Molecular entrapment technology enables direct species to species comparison between indoor and outdoor mold spores. The mTRAP is the only air sampling cassette that incorporates molecular entrapment technology. The table below is from an mTrap report. This particular sample was collected from an upscale apartment in Manhattan, NY. The entire project included three indoor mTRAP samples: Kitchen, Living Room, and Master Bedroom, and one outdoor sample. The report is read from left to right and consists of four columns. Spore concentrations for each species are reported in spores per cubic meter of air. An entry of ND indicates that no spores were detected for that species.
REPORT LAYOUT: The first column is the mold species, the second and third column are the spore concentrations inside and outside, respectively. Column four reports the relative abundance of each species. The relative abundance indicates the contribution of the spores for each species to the total concentrations of spores for the sample and is expressed in percentage.
READING THE REPORT: Examine “Total Spores” first (last row of the report). The concentration inside (5,938) is greater than the concentration outside (3,814). Next scan the Relative Abundance column to find the most abundant indoor species (68.29); it corresponds to the mold Aspergillus sydowii. Compare the inside to outside for A. sydowii, notice that it is elevated indoors (4,055) compared to outdoors (226). Do this for all relative abundance values in decreasing percentages from greatest to least.
The mTRAP is analyzed using DNA technology and is extremely sensitive. As a rule of thumb, any difference between the indoor and outdoor spore concentrations for a specific species that is greater than 100 is suggestive of indoor spore replication. If Stachybotrys chartarum is detected inside and not outside, replication may be occurring inside- even is only one spore is detected. However, if values are greater than five spores- replication is likely.
CONTRAST TO SPORE TRAP: Notice how many species for Aspergillus and Penicillium were detected. The total is nine species. Aspergillus and Penicillium species are considered to be the primary indicators of water intrusion. Moreover, various species have been implicates in respiratory disease, asthma, and toxic exposures. The mTRAP provides the species identity and spore concentration. The general basis of exposure assessment is to determine the airborne concentration of a contaminant to which occupants are being exposed. In chemical analysis we identify the concentration of specific chemicals during exposure assessment. Molecular entrapment works the same way by providing the exact species of mold. Spore traps do not. Spore traps are limited by technology both in capture ability and identification resolution.
Many outdoor fungi produce little round spores, which is an extremely confounding problem for spore trap interpretation. Little round spores are grouped into Aspergillus/Penicillium– like spores during sore trap analysis. This makes it virtually impossible to compare indoor to outdoor concentrations with confidence. However, the majority of investigators inappropriately continue to weigh Aspergillus/Penicillium– like spores heavily on exposure assessment. They do so because of the low cost and fast turnaround that spore trap analysis provides. Only by comparing species is a solid connection between airborne concentration and mold exposure possible, The mTRAP provides an advanced solution for mold exposure assessment.
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