Gene Expression Profiling as a New Real-Time Assay in Human Biomonitoring of Waste-to-Energy Plant Workers

Exposure to heavy metals represents one of the most important risk factors for the health of incinerator workers. Indeed, heavy metals can determine increased generation of reactive oxygen species (ROS). In this work, we introduced the use of transcription profiling of detoxifying genes, involved in redox balance and genome integrity, as a highly sensitive assay of heavy metal exposure and subsequent oxidative stress. For this purpose, blood mRNA levels of OGG1, ST13, NQO1 and MT1A genes, as well as urinary concentrations of nine heavy metals and the oxidized base 8-OHdG of 49 subjects (26 controls and 23 employees in the waste-to-energy plant of San Zeno, Arezzo, Italy) were determined. No significant difference between the two populations was observed, thus highlighting, as far as the biomarkers analysed are concerned, the absence of occupational exposure to heavy metals and systemic oxidative stress induction in the workers of the waste-to-energy plant of San Zeno. Correlation analyses underline a close association between heavy metals exposure and changes in expression levels of a number of genes, even at low exposure doses, thus remarking the greater capacity of detection of transcription profiling compared to other biomarkers and the importance of its introduction in future human biomonitoring programs.