The influence of patina age and pollutant levels on the runoff rate of zinc from roofing materials

Since the early 1990's an increased concern in Europe has focused upon the potential impact that zinc runoff from construction applications can have on the environment as a result of atmospheric corrosion. This means that the future use of zinc could be questioned. The aim of this article is to study the relationship between zinc runoff and corrosion rate and changes in pollutant levels. The potential influence that patina age may have on the release of zinc during precipitation has also been investigated in more detail. Corrosion rates and runoff rates have been determined for unaged and aged zinc panels exposed in Belgium and Sweden.