Concrete — lime — sand — silica (57)

(57th in a series on Martin Tower)

Martin Tower demolition May 19

Gadfly was a literature prof.

He knows “nuthin'” about the real, practical world out there.


Gadfly needs help.

Gadfly do believe (subject to review and documentation) that when asked what will be in the “dust” generated by the Martin Tower implosion — CDI answered twice (subject to review and documentation) that the dust will contain “sand and lime.”

Gadfly thought the dust would contain silica.

CDI did not mention silica.

Gadfly stands to be corrected.

Gadfly wishes somebody would correct him before he goes further, wasting your time.

So Gadfly does poor man’s research on the web and finds this web site: The Center for Construction Research and Training (CPWR — The Center for Construction Research and Training is an international leader in applied research and training for the construction industry, and serves as the National Construction Center for the National Institute for Occupational Safety and Health NIOSH). Sounds legit.

And reads such things as:

  • The dust created by cutting, grinding, drilling or otherwise disturbing these materials can contain crystalline silica particles.  These dust particles are very small. You cannot see them. This respirable silica dust causes lung disease and lung cancer. It only takes a very small amount of airborne silica dust to create a health hazard.

Now this is a web site that focuses on workers, and when the developer has said that factors influencing the choice of implosion over conventional demolition are “safety and time,” I do believe that it is worker safety that is referred to. And we want worker safety too. But substitute “spectator” for “worker.”

And if one goes on in this web site, you find:

  • A worker’s chance of becoming ill from exposure to silica dust depends on the tasks performed, the amount of dust they are exposed to, and the frequency of the exposures. Each exposure to silica adds into the total load of silica in the lungs – in other words, each exposure adds to the lung damage.

So it may be that one exposure to a small amount of dust of short duration might not affect a healthy spectator.

The argument we have heard is that about the same amount of dust has already been generated in the last 18 months will be generated now in one shot. So there is no worry.

I’m not smart enough to get my mind around that argument. But it sounds fishy.

Might not a large amount of dust all at once be possibly more dangerous to a spectator?

Likewise, I’m not smart enough to figure that out.

Let me repeat from post #39 a site that contradicts developer statements:

The most efficient of all commercial demolition methods is explosion or implosion, but it’s typically only suitable when mechanical demolition and deconstruction aren’t an option. There are public health concerns with this type of demolition, including environmental issues, damage to adjacent structures, flying debris, air quality concerns, noise, and more. When used, this is typically the least expensive commercial demolition method.

And look at the link provided by George Lopez in post #45.

I’m bothered by the idea (subject to review and documentation) that CDI mentions sand and lime but not silica.

So, here’s my bottom line:

1) Is CDI “hiding” the presence of silica in the dust? If so, why?

2) If silica is there, is the amount of exposure here dangerous for spectators?

Anyone clearer headed than I want to press their brow against such questions?

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