Clickbaity title IMO, but I'm not sure what to suggest. I think the current title suggests malice on the part of the US gov, but they were actually just doing some interesting research.
Subways are really interesting beasts from the point of view of people who try to model the transport and fate of airborne materials. The trains themselves pump material through the tubes, the cars entrain material in their wake, and the cars capture and carry material along with the passengers (meaning you can disperse material even after a car comes out from underground). All this is intermittent and bi-directional, following the train schedules. And then it's all tightly coupled to the city's above-ground airflow patterns, both because the train stations have massive ventilation exchange with the outdoors, and because there can be passive vents at street level.
Particles add another layer to the problem. As the article states, they deposit out of the air, and they can resuspend, e.g., due to human activity. They can also hitch a ride on people and things. They also get captured in ventilation system filters. Finally the rates at which they do all these things depends strongly on the particle size -- and the particle size can change due to things like coagulation.
As I am reading the title, no malice is suggested. It seems to just be a plain statement of fact.
https://en.wikipedia.org/wiki/Operation_Sea-Spray
Though I wonder what testing was done to prove that the aerosol (made from wheat and corn starch, tagged with DNA) they they are spraying this time is harmless?
I'm not sure that the headline is even clickbaity--don't know how I'd rewrite it. But I can easily see someone reading it to go to the story with an expectation of malice or at least stupidity.
That said, hopefully they can validate models which will provide optimum locations for detectors, as well as action plans once a detection occurs, such as kill all cars near the detection and change venting airflows.
..........WHAT. I'm sorry, but no, seriously a police operator said this?
So while it is useful to understand the way subway systems may disperse particles, this kind of research does not reduce the risk of economic damage from low-sophistication attacks targeted at the subway system.
It is difficult to obtain Anthrax or similar chemical agents, and the number of people needed to pull off a successful attack is fairly large. Machine guns or simple explosives (like those used in the Boston Marathon attack), however, are 100x more likely to succeed and cause the intended economic damage, so long as they either create a fear of traveling by subway or lead to security checkpoints that drastically reduce the subway's throughput.
The key takeaway, in my opinion, is that nobody with access to the NYC subway really wishes to harm it or do terrorism.
I'd estimate that such an attack would result in the subway being closed for weeks, particularly if several happened successfully a few days apart.
Similarly, small explosions dispersing any remotely harmful smoke or chemicals (even chemicals that are easy to obtain) would be amplified by media coverage, and politicians would close the subways as a knee-jerk response.
Sure, an actual banned bioweapon/chemical would be worse, but my point is that terrorism (the tactic not the alleged existential threat) works because it requires little skill, technology, or access to difficult-to-obtain materials to create fear.
They say you're not a "real New Yorker" (whatever that means) until you've lost a finger to the subway pole bacteria...
Obviously there are cheaper ways to cause more expensive damage. That's not what terrorists care about and that's not what potential victims of terrorism care about.
The point of a terrorist act causing loss of life is to create the fear that will cause economic damage, not to somehow wipe out lots of civilians.
In a war, the willingness to kill civilians is proportional to the need to do so to make an impact on the opponent's will to fight. Obviously nobody would prefer to kill civilians over combatants, but all militaries will do it without hesitation if circumstances dictate.
What's the difference?
(That doesn't excuse the TSA's security theater, obviously.)
It's really for preventing destruction of the plane itself. A large bomb on a train underground could cause way casualties, which is why the strictness of the TSA is puzzling.
I wish the research results would be given to the public, though I understand why we won't see the results for some time, or possibly never.
It's also kind of scary that their only listed "remediation" is to have more accurate contamination maps. It really hits home the concept that, once a bad guy actually gets a weapon to a crowd, there's not much more that can be done.
These sorts of tests also aim at helping guide the first response. For a long time, there was an ongoing debate about the proper response to an attack on a subway (it's probably still going on, but I haven't talked with this crowd in a few years). For example, suppose a CCTV spots a bunch of passengers going down in a particular terminal. Should you shut down the ventilation system, in order to try to contain the material? Or should you crank up the system, in order to dilute the hazardous material? How should those decisions change depending on the type of material, the amount released, the atmospheric conditions, and the timing of the response? Should you stop all trains in the tunnels, or should you run them to the nearest station for evacuation? All of this requires estimating potential health impacts, to those on the platform, in the rest of the system, and downwind of the affected stations.
I don't know about subway specifics, but the matter was settled a long time ago for buildings - and it didn't take long to arrive at the conclusion. Containment is the policy. The first thing that happens when any toxic substance is suspected, in a security conscious facility, is the shutdown of HVAC followed by the restriction of uncontrolled movement (elevators sent home, security posted in stairwell, etc). Even in areas equipped with filtration systems (like mail rooms). I've never heard anyone suggest dilution, you'd have to have NBC sensors that can instantly detect every toxic substance in order to avoid unknowingly spreading anthrax piggybacked on an irritant like CS. Such sensors do not exist.
This might not seem like the place and time to preach peace, but now is as good a time as any.
Still, this may be more thorough.
