Air Date: 7-19-2013| Episode: 292
This week we discuss in further detail Advanced Indoor Environmental Quality (IEQ) with our Technical Director; Dr. Dietrich Weyel…
IAQradio’s technical director Dieter Weyel, PhD., an academic and a practitioner; is an entertaining and knowledgeable guy who always brings a unique perspective to the topic at hand. On today’s broadcast of IAQradio, Dieter discussed particles.
Nuggets mined from today’s episode:
• A micron is 1/millionth of a meter. A human hair is 80-100 micrometers in size. The human eye can detect two 40 micron size particles side-by-side.
• The settling rate of particles is influenced by the particles: size, shape and density.
• The AED [Aerodynamic Equivalent Diameter] is based upon particle size, shape and behavior determines particle behavior.
• Particles deposit in human lungs according to size.
• Animal studies are necessary sometimes. Sacrificing animals for scientific study should only be done in return for good data. Animals used for scientific study often have a pedigree.
• 30 micron fibers have been found in human alveoli, fibers behave according to diameter as opposed to length.
• The alveoli, the lowest part of the human lung where oxygen transfer occurs is where health damage occurs. ≤25 micron particles deposit in the lung. ≤10 micron particles are respirable, depositable particles get to the alveoli.
• Smaller particles have a greater chance of entering the blood stream than larger particles.
• Chemical vapors and particles temporarily paralyze the human bodies self cleaning mechanism.
• Cigarette smoke particles quickly coagulate into particles of larger size.
• Indoors it is unlikely that ≤ 1 particles will settle out of the air indoor as dust, but rather attach to ceilings, walls or cold surfaces.
• Dust can adsorb vapors and carry them deep into human lung.
• The relative weight of gases is not relevant in real world situations as gases will inevitably mix together.
• Particle size is the most important factor in capture by air filtration devices.
• Electronic precipitators remove small particles effectively. Electronic precipitators don’t remove vapors. Electronic precipitators require routine maintenance.
• Air pollution studies in Pittsburgh originally focused on PM 10 (Particulate Matter 10 microns), then PM 5 and now PM 2.5.
Today’s Music: Particle Man by They Might Be Giants