Report: Slag: Metals in foliage organisms — Norderney (1988)»

“In this study, the question is whether ageed slag in the water releases bioavailable heavy metals (lead, copper and cadmium) from copper ore smelting (so-called NA slags), which are indicated by enrichments in marine growth. Five species of organisms from the vegetation of NA slag and three natural water building blocks (basalt, sandstone, granite) are tested for accumulation of the aforementioned metals. Not all of these species were represented on all four substrates, so that the study remains incomplete and can only claim oriented character. In addition, some of the slag sites are located in a harbour basin, where other sources of metal load can also play a role. Based on the results, the five types can be assigned to three different groups: 1. Bladder catch (Fucus vesiculosus). No samples of NA slag were examined but only from the three natural rock types. Only moderately increased copper content on basalt, which is presumably reflecting copper pollution of the water (port of the island of Norderney) (time of investigation: 1988). 2. Mussel (Mytilus edulis). The samples come from locations where NASch lacquers and basalt were poured as a mixture or were installed very closely next to each other. Whether the source of the almost identical, moderately increased copper content on both substrates is the slag, the ambient water or both, remains open. The locations are exposed on the sea side. The maximum values of cadmium (on both substrates) reach critical limits when reference values are used for human nutrition. 3. Intestinal tang (Enteromorpha sp.), knot tang (Ascophyllum nodosum), and beach snail (Littorina littorea). In these species, one heavy metal is significantly increased on NA slag compared to a comparison substrate (of each species comparison samples were available only from one natural rock). The intestinal tang has highly enriched lead on NA slag; the absorption from the substrate and from the ambient water may have added up here. However, the same element is also strongly represented on basalt, which is presumably due to loads of port water. However, other organisms from which samples have been studied from the port (knotentang, bladderang, beach snail) are missing unusual lead enrichment, possibly due to species-specific regulatory strategies. The relatively high copper content of Enteromorpha is similar on both substrates. At knot tang, the copper content on Na slag (port basin) is well above the inconspicuous values determined on sandstone (port entrance). The beach snail surpasses all other species studied here with their copper enrichments on NA slag (port basins) and still considerable on sandstone (port entrance). In the literature, a long-term release of lead from aged NA slag is confirmed several times. The delivery of copper is partly confirmed and partly denied (in two recent studies). The findings on the latter three species show significantly higher lead and copper content in the samples of aged NA slag. However, since the sites in question are located in the port, NA slag is probably not the only source of metal pollution. For example, antifouling paints of copper-based ships can cause strain. Therefore, it remains open in this study whether and to what proportion the NA slag is responsible for the maximum values determined.”