Non-microbial sources of microbial volatile organic compounds

• Background: The question regarding the true sources of the purported microbial volatile organic compounds (MVOCs) remains unanswered. Objective: To identify microbial, as well as non-microbial sources of 28 compounds, which are commonly accepted as microbial VOCs (i.e. primary outcome of interest is σ 28 VOCs). Methods: In a cross-sectional investigation of 390 homes, six building inspectors assessed water/mold damage, took air and dust samples, and measured environmental conditions (i.e., absolute humidity (AH, g/m3), temperature (°C), ventilation rate (ACH)). The air sample was analyzed for volatile organic compounds (μg/m3) and; dust samples were analyzed for total viable fungal concentration (CFU/g) and six phthalates (mg/g dust). Four benchmark variables of the underlying sources were defined as highest quartile categories of: 1) the total concentration of 17 propylene glycol and propylene glycol ethers (σ17 PGEs) in the air sample; 2) 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (TMPD-MIB) in the air sample; 3) semi-quantitative mold index; and 4) total fungal load (CFU/g). Results: Within severely damp homes, co-occurrence of the highest quartile concentration of either σ17 PGEs or TMPD-MIB were respectively associated with a significantly higher median concentration of σ 28 VOCs (8.05 and 13.38 μg/m3, respectively) compared to the reference homes (4.30 and 4.86 μg/m3, respectively, both Ps ≤0.002). Furthermore, the homes within the highest quartile range for σ fungal load as well as AH were associated with a significantly increased median σ 28 VOCs compared to the reference group (8.74 vs. 4.32 μg/m3, P=0.001). Within the final model of multiple indoor sources on σ 28 VOCs, one natural log-unit increase in summed concentration of σ17 PGEs, plus TMPD-MIB (σ 17 PGEs + TMPD-MIB) was associated with 1.8-times (95% CI, 1.3-2.5), greater likelihood of having a highest quartile of σ 28 VOCs, after adjusting for absolute humidity, history of repainting at least one room, ventilation rate, and mold index (P-value =0.001). Homes deemed severely mold damaged (i.e., mold index =1) were associated with 1.7-times (95% CI, 0.8-3.6), greater likelihood of having a highest quartile of σ 28 VOCs, even though such likelihood was not significant (P-value =0.164). In addition, absolute humidity appeared to positively interact with mold index to significantly elevate the prevalence of the highest quartile category of σ 28 VOCs. Conclusion: The indoor concentration of σ 28 VOCs, which are widely accepted as MVOCs, are significantly associated with the markers of synthetic (i.e. σ17 PGEs and TMPD-MIB), and to less extent, microbial (i.e., mold index) sources.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Hälsovetenskap -- Folkhälsovetenskap, global hälsa, socialmedicin och epidemiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Health Sciences -- Public Health, Global Health, Social Medicine and Epidemiology (hsv//eng)

Nyckelord

Allergies

Asthma

Dampness

Indoor

Mold

Paint

Public Health Science

Publikations- och innehållstyp

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