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13 pages, 788 KB

Open AccessArticle

Evidence of Malodorous Chloroanisoles in “Mold Houses” Was Omitted When Indoor Air Research Evolved

by Johnny C. Lorentzen and Gunnar Johanson

Microorganisms 2025, 13(6), 1363; https://doi.org/10.3390/microorganisms13061363 - 12 Jun 2025

Cited by 1 | Viewed by 1557

Herein, we address the peculiar lack of scientific reporting on odor potent chloroanisoles (CAs) in the built environment. We have searched and critically examined sources beyond peer-reviewed scientific journals, namely research conferences, parliamentary records, newspaper articles, and cartoons. We provide evidence that CAs evolved on a large scale in Swedish buildings in the early 1970s and evoked a typical sticky malodor that was attributed to mold and gave rise to the term “mold houses”. The term first appeared in Swedish newspapers in 1978, and the media attention increased rapidly. The malodorous “mold houses” reached the Swedish parliament and led to economic compensation for afflicted homeowners. The “mold houses” became “sick houses” as researchers, predominantly from Sweden, introduced and became world leaders on the “sick buildings syndrome” (SBS). Researchers became aware of the CAs but did not mention them in peer-reviewed articles, just as they did not mention a well-known source of the sticky malodor, namely, legacy preserved wood where CAs were formed through microbial methylation of toxic chlorophenols (CPs). Thus, the mold story from the early 1970s was maintained and prevented the malodorous CAs from becoming recognized as indicators of the presence of hazardous CPs. Our study is the first to report the impact of an indoor malodor, not only on a few people, but on society. Full article

(This article belongs to the Special Issue The Urban Microbiome)

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12 pages, 918 KB

Open AccessArticle

Mold Odor from Wood Treated with Chlorophenols despite Mold Growth That Can Only Be Seen Using a Microscope

by Johnny C. Lorentzen, Olle Ekberg, Maria Alm, Folke Björk, Lars-Erik Harderup and Gunnar Johanson

Microorganisms 2024, 12(2), 395; https://doi.org/10.3390/microorganisms12020395 - 16 Feb 2024

Cited by 4 | Viewed by 3636

Abstract

We previously reported that indoor odorous chloroanisoles (CAs) are still being emitted due to microbial methylation of hazardous chlorophenols (CPs) present in legacy wood preservatives. Meanwhile, Swedish researchers reported that this malodor, described since the early 1970s, is caused by hazardous mold. Here, we examined to what extent CP-treated wood contains mold and if mold correlates with perceived odor. We found no studies in PubMed or Web of Science addressing this question. Further, we investigated two schools built in the 1960s with odor originating from crawlspaces. No visible mold was evident in the crawlspaces or on the surfaces of treated wood samples. Using a microscope, varying amounts of mold growth were detected on the samples, all containing both CP(s) and CA(s). Some samples smelled, and the odor correlated with the amount of mold growth. We conclude that superficial microscopic mold on treated wood suffices produced the odor. Further, we argue that CPs rather than mold could explain the health effects reported in epidemiological studies that use mold odor as an indicator of hazardous exposure. Full article

(This article belongs to the Special Issue The Urban Microbiome)

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13 pages, 280 KB

Open AccessReview

Musty and Moldy Taint in Wines: A Review

by Maria Carla Cravero

Beverages 2020, 6(2), 41; https://doi.org/10.3390/beverages6020041 - 16 Jun 2020

Cited by 41 | Viewed by 12031

Abstract

The literature about musty and moldy taint—the so-called cork taint—in wines is varied because there are many different molecules involved in this wine defect. Chloroanisoles are the most relevant compound responsible for cork taint and of these, 2,4,6-trichloroanisole (TCA) is the most common, but 2,3,4,6-tetrachloroanisole (TeCA) and 2,4,6-tribromoanisole (TBA) can also be responsible of this defect. For other compounds involved in cork taint, geosmin and 2-methylisoborneol (2-MIB) are responsible for earthy off-flavor; pyrazines cause vegetable odors, and guaiacol results in smoked, phenolic and medicinal defects. Off-odors of mushroom in wines are caused by 1-octen-3-ol and 1-octen-3-one coming from grapes contaminated by bunch rot (Botrytis cinerea). The sensory aspects of these molecules are illustrated in this review. Generally, the most important cause of this wine contamination is the natural cork of bottle stoppers, but this is not always true. Different origins of contamination include air pollution of the cellars, wood materials, barrels and chips. A review of the possible prevention or remedial treatments to cork taint is also presented. The best solution for this off-flavor is to prevent the wine contaminations. Full article

(This article belongs to the Special Issue Wide World of Beverage Research: Reviews of Current Topics)

20 pages, 1895 KB

Open AccessArticle

Chloroanisoles and Chlorophenols Explain Mold Odor but Their Impact on the Swedish Population Is Attributed to Dampness and Mold

by Johnny C. Lorentzen, Stephanie A. Juran, Lena Ernstgård, Mats J. Olsson and Gunnar Johanson

Int. J. Environ. Res. Public Health 2020, 17(3), 930; https://doi.org/10.3390/ijerph17030930 - 3 Feb 2020

Cited by 10 | Viewed by 5424

Abstract

We recently reported that mold odor may be explained by chloroanisoles (CAs) formed by microbial biotransformation of chlorophenols (CPs) in legacy wood preservatives. Here we examine psychophysical aspects of CAs and trace their historic origins in buildings. Our exposure of healthy volunteers shows that 2,4,6-triCA is often perceived as unpleasant, characterized as musty or moldy and is detected at 13 ng/m³ or lower. Similar concentrations are reported in buildings with odor complaints. Scrutiny of written records reveal that new building construction methods were introduced in the 1950s, namely crawlspaces and concrete slabs on the ground. These constructions were prone to dampness and attack from wood decay fungi, prompting chemical companies and authorities to advocate preservatives against rot. Simultaneously, CPs became household chemicals used for example in indoor paints. When large-scale odor problems evolved, the authorities that once approved the preservatives attributed the odor to hidden mold, with no evidence that substantial microbial biomass was necessary for odor formation. Thereby the public remained unaware of problematic exposure to CPs and CAs. We conclude that the introduction of inappropriate designs of house foundations and CP-based preservatives once ignited and still provide impetus for indoor air research on “dampness and mold”. Full article

(This article belongs to the Special Issue Toxicity of Pesticides and Legacy Pollutants)

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10 pages, 1663 KB

Open AccessArticle

Chloroanisoles and Other Chlorinated Compounds in Cork from Different Geographical Areas

by Pau Salvatella, Chantal Prat, Jordi Roselló and Enriqueta Anticó

Toxics 2019, 7(4), 49; https://doi.org/10.3390/toxics7040049 - 20 Sep 2019

Cited by 3 | Viewed by 4058

Abstract

Cork quality is crucial for the fabrication of corks intended to be used to seal wine bottles. This work has focused on the determination of chloroanisoles (CAs)—exogenous compounds with a low perception threshold—in cork. The identification and quantification of these compounds was carried out with Bond Elut-ENV solid phase extraction and gas chromatography with mass spectrometry detection. Cork samples were obtained from oaks from Catalonia, Extremadura and Italy, and the presence of CAs was evaluated. Moreover, cork affected by the presence of yellow stains (a defect present in cork, mainly originated from the growth of the fungus Armillaria mellea) was analysed separately. The results obtained from cork macerates revealed the presence of trichloroanisole (TCA) in Catalan and Italian cork. Furthermore, TCA concentration was not statistically different when comparing cork affected and non-affected by the growth of A. mellea. Other chlorinated compounds were identified by comparison of their mass spectra with the data from the NIST library. Full article

(This article belongs to the Section Environmental Chemistry)

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