IAEA identifies environmental contamination sources through isotopes

The identification of sources of environmental contamination can be done by an isotopic abundance, an isotopic ratio analysis.

Isotopes are an invaluable tool in geochemistry, but also for modern environmental forensics. For example, sediment cores can be dated using different radioactive isotopes of lead and their decay product. In the present study, the age of the different sediment depths was established based on the ratio of one of the radiogenic isotopes of lead and its decay product using a gamma counter.

The identification of sources of environmental contamination can be done by an isotopic abundance and/or an isotopic ratio analysis of selected trace elements (mercury, lead etc.) in sediment cores. Once the different sources are identified, the isotopic abundances and the isotopic ratios can be used to quantify the contribution of each source by source apportionment.

The analysis of stable isotope ratios is also often used to determine the source of specific components or contaminants in a sediment core. For example, stabile oxygen, hydrogen, nitrogen, and carbon isotopes can be used to see where the organic material in the sediment came from, that is from a terrestrial or marine source, from plants, animals or artificial fertilizers.

Although other approaches can be used to obtain information about the isotopic composition of elements, mass spectrometric techniques clearly dominate the field of isotopic analysis.