit value set for average annual levels of PM2.5 in the EU is 25 μg/m3, which is 2.5 times higher than recommended by the WHO. Photo: © Shutterstock – Image Point Fr

Air pollution death toll much higher than previously thought

Air pollution causes nearly 800,000 early deaths a year in Europe and 8.8 million worldwide, according to a study published in the European Heart Journal.

Using new hazard ratio functions to calculate the effects on death rates due to ambient air pollution in the form of tiny particles (PM2.5) and ground-level ozone, researchers have found that air pollution caused an estimated 790,000 extra deaths in the whole of Europe in 2015, of which 659,000 in the 28 member states of the EU. Between 40 and 80 per cent of these premature deaths were due to cardiovascular diseases (CVD), such as heart attacks and stroke. Air pollution caused twice as many deaths from CVD as from respiratory diseases.

Globally, outdoor air pollution was estimated to cause an estimated 8.8 million extra deaths in 2015, nearly double the previously estimated 4.5 million. This means that air pollution is responsible for 120 extra deaths per year per 100,000 of the population worldwide. In Europe and the EU-28, it is even higher, causing 133 and 129 extra deaths a year per 100,000 people, respectively.

Looking at individual countries, air pollution caused an excess death rate of 154 per 100,000 in Germany (a reduction in mean life expectancy of 2.4 years), 150 in Poland (2.8 years), 136 in Italy (1.9 years), 105 in France (1.6 years), and 98 in the UK (1.5 years). Excess death rates were particularly high in eastern European countries, such as Bulgaria, Croatia, Romania and Ukraine, with over 200 each year per 100,000 of the population.

Professor Jos Lelieveld of the Max-Plank Institute in Mainz, Germany, and co-author of the study, said: “The high number of extra deaths caused by air pollution in Europe is explained by the combination of poor air quality and dense population, which leads to exposure that is among the highest in the world.”

The researchers say that national governments and international agencies must take urgent action to reduce air pollution, including re-evaluating legislation on air quality and lowering the EU’s current air quality standards to match the World Health Organisation’s guidelines.

It is emphasised that, in terms of air pollution, PM2.5 is the main cause of respiratory and cardiovascular disease. Currently, the limit value set for average annual levels of PM2.5 in the EU is 25 μg/m3 (micrograms per cubic metre), which is 2.5 times higher than recommended by the WHO.

Co-author Professor Thomas Münzel of the University Medical Centre Mainz, said: “The current limit of 25 μg/m3 should be adjusted downwards to the WHO guideline of 10 μg/m3. Many other countries, such as Canada, the USA and Australia use the WHO guideline; the EU is lagging a long way behind in this respect. Indeed, new evidence may lead to a further lowering of the WHO guideline in the near future.

Replacing fossil fuels by clean, renewable energy sources is a key measure to reduce air pollution. Prof Lelieveld said: “Since most of the particulate matter and other air pollutants in Europe come from the burning of fossil fuels, we need to switch to other sources for generating energy urgently. When we use clean, renewable energy, we are not just fulfilling the Paris agreement to mitigate the effects of climate change, we could also reduce air pollution-related death rates in Europe by up to 55 per cent.”

According to Prof Lelieveld, the levels of PM2.5 in the air could be reduced further by limiting agricultural emissions, which are responsible for a comparatively large amount of particulate matter pollution and for the associated extra number of deaths in Europe.

He said: “In Germany, for instance, agriculture contributes up to 45 per cent of PM2.5 to the atmosphere. When manure and fertiliser are used on agricultural land, ammonia is released into the atmosphere, which reacts with sulphur and nitrogen oxides and associated sulphuric and nitric acids, forming salts such as ammonium sulphate and nitrate. These substances contribute significantly to the formation and composition of fine particles, interacting further with soot and organic aerosol compounds.”

Christer Ågren

The study “Cardiovascular disease burden from ambient air pollution in Europe reassessed using novel hazard ratio functions”, by Jos Lelieveld, Thomas Münzel et al. Published in the European Heart Journal. doi:10.1093/eurheartj/ehz135.
Source: European Heart Journal press release, 12 March 2019.


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