1/ @CDCgov has bought into layered inhalation dose, and therefore risk, reduction strategies. Pleased by this recognition, but not ready to shower the agency with adulation. The agency's credibility has taken a hit. I want to see a sustained effort of focus & doing right.
2/ My life has been about looking forward. But it is difficult not to reflect on where we would have been today had recognition of inhalation of virus-laden aerosol particles in both the near and far fields been recognized by @CDC 10 months ago.
3/ Future planning for the next pandemic or continued battle with SARS-CoV-2 must rely on continued innovation, but also on a deep forensics analysis of all of the failures (on so many fronts - not just @CDC) that fueled an inferno of infection in the US & elsewhere.
4/ Failure to do a retrospective analysis would be another failure. IMO we need interdisciplinary efforts by researchers to marry lessons learned w/ future efforts to appropriately PREVENT infection, as opposed to simply treating it & waiting for a vaccine. We need both (badly).
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1/ It is difficult, and especially if you want more than total VOCs (TVOC) using a photoionization detector with factor of three accuracy (that tells you nothing about actual chemicals). more ...
2/ In flight to Beijing for Indoor Air 2005, a large number of academics from the US brought onboard small passive ozone samplers and taped to backs of seats. These were collected and shipped back to the US for analysis. The same could be done w/ passive samplers for VOCs.
3/ What you gain from this approach is speciation of VOCs. What you lose is temporal variation, e.g., peak concentrations when high levels of hydrocarbons are emitted when an engine is first activated & during take-off.
Over 100,000 Americans currently in hospitals with COVID-19 and over 210,000 new cases today. We are converging on and will soon surpass the 9/11 death toll EVERY SINGLE DAY. And we are going to see a huge surge in the next several weeks & months.
2/ Hospital infrastructure is strained. Morgues have overflown. Front line health care workers are physically and mentally exhausted. This is a tragedy inside of a catastrophe.
3/ Despite all of this, too many people refuse to do what is needed to starve this virus of its hosts. Too many are too accepting of the death and devastation. Too many are fueling an inferno of infectiousness. It's all been said before, but ....
1/ I was asked in an interview today about the history of Indoor Air Quality. I surprised the journalist by starting about 1 million years ago with controlled fires brought into caves.
2/ There is evidence of early recognition of the importance of local exhaust, with fires placed below shafts to the outdoors. How many died from carboxyhemoglobin poisoning before recognition of the importance of ventilation?
3/ Perhaps we can ask the same question today but replace carboxyhemoglobin with COVID-19 and fire in caves with SARS-CoV-2 in (pick your favorite crowded and poorly ventilated indoor space).
Perhaps it is time we learn something from Homo erectus.
2/ The air pollution that we breathe during our lifetime, even pollution of outdoor origin, is dominated by the air we breathe INDOORS.
3/ We can dramatically reduce our exposure to air pollution by reducing emissions from indoor sources, removing pollutants of indoor origin (ventilation & good engineering controls), & designing/operating buildings to reduce outdoor pollution from penetrating indoors.
Highest % of courses with a hands-on component in the entire CSU system.
3rd highest % of students in natural resources and STEM programs in CSU.
CSU’s highest % of STEM grads who go on to earn doctoral degrees, ranking 8th nationally among 660 master’s level institutions.
It's always had a robust Environmental (Resources) Engineering degree program, among the largest and oldest in the US. That program has graduated a large number of highly-qualified engineers who have served the State of California & beyond.
1/ I agree with @Don_Milton. It is important to distinguish between near- and far-field aerosol particles. In the near field (close contact) there is potential for much higher concentration of aerosol particles in the breathing zone of a receptor.
2/ The actual concentration depends on extent of emissions from infector, body positioning of infector and receptor, mixing conditions between infector and receptor (which depends on a number of other factors), and DISTANCE between infector and receptor.
3/ Aerosol particles do not vanish beyond the near field. They exist in the far field and will accumulate until an approximate steady-state is achieved (more on this later) as long as the infector(s) stay in the space.