Cellular reactions to long-term volatile organic compound (VOC) exposures

Abstract

Investigations of cellular processes initiated by volatile organic compounds (VOCs) are limited when modelling realistic long-term exposure scenarios at low concentrations. Exposure to indoor VOCs is associated with a range of adverse effects, but data on molecular changes at regulatory threshold limits are lacking. Activity analysis of VOC in vitro can be a valuable complement to inhalation toxicological evaluations. We developed an exposure platform that generates a stable VOC atmosphere and allows the exposure of cells for longer periods. Using formaldehyde as a model analyte, air-liquid interface cultured A549 lung epithelial cells were exposed to critical concentrations of 0.1 and 0.5 ppm for 3 days. Owing to the lack of known exposure biomarkers, we applied a genome-wide transcriptional analysis to investigate cellular responses at these sublethal concentrations. We demonstrate a minor overlap of differentially expressed transcripts for both treatment concentrations, which can be further analyzed for their use as exposure biomarkers. Moreover, distinct expression patterns emerge for 0.1 and 0.5 ppm formaldehyde exposure, which is reflected in significant enrichment of distinct biological processes. More specifically, metabolism of specific compound classes, lipid biosynthesis and lung-associated functions are affected by lower exposure levels and processes affecting proliferation and apoptosis dominate the higher exposure levels.

RNA oxidation in chromatin modification and DNA-damage response following exposure to formaldehyde

“…Likewise, human tracheal fibroblast Hs 680.Tr cells treated with media containing 100 µM (3 ppm) formaldehyde for 4 h caused ~ 50% reduced viability (determined by MTT colorimetric assay) 88 . Conversely, studies in A549 cells detect a negligible reduction in viability after 0.5 ppm formaldehyde exposure for 72 h using the ALI, and in BEAS-2B cells show over 90% viability over a period of 6 h with exposure concentrations up to 15 ppm 42,89 . The latter observation, also based on BEAS-2B cells, is most consistent with our results, albeit using much higher levels of formaldehyde exposures.…”

Short-term and Long-term Exposure of the MucilAir™ Model to Polycyclic Aromatic Hydrocarbons

“…To the best of our knowledge, fewer than 20 peer-reviewed articles have been published on studies involving the MucilAir model, and less than half of these address the effects of air pollutants. [22][23][24][25] Furthermore, none of these studies (including those based on other ALI cell models [26][27][28] ) have focused on the effects of long-term exposure (i.e. lasting several weeks).…”

Estimating Occupational Exposure to VOCs, SVOCs, Particles and Participant Survey Reported Symptoms in Central Thailand Rice Farmers Using Multiple Sampling Techniques

“…The results showed that most of the samples collected during pesticide application had detectable VOCs and SVOC compounds, in part because the farmers hung the mechanical sprayer on their shoulders, very close to their breathing zone. Since farmers may have been exposed to chemicals including VOCs, SVOCs, and pesticides, long-term exposure and the possible resultant health effects have been suggested for further study [54][55][56][57][58]. Eleven VOCs compounds were found in these air samples including Methlylene Chloride; Ethylbenzene; o-Xylene; m-Xylene; p-Xylene; Styrene; 1-Methyl Ethylbenzene; Tert-Butyl Benzene; 1, 3, 5-Trimethyl Benzene; 1-Methyl Propyle Benzene; and 1, 4-Dichloro Benzene.…”