Q: How does the InstaScope compare with traditional tools and techniques used by mold or indoor air quality (IAQ) inspectors?
A: The InstaScope is best applied as a gross inspection tool with deeper analysis available using impactors, impingers, DNA Polymerase Chain Reaction (PCR), etc. This instrument has limitations like any technology; however, what we have seen in the field is that the value of the instrument is in providing real-time, accurate analysis of the aerosol room-by-room for the entire structure. This allows inspectors to see the effects of aerosol pressurization schema and locate issues that are missed or ignored with traditional sampling due to the excessive cost and time required to do distributed room-by-room sampling and analysis with impactors, etc. Anecdotally, the IAQ professionals who currently use the InstaScope leverage it as a gross inspection tool that guides them to a better understanding of where to sample with more granular methods if necessary. That said, the bulk of inspection requirements appear to be satisfied with the InstaScope inspection and only when the case is being driven by an M.D. or J.D. do the IAQ professionals prefer to draw other sample methods. Put simply, IAQ professionals who have access to the InstaScope rarely use impactor samples now and instead are able to quickly assay the aerosol and move on to point-source forensics that ultimately deliver a remediation solution to the customer that is both more comprehensive in scope and more efficient in project time and materials.
Q: Is the device able to conclusively say that these particles are mold spores and not just similarly sized other biological particles?
The InstaScope is not able to say with the same level authority as a DNA test that the fluorescent particles are mold. However, neither can a microscopist. Both the InstaScope and direct microscopy generate results based on optical recognition and binning. Both methods statistically calculate an aerosol loading (p/m3) as a function of the sample analyzed. InstaScope is unique in the analysis phase in that 99% of all particles sampled are analyzed as opposed to microscopy where only a small fraction (less than 1%) of the particles sampled are typically analyzed. The InstaScope is specifically delivering a calculated result of particles per cubic meter which have a 90% or greater optical match to known mold particle signatures as determined by their composite signature or “fingerprint” (particle size, fluorescent spectra, fluorescent intensity, etc).
Q: How is the InstaScope different than a particle counter?
The instrument is a wideband integrated bioaerosol spectrometer. It delivers both quantitative (particle counter) and qualitative (fluorescent spectrum) analysis on a particle-by-particle basis. The InstaScope is not simply concerned with the presence or absence of fluorescent biomolecules (Tryptophan being just one of a host of biomolecules that fluoresce in organic material) but rather the unique composite signature generated by those fluorescent particles. This composite signature or “fingerprint” (particle size, fluorescent spectra, fluorescent intensity, etc) is compared to known signatures from a library of molds cultured and sampled by Dr. Mark Hernandez at the University of Colorado specifically for the InstaScope. The library currently contains the genera listed on the EPA’s ERMI list and continues to grow. Those particles whose signatures have a 90% or greater optical match with this library are identified as mold and then further binned into phenotypic groups. The same qualitative analysis applies to other biological particles (bacteria, pollens, etc), however at this time the primary purpose of that analysis is to differentiate those particles from mold and gate them out.
Q: What interferences can be expected? Is there a possibility of false-positives in the report?
A: PAH’s (polycyclic aromatic hydrocarbons) can generate false positives, when they exist as particles the same size as microbes, or when sorbed to particles of similar size and shape. We see this mainly with high VOC household cleaners and soaps. However, the volatility of these compounds mean that the interference is very rarely persistent beyond a few hours after point of application. This issue is addressed by requiring the property owner to follow a pre-inspection protocol that includes not using household cleaners or air fresheners for 24hrs prior to the inspection. Also, technicians are trained to recognize counter-intuitive results and identify potential sources of interference. Interference is a reality, but in practice it is an issue in only a very small percentage of the samples collected.
Q: Does the InstaScope provide explicit identification of the 36 ERMI species?
A: The signatures of the ERMI species are at the core of the InstaScope analysis. The InstaScope algorithm uses these signatures to generate phenotypic groups along with concentration data from all scans to exposure conditions (GYR). Droplet Measurement Technology (DMT), owner and developer of the InstaScope, does not expose to the end user the proprietary differentiation of phenotypic groups in the algorithm. Although this information would lend additional capability to the instrument, it is not required to support the business case of the technician providing a gross inspection of the aerosol state of a given property.
Q: What effect does the room volume (ft3) have on the green-yellow-red (GYR) assessment?
A: The room volumes only affect the length of the scan but not the analysis of the data collected . The logic is 0:45 scan time for every 1000ft3 with a 3 minute minimum scan. We measure concentrations using the absolute flow rate of the instrument not the volume of the room.
Q: What effect does the exterior aerosol sample (baseline) have on the green-yellow-red (GYR) assessment?
A: The baseline measurement is one part of the GYR algorithm. The algorithm is a very complex set of if-then statements that integrate and analyze multiple date points including the exterior aerosol (baseline), other samples in the set, variations in the local sample, and a national database of statistically derived thresholds.
Q: Does the temperature and relative humidity (RH) affect the report?
A: The temperature and RH are simply reported as values collected from the sensor, they do not change the GYR logic of a room. This information is useful to the technician in diagnosing environmental conditions that might give additional insight to the aerosol results provided by the InstaScope.
Q: What is the purpose of the InstaScope reporting PM2.5 and PM10 instead of total particle counts?
A: In the absence of uniform regulation or industry standard for indoor total particle loads, the InstaScope grounds the objective assessment of this measurement in the EPA NAAQS standard for ambient air. ASHRAE 62-1989 states: “Indoor air quality shall be considered acceptable if the required rates of acceptable outdoor air are provided for the occupied space.” ASHRAE 62-1989 references the national primary ambient air quality standard for outdoor air as set by the U.S. EPA. The NAAQS primary standards currently in force were originally developed as thresholds for human exposures outdoors; however, they are often referred to by regulatory agencies and non-governmental organizations as thresholds to judge the quality of indoor air as well. The extension of NAAQS thresholds to generic indoor exposure contexts have been referred to in current practice by OSHA (Occupational Safety and Health Administration), NIOSH (National Institute for Occupational Safety and Health), and ACGIH (American Conference of Governmental Industrial Hygienists).
Q: What is size range limit of detection for the InstaScope?
A: InstaScope measure from 0.5um to 10um with the majority of the biological “particles of interest” presenting in the 1-5um range. The instrument provides ”real-time” results, however the mechanics of delivering the sample to the optical chamber from the sample wand tip creates a 3-5 second delay from point-source to detection. In practice this delay is inconsequential given the purpose of the instrument as a gross inspection tool.
Q: Does the InstaScope have the ability to make accurate “exposure condition” assessments when a gross count comparison is insufficient to fully analyze the environmental dynamics?
A: Assuming that the particle-level analysis is accurate, the important questions are whether the sample set is representative AND if the comparative analysis of all samples in that set accurately diagnoses trends and outliers in the aerosol that are indicative of other issues with the Indoor Environmental Quality (IEQ). The InstaScope algorithm compares each sample or “room” quantitatively AND qualitatively to all other samples in the set including the outdoor sample. In gross terms, the algorithm determines to what degree a sample is “more” or “different” than other samples in the set. For instance, if a sample had less total mold concentration than outside but had a higher concentration of a specific mold genera (identified as a distinct phenotypic group) then the InstaScope would identify this room as an outlier and assign it a “yellow” or “red” result based on additional criteria. The InstaScope team compared the algorithm’s assessment of samples in a blind side-by-side test against traditional impactor sampling and analysis by a team of IAQ professionals and found that the InstaScope had a greater than 95% agreement with traditional analysis.