Sheldon K. Friedlander & David Y.H. Pui , of UCLA (University California, Los Angeles) put together a document called "NSF Aerosol Particle Report", its intention to present and focus on“Emerging Issues in Nanoparticle Aerosol Science and Technology (NAST)”
Summarizing, what the report goes over details that indeed there are atmospheric particles smaller than 100 nanometers, and particles which exist in the critical range below or <50 nanometers.
I will excerpt some quotes from the article and then get into some discussion about significance of these points.
The above defines the parameters needed for how a cloud can appear in the presence of small nucleation starting points (like microscopic seed points form starting locations from which the rest of the condensing process can continue, making up larger and larger (and visible) particles (or droplets if moisture is condensing).Fundamentals of Nanoparticle Aerosol Formation - Particles form in gases by various mechanisms.
At least 3 types of nuclei (core particles) were activated when atmospheric air was saturated during "adiabatic expansion",
Def: "Adiabatic" - Changes in temperature caused by the expansion (cooling) or compression (warming) of a body of air as it rises or descends in the atmosphere, with no exchange of heat with the surrounding air.) Expanding air creating cooling and condensing, in other words, is the significance.
1) existing aerosol particles at saturation ratios near unity (1:1 ratios of background carrier gas and particle/molecule present),
2) ionized (electrically charged) gas molecules at higher values than super-saturation and
3) water molecules themselves at much higher super-saturations.
In 2003, the date of the report, conference and workshop, representatives of several important official organizations attended:Applications are to reducing major uncertainties in the global radiation balance, especially the poorly understood "indirect effects" produced by nuclei that modify the global cloud cover and the hydrologic cycle. Other important applications are to aerosols produced when hot vapors from pollution sources are injected into the atmosphere.
1) NIST, Gaithersburg, Maryland
2) EPA, Research Triangle Park, North Carolina
3) NSF, Arlington, Virginia
4) California Air Resources Board, Sacramento, California
5) NIOSH, Cincinnati, Ohio
as well as numerous university participants (Yale, Caltech, Carnegie-Mellon, UCSD, University of Colorado, Kansas State, Clarkson University, Washington University, University of Minnesota), and industry participants.
One of the topics discussed was: Formation of Atmospheric ultrafine particles (UFP's) - with diameters less than about 0.10 µm (under, or < 100 nanometers, or nano-particles..)
Clearly (as much as we can read in the scientific terminology), these scientists have stated that there are nano-particles in the atmosphere and have determined that the particles do indeed form through the combustion process. They also say:These nanoparticles are formed from gases by a variety of gas-to-particle conversion processes.
There are at least three sources of gases, which may be converted to particles.
UFP's may be formed at high temperature sources and emitted directly to the atmosphere. Some processes may emit hot supersaturated vapors, which undergo nucleation and condensation while cooling to ambient temperatures. Chemical reactions in the atmosphere may lead to (new) chemical species with very low saturation vapor pressures. (At altitudes for instance)
These chemical species may form particles by a variety of nucleation processes. UFP's are particularly important in atmospheric chemistry and environmental health.
Toxicological and epidemiological evidence linking respiratory health effects and exposures to UFP's has been increasing over the last several years.
More recent toxicological studies indicate that ultrafine particles are most potent in inducing oxidative stress.
UFP's (pass thru the cell walls and) also localize in (cellular) mitochondria where they induce major structural damage.
There is a fundamental lack of information on how (all the methods that) nanoparticles form and grow to sizes that can serve as cloud condensation nuclei (CCN) and affect the earth’s climate.
Little information is also available on the concentrations or physical/chemical properties of UFP's in places where people live and work.
Studies focusing on heath effects are also needed to identify mechanisms by which UFP's induce cellular damage and generate oxidative stress, how they penetrate the cellular structure, and how the above effects depend on (their) chemical composition.
This information is essential in reducing emissions of UFP's that are a risk to public health. Finally, there is a need to better detect UFP's that pose a biological threat.
They know that these nano-particles are participating in cloud formation.
And they know that the nano-particles (UFP's) are dangerously "oxidative", that the concentrations of the nano-particles seem to be lodging in the cellular "mitochondria" (the mechanism of the cells where energy formation happens), and inducing major damage.
They know that engine exhaust does indeed form nano-particles.
They know that there are engine exhausts emitting particulates in the atmosphere; they know that there are wood burning, coal burning, gas burning fires.
I should also point out that OIL/GAS well associated gas "FLARING" has been recognized as a major source of nano-soot, and a major cause of world global air pollution, so much so that the World Bank has said it will no longer provide loans to countries wishing to develop their oil and gas resources if they FLARE (burn off the associated gas at the wellhead).
Oil/Gas well flaring
And they know that these nano-particles are indeed a Biological threat.
They know that nucleation and rapid growth occurs as hot pollutant exhaust gases mix with cooler air in the ambient environment.
Can we draw a conclusion then that NORMAL engine exhausts in the high altitudes of flight will produce nano-particles? If we look at the above science, one would say yes, such does naturally form.
What the scientists at this conference say also is, the nano-particle formation tends to STAY within a close area to the emission source.
If the emission source is moving then, can we assume that a "trail" of nano-particles would be formed?
Whether or not the nano-particles then would proceed to grow larger, and move out of the critial size window <50 nanometers size, is determined by the amount of saturation of vapor present at the temperature the particles are formed.
When the super-saturation forms, the nucleation allows for particle agglomeration, or growth to happen, finally to the point of visible "clouds".. At the point of visual cloud formation, the particles are PAST the size of the <50 nanometer sized dangerous window.
That observation about when it becomes VISIBLE, the particles are larger than the critical danger window (<50 nanometer sizes) - and such begs us to connect some dots.
If the emissions happen (and we know they do), and if there is not super-saturation (the air is dry), then there will be virtually invisible particles under or <50 nanometers formed.
That being the case, the exhaust trails WITHOUT cloud (contrail) formations could very well harbor the dangerous particles.
Will the particles dissipate? We assume that they do as clouds can be seen to grow larger or "evaporate" under different conditions.
At what rate, when dissipating will the particles aggregate, or become larger, and out of the dangerous window, <50 nanometers?
We simply don't know the answers to these questions and the scientists during the 2003 conference made it quite clear that they don't know either..
What these folks have said, is there is indeed aerosol nano-particle production during the combustion process and exhaust emission into the atmosphere.
(more to come)