STANDARDIZED GRASS CULTURES - THE PROBLEM OF DETECTION LIMIT, CLASSIFICATION AND ATMOSPHERIC LOAD - THE EXAMPLE OF BERLIN AND ITS CONURBATION

In summer 1992 in Berlin and nearby surroundings standardized grass cu ltures (Lolium multiflorum) were exposed at 31 sites and at one addito nal site as control. Heavy metals such as cadmium, copper, lead, zinc and halogenides such as chlorine and fluorine were analysed. Because o f non-normality of some data the use of the standard deviation to defi ne the limit of detection rises statistical implications. As solution of this problem median linked measures of dispersion are used. These m easures permit the grouping of the data but are not a suitable tool to describe the whole status of air pollution effects on the indicator. Clustering is preferred. The accumulation of heavy metals and halogeni des revealed low level pollution. Regression analysis between heavy me tals in vegetables (1988) and grass cultures (1992) in polluted allotm ent gardens pointed to the atmospheric path only for lead and not for zinc or cadmium. Retrospectively transfer factors could be evaluated f or two species of vegetables.