Fundamentals for Determining Use-Related, Highest Acceptable Contaminant Levels in Inner City and Urban Soils

“Orientation data for acceptable total levels of certain elements in agricultural soils” were published (12) in 1977. In 1980 some of the level data were corrected in addition to levels being added (13) for four further elements. The specified data, also referred to as “Reference Values 80” are intended to indicate the levels in the soil at which no negative effects for ecosystems, plants, animals and man can be expected — with the exception of special cases under extreme marginal conditions. A further aim of these levels, mainly intended for soils in agricultural areas, is to draw attention to the fact that further increases in the levels of these elements could lead to irreparable damage to the soil with flora and fauna suffering the consequences. The orientation data specified for the elements cadmium, chromium, copper, mercury, nickel, lead and zinc were incorporated in regulations governing sewage sludge to set trigger values for applying sewage sludge (5). The orientation data also contributed to determining trigger values in TA-Luft (Technische Anleitung Luft = technical instructions for air emission control = component part of legal stipulations) for lead and cadmium precipitation (6) and the trigger values of certain elements in fertilizers (2,7) as well as in the petrol-lead law (1). The aim of these laws and regulations was to limit the build-up of contaminants in the soil.