Air quality monitoring report for NYU Downtown Hospital, Sep 2001

NYC 9/11 Public Portal Document

For your convenience, a list of some of the cited regulatory standards (Such as PEL) follows below.

General — A PEL is the maximum concentration that the Occupational Safety and Health Administration (OSHA) established as acceptable for an eight (8) hour per day, five (5) day per week exposure. This is the standard that the hospital is responsible for compliance with. Hospital staff must not be exposed to concentrations in excess of the PEL.

The US Environmental Protection Agency (USEPA) has standards related to emissions to the environment, and the outdoor (Ambient) air. The entity emitting the contaminants can be held responsible for elevations above these limits, referred to as the National Ambient Air Quality Standards (NAAQS). The hospital is not emitting the involved emissions, and is therefore not responsible for them.

These standards are more relevant to the quality of the fresh air drawn in by the building's HVAC system, and the potential impact upon components of the drawn in contaminants that can subsequently accumulate in the building.

The accumulations can be of particulates, which do not break down over time, such as asbestos or silicates for example.

Non-particulates, such as carbon monoxide, a gas, will not accumulate, as- they break down and dissipate in a short time.

Carbon dioxide, produced by the 'occupant's exhalation, can accumulate if insufficient fresh air is drawn in. Closing of outside air intakes to keep out exterior contaminants can cause interior emissions to build up.

Some parameters, such as microbials, have no regulatory limits. These are typically compared to the outside air for indoor air clearance criteria. The indoor air's concentration should be statistically no higher than the outdoor air's concentration. The current scenario requires some adjustment in interpretation, as the outdoor air can be considered to be somewhat compromised by recent terrorist activities.

Specific contaminants have individual PELs. Some of the parameters measured at the hospital are asbestos, carbon dioxide, and dust.

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