Researchers at the National Institute of Standards and Technology-NIST have revealed that the so-called "ultrafine particles" -UFP- range in size from 2 to 10 nanometers, compared with the 10 nm to 30 nm particles identified in previous studies.
The team said that they conducted a series of 150 experiments using gas and electric stoves and electric toaster ovens to determine their impacts on indoor levels of nano-sized particles.
While earlier research projects have been limited to measuring particles with diameters greater than 10 nm, the researchers said that the new technology they used in their experiments allowed them to measure down to 2 nm particles-approximately 10 times the size of a large atom.
According to them, the smaller nanoparticles more than 90 percent of all the particles produced by the electric and gas stovetop burners/coils.
The gas and electric ovens and the toaster oven produced most of their UFP in the 10 nm to 30 nm range, they said.
The researchers believe that their findings would affect future studies of human exposure to particulates and associated health effects, particularly since personal exposure to the indoor UFP sources can often exceed exposure to the outdoor UFP.
They said that they would continue to explore the production of UFP by indoor sources like hair dryers, steam irons, and electric power tools, which include heating elements or motors that may produce such particles.