Elusive Ultrafine Indoor Air Contaminants Yield To NIST Analysis
Researchers at the National Institute of Standards and
Technology (NIST) spent 75 days on the job carrying out some
very important homework—measurements in a “typical dwelling” of
the release, distribution and fate of particles almost as tiny
as the diameter of a single DNA molecule. Particles ranging in
size from 100 nanometers down to 2.5 nanometers that were
emitted by gas and electric stoves, hair dryers, power tools and
candles were tracked and analyzed. Monitoring such tiny
particles was made possible by NIST advances in measurement
capabilities. Measurements were carried out in weeks of
experiments at a 340-square-meter (1,500-square-feet) test house
on the NIST campus in Gaithersburg, Md. The researchers used the
data to develop a model for predicting changes in the size and
distribution of so-called ultrafine particles (technically,
particles smaller than 100 nanometers) discharged by tools,
appliances and other sources. The measurement