Composition, Transformation and Effects of Nanoparticles in the Atmosphere

Abstract Airborne nano‐ and microparticles (aerosols) are of central importance for atmospheric chemistry and physics, the biosphere, climate and public health. They influence the Earth's energy balance, the hydrological cycle and atmospheric circulation and the abundance of greenhouse and reactive trace gases. Moreover, they play important roles in the reproduction of biological organisms and can cause or enhance diseases. The primary parameters that determine the environmental and health effects of aerosol particles are their size, composition and concentration. These parameters, however, are spatially and temporally highly variable. This chapter outlines the current state of knowledge, major open questions and research perspectives concerning the composition, transformation and effects of particles in the atmosphere.