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The Elements in the Second Rank 2 Selecting Elements for this Study
2.1 The classical heavy metalsThe project title "the elements in the second rank" indicates that there are also elements in the first rank. The first rank elements are those, which have been known for their adverse health and environmental effects for a number of years. Hence, they are regulated by limit concentrations, emission restrictions, ban, and out phasing programs exist on a national or international level. Furthermore, they are well examined regarding information on their use health and environmental effects. From these criteria, the elements in the first rank are the classical heavy metals lead, cadmium, chromium, copper, mercury, nickel and zinc, and the metalloid arsenic. The rare, but very toxic metal thallium could be included in this group. Today, its use has been restricted significantly. Also tin has received much attention in the last 10 to 15 years due to the toxicity of the organic tin compounds (especially butyl compounds) in the aquatic environment. 2.2 Selecting elements for this studyThe elements in the second rank are more "exotic" than the elements mentioned above, and they have not received much attention. Therefore, the regulation on their presence and concentration in products, emissions or waste products is limited. To be regarded as a "second rank" element for this study, the element should have inherent properties, consumption pattern or disposal routes, which makes it a potential risk for the environment or human health. In other words, the elements in the second rank are characterized by a potential for significant adverse health and environmental effects, including long-term effects. They are used in significant or increasing amounts in e.g. production of electronics, and the use or disposal pattern can result in dispersal in the environment. Regarding health effects, the so-called CREAM effects (carcinogenicity, reprotoxicity, endocrine disruption effcts, allergenicity and mutagenicity) were considered. Regarding environmental effects, especially toxicity in long-term tests, persistency in the environment and potential for bioaccumulation were considered. It is noted that test of morphological, cellular and subcellular effects are relevant also, but these effects are generally little investigated. Therefore it was not expected to find data on these effects. In the toxicological evaluation the organometalic compounds have not been considered, but inorganic compounds, e.g. salts, were included in the survey. It was not possible to obtain data on all mentioned effects before selecting the second rank elements for this study. Hence, the selection was mainly based on data achieved from search in data compilations. This resulted in a gross list from which the elements for the final study were selected.
- antimony Among the elements on the gross list, aluminum, barium, cobalt, manganese, selenium and titanium were excluded due to recent, well documented evaluations and/or because they did not rise concern (e.g. titanium). Silver and tellurium were given low priority due to their stable consumption and lack of new application areas.
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