Lead and Cadmium in Plants 1991
Classification by Available Limits and Index
Lead and cadmium levels of all tested food and feed crop samples were evaluated individually. The evaluation of plants and plant parts used as foodstuffs were tested in their form of consumption according to the medium and element-specific Foodstuff Index Values published by the Zentrale Erfassungs- und Bewertungsstelle für Umweltchemikalien des Bundesgesundheitsamtes (Central Registry and Evaluation Office for Environmental Chemicals of the Federal Health Agency (ZEBS 1990). Plant parts used only as feed were categorized according to the Grenzwerten der Futtermittelverordnung (FuttermittelVO) (Feed Crop Limit Value Regulations) from 1988.
Each lead and cadmium value was classified into one of three contamination categories on the basis of the medium-specific index value or limit value:
- does not exceed the ZEBS Guideline or Feed Crop Limit Value Regulations
- exceeds the ZEBS Guideline or Feed Crop Limit Value Regulations
- exceeds the ZEBS Guideline by 200% or the Feed Crop Limit Value Regulations by 250%
Measurement levels for other elements tested in the Heavy Metal Measurement Survey are not included in the evaluation because no index values or limit values are available.
Symbols on the map characterize sites of the Heavy Metal Measurement Survey. The contamination situation for each of these sites is summarized. Data is also given on the use of the area and for the type of crop contaminated (food or feed):
- Sites depicted with black points or crosses did not exceed any index or limit values. Sites depicted with points were used as allotment gardens or house yards at the time of testing. Sites depicted with a cross were used for agriculture or horticulture.
- Sites depicted with color symbols exceeded index or limit values. The intensity of color relates the degree of contamination.
- The contamination category of the highest lead or cadmium level is always depicted. Uncontaminated samples from contaminated sites were usually tested because of the differences in heavy metal accumulation behavior and exposure of the tested crops; and the heterogeneous causes of pollution. Classification into the highest contamination category followed for precautionary reasons. Even when a plant sample is assigned the lowest level of ‘contaminated’, it should be determined whether or not use recommendations or limitations are to be issued for this location.
- The type of symbol indicates for which element a contamination has been determined. A contamination by lead and cadmium may have been determined in various tests or media.
- Two different rows of color differentiate the use of the area at the time of sampling.
- Both foodstuffs and feed were tested in some agricultural areas. Contaminant levels for feed are given only when the same site showed no contamination in foodstuff crops, because heavy metal contamination of foodstuff crops is more critical. Sites determined to have heavy metal contamination of feed crops are depicted with special symbols.
The map does not show which and how many of the analyzed crops or samples were determined to be contaminated. This information can be received from the total databank of the measurement program, which is in the Heavy Metal Databank administered by Department IIIA5 of the Berlin Department of Urban Development and Environmental Protection.