5'UTR methylation in different genes from workers exposed to volatile organic compounds: a new insight for considering an epigenetic mark as a functional correlate.

•Toluene exposure causes lower activity and higher mRNA expression for CYP2E1 in lymphocites.•Exposure to VOC mixtures in blood cells has shown hypermethylation in promoter area of different genes.•We studied gene-specific methylation at the 5′UTR region in workers exposed to mixtures of VOC’s and to a single solvent.•We found differences for CYP2E1 (toluene-exposed), IL-6 and TNF-a methylation levels (exposed to a solvent mixture).•CYP2E1 lower activity concur with lower methylation levels at the 5′UTR region, we consider this a functional correlate.