Carbon 14 dating forensic science
The police chief leading the Jersey abuse inquiry says attempts to carbon date remains from at least five children are unlikely to yield results.
So far, police have found 65 milk teeth and more than 100 bone fragments during their search of the former Haut de la Garenne children's home.
But even before the "bomb carbon" period, humans were already disrupting the natural radiocarbon signal by burning fossil fuels such as oil, coal and gas.
"Nuclear bomb testing that started in the late 1950s significantly contaminated the whole of the atmosphere.
So you have very high levels of carbon-14 through that period that didn't exist prior to that," said Professor Gerry Mc Cormac, an expert on radiocarbon dating from Queen's University Belfast.
Humans take this radioactive carbon into their bodies by eating plants and animals.
Scientists can use this fact to measure how much radioactive carbon is left and how much has disappeared.By comparing this against modern levels, they can calculate a date for the death of the organism.