Benedetta Paolino

This study presents the technical–scientific investigation of a polychrome wooden sculpture attributed to Neroccio di Bartolomeo de’ Landi (1447–1500), a key figure in fifteenth-century Sienese art whose sculptural practice has remained analytically undocumented. The unpublished sculpture, likely representing Saint Ansanus and originally created in the 1470s, was historically reinterpreted as Saint Lazarus following its relocation to the former Hospital of San Lazzaro in Siena (Italy). A multi-analytical diagnostic campaign was undertaken to clarify its complex stratigraphy, guide conservation decisions, and reconstruct the artist’s original materials and techniques. The study integrated multispectral imaging, ATR-FTIR spectroscopy, portable ED-XRF, mechanical stratigraphic assays, and cross-section microscopy, enabling a comprehensive reconstruction of both the original polychromy and subsequent repainting campaigns. Results revealed area-specific original paint systems, including a possible organic red lake on an alumina substrate, stable copper-based blue paint layers, and a sophisticated flesh-tone stratigraphy combining cinnabar-modulated “imprimitura” layers with lead-white-based upper tones. The analytical evidence also documented the material traces of the sculpture’s iconographic recontextualization and its post-industrial interventions, firmly dated by the presence of titanium dioxide associated with an iron-based blue compatible with Prussian blue. The conservation treatment, informed by stratigraphic and analytical data, enabled the selective removal of non-original layers while preserving historically significant early reworkings. The findings provide the earliest material characterisation of Neroccio’s polychrome technique, offering new insight into his workshop practice and laying the foundation for future comparative studies across media. More broadly, the study contributes to the technical literature on Italian Renaissance polychrome sculpture and demonstrates the interpretive value of integrated scientific methods in reconstructing the cultural biography of multilayered devotional artefacts.

Quaternary ammonium compounds (QACs) have dominated biocidal practice in cultural heritage conservation for decades, yet growing evidence of environmental persistence, aquatic ecotoxicity, and antimicrobial resistance induction has prompted the search for safer alternatives. Essential oils (EO) have emerged as promising bio-based biocides, though their environmental performance has rarely been quantified through rigorous life cycle approaches. This study presents a comparative Life Cycle Impact Assessment (LCIA) of EO-based and QAC-based biocidal formulations across representative conservation scenarios, following ISO 14040/14044 standards and the Environmental Footprint 3.1 methodology with USEtox^® 2.1 characterization factors. Three complementary functional units were employed: formulation-based, surface-based, and intervention-based. The results reveal a fundamental trade-off: EO-based systems exhibit 81% higher climate change impacts but 82–89% lower human toxicity and freshwater ecotoxicity impacts compared to QAC-based systems. Surface-normalized comparisons reduce the climate gap to 32%, while toxicity advantages remain robust across all sensitivity scenarios. Monte Carlo analysis confirms the robustness of toxicity findings (p > 99%), whereas climate comparisons remain scenario-dependent. These findings support context-dependent adoption of EO-based biocides in conservation practice and demonstrate that EO-related climate impacts are technically mitigable, while QAC toxicity is intrinsic to their molecular structure.

The environmental sustainability of cleaning materials used in heritage conservation remains poorly quantified despite growing attention to the replacement of hazardous petroleum-based solvents with bio-based alternatives. This study applies a comprehensive Life Cycle Assessment (LCIA) to compare conventional solvents with innovative bio-based formulations, including Fatty Acid Methyl Esters (FAMEs), Deep Eutectic Solvents (DES), and aqueous or organogel systems used for cleaning painted surfaces. Following ISO 14040/14044 standards and using the Ecoinvent v3.8 database with the EF 3.1 impact method, three functional units were adopted to reflect material and system-level scales. Results demonstrate that water-rich systems, such as agar gels and emulsified organogels, yield significantly lower climate and toxicity impacts (up to 85–90% reduction) compared with petroleum-based benchmarks, while FAME and DES exhibit outcomes highly dependent on allocation rules and baseline datasets. When including application materials, cotton wipes dominate total environmental burdens, emphasizing that system design outweighs solvent substitution in improving sustainability. The study provides reproducible data and methodological insights for integrating LCIA into conservation decision-making, contributing to the transition toward evidence-based and environmentally responsible heritage practices.

This study introduces a pilot protocol for evaluating the environmental impact of materials used in the conservation of canvas paintings, applying a Life Cycle Impact Assessment (LCIA) approach. There are five common treatment phases: disinfection, consolidation (including paint layer softening and stabilization), varnish removal, and retouching. These interventions were assessed across three scenarios: Baseline Scenario; Scenario 1, involving material substitution; and Scenario 2, focusing on process optimization. The analysis reveals that solvent-intensive phases, particularly paint softening with Methyl Ethyl Ketone (MEK) and varnish removal using White Spirit and ethanol, have the highest environmental impacts, including climate change, ecotoxicity, and human toxicity. Biocidal treatments, although used in small quantities, also show significant toxicity impacts. Scenario 1 demonstrates that targeted substitution with lower-impact solvents can reduce key impact categories, while Scenario 2 indicates that operational improvements lead to more moderate but widespread benefits. The results confirm that even in specialized fields such as cultural heritage conservation, measurable environmental improvements are achievable through informed material choices and more efficient application practices.

In this study, a historically significant journal subject to fungal colonization was used as a case study for experimenting with a fumigation treatment using essential oils. The experiments were carried out both in vitro and in vivo directly on the artifact. Post-treatment monitoring showed that the succession of two fumigation treatments (alternately using rosemary and lavender oil) resulted in the complete disinfection of the first and second populations detected on the substrate. The latter was identified as Trichoderma longibrachiatum, a human pathogenic species, which was found to be sensitive to various concentrations of rosemary essential oil (1.2% v/v) and lavender essential oil (0.4% v/v), while it was not contained by the standard biocide based on benzalkonium chloride. The results obtained allowed the proposal of an application protocol for the fumigation of paper items that need to undergo biocidal treatment, which consists of alternating essential oils to increase the action spectrum of the natural substances and implementing a rotation principle to prevent the development of bio-resistances.

Eco-friendly decontamination treatments on works of art made from organic materials are of growing interest. The high risks to human health and the environment associated with traditional biocides (e.g. ecotoxicity, development of biotic resistance) have made it necessary to search for safer alternatives, also looking at the past but innovating it. The current state of the art is explored here, delving into the literature on the topic from 2000 to today, and outlining trends in terms of the most tested artistic supports and types of published research (in vitro/in vivo). An overview of the characteristics and mechanisms of biodegradation processes on different types of organic products and on the microorganisms mainly involved is thus provided. The main chemical-physical action techniques tested are illustrated and their practical-applicative aspects are discussed on the basis of evidence from case studies. Taking stock of the actual situation, literature consultation highlights that if on the one hand research is advancing rapidly towards the discovery of new ecological and safe solutions, on the other hand these are often biocidal treatments whose protocols have yet to be explored and validated.

In the context of bio-deterioration of cultural heritage, the Lavandula angustifolia Mill. plant proves to be of interest for a green approach to the preservation of art manufacts on organic media. Supercritical CO₂ fluid extraction (SFE) was utilized to obtain both lavender essential oil (E2LS3) and hydrolate (E2LS3A), while ultrasound assisted maceration in n-hexane:ethanol (99:1, v:v) provided LA2/1 extract. The extracts, all chemically characterized by UHPLC-HRMS and GC–MS analyses, were screened for their antifungal capability towards six fungi isolated from the plywood support of Haim Steinbach's contemporary artwork "Un-color becomes alter ego #2" (1984). To this purpose, disk diffusion method was applied on both mycelium and conidial suspensions to unravel whether the inhibitory activity affects the growth of fungi at different life cycle stages. The micro-atmosphere method was also explored to assess the response of fungal growth in a saturated atmosphere. Data acquired highlighted that SFE-obtained lavender essential oil, whose oxygenated monoterpene part mostly accounting for terpinene-4-ol, borneol, linalool, camphor, and 1,8-cineole, proves to be a dose- and time-dependent inhibitor of fungal growth. It has also been shown that exposure to the oil vapor phase is more effective at very low dose levels. The promising results allow us to hypothesize the use of the essential oil for treating fungal colonization by exposure to its volatile components in a modified atmosphere environment, with no direct contact with the artwork. Graphical abstract