EU's PM2.5 Limit Festering: New Study Linked PM with Heart Attack
Description: Smog from motorized vehicles is one of the common environmental problems in large cities of Asia and Southeast Asia (Haze in Kuala Lumpur, Malaysia).
Air pollution is a significant environmental determinant of human health. Over the past decades, studies conducted in various parts of the world documented a number of hazardous effects of ambient air pollution on health. A recent WHO report also suggests that the pollution kills about 1 in 8 people globally.
Of the many determinants of air pollution, the adverse effects of particulate matter [↗] (PM) on health outcomes are well documented. However, while there is no evident and appropriate safe level of exposure, the PM issue has been seriously underestimated in most of the developing countries, particularly countries in the Middle East and South Asia. More surprisingly, the EU limit for PM 2.5 [↗] is still more than twice of the WHO recommendation.
In 2008, the EU directive established an annual average PM 2.5 threshold level of 25 micrograms per cubic meter (µg/m3), to be met by 2015 and suggested another threshold level of 20 µg/m3 from 2020. On the other hand, the 2005 AQGs of WHO established that the annual average threshold level for PM2.5 should be 10 µg/m3.
A new study published January 21, 2014 by the British Medical Journal suggested that long-term exposure to PM increases the risk of heart attack (see REFERENCE). The study also reported that PM exposure was observed in levels below the currently specified EU limit.
For the study, scientists evaluated data from more than 100,000 participants in Europe. At enrollment, these individuals were found with no history of cardiovascular diseases [↗]. They were followed for an average of 11.5 years. During the follow-up period, a total of 5,157 individuals had coronary events such as heart attack or angina [↗].
The study found that an increase of annual exposure to PM 2.5 air pollutants of just 5µg/m3 was associated with a 13 percent increased risk of coronary events, even taking into account other risk factors such as smoking habit [↗] or high blood pressure [↗].
This is, however, not the first time the EU clean air standard is challenged! Last year, many researchers voiced their concern when a new WHO scientific report on PM 2.5 published on January 31, 2013.
According to the WHO report, long-term exposure to airborne particulate (PM 2.5) are associated with both cardiovascular mortality and morbidity and can trigger several detrimental consequences for health, including atherosclerosis, adverse birth results and childhood respiratory illness.
The report also noted possible links between PM 2.5 and other chronic health conditions, including neurodevelopment disorders, poor cognitive function, diabetes, and respiratory diseases.
Besides suggesting to lower the PM 2.5 level, the WHO report recommended a new Air Quality Guidelines (AQGs) for vehicle engines, power generation, and nitrogen dioxide (NO2). In addition, the report suggested AQGs for long-term average ozone (O3) concentrations, as well.
The Ambient Air Quality Directive of EU is still more than twice as high as the 2005 AQGs of WHO. As a result, today more than 80% of the EU countires are standing behind the WHO standards for PM. In addition, on average, this exposure to PM deprives each resident of 8.6 months of life.
No doubt, the EU limit for PM2.5 lacks pragmatism and needs reconsideration in terms of reducing health risks. However, although the WHO report came as a shock and stirred EU policy makers, the commission has so far decided only to revamp and tighten its policies, where needed.
There is also concern regarding the release of the new review by EU. The EU was expected to revamp its PM 2.5 limit before the end of 2013; still, there is no sign of changes in the EU policies on air pollution. Experts believe the change can't be implemented ahead of EU elections.
Reference
Cesaroni G, Forastiere F, Stafoggia M, Andersen ZJ, Badaloni C, Beelen R, Caracciolo B, de Faire U, Erbel R, Eriksen KT, Fratiglioni L. Long term exposure to ambient air pollution and incidence of acute coronary events: prospective cohort study and meta-analysis in 11 European cohorts from the ESCAPE Project. Bmj. 2014 Jan 21;348:f7412.
