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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. [ABSTRACT FROM AUTHOR]

Melanin is a natural pigment present in almost all biological groups, and is composed of indolic polymers and characterized by black-brown colorization. Furthermore, it is one of the pigments produced by extremophiles including those living in the Antarctic desert, and is mainly involved in their protection from high UV radiation, desiccation, salinity and oxidation. Previous studies have shown that melanized species have an increased capability to survive high level of radiation compared with the non-melanized counterpart. Understanding the molecular composition of fungal melanin could help to understand this peculiar capability. Here, we aimed to characterize the melanin pigment extracted from the Antarctic black fungus Cryomyces antarcticus, which is a good test model for radioprotection researches, by studying its chemical properties and spectral data. Our results demonstrated that, in spite of having a specific type of melanin as the majority of fungi, the fungus possesses the ability to produce both 1,8-dihydroxynaphthalene (DHN) and l 3-4 dihydroxyphenylalanine (L-DOPA) melanins, opening interesting scenarios for the protection role against radiation. Researches on fungal melanin have a huge application in different fields, including radioprotection, bioremediation, and biomedical applications. Key Points: • Isolation and characterization by multidisciplinary approaches of fungal melanins. • Discovery that pathways for producing DOPA and DHN are both active even in its extreme habitat. • Hypothesis supporting the possibility of using melanin pigment for radioprotection. [ABSTRACT FROM AUTHOR]