Comparing the distribution of nitrated phenols in the atmosphere of two German hill sites

Abstract

Nitrated phenols belong to a class of widely dispersed organic trace pollutants in the atmosphere. Their concentrations in the ambient air depend on the concentrations of their precursor compounds and, or of the emission strength of nitrophenols themselves, the vertical exchange of air masses within the polluted troposphere, and the existence of physical and chemical sinks. Photochemical activity does not seem to be as important for generation as for degradation. Nevertheless, nitrophenols are stable enough within the atmosphere to be transported even into distant areas. Along that way we observe an enrichment of the photooxidatively more stable dinitrophenols. Downwind of conurbations, in weather conditions where cloud‐ and fog deposition make up a greater contribution to the total precipitation, we recognize high rates of deposition of nitrated phenols at hill sites. The seasonal variance of deposition rates can be related to the frequency of fogs, clouds and atmospheric inversions.