Cadmium: verschil tussen versies

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===Environmental standards===
 
===Environmental standards===
 
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<u>water framework directive</u>  
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<u>Water framework directive</u>  
  
 
Annual average concentration in marine surface waters: '''0,2 µg/l'''
 
Annual average concentration in marine surface waters: '''0,2 µg/l'''
  
 
Maximum allowable concentration in marine surface waters: '''0,45 µg/l'''. However, allowable concentrations may rise up to 1,5 µg/l in areas with a lot of dissolved CaCO<sub>3</sub>.  
 
Maximum allowable concentration in marine surface waters: '''0,45 µg/l'''. However, allowable concentrations may rise up to 1,5 µg/l in areas with a lot of dissolved CaCO<sub>3</sub>.  
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<u>'''OSPAR convention'''</u>
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<u>OSPAR convention</u>
  
  

Versie van 30 jul 2009 om 13:56

Definition of cadmium:
Cadmium is a heavy metal with symbol Cd and atomic number 48 [1]
This is the common definition for cadmium, other definitions can be discussed in the article

Notes

Cadmium © Greg Robson

The main anthropogenic sources are copper and zinc smelting, batteries and fuel combustion. It mostly enters the marine ecosystem through atmospheric loading and riverine discharges.[2]

Cadmium is regarded as one of the most toxic metals. It causes sublethal and behavioral effects at lower concentrations than mercury and lead. It causes cancer in animals, and in vertebrates it causes kidney toxicity. [3] In humans it might also lead to skeletal deficiencies and lung damage. [4] Environmental concentrations of 5µg/l have affected the reproduction of copepods, decreased the abundance of isopods and depressed the growth of juvenile plaice. Laboratory LC50 (the concentration at which 50% of the test subjects die) toxic levels for copepods were higher than 0,34mg/l. [2]

Like other heavy metals, cadmium does not have biomagnifying properties. Higher trophic levels accumulate low amounts of cadmium and are able to deal with them efficiently with metallothioneins. Mollusks contain large amounts of cadmium and seem to accumulate them.[5]

Environmental standards and legislation

Environmental standards

Water framework directive Annual average concentration in marine surface waters: 0,2 µg/l Maximum allowable concentration in marine surface waters: 0,45 µg/l. However, allowable concentrations may rise up to 1,5 µg/l in areas with a lot of dissolved CaCO3.

OSPAR convention

legislation

OSPAR list of priority substances

OSPAR background document on Cadmium

Water framework list of priority substances


Case studies

PCB and heavy metals in beached sperm whales

Heavy metal content of mussels in the Western Scheldt estuary

Common starfish can act as a bioindicator for heavy metal pollution

Effects of heavy metals on the sperm quality and the larvae survival of sea urchins

Heavy metals in various Belgian benthic invertebrates

See also

Cadmium on the ED North Database


References

  1. http://en.wikipedia.org/wiki/Cadmium
  2. 2,0 2,1 Kennish, M. J. (1996): Practical Handbook of Estuarine and Marine Pollution, CRC Press 524 pp
  3. Biology of marine birds. Schreiber, E.A. & Burger, J. (Eds). 2002. Boca Raton, Florida: CRC Press. 722 pp.
  4. eds.J. Vos, G. Bossart, M. Fournier, and T. O'Shea, 2004; New perspectives: Toxicology and the environment. Toxicology of marine mammals, New York: Taylor & Francis. 643p
  5. Clark, R,B., 1999. Marine pollution. Oxford University press, Fourth edition, pp 161