Human activities are the main cause of poor air quality, but natural sources of air pollution also play a role. A new report from the European Environment Agency (EEA) considers how particulate matter from these natural sources affects the air we breathe.
The report is the first evaluation of Member State reporting under the EU's Air Quality Directive. The directive sets legally binding limit values to improve air quality. However, countries can subtract the pollution from natural sources, as they are only obliged to reduce man-made air pollutant emissions. So the report also includes European Union (EU) Member States documentation of natural contributions which led to exceedances of air quality limit values set by EU legislation.
It is difficult to calculate the exact amount of pollutants emitted from natural sources, the report notes, but in many countries the contribution to particulate matter levels in the air can be significant.
The most common natural sources of particulate matter in Europe are desert dust, volcanoes, forest and grassland fires, and salt from sea spray. The particular source of pollution can be identified using various methods including chemical analysis of particles sampled from the air, meteorological data satellite measurements and modelling.
Eleven EU Member States reported that natural sources pushed particulate matter concentrations over the limit values in 2008 or 2009 (Austria, Cyprus, Germany, Greece, France, Italy, Latvia, Malta, Portugal, Spain and the United Kingdom). The highest numbers of cases were reported by Mediterranean countries (Cyprus, France, Greece, Italy and Spain). Spain had the highest number of measuring stations reporting exceedances caused at least in part by natural sources.
"Poor air quality from natural sources is by definition outside of our control," EEA Executive Director Jacqueline McGlade said. "But this analysis shows that authorities should make extra efforts to reduce the air pollution they can control, because the cumulative effect of natural and man-made particulates can damage people's health."
Natural sources of particulate matter
11 July, 2012.