France's national health agency has warned that nearly half the population exceeds the recommendation for exposure to the heavy metal cadmium, with breakfast cereals and baguettes contaminated.

France is mulling how to prevent people from ingesting too much of the heavy metal cadmium, after a warning their breakfast cereal and baguettes could be contaminated with the toxin.

Here is what to know.

What is cadmium?

Cadmium is a chemical element naturally found in the ground at low levels, particularly in limestone-rich areas.