Abstract

The RIVM has evaluated the environmental impact of the emissions from construction metals. Based on this risk assessment, indicative emission limit values for construction metals and values for the maximum permissible surface area of construction metals have been proposed. Rainwater running off a variety of construction materials in which zinc, copper and lead are processed, such as roof gutter, crash barriers and drinking-water pipes, contain dissolved quantities of these elements. The result is a long-lasting enrichment of the environment with copper, lead and zinc. The environmental risks strongly depend on the circumstances; for example, the amount of run-off water and the type of drainage have a large effect on the exposure of the environment. The highest risks are associated with the so-called disconnected drainage systems, which allow the direct infiltration (discharge) of metals into the soil. The RIVM has computed indicative emission limit values for standard construction applications, such as zinc gutters, zinc crash barriers, lead flashing and copper drinking water pipes. This form of quality standards can be realized by implementing regulations and measures. Generic limit values are less suitable for construction applications which are less general, such as copper and zinc in roofs and wall fronts. In these cases, it is important that the environmental exposure be reduced by tailoring the application to local conditions, such as by taking into account the amount of building materials and the drainage method.