Jim Pearson, chairman of the Mechanical Systems Hygiene Institute (MSHI), recently talked about the effects of the devastating collapse of the World Trade Center, as it applies to indoor air quality (IAQ).

“I’ve had some time to think about this. The problem with asbestos [from collapsed buildings] at this point pales compared to everything else that happened.

“But down the line, there will be some situations possible, such as personal injury. Every one of those buildings had fresh air pulled into them through their hvac systems, about 15 cubic feet of air — enough to fill a four-drawer file cabinet — every minute for every person in the building. That fresh air comes in and mixes with the inside air and then is circulated by the hvac system.

“So that’s a lot of air for some of those big buildings, which have big intakes. Most of those [buildings] have filtration banks that are not fine enough to take care of this stuff [asbestos]. It’s just for the larger stuff. Rarely will you find a HEPA filter in the larger buildings.

“What we’ve got is contaminated structures. Let’s say they clean the building but not the hvac system, especially if they’re dirty systems. The buildings and the hvac systems have to be decontaminated.

“Just cleaning the building will not be enough. A big building will be filled with tons of particulates and airflow through there affecting everything.

“The asbestos is in or on everything: pipe insulation, ceiling tile, etc. Some of those buildings are very old and filled with all types of asbestos. It’s further reaching than people think. If I were the manager of a building, I’d seal up that air intake.

“If they have a full complement of people, they could open windward windows, which would be good. It depends on where the air intake is or how the wind is blowing. The buildings will eventually be operating at a reduced capacity, but right now it’s summertime and they’re probably operating full bore. And that’s not much of a concern now, given the gravity of the situation. But that will be a concern in the next few months.

“An army of cleaners will be needed just to reduce the dust nuisance. It’s a tremendous need, and all of the workers will need to be outfitted with respirators, because all of the cleaning will have to be done in asbestos abatement-type cleaning, and they will be taking decontamination showers so their homes or hotel rooms aren’t being contaminated.

“Those people who ran out [of the area] will see short-term exposure. It’s the cleaners who will be going in to clean this mess up over the long haul who will be exposed long-term. That’s why they’ll need HEPA ventilators. The threat may very well be to the people in those offices with the hvac systems circulating that stuff around, and for the cleaners who will clean that up.

“How much is too much? Any amount of damage today is intolerable, but cleaners won’t be hurt if they can control filtration. People who own large cleaning companies must understand that their employees may be faced with asbestos exposure and that somewhere down the line they may be putting their employees and their company in a position that they don’t want to be in.

“This is a situation that none of us have ever had to face before. It’s not your regular cleaning job. But you have to look at the long-term liability here because no judge or jury later on is going to say that because a little girl’s mommy died, they did the best they could at the time.”

Publication date: 09/24/2001