Is there a glossary for the scientific terms?

In describing and interpreting results from the simulation of exposure to secondhand tobacco smoke (SHS), we make use of common scientific terms. Below is a list of some of these terms and their explanation.

The artificial depiction of events with the intention of closely mimicking reality.

Steady State
The condition that is reached when material entering a system is balanced by material leaving a system. When this happens the concentrations in the system do not vary over time, i.e., they reach a "steady state concentration".

Micrograms per Cubic Meter, μg m-3
The units of air pollutant concentration commonly used for particulate matter. Micrograms are a millionth of a gram. A cubic meter is the volume of a 3D space that has dimensions of 1 meter along each side. Micrograms per cubic meter is usually abbreviated as μg m-3.

A quantity equal to the mass of suspended material that is mixed in a given volume of air. Concentration is typically reported in units of micrograms per cubic meter (μg m-3) for air pollutants.

Particulate Matter (PM)
Material in the air that is in the particle (condensed) phase. Also called "airborne particles" or "aerosol". Sometimes PM is qualified by the maximum diameter of the particles in microns, e.g., PM2.5 or PM10.

Micron or Micrometer, μm
A unit of length equal to a millionth of a meter. Usually abbreviated as μm.

Air Standard
A guideline established by an organization such as the US Environmental Protection Agency to indicate unhealthful amounts of air pollution. Air standards exist for particulate matter, carbon monoxide, ozone, and other toxic air contaminants. The standards are typically reported as an average air concentration over periods of 1 hour, 8 hours, 24 hours, or an entire year.