MRS Mold Identification and Assessment 2 — Questions and Answers
Question 1: Which sampling method collects mold spores by impacting air onto a sticky surface for microscopic analysis?
- Bulk sampling
- Swab sampling
- Air sampling via spore trap (Correct answer)
- Wipe sampling
Correct answer: Air sampling via spore trap
Spore trap air sampling draws a measured volume of air through a cassette, impacting spores onto an adhesive surface for analysis.
Question 2: What does a musty odor in a building without visible mold most likely indicate?
- The building is free of mold contamination
- Mold may be hidden inside walls, under flooring, or in HVAC systems (Correct answer)
- The odor is always from bacteria, not mold
- Seasonal pollen infiltration
Correct answer: Mold may be hidden inside walls, under flooring, or in HVAC systems
Musty odors are produced by microbial volatile organic compounds (MVOCs) from mold growing in concealed locations.
Question 3: Which genus of mold is most commonly associated with water-damaged drywall and produces greenish-blue colonies?
- Stachybotrys
- Penicillium (Correct answer)
- Alternaria
- Trichoderma
Correct answer: Penicillium
Penicillium species commonly colonize water-damaged drywall and building materials, producing characteristic blue-green spore masses.
Question 4: What is the primary purpose of using moisture meters during mold assessment?
- To identify mold species
- To detect elevated moisture content that supports mold growth (Correct answer)
- To measure airborne spore concentrations
- To test HVAC filter efficiency
Correct answer: To detect elevated moisture content that supports mold growth
Moisture meters detect elevated moisture levels in building materials, identifying conditions that support mold growth before visible colonies appear.
Question 5: When performing a pre-remediation mold assessment, what is the purpose of establishing a baseline outdoor air sample?
- To confirm the building is sealed properly
- To compare indoor spore types and counts against ambient outdoor levels (Correct answer)
- To identify which mold species are native to the region
- To satisfy EPA reporting requirements
Correct answer: To compare indoor spore types and counts against ambient outdoor levels
Outdoor baseline samples allow assessors to determine whether indoor spore levels and types are elevated beyond normal environmental background.
Question 6: Which mold is commonly called 'black mold' and produces mycotoxins on cellulose-rich materials in chronically wet conditions?
- Cladosporium
- Aspergillus niger
- Stachybotrys chartarum (Correct answer)
- Aureobasidium pullulans
Correct answer: Stachybotrys chartarum
Stachybotrys chartarum thrives on wet cellulose materials like drywall and produces trichothecene mycotoxins, earning it the 'black mold' label.
Question 7: What does 'Colony Forming Unit' (CFU) measure in mold air sampling results?
- The total weight of mold spores collected
- The number of viable mold spores capable of growing (Correct answer)
- The toxicity level of mold contamination
- The surface area of visible mold growth
Correct answer: The number of viable mold spores capable of growing
CFU measures viable, living mold spores that can germinate and form colonies, as determined by culture-based laboratory analysis.
MRS Mold Identification and Assessment 2
Which sampling method collects mold spores by impacting air onto a sticky surface for microscopic analysis?