...scientists now find that bacteria can sprinkle gold dust onto the hair of corpses, which suggests microbes could deposit arsenic and other poisonous metals on bodies as well, potentially complicating criminal and archaeological investigations.
Appenzeller and his colleagues incubated samples of Appenzeller's hair for up to six months in soil from an Australian gold mine. In some experiments, this soil contained the bacterium Cupriavidus metallidurans, which thrives in environments loaded with heavy metals and can help form grains of gold.
The researchers found gold levels did not increase in the hair to any statistically significant degree when it was incubated without the microbes in naturally gold-laden soils. However, gold levels rose dramatically in the hair if the bacterium was there.