Customize Consent Preferences

We use cookies to help you navigate efficiently and perform certain functions. You will find detailed information about all cookies under each consent category below.

The cookies that are categorized as "Necessary" are stored on your browser as they are essential for enabling the basic functionalities of the site. ... 

Always Active

Necessary cookies are required to enable the basic features of this site, such as providing secure log-in or adjusting your consent preferences. These cookies do not store any personally identifiable data.

No cookies to display.

Functional cookies help perform certain functionalities like sharing the content of the website on social media platforms, collecting feedback, and other third-party features.

No cookies to display.

Analytical cookies are used to understand how visitors interact with the website. These cookies help provide information on metrics such as the number of visitors, bounce rate, traffic source, etc.

No cookies to display.

Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better user experience for the visitors.

No cookies to display.

Advertisement cookies are used to provide visitors with customized advertisements based on the pages you visited previously and to analyze the effectiveness of the ad campaigns.

No cookies to display.

Education

Weighing beside the scales

.chap IRI-researchers forecast toxicity using fewer laboratory animals.The toxicity of mixed metals is hard to predict. Researchers of IRI try to change that.

They are working on a new model, a glass ball for toxicologist. Guinea pigs can rejoice.

Toxicologist can now prescribe a substance%s toxicity without having to use the substance itself. %It doesn%t matter if we look at copper, iron or silver in any concentration in any organism, whether it%s a mouse, water flea, enzyme system, etc.,” says Bert Wolterbeek, senior scientific researcher at IRI. %We can figure out metal toxicity without adding the metal to an animal. This will hopefully lead to using fewer laboratory animals.”

Wolterbeek studied four general characteristics of all the elements of the periodic table. These four properties % how easy they take up electrons, their electro potential, their ionisation potential, and the size and weight of the atoms % combine to form the chemical reactivity of the elements and to describe how the elements tend to join into reactions.

Germanium, caesium, boron, lithium, uranium, manganese and selenium were ultimately the cornerstones, representing the minimal and maximal values of these characteristics. %Because we have the extremes for the chemical properties, we could design a scale for toxicity which included everything,” Wolterbeek explains. For example, the next time scientists look for the concentrations at which mice lose their hair, they will first make a scale with all the cornerstone elements. Mice receive the cornerstones via their food, so the concentrations at which they start losing hair is known. Lead lies between the extremes of chemical properties and no longer needs to be added. %Lead toxicity can be predicted now, as well as all other elements, because all extremes are taken along in the calibration.”

Until now, toxicologists didn%t know the extremes; they concluded toxicity from measured toxic concentrations to estimate greater concentrations, but the scale division was wrong. %Some toxicologist made the mistake of measuring outside the permitted area. The model I made, has the right scale division, so you never measure beside the scale.”

To know how an element behaves in solutions is one thing, but mixtures are much more common in nature. %Predicting the behaviour of mixtures is the most difficult part of toxicology,” Wolterbeek says. %Now we can forecast one element in all kinds of organisms, and we have a good base to go on.”

Wolterbeek has received lots of positive reactions from his colleagues and hopes for more. %Everybody has his own manner of experimenting. When someone uses my method, they will come to questions. Things I did not think of. In that way, the model will be adjusted and improved every time someone uses it. Finally, we can use this to design a model for predicting element mixtures. Perhaps then, we can predict a real mixture situation.”

.chap IRI-researchers forecast toxicity using fewer laboratory animals.

The toxicity of mixed metals is hard to predict. Researchers of IRI try to change that. They are working on a new model, a glass ball for toxicologist. Guinea pigs can rejoice.

Toxicologist can now prescribe a substance%s toxicity without having to use the substance itself. %It doesn%t matter if we look at copper, iron or silver in any concentration in any organism, whether it%s a mouse, water flea, enzyme system, etc.,” says Bert Wolterbeek, senior scientific researcher at IRI. %We can figure out metal toxicity without adding the metal to an animal. This will hopefully lead to using fewer laboratory animals.”

Wolterbeek studied four general characteristics of all the elements of the periodic table. These four properties % how easy they take up electrons, their electro potential, their ionisation potential, and the size and weight of the atoms % combine to form the chemical reactivity of the elements and to describe how the elements tend to join into reactions.

Germanium, caesium, boron, lithium, uranium, manganese and selenium were ultimately the cornerstones, representing the minimal and maximal values of these characteristics. %Because we have the extremes for the chemical properties, we could design a scale for toxicity which included everything,” Wolterbeek explains. For example, the next time scientists look for the concentrations at which mice lose their hair, they will first make a scale with all the cornerstone elements. Mice receive the cornerstones via their food, so the concentrations at which they start losing hair is known. Lead lies between the extremes of chemical properties and no longer needs to be added. %Lead toxicity can be predicted now, as well as all other elements, because all extremes are taken along in the calibration.”

Until now, toxicologists didn%t know the extremes; they concluded toxicity from measured toxic concentrations to estimate greater concentrations, but the scale division was wrong. %Some toxicologist made the mistake of measuring outside the permitted area. The model I made, has the right scale division, so you never measure beside the scale.”

To know how an element behaves in solutions is one thing, but mixtures are much more common in nature. %Predicting the behaviour of mixtures is the most difficult part of toxicology,” Wolterbeek says. %Now we can forecast one element in all kinds of organisms, and we have a good base to go on.”

Wolterbeek has received lots of positive reactions from his colleagues and hopes for more. %Everybody has his own manner of experimenting. When someone uses my method, they will come to questions. Things I did not think of. In that way, the model will be adjusted and improved every time someone uses it. Finally, we can use this to design a model for predicting element mixtures. Perhaps then, we can predict a real mixture situation.”

Editor Redactie

Do you have a question or comment about this article?

delta@tudelft.nl

Comments are closed.