Zinc oxide nanoparticles are used in food packaging for their antimicrobial properties. Generally lining the inside of certain canned goods, these inorganic nanoparticles are traditionally considered to be relatively harmless, but a small body of evidence is beginning to suggest that they may have unforeseen health implications.

Using mass spectrometry, this new study first examined several samples of canned food – corn, tuna, asparagus and chicken – to understand how many zinc oxide nanoparticles were being transferred to the food. In some instances, the study found these foods contained up to one hundred times the recommended daily dietary allowance of zinc.