Indoor Air Quality Assessment Flashcards

The term 'sick building syndrome' (SBS) differs from 'building-related illness' (BRI) primarily because:

Answer: SBS symptoms resolve after leaving the building while BRI has a diagnosable cause that persists

Sick Building Syndrome (SBS) describes nonspecific symptoms that resolve after leaving the building and lack a single identifiable cause, while Building-Related Illness (BRI) has a documented, diagnosable cause (such as Legionnaires' disease or hypersensitivity pneumonitis) that can persist even after leaving. Both can affect any type of occupant, not just industrial workers. Mold can contribute to both conditions, and BRI is not limited to chemical causes.

When collecting settled dust for mycotoxin analysis, which laboratory technique is most commonly employed?

Answer: ELISA (enzyme-linked immunosorbent assay)

ELISA (enzyme-linked immunosorbent assay) uses antibodies specific to individual mycotoxins (such as trichothecenes or aflatoxins) to detect and quantify them in settled dust at very low concentrations, making it the standard method for mycotoxin analysis in building investigations. GC-MS is used for volatile chemical compound identification, not mycotoxins in dust. Direct microscopy cannot detect mycotoxins at all, and infrared spectroscopy identifies molecular bond structures but is not used for mycotoxin quantification in environmental samples.

An inspector finds that spore trap samples show elevated Penicillium/Aspergillus counts in one office but not others. The most methodical next step is:

Answer: Investigate the HVAC supply zones and local moisture sources serving that specific office

Elevated spore counts in one office point to a localized source, so the methodical next step is tracing the HVAC supply zone and checking for moisture intrusion specific to that area. Full-floor remediation is premature without a confirmed source; dismissing the result ignores a real signal; and outdoor samples alone won't explain an indoor-specific elevation.

Which ventilation standard published by ASHRAE specifies minimum outdoor air delivery rates for acceptable indoor air quality in commercial buildings?

Answer: ASHRAE 62.1

ASHRAE 62.1 is titled 'Ventilation for Acceptable Indoor Air Quality' and sets minimum outdoor air delivery rates for commercial buildings. ASHRAE 55 covers thermal comfort, ASHRAE 90.1 addresses energy efficiency, and ASHRAE 189.1 covers green building design — none of these specify outdoor air delivery rates for IAQ.

A particulate matter (PM2.5) reading elevated well above EPA outdoor standards in an indoor space with no identified chemical source most likely indicates:

Answer: Infiltration of outdoor pollution or an indoor combustion or resuspension source

Elevated indoor PM2.5 with no chemical source points to either outdoor pollution infiltrating through the envelope or an indoor source like combustion appliances, candles, or resuspended dust. Adequate pressurization would bring in clean air, not polluted air; seasonal biological variation doesn't explain PM2.5 elevation; and maximum recirculation would reduce outdoor infiltration, not raise PM2.5.

During an IAQ walkthrough, an inspector detects a musty odor but finds no visible mold. The best explanation for this finding is:

Answer: MVOCs (microbial volatile organic compounds) can be present when mold is hidden inside walls or under flooring

Mold produces microbial volatile organic compounds (MVOCs) during active growth, which create musty odors even when the colony is hidden inside wall cavities or beneath flooring. Building material off-gassing has a distinct chemical smell rather than a musty one; outdoor pollen doesn't produce musty odors; and an overloaded HVAC filter typically causes dusty, not musty, odors.