Key Concerns
Copper is an essential element for all biota, therefore any adverse effects must be balanced against its essentiality. This means that for all organisms, there will be range of optimal copper concentrations. Exposure to copper concentrations outwith this range, will result in adverse effects, due to either copper deficiency, or copper toxicity.
Key concerns
Cobalt in soil is retained by oxides, such as iron and manganese oxide, crystalline materials including aluminosilicates and goethite, and natural organic substances found in soil. In clay soils, the adsorption may be due to ion exchange at the cationic sites on clay with either simple ionic cobalt or hydroloysed ionic species such as cobalt hydroxide (ATSDR 1992).
There is a paucity of data on the effects of cobalt on species indicative of terrestrial ecosystems.
Key concerns
Key concerns
Cadmium has been shown reduce the growth of plants. Most of the data are from laboratory studies, in which plants were exposed to nutrient solutions containing soluble cadmium salts in the mg/l concentration range. Cadmium found in the environment is likely to be bound to soil and is subsequently less bioavailable (Eisler 1985; WHO 1992).
Key concerns:
Boron toxicity in plants is most likely to occur following the continued use of boron-contaminated irrigation waters, however, direct exposure from airborne emissions may also produce localized toxic effects (Howe 1998). Symptoms of boron toxicity in plants include yellowing, spotting or drying of leaf tissues, especially on the tips and sides of older leaves (Gupta et al. 1985).
Key Concerns:
Concentrations of arsenic in soil reported to be toxic to plants span a broad range (WHO 2001), and toxicity is generally higher in sandy soils than clay soils (Sheppard 1992).
Additional Comments:
Key Concerns:
There is a paucity of data on the effects of antimony on species and their ecosystems.
Emissions of antimony, such as those from smelters, can remain in the atmosphere for more than one month and therefore be transported over long distances (ATSDR 1992; Steinnes 1997). Antimony in soil is likely to be in the form of antimony sulphide, which is slightly soluble, and therefore potentially bioavailable.
Key concerns:
There is a paucity of data on the effects of PAHs on species indicative many terrestrial ecosystems. Some PAHs are known or suspected carcinogens, although the ecological consequences have not been established, as most organisms will be predated before they develop carcinomas. However tumours in fish can present a problem for the human food chain.
Key Concerns:
Key Concerns:
