Metals in the environment

"The state of the science on metal mixtures in the environment"

This website is aimed at providing scientifically robust information about metal bioavailability and metal mixtures for users of all levels of background and experience. The website provides an animated video introduction to key concepts on metal bioavailability and metal mixtures, leading to fact sheets on topics such as metal bioavailability, metal mixture toxicity and modelling. More advanced users can directly access study reports and publications on metals bioavailability and mixtures to gain greater knowledge of the underpinning science.

Metals are present naturally in the environment and can be introduced through human activities such as the manufacture of metal goods, processing of metal ores and through a wide range of industrial and agricultural activities. Some metals are essential to plants and animals, but all metals are potentially toxic at high enough doses.

Nevertheless, it is not the total amount of metal present in, for example a river or stream, that is most important, as some of the metal will be bound to dissolved organic carbon and other ions. The remaining fraction of total metal that actually interacts with aquatic organisms is called the bioavailable metal. In the environment, metals do not often occur singly, but as mixtures. Therefore, in order to be able to begin to fully understand the ecological effects of metals in the environment we must look at mixtures.

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What is bioavailable metal?


Why is understanding metal mixtures important?

Most regulatory jurisdictions around the world set limits on individual metal concentrations in aquatic environments. However, in the environment there are rarely just single metals occurring on their own. Indeed, mixtures of different metals are always found in the environment.

However, again, researchers have found that it is not the total amount of metals present in the mixtures in the water that influence the toxicity of the mixture to aquatic creatures but the bioavailability of those metals.

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Many organizations have contributed to our understanding of metals mixtures in the environment. More in depth information in the form of reports, manuscripts, videos, etc. can be found here

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