Searching for the sources of particulate matter

Award winner Alexander Vogel carries out research for better air quality

Released at: Thu, 29 Nov 2018 08:41 (060)

FRANKFURT. Particulate matter is a form of pollution whose sources are not all understood to this day. The very complex mixture is formed in the atmosphere from various gaseous precursor molecules. Identifying their sources and improving air quality is the goal of Alexander Vogel, Professor for Atmospheric Environmental Analytics at Goethe University. For his research projects, he received the Adolf Messer Foundation Award at a ceremony on 26th November. In honour of its 25th anniversary, the award amounts to € 50,000 this year. 

University President Professor Birgitta Wolff: “Congratulations to Alexander Vogel! He is doing research on an issue of global importance that affects us all, especially in metropolitan areas: particulate matter. His research can contribute to a better understanding of this threatening phenomenon and make the cities of the world healthier. We thank the Foundation for its tireless work on behalf of early career researchers at Goethe University. And we welcome the fact that the Foundation has addressed its historical responsibility in its recently published clarification on the role of its namesake Adolf Messer.” 

Hessian Minister for Education, Culture and the Arts Boris Rhein: „My warmest congratulations to Professor Alexander Vogel. His research is highly relevant – particulate matter threatens our health and is something we must understand and learn to combat. Excellent research, such as that done by Professor Vogel and many of his colleagues, requires excellent conditions. Now the government of the state of Hesse and the universities in Hesse have both signed the Higher Education Pact for the years 2016 to 2020, creating financial planning certainty for Hesse’s universities through 2020. The Higher Education Pact is a milestone for Hesse as a science location and guarantees Hesse’s universities € 9 million in financial resources for the next five years. That is the largest sum ever made available to Hesse’s universities.” 

Foundation Board Chair, Stefan Messer, stressed: “Every foundation should make it their job to support projects and ideas that are not adequately covered by basic government funding. This is the idea pursued by our non-profit foundation in its funding and recognition of scientists stand out due to their exceptional achievements. We are very happy that in 2018, innovation, scientific curiosity, and pioneering spirit have been recognized for the 25th time in this manner.” 

About the award winning project

According to estimates by the World Health Organisation, about 6.5 million people worldwide die prematurely due to air pollution, most of which can be attributed to particulate air pollution. Contrary to popular opinion, most particulate matter doesn’t enter the atmosphere straight from tailpipes or power plants, but is formed in the atmosphere itself out of gaseous precursor molecules. This secondary particulate matter consists of the tiniest particles with an average diameter in the nanometre-range. These can penetrate deep into the lung and even enter the blood via the alveoles.  An example for the formation of secondary particulate matter is the oxidation of nitrogen oxides from diesel engines: the resulting nitric acid molecules react with ammonia in the atmosphere to create ammonium nitrate.

The inorganic precursor molecules and their development to secondary particulate matter have been well investigated: nitrogen oxides from traffic and industry, sulphur dioxide from coal-burning power plants and ammonia from agriculture. But there are numerous organic molecules on top of this that also occur in nature, such as the terpenes emitted by spruce forests. Organic precursor molecules emitted by human activity in relation to the formation of secondary particulate matter is a highly topical research area. These precursor molecules and their interaction with inorganic trace gases have only been rudimentarily investigated to date. The clear identification of the products of these chemical reactions is made difficult by the fact that the molecules often have the same mass, although their structures are different.

While he was a postdoctoral fellow at the Paul Scherrer Institute in Switzerland, Alexander Vogel developed a method for creating a molecular fingerprint from atmospheric particular matter samples. By analysing them, he can determine the secondary formation mechanism. The molecular fingerprint of particulate matter samples from Los Angeles, for example, exhibits a high percentage of nitrogen-containing organic molecules. “This allows the assumption that a reduction in nitrogen oxide emissions would also lead to a reduction of organic particulate air pollution in urban areas,” Vogel explains.

However, to elucidate the formation mechanisms of individual substances, further analyses of atmospheric samples and specific laboratory experiments in which the formation of particulate matter is simulated are necessary. By comparing field measurements with experiments, Alexander Vogel can already assign a portion of the signals in the real samples to certain processes and precursor molecules. Of the remaining unknowns, at least the molecular formula can be determined, so that potential sources and formation mechanisms can be investigated in further laboratory tests.

Alexander Vogel will now set up the experimental method he developed at the Paul Scherrer Institute at Goethe University. Among other things, he requires a machine for high performance liquid chromatography, which thanks to the Adolf Messer Foundation can now be acquired. His research approach has been met with great interest among environmental science master degree students. The measurements are due to begin at the start of 2019. Applications for master’s and doctoral theses are already coming in.

The great relevance of this topic will also be emphasized in a symposium accompanying the award. With the title “Understanding particulate matter: A grand challenge of the 21st century?”, particulate matter measurement at the Frankfurt International Airport, smog in Chinese cities, and the health effects of particulate matter will be discussed.

Alexander Vogel, born in 1984, studied chemistry at Johannes Gutenberg-Universität Mainz. After receiving his Ph.D. (2014), research on the CLOUD experiment took him to the European Organization for Nuclear Research CERN by Geneva and the Paul Scherrer Institute in Villigen, Switzerland. He has been a tenure-track professor for atmospheric environmental analysis at Goethe University since January 2018.

Further information: Professor Alexander Vogel, Institute for Atmosphere and Environment, Faculty of Geosciences, Riedberg Campus, Tel.: +49 69 798-40225,