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So-called safe EU air pollution levels may still be deadly

5 µg/m3 increase in exposure to fine-particle pollution raises risk of dying from natural causes by 7%

Adrian O'Dowd

Monday, 09 December 2013

The risks of exposure to air pollution are still potentially fatal even at lower than accepted European Union (EU) safe levels, according to a study published online today in The Lancet.

A team of international researchers found that the air quality limits in Europe might be insufficient to protect people from the harms caused by soot in the air from traffic and factories.

The research examining two decades of data from more than 360,000 residents of large cities in 13 European countries found that prolonged exposure to tiny particles of soot or dust found in traffic fumes and industrial emissions may be more deadly below current EU air quality limits than previously thought.

The study estimated that for every increase of 5 microgrammes per cubic metre (5 µg/m3) in annual exposure to fine-particle air pollution (PM2.5), the risk of dying from natural causes rises by 7%.

Using data from the European Study of Cohorts for Air Pollution Effects (ESCAPE), the investigators pooled data from 22 cohort studies including 367,251 people.

They linked annual average air pollution concentrations of nitrogen oxides and particulate matter to home addresses using land-regression models to estimate exposures.

Traffic density on the nearest road and total traffic load on all major roads within 100m of the residence were also recorded.

Among the participants, 29,076 people died from natural causes during the average 13.9 years of follow up.

The results showed that long-term exposure to fine particles with a diameter of less than 2.5 micrometres (PM2.5) posed the greatest threat to health even within concentration ranges well below the limits in current European legislation.

The association between prolonged exposure to PM2.5 and premature death remained significant even after adjusting for a wide range of factors such as smoking, socioeconomic status, physical activity, education level, and BMI.

Study leader Dr Rob Beelen from the Institute for Risk Assessment Sciences, Utrecht University, The Netherlands, said: “Our findings support health impact assessments of fine particles in Europe which were previously based almost entirely on North American studies.

“Our findings suggest that significant adverse health effects occur even at PM2.5 concentrations well below the EU annual average air-quality limit value of 25 µg/m3. The WHO air-quality guideline is 10 µg/m3 and our findings support the idea that significant health benefits can be achieved by moving towards this target.”

Writing in a linked comment in the journal, Jeremy Langrish and Nicholas Mills from the University of Edinburgh’s BHF Centre for Cardiovascular Sciences, said: “Despite major improvements in air quality in the past 50 years, the data from Beelen and colleagues’ report draw attention to the continuing effects of air pollution on health.

“These data, along with the findings from other large cohort studies, suggest that further public and environmental health policy interventions are necessary and have the potential to reduce morbidity and mortality across Europe. Movement towards more stringent guidelines, as recommended by WHO, should be an urgent priority.”

DOI:10.1016/S0140-6736(13)62158-3
DOI:10.1016/S0140-6736(13)62570-2

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