The Science
What is MSQPCR?
How do we use MSQPCR?
The Dust Test utilizes mold-specific quantitative PCR (MSQPCR) technology as a screening tool to identify the top 36 different species as well as toxins produced by both molds and bacteria that typically inhibit unhealthy homes, depending upon the test you select.
MSQPCR obviates the limitations of these century-old methods of detecting and quantifying molds. MSQPCR is objective and specific because it is a detection system based on unique DNA sequences.
How widespread is mold in homes?
In 2004, the Department of Housing and Urban Development’s (HUD) commissioned the first American Healthy Homes Survey (AHHS I), which sampled 1,096 homes selected to be representative of the U.S. housing stock. In AHHS I, a dust sample from each home was analyzed using quantitative PCR assays (qPCR) for 36 common indoor molds: 26 Group 1 molds, which were associated with water damage in homes and 10 Group 2 molds, which primarily enter the home from the outside environment.
In 2019, HUD completed a second American Healthy Homes Survey (AHHS II) to track changes in the condition of the U.S. housing stock. One of our goals was to examine the stability of the ERMI scale in U.S. housing over time. Another goal was to document changes in mold contamination in homes built before 1978, the year lead was banned from paint in the U.S. (U.S. Consumer Product Safety Commission 1977).
The results were staggering!
Between 2004 and 2019, 34 out of 36 species showed an increase in prevalence of mold contamination in the sampled homes.
The AHHS II concluded:
"By using the ERMI metric, we were able to demonstrate that water damage and mold growth were more likely to occur as homes get older."
Read More: You can learn more about the American Healthy Homes Survey (AHHS II):
"The Environmental Relative Moldiness Index reveals changes in mold contamination in United States homes over time" here.
Below, you will find a summary of the occurrence in mold species from AHHS I to AHHS II.
Mold species in Groups | % | % |
---|---|---|
Occurance | Occurance | |
AHHS I | AHHS II | |
Group 1 | ||
Aspergillus flavus | 36 | 47 |
Aspergillus fumigatus | 62 | 70 |
Aspergillus niger | 69 | 97 |
Aspergillus ochraceus | 27 | 74 |
Aspergillus penicillioides | 90 | 99 |
Aspergillus restrictus | 12 | 76 |
Aspergillus sclerotiorum | 26 | 54 |
Aspergillus sydowii | 29 | 6 |
Aspergillus unguis | 20 | 36 |
Aspergillus versicolor | 30 | 70 |
Aureobasidium pullulans | 94 | 100 |
Chaetomium globosum | 51 | 72 |
Cladosporium sphaerospermum | 82 | 98 |
Eurotium amstelodami | 98 | 100 |
Paecilomyces variotii | 46 | 64 |
Penicillium brevicompactum | 52 | 89 |
Penicillium corylophilum | 17 | 68 |
Penicillium group 2 | 8 | 63 |
Penicillium purpurogenum | 15 | 25 |
Penicillium spinulosum | 20 | 5 |
Penicillium variabile | 50 | 87 |
Scopulariopsis brevicaulis | 53 | 64 |
Scopulariopsis chartarum | 38 | 75 |
Stachybotrys chartarum | 35 | 38 |
Trichoderma viride | 27 | 78 |
Wallemia sebi | 75 | 100 |
Group 2 | ||
Acremonium strictum | 57 | 82 |
Alternaria alternata | 88 | 100 |
Aspergillus ustus | 40 | 60 |
Cladosporium cladosporioides 1 | 99 | 100 |
Cladosporium cladosporioides 2 | 70 | 95 |
Cladosporium herbarum | 84 | 99 |
Epicoccum nigrum | 93 | 98 |
Mucor racemosus | 92 | 97 |
Penicillium chrysogenum 2 | 66 | 95 |
Rhizopus stolonifer | 29 | 52 |
Mold species in Groups | % | % | % |
Occur | Occur | Change | |
AHHS I | AHHS II | ||
2004 | 2019 | ||
Group 1 | |||
Aspergillus flavus | 36 | 47 | 30.56% |
Aspergillus fumigatus | 62 | 70 | 12.90% |
Aspergillus niger | 69 | 97 | 40.58% |
Aspergillus ochraceus | 27 | 74 | 174.07% |
Aspergillus penicillioides | 90 | 99 | 10.00% |
Aspergillus restrictus | 12 | 76 | 533.33% |
Aspergillus sclerotiorum | 26 | 54 | 107.69% |
Aspergillus sydowii | 29 | 6 | -79.31% |
Aspergillus unguis | 20 | 36 | 80.00% |
Aspergillus versicolor | 30 | 70 | 133.33% |
Aureobasidium pullulans | 94 | 100 | 6.38% |
Chaetomium globosum | 51 | 72 | 41.18% |
Cladosporium sphaerospermum | 82 | 98 | 19.51% |
Eurotium amstelodami | 98 | 100 | 2.04% |
Paecilomyces variotii | 46 | 64 | 39.13% |
Penicillium brevicompactum | 52 | 89 | 71.15% |
Penicillium corylophilum | 17 | 68 | 300.00% |
Penicillium group 2 | 8 | 63 | 687.50% |
Penicillium purpurogenum | 15 | 25 | 66.67% |
Penicillium spinulosum | 20 | 5 | -75.00% |
Penicillium variabile | 50 | 87 | 74.00% |
Scopulariopsis brevicaulis | 53 | 64 | 20.75% |
Scopulariopsis chartarum | 38 | 75 | 97.37% |
Stachybotrys chartarum | 35 | 38 | 8.57% |
Trichoderma viride | 27 | 78 | 188.89% |
Wallemia sebi | 75 | 100 | 33.33% |
Group 2 | |||
Acremonium strictum | 57 | 82 | 43.86% |
Alternaria alternata | 88 | 100 | 13.64% |
Aspergillus ustus | 40 | 60 | 50.00% |
Cladosporium cladosporioides 1 | 99 | 100 | 1.01% |
Cladosporium cladosporioides 2 | 70 | 95 | 35.71% |
Cladosporium herbarum | 84 | 99 | 17.86% |
Epicoccum nigrum | 93 | 98 | 5.38% |
Mucor racemosus | 92 | 97 | 5.43% |
Penicillium chrysogenum 2 | 66 | 95 | 43.94% |
Rhizopus stolonifer | 29 | 52 | 79.31% |