How smog and heat damage health

From the Lower Rhine to Bavaria
Dr Mariano Mertens has always been interested in natural sciences, the environment and environmental protection: "Even as a child, I liked the book 'Ulli and the Environment'. That was probably my introduction to this complex topic." He studied geophysics in Münster, where he developed his interest in geodynamics in general and mantle convection, the slow flow in the Earth's mantle, in particular at a very early age. "I've always found it incredibly exciting to understand how our planet works, but also how complex systems work in general. I want to understand the processes of such systems and derive things from them for our daily actions."
Today, the 36-year-old conducts research in Earth System Modeling at the DLR Institute of Atmospheric Physics in Oberpfaffenhofen, Bavaria.

Junior research group IMPAC²T
Together with Dr Alexandra Schneider of Helmholtz Munich, the German Research Center for Environmental Health, he leads the BMBF-funded junior research group IMPAC²T (Impacts of transport emissions on air pollution, human health and vegetation under climate change and possible mitigation options). The research topic is very important to Mertens: "Humans, animals and plants on our planet are exposed to a variety of environmental influences, such as air temperature, precipitation or air pollution. All these environmental influences affect the growth and health of living organisms and plants. The environmental influences are closely interrelated and must therefore be considered together." Dr Mertens continues: "High air temperatures, for example, have a negative impact on human health, as does air pollution. In combination, these two effects can amplify each other's negative impacts."
Climate change, he said, is a kind of effect amplifier. Air temperatures will continue to increase as the climate changes. In addition, climate change can alter air pollution because, for example, precipitation modifies the leaching of air pollutants. "The energy transition in the transport sector, i.e. primarily the switch to electric mobility and other electricity-based fuels, or changes in other sectors such as the heating transition, are expected to reduce air pollution in the future. However, the extent of the reduction also heavily depends on the impact of climate change on air pollution."

Collaboration with Helmholtz Munich
Merten's professional background is in atmospheric sciences. "By using a complex model that realistically describes the physics and chemistry of our atmosphere, called a climate-chemistry model, we are investigating in the IMPAC²T project how air pollution might change under specific climate and emission scenarios." However, this work alone cannot answer the project's important scientific and societal questions. Close cooperation with Dr Alexandra Schneider and her team at Helmholtz Munich, whose expertise includes epidemiology, will allow further research questions to be answered. "Among other things, the close cooperation allows for further investigation of effects of increased air temperature and air pollution, as simulated for the scenarios, on human health. In addition, this collaboration allows me to further develop my technical education in the field of epidemiology and to broaden my own expertise accordingly."

Adapting to climate reality
The topic of his research is also very important to Mertens as a citizen: "Over the last few years, we have noticed more and more that the climate is changing. We will have to live with these changes and these changes will continue to intensify." According to Mertens, the intensification of climatic effects depends heavily on how many climate-damaging emissions are emitted or reduced over the next few decades. But he is also concerned how we adapt to the 'new reality.' In this context, he asks many questions: "How can cities be created that are also pleasant places in summer? How can mobility succeed that is climate and environmentally friendly? What requirements must crops have in order to ensure a high-quality food supply? These are all questions that concern me as a citizen, and our research in IMPAC²T is helping to provide some answers."

Research and society
It is important for Mariano Mertens that the research community does not sit in an ivory tower "where we do research for ourselves." For this very reason, he says, it is necessary to involve citizens on the pressing issues of climate, environmental and health protection and to take them along with us. "We are planning various public events as part of the project, in which we will report on the scientific background and our research results. In addition, various government agencies are involved in our project to ensure a close exchange between research and decision makers."

IMPAC2T and career
For Mertens, heading the junior research group is an excellent opportunity to gain further scientific qualifications and strengthen his scientific profile. Especially in science, he says, it is not always easy to plan ahead for one's career over many years. "But from my point of view, the project offers a unique opportunity to build up a new, interdisciplinary research field with partners and to do excellent science here, which includes both basic research and very practically relevant results. In my view, this is a very good starting point for a further scientific career." The opportunities offered by the BMBF as part of this support for young scientists are outstanding, he said. "They give me planning security for both my private life and my scientific career over a relatively long period of time." At the same time, he said, the funding provided by the funding program enables an appropriate number of young scientists to be involved in the project, thus establishing the possibility of new research fields and methods. "From my point of view, this is the only way to achieve a sustainable gain in knowledge."